fix(cli): fail closed acp coordination

Run user shell commands concurrently with model execution, retain their output in one shell entry, and admit non-waking completion messages. Share result capture and notification formatting across shell callers.

.gitattributes

@@ -2,3 +2,4 @@ packages/core/migration/**/snapshot.json linguist-generated
 packages/core/src/database/migration.gen.ts linguist-generated
 packages/core/src/models-dev/snapshot.txt linguist-generated
 packages/core/src/**/*.txt text eol=lf
+packages/httpapi-codegen/test/generated/*.ts text eol=lf

AGENTS.md

@@ -1,6 +1,7 @@
 - After changing the public Protocol or Server `HttpApi`, run `bun run generate` from `packages/client`. Do not edit generated client files directly.
 - Keep runtime dependencies directed from Schema to Core and Protocol, then from Core and Protocol to Server. Client runtime code may depend on Schema and Protocol but never Core or Server; `sdk` composes Client, Core, and Server.
 - Current implementation changes belong in `packages/core`, `packages/cli`, `packages/server`, `packages/protocol`, `packages/schema`, and related generated client surfaces when required.
+- This repository does not use Changesets. Do not add `.changeset` files; follow the existing release workflow instead.
 - The default branch in this repo is `v2`.
 - Base all new branches and worktrees on `v2`, or `origin/v2` when the local `v2` ref is unavailable. Do not base them on `dev`.
 - Local `main` ref may not exist; use `v2` or `origin/v2` for diffs.

packages/ai/src/protocols/open-responses.ts

@@ -1,4 +1,4 @@
-import { Effect, Schema } from "effect"
+import { Effect, Option, Schema } from "effect"
 import type { Content } from "@opencode-ai/schema/tool"
 import { HttpTransport } from "../route/transport/index.js"
 import { Protocol } from "../route/protocol.js"
@@ -845,6 +845,21 @@ const onOutputTextDone = (state: ParserState, event: Event, id: string): StepRes
   return [{ ...state, lifecycle: Lifecycle.textEnd(state.lifecycle, events, id) }, events]
 }
 
+const decodeMessagePart = Schema.decodeUnknownOption(
+  Schema.Union([OpenResponsesOutputText, Schema.Struct({ type: Schema.tag("refusal"), refusal: Schema.String })]),
+)
+
+const decodeSummaryPart = Schema.decodeUnknownOption(OpenResponsesReasoningSummaryText)
+
+const decodeReasoningPart = Schema.decodeUnknownOption(
+  Schema.Struct({ type: Schema.tag("reasoning_text"), text: Schema.String }),
+)
+
+const joinReasoningText = (parts: ReadonlyArray<string | undefined>) => {
+  if (!parts.some((part) => part !== undefined && part.length > 0)) return undefined
+  return parts.filter((part) => part !== undefined).join("\n\n")
+}
+
 export const outputItemID = (state: ParserState, event: Event) =>
   event.output_index === undefined ? event.item_id : (state.outputItems[event.output_index] ?? event.item_id)
 
@@ -1065,24 +1080,33 @@ const onFunctionCallArgumentsDelta = Effect.fn("OpenResponses.onFunctionCallArgu
   return [{ ...state, lifecycle, tools: result.tools }, events] satisfies StepResult
 })
 
-const onOutputItemDone = Effect.fn("OpenResponses.onOutputItemDone")(function* (state: ParserState, event: Event) {
-  const item = event.item
+const onOutputItemDone = Effect.fn("OpenResponses.onOutputItemDone")(function* (
+  state: ParserState,
+  item: Event["item"],
+) {
   if (!item) return [state, NO_EVENTS] satisfies StepResult
 
   if (item.type === "message" && item.id !== undefined) {
+    const message = state.message?.id === item.id ? state.message : undefined
     const itemPhase = messagePhase(item.phase)
-    const phase = itemPhase === undefined && state.message?.id === item.id ? state.message.phase : itemPhase
+    const phase = itemPhase === undefined ? message?.phase : itemPhase
+    const parts: ReadonlyArray<unknown> = Array.isArray(item.content) ? item.content : []
+    const content: string[] = []
+    for (const part of parts) {
+      const decoded = Option.getOrUndefined(decodeMessagePart(part))
+      if (!decoded) continue
+      content.push(decoded.type === "output_text" ? decoded.text : decoded.refusal)
+    }
+    const text = content.length > 0 ? content.join("") : undefined
+    const metadata = providerMetadata(state, { itemId: item.id, ...(phase === undefined ? {} : { phase }) })
     const events: LLMEvent[] = []
+    const lifecycle =
+      message && text ? Lifecycle.textStart(state.lifecycle, events, item.id, metadata) : state.lifecycle
     return [
       {
         ...state,
-        lifecycle: Lifecycle.textEnd(
-          state.lifecycle,
-          events,
-          item.id,
-          providerMetadata(state, { itemId: item.id, ...(phase === undefined ? {} : { phase }) }),
-        ),
-        message: state.message?.id === item.id ? undefined : state.message,
+        lifecycle: Lifecycle.textEnd(lifecycle, events, item.id, metadata, text),
+        message: message ? undefined : state.message,
       },
       events,
     ] satisfies StepResult
@@ -1137,17 +1161,33 @@ const onOutputItemDone = Effect.fn("OpenResponses.onOutputItemDone")(function* (
   }
 
   if (isReasoningItem(item)) {
-    const events: LLMEvent[] = []
+    if (state.reasoningItems[item.id]?.open === false) return [state, NO_EVENTS] satisfies StepResult
     const metadata = reasoningMetadata(state, item)
+    const summaryParts: ReadonlyArray<unknown> = Array.isArray(item.summary) ? item.summary : []
+    const summary: Array<string | undefined> = []
+    for (const part of summaryParts) {
+      const decoded = Option.getOrUndefined(decodeSummaryPart(part))
+      // Keep missing entries so the array still matches the provider's summary indexes.
+      summary.push(decoded?.text)
+    }
+    const reasoningParts: ReadonlyArray<unknown> = Array.isArray(item.content) ? item.content : []
+    const content: string[] = []
+    for (const part of reasoningParts) {
+      const decoded = Option.getOrUndefined(decodeReasoningPart(part))
+      if (decoded) content.push(decoded.text)
+    }
+    const itemText = joinReasoningText(summary) ?? joinReasoningText(content)
+    const events: LLMEvent[] = []
     const reasoningItem = state.reasoningItems[item.id]
     if (reasoningItem) {
-      if (!reasoningItem.open) return [state, NO_EVENTS] satisfies StepResult
-      const lifecycle = Object.entries(reasoningItem.summaryParts)
-        .filter((entry) => entry[1] === "active" || entry[1] === "can-conclude")
-        .reduce(
-          (lifecycle, entry) => Lifecycle.reasoningEnd(lifecycle, events, `${item.id}:${entry[0]}`, metadata),
-          state.lifecycle,
-        )
+      const fragments = Object.entries(reasoningItem.summaryParts)
+      let lifecycle = state.lifecycle
+      for (const [index, status] of fragments) {
+        if (status === "concluded") continue
+        // Do not repeat earlier summaries that were already emitted as separate fragments.
+        const finalText = fragments.length === 1 ? itemText : summary[Number(index)]
+        lifecycle = Lifecycle.reasoningEnd(lifecycle, events, `${item.id}:${index}`, metadata, finalText || undefined)
+      }
       return [
         {
           ...state,
@@ -1167,7 +1207,13 @@ const onOutputItemDone = Effect.fn("OpenResponses.onOutputItemDone")(function* (
     if (!state.lifecycle.reasoning.has(item.id)) {
       const lifecycle = Lifecycle.stepStart(state.lifecycle, events)
       events.push(LLMEvent.reasoningStart({ id: item.id, providerMetadata: metadata }))
-      events.push(LLMEvent.reasoningEnd({ id: item.id, providerMetadata: metadata }))
+      events.push(
+        LLMEvent.reasoningEnd({
+          id: item.id,
+          providerMetadata: metadata,
+          text: itemText,
+        }),
+      )
       return [
         {
           ...state,
@@ -1195,32 +1241,24 @@ const onOutputItemDone = Effect.fn("OpenResponses.onOutputItemDone")(function* (
 })
 
 const onResponseFinish = Effect.fn("OpenResponses.onResponseFinish")(function* (state: ParserState, event: Event) {
-  const reconciled =
-    event.type === "response.completed"
-      ? yield* Effect.reduce(
-          event.response?.output ?? [],
-          () => [state, NO_EVENTS] satisfies StepResult,
-          ([current, events], item) => {
-            const id = item.id ?? (item.type === "function_call" ? item.call_id : undefined)
-            if (
-              id === undefined ||
-              ((item.type !== "function_call" || !current.tools[id]) &&
-                (item.type !== "reasoning" || !current.reasoningItems[id]?.open))
-            )
-              return Effect.succeed([current, events] satisfies StepResult)
-            return onOutputItemDone(current, { type: "response.output_item.done", item }).pipe(
-              Effect.map(([next, emitted]) => [next, [...events, ...emitted]] satisfies StepResult),
-            )
-          },
-        )
-      : ([state, NO_EVENTS] satisfies StepResult)
-  const current = reconciled[0]
+  let current = state
+  const events: LLMEvent[] = []
+  if (event.type === "response.completed") {
+    for (const item of event.response?.output ?? []) {
+      const id = item.id ?? (item.type === "function_call" ? item.call_id : undefined)
+      if (id === undefined) continue
+      if (item.type !== "function_call" || !current.tools[id]) continue
+      const [next, emitted] = yield* onOutputItemDone(current, item)
+      current = next
+      events.push(...emitted)
+    }
+  }
   // Some compatible providers omit output_item.done even after completing the response.
   const pending =
     event.type === "response.completed"
       ? yield* ToolStream.finishAll(current.id, current.tools)
       : { tools: current.tools, events: NO_EVENTS }
-  const events: LLMEvent[] = [...reconciled[1], ...pending.events]
+  events.push(...pending.events)
   const hasFunctionCall =
     pending.events.some((event) => LLMEvent.is.toolCall(event) || LLMEvent.is.toolInputError(event)) ||
     current.hasFunctionCall
@@ -1346,7 +1384,7 @@ export const step = (state: ParserState, input: Event) => {
   if (event.type === "response.output_item.done") {
     if (event.item?.type === "message" && event.item.id === undefined)
       return ProviderShared.eventError(state.id, `${event.type} message is missing id`)
-    return onOutputItemDone(state, event)
+    return onOutputItemDone(state, event.item)
   }
   if (event.type === "response.completed" || event.type === "response.incomplete") return onResponseFinish(state, event)
   if (event.type === "response.failed") return providerFailure(event, `${state.name} response failed`)

packages/ai/src/protocols/openai-chat.ts

@@ -815,7 +815,12 @@ const mapFinishReason = Effect.fn("OpenAIChat.mapFinishReason")(function* (event
     case "tool_calls":
       return "tool-calls" as const
     default:
-      return "unknown" as const
+      return yield* new AIError({
+        reason: new UnknownProviderError({
+          message: `Provider finish_reason: ${reason}`,
+          body: ProviderShared.encodeJson(event),
+        }),
+      })
   }
 })
 
@@ -1054,17 +1059,25 @@ const step = (state: ParserState, event: OpenAIChatEvent) =>
       events.push(...result.events)
     }
 
-    if (finishReason !== undefined && state.finishReason === undefined && Object.keys(pendingTools).length > 0)
+    const incompleteTools = finishReason?.normalized === "content-filter" || finishReason?.normalized === "length"
+    if (
+      finishReason !== undefined &&
+      !incompleteTools &&
+      state.finishReason === undefined &&
+      Object.keys(pendingTools).length
+    )
       return yield* ProviderShared.eventError(
         ADAPTER,
         "OpenAI Chat tool call delta is missing id or name",
         ProviderShared.encodeJson(event),
       )
 
-    // Finalize accumulated tool inputs eagerly when finish_reason arrives so
-    // valid calls and malformed local calls settle independently.
+    // Filtering or truncation terminates the response without confirming pending tool calls.
     const finished =
-      finishReason !== undefined && state.finishReason === undefined && Object.keys(tools).length > 0
+      finishReason !== undefined &&
+      !incompleteTools &&
+      state.finishReason === undefined &&
+      Object.keys(tools).length > 0
         ? yield* ToolStream.finishAll(ADAPTER, tools)
         : undefined
 

packages/ai/src/provider-error.ts

@@ -76,6 +76,8 @@ const INVALID_REQUEST_CODES = new Set(["invalid_prompt", "invalid_request_error"
 const RATE_LIMIT_TEXT = /rate increased too quickly|rate[-_\s]?limit|too[_\s]?many[_\s]?requests/i
 const QUOTA_TEXT = /insufficient[-_\s]?quota|quota[-_\s]?exceeded/i
 const CONTENT_POLICY_TEXT = /content[-_\s]?policy|content_filter|safety/i
+const SERVER_ERROR_TEXT =
+  /\b(?:try again|(?:please |you can )?retry (?:the |this |your )?request|try (?:the |this |your )?request again|(?:currently |temporarily )?at capacity|overloaded|temporarily unavailable|service[-_\s]?unavailable|(?:server|internal)[-_\s]?error|server (?:is )?busy|provider returned (?:an )?error|resource[-_\s]?exhausted|upstream (?:connect|connection|request)|request buffer limit while retrying upstream)\b/i
 
 export interface ProviderFailure {
   readonly message: string
@@ -139,6 +141,9 @@ export function classifyProviderFailure(input: ProviderFailure): AIError["reason
     input.status === 408 ||
     input.status === 409 ||
     (input.status !== undefined && input.status >= 500) ||
+    ((input.status === undefined || input.status < 400) &&
+      !codes.some((code) => INVALID_REQUEST_CODES.has(code)) &&
+      SERVER_ERROR_TEXT.test(text)) ||
     codes.some((code) => SERVER_CODES.has(code) || code.includes("exhausted") || code.includes("unavailable"))
   )
     return new ProviderInternalError({

packages/ai/test/provider-error.test.ts

@@ -81,6 +81,46 @@ describe("provider error classification", () => {
     ).toEqual(["ProviderInternal", "ProviderInternal", "ProviderInternal"])
   })
 
+  test("classifies retryable server messages as provider internal", () => {
+    const message =
+      "The model is currently at capacity due to high demand. Please try again in a few minutes, or use a higher service tier for priority processing."
+
+    expect(
+      [
+        message,
+        "Try again",
+        "Please retry your request shortly.",
+        "You can retry the request.",
+        "Try your request again.",
+        "The service is temporarily at capacity.",
+        "The model is overloaded.",
+        "Service unavailable",
+        "Internal server error",
+        "The server is busy.",
+        "Provider returned error",
+        "Provider returned an error",
+        "ResourceExhausted",
+        "Upstream connection failed",
+        "Exceeded request buffer limit while retrying upstream",
+      ].map((message) => classifyProviderFailure({ message })._tag),
+    ).toEqual(Array(15).fill("ProviderInternal"))
+    expect(
+      classifyProviderFailure({ message: "Provider request failed", rawBody: "Please try again later." })._tag,
+    ).toBe("ProviderInternal")
+  })
+
+  test("prioritizes specific failures over retryable server text", () => {
+    expect(
+      [
+        classifyProviderFailure({ message: "Invalid credentials, try again", status: 401 }),
+        classifyProviderFailure({ message: "Quota exceeded, try again", status: 429 }),
+        classifyProviderFailure({ message: "Rate limit exceeded, try again" }),
+        classifyProviderFailure({ message: "Upstream request failed: validation failed", status: 400 }),
+        classifyProviderFailure({ message: "Try again", status: 200 }),
+      ].map((failure) => failure._tag),
+    ).toEqual(["Authentication", "QuotaExceeded", "RateLimit", "InvalidRequest", "ProviderInternal"])
+  })
+
   test("classifies transient client statuses as provider internal", () => {
     expect([408, 409].map((status) => classifyProviderFailure({ message: `HTTP ${status}`, status })._tag)).toEqual([
       "ProviderInternal",
@@ -111,7 +151,6 @@ describe("provider error classification", () => {
     expect(classifyProviderFailure({ message: '{"type":"error","error":{"code":123}}' })._tag).toBe("UnknownProvider")
     expect(classifyProviderFailure({ message: "not-json" })._tag).toBe("UnknownProvider")
     expect(classifyProviderFailure({ message: "network error" })._tag).toBe("UnknownProvider")
-    expect(classifyProviderFailure({ message: "Provider returned error" })._tag).toBe("UnknownProvider")
   })
 })
 

packages/ai/test/provider/open-responses-finals.test.ts

@@ -0,0 +1,209 @@
+import { describe, expect } from "bun:test"
+import { Effect } from "effect"
+import { LLM, LLMEvent } from "../../src/index.js"
+import { OpenResponses } from "../../src/protocols/open-responses.js"
+import { configure } from "../../src/providers/openai-compatible-responses.js"
+import { LLMClient } from "../../src/route.js"
+import { it } from "../lib/effect.js"
+import { fixedResponse } from "../lib/http.js"
+import { sseEvents } from "../lib/sse.js"
+
+const request = LLM.request({
+  model: configure({ apiKey: "test-key", baseURL: "https://responses.example.test/v1" }).model("example-model"),
+  prompt: "Respond.",
+})
+const completed = { type: "response.completed", response: { id: "resp_1" } }
+const generate = (...events: OpenResponses.Event[]) =>
+  LLMClient.generate(request).pipe(Effect.provide(fixedResponse(sseEvents(...events))))
+
+describe("Open Responses completed item text", () => {
+  ;["Draft expanded", "D", "Replacement", ""].forEach((text) => {
+    it.effect(`replaces streamed text with completed item text ${JSON.stringify(text)}`, () =>
+      Effect.gen(function* () {
+        const response = yield* generate(
+          { type: "response.output_item.added", item: { type: "message", id: "msg_1", phase: "commentary" } },
+          { type: "response.output_text.delta", item_id: "msg_1", delta: "Draft" },
+          { type: "response.output_text.done", item_id: "msg_1", text: "Part final" },
+          {
+            type: "response.output_item.done",
+            item: { type: "message", id: "msg_1", phase: "final_answer", content: [{ type: "output_text", text }] },
+          },
+          completed,
+        )
+        expect(response.text).toBe(text)
+        expect(response.events.filter(LLMEvent.is.textDelta).map((event) => event.text)).toEqual(["Draft"])
+        expect(response.events.filter(LLMEvent.is.textEnd)).toEqual([
+          {
+            type: "text-end",
+            id: "msg_1",
+            text,
+            providerMetadata: { "openai-compatible": { itemId: "msg_1", phase: "final_answer" } },
+          },
+        ])
+      }),
+    )
+  })
+
+  it.effect("joins completed text and refusal parts without streamed text", () =>
+    Effect.gen(function* () {
+      const response = yield* generate(
+        { type: "response.output_item.added", item: { type: "message", id: "msg_1" } },
+        {
+          type: "response.output_item.done",
+          item: {
+            type: "message",
+            id: "msg_1",
+            content: [
+              { type: "output_text", text: "Answer. " },
+              { type: "refusal", refusal: "Cannot help." },
+            ],
+          },
+        },
+        completed,
+      )
+      expect(response.text).toBe("Answer. Cannot help.")
+      expect(response.events.filter(LLMEvent.is.textStart)).toHaveLength(1)
+      expect(response.events.filter(LLMEvent.is.textEnd)).toHaveLength(1)
+    }),
+  )
+
+  it.effect("does not create an empty text fragment for an empty completed message", () =>
+    Effect.gen(function* () {
+      const response = yield* generate(
+        { type: "response.output_item.added", item: { type: "message", id: "msg_1" } },
+        { type: "response.output_text.done", item_id: "msg_1", text: "" },
+        {
+          type: "response.output_item.done",
+          item: { type: "message", id: "msg_1", content: [{ type: "output_text", text: "" }] },
+        },
+        completed,
+      )
+      expect(response.message.content).toEqual([])
+      expect(response.events.filter(LLMEvent.is.textStart)).toEqual([])
+    }),
+  )
+})
+
+describe("Open Responses completed item reasoning", () => {
+  ;[
+    {
+      name: "summary",
+      summary: [
+        { type: "summary_text", text: "Final" },
+        { type: "summary_text", text: "summary" },
+      ],
+      content: [{ type: "reasoning_text", text: "Raw" }],
+      text: "Final\n\nsummary",
+    },
+    {
+      name: "raw text",
+      summary: [
+        { type: "summary_text", text: "" },
+        { type: "summary_text", text: "" },
+      ],
+      content: [{ type: "reasoning_text", text: "Raw" }],
+      text: "Raw",
+    },
+    {
+      name: "streamed fallback",
+      summary: [
+        { type: "summary_text", text: "" },
+        { type: "summary_text", text: "" },
+      ],
+      content: [
+        { type: "reasoning_text", text: "" },
+        { type: "reasoning_text", text: "" },
+      ],
+      text: "Draft",
+    },
+  ].forEach((fixture) => {
+    it.effect(`uses ${fixture.name} at item completion`, () =>
+      Effect.gen(function* () {
+        const response = yield* generate(
+          { type: "response.output_item.added", item: { type: "reasoning", id: "rs_1" } },
+          { type: "response.reasoning_summary_text.delta", item_id: "rs_1", delta: "Draft" },
+          { type: "response.reasoning_summary_text.done", item_id: "rs_1", text: "Part final" },
+          {
+            type: "response.output_item.done",
+            item: {
+              type: "reasoning",
+              id: "rs_1",
+              summary: fixture.summary,
+              content: fixture.content,
+              encrypted_content: "encrypted",
+            },
+          },
+          completed,
+        )
+        expect(response.reasoning).toBe(fixture.text)
+        expect(response.events.filter(LLMEvent.is.reasoningEnd)).toHaveLength(1)
+        expect(response.message.content.find((part) => part.type === "reasoning")?.providerMetadata).toEqual({
+          "openai-compatible": { itemId: "rs_1", reasoningEncryptedContent: "encrypted" },
+        })
+      }),
+    )
+  })
+
+  it.effect("replaces only the still-open summary without repeating earlier text", () =>
+    Effect.gen(function* () {
+      const response = yield* generate(
+        { type: "response.output_item.added", item: { type: "reasoning", id: "rs_1" } },
+        { type: "response.reasoning_summary_text.delta", item_id: "rs_1", summary_index: 0, delta: "First " },
+        { type: "response.reasoning_summary_part.added", item_id: "rs_1", summary_index: 1 },
+        { type: "response.reasoning_summary_text.delta", item_id: "rs_1", summary_index: 1, delta: "draft" },
+        {
+          type: "response.output_item.done",
+          item: {
+            type: "reasoning",
+            id: "rs_1",
+            summary: [
+              { type: "summary_text", text: "First " },
+              { type: "summary_text", text: "final" },
+            ],
+          },
+        },
+        completed,
+      )
+      expect(response.reasoning).toBe("First final")
+      expect(response.events.filter(LLMEvent.is.reasoningEnd).map((event) => event.text)).toEqual([undefined, "final"])
+    }),
+  )
+})
+;["response.completed", "response.incomplete"].forEach((type) => {
+  it.effect(`keeps streamed text when part finals are followed by ${type} without item completion`, () =>
+    Effect.gen(function* () {
+      const response = yield* generate(
+        { type: "response.output_item.added", item: { type: "message", id: "msg_1" } },
+        { type: "response.output_text.delta", item_id: "msg_1", content_index: 0, delta: "Hel" },
+        { type: "response.output_text.delta", item_id: "msg_1", content_index: 1, delta: "world" },
+        { type: "response.output_text.done", item_id: "msg_1", content_index: 0, text: "Hello " },
+        {
+          type: "response.content_part.done",
+          item_id: "msg_1",
+          content_index: 0,
+          part: { type: "output_text", text: "Hello " },
+        },
+        { type: "response.output_item.added", item: { type: "reasoning", id: "rs_1" } },
+        { type: "response.reasoning_summary_text.delta", item_id: "rs_1", delta: "Draft" },
+        { type: "response.reasoning_summary_text.done", item_id: "rs_1", text: "Part final" },
+        {
+          type: "response.reasoning_summary_part.done",
+          item_id: "rs_1",
+          summary_index: 0,
+          part: { type: "summary_text", text: "Part final" },
+        },
+        {
+          type,
+          response: {
+            id: "resp_1",
+            incomplete_details: type === "response.incomplete" ? { reason: "max_output_tokens" } : undefined,
+          },
+        },
+      )
+      expect(response.text).toBe("Helworld")
+      expect(response.reasoning).toBe("Draft")
+      expect(response.events.filter(LLMEvent.is.textEnd).map((event) => event.text)).toEqual([undefined])
+      expect(response.events.filter(LLMEvent.is.reasoningEnd).map((event) => event.text)).toEqual([undefined])
+    }),
+  )
+})

packages/ai/test/provider/open-responses-lifecycle.test.ts

@@ -129,7 +129,7 @@ describe("Open Responses basic-item lifecycles", () => {
     }),
   )
 
-  it.effect("preserves done-only encrypted reasoning without replaying its summary or late events", () =>
+  it.effect("preserves done-only reasoning text and encryption without replaying late events", () =>
     Effect.gen(function* () {
       const item = {
         type: "reasoning",
@@ -157,6 +157,7 @@ describe("Open Responses basic-item lifecycles", () => {
         {
           type: "reasoning-end",
           id: "rs_1",
+          text: "Not streamed",
           providerMetadata: { "openai-compatible": { itemId: "rs_1", reasoningEncryptedContent: "encrypted-state" } },
         },
       ])
@@ -301,7 +302,7 @@ describe("Open Responses basic-item lifecycles", () => {
     )
   })
 
-  it.effect("recovers pending items in completed output order with terminal encrypted metadata", () =>
+  it.effect("recovers pending calls without reconciling terminal reasoning", () =>
     Effect.gen(function* () {
       const events = yield* collect(
         {
@@ -325,11 +326,6 @@ describe("Open Responses basic-item lifecycles", () => {
         },
       )
       expect(events.slice(5, -2)).toEqual([
-        {
-          type: "reasoning-end",
-          id: "rs_1:0",
-          providerMetadata: { "openai-compatible": { itemId: "rs_1", reasoningEncryptedContent: "terminal-state" } },
-        },
         {
           type: "tool-input-end",
           id: "call_1",
@@ -341,8 +337,10 @@ describe("Open Responses basic-item lifecycles", () => {
           id: "call_1",
           name: "lookup",
           input: { query: "final" },
+          providerExecuted: undefined,
           providerMetadata: { "openai-compatible": { itemId: "fc_1" } },
         },
+        { type: "reasoning-end", id: "rs_1:0" },
       ])
     }),
   )

packages/ai/test/provider/openai-chat.test.ts

@@ -1460,6 +1460,162 @@ describe("OpenAI Chat route", () => {
     }),
   )
 
+  it.effect("does not finalize streamed tool calls when content is filtered", () =>
+    Effect.gen(function* () {
+      const body = sseEvents(
+        deltaChunk({
+          tool_calls: [{ index: 0, id: "call_1", function: { name: "lookup", arguments: '{"query":"weather"' } }],
+        }),
+        deltaChunk({}, "content_filter"),
+      )
+      const response = yield* LLMClient.generate(
+        LLMRequest.update(request, {
+          tools: [ToolDefinition.make({ name: "lookup", description: "Lookup data", inputSchema: { type: "object" } })],
+        }),
+      ).pipe(Effect.provide(fixedResponse(body)))
+
+      expect(response.events).toEqual([
+        { type: "step-start", index: 0 },
+        {
+          type: "tool-input-start",
+          id: "call_1",
+          name: "lookup",
+          providerExecuted: undefined,
+          providerMetadata: undefined,
+        },
+        {
+          type: "tool-input-delta",
+          id: "call_1",
+          name: "lookup",
+          text: '{"query":"weather"',
+          input: { query: "weather" },
+        },
+        {
+          type: "step-finish",
+          index: 0,
+          reason: { normalized: "content-filter", raw: "content_filter" },
+          usage: undefined,
+          providerMetadata: undefined,
+        },
+        { type: "finish", reason: { normalized: "content-filter", raw: "content_filter" }, usage: undefined },
+      ])
+      expect(response.toolCalls).toEqual([])
+
+      const missingIdentity = yield* LLMClient.generate(request).pipe(
+        Effect.provide(
+          fixedResponse(
+            sseEvents(
+              deltaChunk({ tool_calls: [{ index: 0, id: "call_2", function: { arguments: "{}" } }] }),
+              deltaChunk({}, "content_filter"),
+            ),
+          ),
+        ),
+      )
+      expect(missingIdentity.finishReason).toEqual({ normalized: "content-filter", raw: "content_filter" })
+      expect(missingIdentity.toolCalls).toEqual([])
+    }),
+  )
+
+  it.effect("does not finalize streamed tool calls when output is truncated", () =>
+    Effect.gen(function* () {
+      const body = sseEvents(
+        deltaChunk({
+          tool_calls: [{ index: 0, id: "call_1", function: { name: "lookup", arguments: '{"query":"weather"}' } }],
+        }),
+        deltaChunk({}, "length"),
+      )
+      const response = yield* LLMClient.generate(
+        LLMRequest.update(request, {
+          tools: [ToolDefinition.make({ name: "lookup", description: "Lookup data", inputSchema: { type: "object" } })],
+        }),
+      ).pipe(Effect.provide(fixedResponse(body)))
+
+      expect(response.events).toEqual([
+        { type: "step-start", index: 0 },
+        {
+          type: "tool-input-start",
+          id: "call_1",
+          name: "lookup",
+          providerExecuted: undefined,
+          providerMetadata: undefined,
+        },
+        {
+          type: "tool-input-delta",
+          id: "call_1",
+          name: "lookup",
+          text: '{"query":"weather"}',
+          input: { query: "weather" },
+        },
+        {
+          type: "step-finish",
+          index: 0,
+          reason: { normalized: "length", raw: "length" },
+          usage: undefined,
+          providerMetadata: undefined,
+        },
+        { type: "finish", reason: { normalized: "length", raw: "length" }, usage: undefined },
+      ])
+      expect(response.toolCalls).toEqual([])
+
+      const missingIdentity = yield* LLMClient.generate(request).pipe(
+        Effect.provide(
+          fixedResponse(
+            sseEvents(
+              deltaChunk({ tool_calls: [{ index: 0, id: "call_2", function: { arguments: "{}" } }] }),
+              deltaChunk({}, "length"),
+            ),
+          ),
+        ),
+      )
+      expect(missingIdentity.finishReason).toEqual({ normalized: "length", raw: "length" })
+      expect(missingIdentity.toolCalls).toEqual([])
+    }),
+  )
+
+  it.effect("rejects unknown finish reasons without finalizing streamed tool calls", () =>
+    Effect.gen(function* () {
+      const body = sseEvents(
+        deltaChunk({
+          tool_calls: [{ index: 0, id: "call_1", function: { name: "lookup", arguments: '{"query":"weather"' } }],
+        }),
+        deltaChunk({}, "future_reason"),
+      )
+      const events = yield* Ref.make<ReadonlyArray<LLMEvent>>([])
+      const error = yield* LLMClient.stream(
+        LLMRequest.update(request, {
+          tools: [ToolDefinition.make({ name: "lookup", description: "Lookup data", inputSchema: { type: "object" } })],
+        }),
+      ).pipe(
+        Stream.tap((event) => Ref.update(events, (current) => [...current, event])),
+        Stream.runDrain,
+        Effect.provide(fixedResponse(body)),
+        Effect.flip,
+      )
+
+      expect(error).toMatchObject({
+        reason: { _tag: "UnknownProvider" },
+        message: "Provider finish_reason: future_reason",
+      })
+      expect(yield* Ref.get(events)).toEqual([
+        { type: "step-start", index: 0 },
+        {
+          type: "tool-input-start",
+          id: "call_1",
+          name: "lookup",
+          providerExecuted: undefined,
+          providerMetadata: undefined,
+        },
+        {
+          type: "tool-input-delta",
+          id: "call_1",
+          name: "lookup",
+          text: '{"query":"weather"',
+          input: { query: "weather" },
+        },
+      ])
+    }),
+  )
+
   it.effect("ignores empty identity fields on later tool call deltas", () =>
     Effect.gen(function* () {
       const body = sseEvents(

packages/ai/test/provider/openai-compatible-chat.test.ts

@@ -554,6 +554,19 @@ describe("OpenAI-compatible Chat route", () => {
         reason: { _tag: "UnknownProvider" },
         message: "Provider reported an error (finish_reason: error)",
       })
+
+      const unknown = yield* LLMClient.generate(request).pipe(
+        Effect.provide(fixedResponse(sseEvents(deltaChunk({}, "future_reason")))),
+        Effect.flip,
+      )
+      expect(unknown).toMatchObject({
+        reason: { _tag: "UnknownProvider" },
+        message: "Provider finish_reason: future_reason",
+      })
+      expect(decodeJson(unknown.reason.body ?? "")).toMatchObject({
+        id: "chatcmpl_fixture",
+        choices: [{ finish_reason: "future_reason" }],
+      })
     }),
   )
 
@@ -581,17 +594,13 @@ describe("OpenAI-compatible Chat route", () => {
     }),
   )
 
-  it.effect("preserves provider finish outcomes in the common reason algebra", () =>
+  it.effect("preserves content-filter finishes in the common reason algebra", () =>
     Effect.gen(function* () {
       const filtered = yield* LLMClient.generate(request).pipe(
         Effect.provide(fixedResponse(sseEvents(deltaChunk({}, "content_filter")))),
       )
-      const future = yield* LLMClient.generate(request).pipe(
-        Effect.provide(fixedResponse(sseEvents(deltaChunk({}, "future_reason")))),
-      )
 
       expect(filtered.finishReason).toEqual({ normalized: "content-filter", raw: "content_filter" })
-      expect(future.finishReason).toEqual({ normalized: "unknown", raw: "future_reason" })
     }),
   )
 

packages/ai/test/provider/openai-compatible-responses.test.ts

@@ -406,7 +406,7 @@ describe("Open Responses-compatible route", () => {
     })
 
     routings.forEach((routing) => {
-      it.effect(`preserves reasoning summary boundaries and terminal metadata with ${routing.name}`, () =>
+      it.effect(`preserves reasoning summary boundaries without terminal reconciliation with ${routing.name}`, () =>
         Effect.gen(function* () {
           const address = { item_id: routing.item_id, output_index: routing.output_index }
           const response = yield* LLMClient.generate(request).pipe(
@@ -444,21 +444,18 @@ describe("Open Responses-compatible route", () => {
               type: "reasoning",
               text: "Second.",
               providerMetadata: {
-                "openai-compatible": { itemId: routing.id, reasoningEncryptedContent: "final-state" },
+                "openai-compatible": { itemId: routing.id, reasoningEncryptedContent: null },
               },
             },
           ])
           expect(response.events.filter(LLMEvent.is.reasoningEnd)).toEqual([
-            expect.objectContaining({
+            {
+              type: "reasoning-end",
               id: `${routing.id}:0`,
+              text: undefined,
               providerMetadata: { "openai-compatible": { itemId: routing.id } },
-            }),
-            expect.objectContaining({
-              id: `${routing.id}:1`,
-              providerMetadata: {
-                "openai-compatible": { itemId: routing.id, reasoningEncryptedContent: "final-state" },
-              },
-            }),
+            },
+            { type: "reasoning-end", id: `${routing.id}:1` },
           ])
         }),
       )
@@ -671,7 +668,7 @@ describe("Open Responses-compatible route", () => {
     }),
   )
 
-  it.effect("preserves terminal reasoning metadata when item completion is missing", () =>
+  it.effect("ignores terminal reasoning output when item completion is missing", () =>
     Effect.gen(function* () {
       const model = configure({
         apiKey: "test-key",
@@ -697,8 +694,9 @@ describe("Open Responses-compatible route", () => {
         ),
       )
 
-      expect(response.events.find((event) => event.type === "reasoning-end")).toMatchObject({
-        providerMetadata: { "openai-compatible": { itemId: "rs_raw", reasoningEncryptedContent: "raw-state" } },
+      expect(response.events.find((event) => event.type === "reasoning-end")).toEqual({
+        type: "reasoning-end",
+        id: "rs_raw:0",
       })
     }),
   )

packages/ai/test/provider/openai-responses.test.ts

@@ -2554,7 +2554,7 @@ describe("OpenAI Responses route", () => {
     }),
   )
 
-  it.effect("preserves terminal reasoning metadata when output item completion is missing", () =>
+  it.effect("ignores terminal reasoning output when item completion is missing", () =>
     Effect.gen(function* () {
       const response = yield* LLMClient.generate(
         LLMRequest.update(request, { providerOptions: { store: false } }),
@@ -2595,29 +2595,13 @@ describe("OpenAI Responses route", () => {
 
       expect(response.reasoning).toBe("Checked the diff.")
       expect(response.events.filter((event) => event.type === "reasoning-end")).toEqual([
-        {
-          type: "reasoning-end",
-          id: "rs_1:0",
-          providerMetadata: { openai: { itemId: "rs_1", reasoningEncryptedContent: "terminal-state" } },
-        },
+        { type: "reasoning-end", id: "rs_1:0" },
       ])
       expect(response.message.content).toContainEqual({
         type: "reasoning",
         text: "Checked the diff.",
-        providerMetadata: { openai: { itemId: "rs_1", reasoningEncryptedContent: "terminal-state" } },
+        providerMetadata: { openai: { itemId: "rs_1", reasoningEncryptedContent: null } },
       })
-
-      const prepared = yield* compileRequest(
-        LLM.request({ model, messages: [response.message], providerOptions: { store: false } }),
-      )
-      expect(prepared.body.input).toEqual([
-        {
-          type: "reasoning",
-          id: "rs_1",
-          summary: [{ type: "summary_text", text: "Checked the diff." }],
-          encrypted_content: "terminal-state",
-        },
-      ])
     }),
   )
 
@@ -2644,7 +2628,7 @@ describe("OpenAI Responses route", () => {
     }),
   )
 
-  it.effect("reconciles pending reasoning and function calls in completed output order", () =>
+  it.effect("recovers pending function calls without reconciling terminal reasoning", () =>
     Effect.gen(function* () {
       const response = yield* LLMClient.generate(
         LLMRequest.update(request, { providerOptions: { store: false } }),
@@ -2682,14 +2666,15 @@ describe("OpenAI Responses route", () => {
         ),
       )
 
-      expect(response.events.find((event) => event.type === "reasoning-end")).toMatchObject({
-        providerMetadata: { openai: { itemId: "rs_1", reasoningEncryptedContent: "terminal-state" } },
+      expect(response.events.find((event) => event.type === "reasoning-end")).toEqual({
+        type: "reasoning-end",
+        id: "rs_1:0",
       })
       expect(response.events.filter(LLMEvent.is.toolCall)).toEqual([
         expect.objectContaining({ id: "call_1", input: { query: "weather" } }),
       ])
-      expect(response.events.findIndex((event) => event.type === "reasoning-end")).toBeLessThan(
-        response.events.findIndex(LLMEvent.is.toolCall),
+      expect(response.events.findIndex(LLMEvent.is.toolCall)).toBeLessThan(
+        response.events.findIndex((event) => event.type === "reasoning-end"),
       )
       expect(response.finishReason.normalized).toBe("tool-calls")
     }),
@@ -3019,6 +3004,7 @@ describe("OpenAI Responses route", () => {
         {
           type: "reasoning-end",
           id: "rs_1:0",
+          text: "Checked the diff.",
           providerMetadata: { openai: { itemId: "rs_1", reasoningEncryptedContent: "encrypted-state" } },
         },
       ])

packages/app/e2e/regression/workspace-accent.spec.ts

@@ -20,95 +20,134 @@ const inventory: WorktreeDirectory[] = [
 
 test.use({ serviceWorkers: "block" })
 
-for (const scenario of [
-  { name: "managed Git worktree", directory: workspace, accent: true },
-  { name: "linked Git worktree outside main", directory: "C:/OpenCode/LinkedWorkspace", accent: true },
-  {
-    name: "linked Git worktree on a narrow screen",
-    directory: "C:/OpenCode/LinkedWorkspace",
-    accent: true,
-    viewport: { width: 390, height: 844 },
-  },
-  { name: "main root with Windows case and separators", directory: "c:\\OPENCODE\\workspaceaccent\\", accent: false },
-  { name: "nested main directory", directory: `${root}/packages/app`, accent: false },
-  { name: "nested workspace inside main", directory: `${workspace}/packages/app`, accent: true },
-  {
-    name: "workspace with Windows case and separators",
-    directory: "c:\\opencode\\WORKSPACEACCENT\\.worktrees\\FEATURE\\src\\",
-    accent: true,
-  },
-  { name: "unregistered sibling with the same prefix", directory: `${workspace}-unregistered`, accent: false },
-  { name: "workspace using another strategy", directory: "C:/OpenCode/WorkspaceCopy", accent: true },
-  { name: "registered directory without a strategy", directory: "C:/OpenCode/RegisteredDirectory", accent: true },
-]) {
-  test(`existing session send button: ${scenario.name}`, async ({ page }, testInfo) => {
-    if (scenario.viewport) await page.setViewportSize(scenario.viewport)
-    const view = await openSession(page, scenario.directory)
-    await view.input.fill("Inspect this fixture workspace.")
-    await expect(view.send).toBeEnabled()
+for (const theme of ["light", "dark"] as const) {
+  test.describe(theme, () => {
+    test.beforeEach(async ({ page }) => {
+      await page.addInitScript((theme) => {
+        localStorage.setItem("opencode-theme-id", "oc-2")
+        localStorage.setItem("opencode-color-scheme", theme)
+      }, theme)
+    })
 
-    if (scenario.name === "managed Git worktree") {
-      // Capture before the color assertion so both red and green runs have evidence.
-      const path = testInfo.outputPath("workspace-accent.png")
-      await view.composer.screenshot({ path })
-      await testInfo.attach("workspace-accent", { path, contentType: "image/png" })
+    for (const scenario of [
+      { name: "managed Git worktree", directory: workspace, accent: true },
+      { name: "linked Git worktree outside main", directory: "C:/OpenCode/LinkedWorkspace", accent: true },
+      {
+        name: "linked Git worktree on a narrow screen",
+        directory: "C:/OpenCode/LinkedWorkspace",
+        accent: true,
+        viewport: { width: 390, height: 844 },
+      },
+      {
+        name: "main root with Windows case and separators",
+        directory: "c:\\OPENCODE\\workspaceaccent\\",
+        accent: false,
+      },
+      { name: "nested main directory", directory: `${root}/packages/app`, accent: false },
+      { name: "nested workspace inside main", directory: `${workspace}/packages/app`, accent: true },
+      {
+        name: "workspace with Windows case and separators",
+        directory: "c:\\opencode\\WORKSPACEACCENT\\.worktrees\\FEATURE\\src\\",
+        accent: true,
+      },
+      { name: "unregistered sibling with the same prefix", directory: `${workspace}-unregistered`, accent: false },
+      { name: "workspace using another strategy", directory: "C:/OpenCode/WorkspaceCopy", accent: true },
+      { name: "registered directory without a strategy", directory: "C:/OpenCode/RegisteredDirectory", accent: true },
+    ]) {
+      test(`existing session send button: ${scenario.name}`, async ({ page }, testInfo) => {
+        if (scenario.viewport) await page.setViewportSize(scenario.viewport)
+        const view = await openSession(page, scenario.directory)
+        await view.input.fill("Inspect this fixture workspace.")
+        await expect(view.send).toBeEnabled()
+
+        if (scenario.name === "managed Git worktree") {
+          // Capture before the color assertion so both red and green runs have evidence.
+          const path = testInfo.outputPath("workspace-accent.png")
+          await view.composer.screenshot({ path })
+          await testInfo.attach("workspace-accent", { path, contentType: "image/png" })
+        }
+
+        await expectBackground(view.send, "contrast")
+        await view.send.hover()
+        await expectBackground(view.send, "contrast")
+        await view.composer.locator('[data-action="composer-model"]').press("Tab")
+        await expect(view.send).toBeFocused()
+        await expectBackground(view.send, "contrast")
+        const message = page.locator('[data-slot="user-message-text"]')
+        await expect(message).toHaveText("Check this fixture workspace.")
+        await expectBackground(
+          message,
+          scenario.accent ? "accent" : theme === "light" ? "layer-02" : "layer-01",
+          "background-color",
+        )
+      })
     }
 
-    await expectBackground(view.send, scenario.accent ? "accent" : "contrast")
-    const message = page.locator('[data-slot="user-message-text"]')
-    await expect(message).toHaveText("Check this fixture workspace.")
-    await expectBackground(message, scenario.accent ? "accent" : "layer-02", "background-color")
+    test("inventory updates leave send neutral; disabled and stop stay neutral", async ({ page }) => {
+      const view = await openSession(page, workspace, [{ directory: root }])
+      await view.input.fill("Keep this draft while the inventory changes.")
+      await expect(view.send).toBeEnabled()
+      await expectBackground(view.send, "contrast")
+      const url = page.url()
+
+      const refreshed = page.waitForResponse(
+        (response) =>
+          new URL(response.url()).pathname === `/api/worktree/${projectID}` && response.request().method() === "GET",
+      )
+      view.worktrees.push({ directory: workspace, strategy: "git" })
+      view.events.push({
+        id: "evt_workspace_accent_inventory",
+        created: 1700000001000,
+        type: "worktree.updated",
+        data: { projectID },
+      })
+      expect((await refreshed).ok()).toBe(true)
+      await expectBackground(view.send, "contrast")
+      await expect(page).toHaveURL(url)
+      await expect(view.input).toHaveText("Keep this draft while the inventory changes.")
+      await expect(view.send).toBeEnabled()
+
+      await view.input.fill("")
+      await expect(view.send).toBeDisabled()
+      await expectBackground(view.send, "contrast")
+
+      view.events.push({
+        id: "evt_workspace_accent_running",
+        created: 1700000002000,
+        type: "session.execution.started",
+        durable: { aggregateID: sessionID, seq: 1, version: 1 },
+        data: { sessionID },
+      })
+      const stop = view.composer.getByRole("button", { name: "Stop", exact: true })
+      await expect(stop).toBeEnabled()
+      await expectBackground(stop, "contrast")
+
+      await view.input.fill("Send a follow-up instead of stopping.")
+      await expect(view.send).toBeEnabled()
+      await expectBackground(view.send, "contrast")
+      await expect(page).toHaveURL(url)
+    })
+
+    test("new workspace send button stays neutral", async ({ page }) => {
+      const view = await openSession(page, root, [...inventory], true)
+      await expect(view.send).toBeDisabled()
+      await expectBackground(view.send, "contrast")
+      await page.getByRole("button", { name: "Local", exact: true }).click()
+      await page.getByRole("menuitem", { name: "New workspace", exact: true }).click()
+      await expect(page.getByRole("button", { name: "New workspace", exact: true })).toBeVisible()
+      await view.input.fill("Inspect this fixture workspace.")
+      await expect(view.send).toBeEnabled()
+      await expectBackground(view.send, "contrast")
+      await view.send.hover()
+      await expectBackground(view.send, "contrast")
+      await view.composer.locator('[data-action="composer-model"]').press("Tab")
+      await expect(view.send).toBeFocused()
+      await expectBackground(view.send, "contrast")
+    })
   })
 }
 
-test("inventory updates recolor the send button without navigation; disabled and stop stay neutral", async ({
-  page,
-}) => {
-  const view = await openSession(page, workspace, [{ directory: root }])
-  await view.input.fill("Keep this draft while the inventory changes.")
-  await expect(view.send).toBeEnabled()
-  await expectBackground(view.send, "contrast")
-  const url = page.url()
-
-  const refreshed = page.waitForResponse(
-    (response) =>
-      new URL(response.url()).pathname === `/api/worktree/${projectID}` && response.request().method() === "GET",
-  )
-  view.worktrees.push({ directory: workspace, strategy: "git" })
-  view.events.push({
-    id: "evt_workspace_accent_inventory",
-    created: 1700000001000,
-    type: "worktree.updated",
-    data: { projectID },
-  })
-  expect((await refreshed).ok()).toBe(true)
-  await expectBackground(view.send, "accent")
-  await expect(page).toHaveURL(url)
-  await expect(view.input).toHaveText("Keep this draft while the inventory changes.")
-  await expect(view.send).toBeEnabled()
-
-  await view.input.fill("")
-  await expect(view.send).toBeDisabled()
-  await expectBackground(view.send, "contrast")
-
-  view.events.push({
-    id: "evt_workspace_accent_running",
-    created: 1700000002000,
-    type: "session.execution.started",
-    durable: { aggregateID: sessionID, seq: 1, version: 1 },
-    data: { sessionID },
-  })
-  const stop = view.composer.getByRole("button", { name: "Stop", exact: true })
-  await expect(stop).toBeEnabled()
-  await expectBackground(stop, "contrast")
-
-  await view.input.fill("Send a follow-up instead of stopping.")
-  await expect(view.send).toBeEnabled()
-  await expectBackground(view.send, "accent")
-  await expect(page).toHaveURL(url)
-})
-
-async function openSession(page: Page, directory: string, worktrees = [...inventory]) {
+async function openSession(page: Page, directory: string, worktrees = [...inventory], draft = false) {
   const events: OpenCodeEvent[] = []
   await mockOpenCodeServer(page, {
     directory,
@@ -159,18 +198,32 @@ async function openSession(page: Page, directory: string, worktrees = [...invent
     if (route.request().method() !== "GET") return route.fallback()
     return route.fulfill({ json: worktrees, headers: { "access-control-allow-origin": "*" } })
   })
-  await page.addInitScript(() => {
-    localStorage.setItem("opencode-theme-id", "oc-2")
-    localStorage.setItem("opencode-color-scheme", "light")
-  })
+  if (draft)
+    await page.addInitScript(
+      ({ root, server }) => {
+        localStorage.setItem(
+          "opencode.global.dat:server",
+          JSON.stringify({
+            projects: { local: [{ worktree: root, expanded: true }] },
+            lastProject: { local: root },
+          }),
+        )
+        localStorage.setItem(
+          "opencode.window.browser.dat:tabs",
+          JSON.stringify([{ type: "draft", draftID: "draft_workspace_accent", server, directory: root }]),
+        )
+      },
+      { root, server },
+    )
   const loaded = page.waitForResponse(
     (response) =>
       new URL(response.url()).pathname === `/api/worktree/${projectID}` && response.request().method() === "GET",
   )
-  await page.goto(`/server/${base64Encode(server)}/session/${sessionID}`)
+  await page.goto(
+    draft ? "/new-session?draftId=draft_workspace_accent" : `/server/${base64Encode(server)}/session/${sessionID}`,
+  )
   expect((await loaded).ok()).toBe(true)
-  await expectSessionReady(page, { server, sessionID, title })
-  await expect(page.locator("html")).toHaveAttribute("data-color-scheme", "light")
+  if (!draft) await expectSessionReady(page, { server, sessionID, title })
   const composer = page.locator('[data-component="composer"]')
   await expectAppVisible(composer)
   const input = composer.getByRole("textbox", { name: "Prompt", exact: true })

packages/app/src/composer/composer.tsx

@@ -12,12 +12,7 @@ import { formatKeybind, useCommand } from "@/shell/commands/command"
 import { useLanguage } from "@/runtime/i18n/language"
 import type { ComposerModel } from "./model"
 
-export function Composer(props: {
-  class?: string
-  model: ComposerModel
-  borderUnderlay?: boolean
-  accentSubmit?: boolean
-}) {
+export function Composer(props: { class?: string; model: ComposerModel; borderUnderlay?: boolean }) {
   const dialog = useDialog()
   const command = useCommand()
   const language = useLanguage()
@@ -26,7 +21,6 @@ export function Composer(props: {
     <div class="flex flex-col gap-3">
       <ComposerEditor
         controller={props.model}
-        accentSubmit={props.accentSubmit}
         borderUnderlay={props.borderUnderlay}
         class={props.class}
         modelControlsVisible={!props.model.model.loading}

packages/app/src/composer/editor/editor.tsx

@@ -37,7 +37,6 @@ export type ComposerMode = "normal" | "shell"
 
 export type ComposerEditorProps = {
   controller: ComposerEditorModel
-  accentSubmit?: boolean
   disabled?: boolean
   readOnly?: boolean
   borderUnderlay?: boolean
@@ -265,7 +264,6 @@ export function ComposerEditor(props: ComposerEditorProps) {
             mode={state.mode}
             stopping={view.submit.stopping()}
             disabled={!props.controller.canSubmit()}
-            accent={props.accentSubmit}
             sendLabel={i18n.t("ui.promptInput.send")}
             stopLabel={i18n.t("ui.promptInput.stop")}
             onSubmit={() => props.controller.submit()}
@@ -751,7 +749,6 @@ export function ComposerEditorSubmitButton(props: {
   mode: ComposerMode
   stopping: boolean
   disabled: boolean
-  accent?: boolean
   sendLabel: string
   stopLabel: string
   onSubmit: () => void
@@ -770,16 +767,10 @@ export function ComposerEditorSubmitButton(props: {
         tabIndex={props.mode === "normal" ? undefined : -1}
         icon={<Icon name={props.stopping ? "stop" : props.mode === "shell" ? "arrow-undo-down" : "arrow-up"} />}
         variant="contrast"
-        class="size-7 rounded-md p-[6px] shadow-[var(--v2-elevation-button-contrast)] disabled:opacity-50"
-        classList={{
-          "text-v2-text-text-contrast": !!props.accent && !props.stopping && !props.disabled,
-          "text-v2-icon-icon-muted": !props.accent || props.stopping || props.disabled,
-        }}
+        class="size-7 rounded-md p-[6px] text-v2-icon-icon-muted shadow-[var(--v2-elevation-button-contrast)] disabled:opacity-50"
         style={{
           "background-image":
-            props.accent && !props.stopping && !props.disabled
-              ? "linear-gradient(180deg,var(--v2-alpha-light-20) 0%,var(--v2-alpha-light-0) 100%),linear-gradient(90deg,var(--v2-background-bg-accent) 0%,var(--v2-background-bg-accent) 100%)"
-              : "linear-gradient(180deg,var(--v2-alpha-light-20) 0%,var(--v2-alpha-light-0) 100%),linear-gradient(90deg,var(--v2-background-bg-contrast) 0%,var(--v2-background-bg-contrast) 100%)",
+            "linear-gradient(180deg,var(--v2-alpha-light-20) 0%,var(--v2-alpha-light-0) 100%),linear-gradient(90deg,var(--v2-background-bg-contrast) 0%,var(--v2-background-bg-contrast) 100%)",
         }}
         aria-label={props.stopping ? props.stopLabel : props.sendLabel}
         onClick={(event) => {

packages/app/src/new-session/view.tsx

@@ -48,7 +48,7 @@ export function NewSessionView(props: {
           <div class={NEW_SESSION_CONTENT_WIDTH}>
             <Wordmark class="h-auto w-full text-v2-background-bg-inverse" />
             <div class="mt-8 flex flex-col gap-8">
-              <Composer model={props.composer} accentSubmit={props.workspace.selection.workspace()} />
+              <Composer model={props.composer} />
               <Show when={props.project.empty()}>
                 <PromptProjectAddButton controller={props.project} />
               </Show>

packages/app/src/session/composer/region.tsx

@@ -216,7 +216,6 @@ export type ActiveSessionRegionModel = ReturnType<typeof createActiveSessionRegi
 export function ActiveSessionComposerRegion(props: {
   model: ActiveSessionRegionModel
   session: SessionModel
-  accentSubmit: boolean
   onResponseSubmit: () => void
 }) {
   const settings = useSettings()
@@ -251,7 +250,7 @@ export function ActiveSessionComposerRegion(props: {
         <div class="relative">
           <SessionQueuePanel queue={queue} />
           <div class="relative z-10">
-            <Composer model={composer} borderUnderlay accentSubmit={props.accentSubmit} />
+            <Composer model={composer} borderUnderlay />
           </div>
         </div>
       }

packages/app/src/session/screen.tsx

@@ -145,12 +145,7 @@ export function SessionScreen(props: { session: SessionModel }) {
 
       <Show when={!review.mobile.changes() ? session.identity.params.id : undefined} keyed>
         {(_id) => (
-          <ActiveSessionComposerRegion
-            model={composer}
-            session={session}
-            accentSubmit={session.workspace.current()}
-            onResponseSubmit={timeline.actions.resume}
-          />
+          <ActiveSessionComposerRegion model={composer} session={session} onResponseSubmit={timeline.actions.resume} />
         )}
       </Show>
       <Show when={!!session.identity.params.id && mobileTabsBottom()}>

packages/cli/src/acp/event.ts

@@ -22,6 +22,9 @@ type Connection = Pick<AgentSideConnection, "sessionUpdate" | "requestPermission
 
 export type TurnControl = {
   cancelled: boolean
+  admitted?: boolean
+  interrupting?: boolean
+  stream?: AbortController
   readonly admission: AbortController
 }
 
@@ -69,6 +72,44 @@ function emptyToolState(): ToolState {
   return { name: "tool", input: {}, metadata: {}, content: [] }
 }
 
+async function openEventStream(input: {
+  readonly client: OpenCodeClient
+  readonly streamController: AbortController
+  readonly admission: AbortController
+  readonly connectionSignal?: AbortSignal
+  readonly sessionSignal?: AbortSignal
+}) {
+  const connectionAbort = () => {
+    input.streamController.abort()
+    input.admission.abort()
+  }
+  const sessionAbort = () => {
+    input.streamController.abort()
+    input.admission.abort()
+  }
+  let stream: AsyncIterator<EventSubscribeOutput> | undefined
+  let opened = false
+  const close = async () => {
+    input.streamController.abort()
+    input.connectionSignal?.removeEventListener("abort", connectionAbort)
+    input.sessionSignal?.removeEventListener("abort", sessionAbort)
+    await stream?.return?.(undefined).catch(() => {})
+  }
+  try {
+    input.connectionSignal?.addEventListener("abort", connectionAbort, { once: true })
+    input.sessionSignal?.addEventListener("abort", sessionAbort, { once: true })
+    if (input.connectionSignal?.aborted) connectionAbort()
+    if (input.sessionSignal?.aborted) sessionAbort()
+    stream = input.client.event.subscribe({ signal: input.streamController.signal })[Symbol.asyncIterator]()
+    const connected = await stream.next()
+    if (connected.done) throw new Error("event stream disconnected before prompt admission")
+    opened = true
+    return { stream, close }
+  } finally {
+    if (!opened) await close()
+  }
+}
+
 export async function streamTurn(input: {
   readonly client: OpenCodeClient
   readonly connection: Connection
@@ -83,12 +124,17 @@ export async function streamTurn(input: {
   readonly connectionSignal?: AbortSignal
   readonly sessionSignal?: AbortSignal
 }): Promise<PromptResponse> {
-  const streamController = new AbortController()
-  const connectionAbort = () => streamController.abort()
-  input.connectionSignal?.addEventListener("abort", connectionAbort, { once: true })
-  const stream = input.client.event.subscribe({ signal: streamController.signal })[Symbol.asyncIterator]()
-  const connected = await stream.next()
-  if (connected.done) throw new Error("event stream disconnected before prompt admission")
+  const streamController = input.control.stream ?? new AbortController()
+  input.control.stream = streamController
+  const opened = await openEventStream({
+    client: input.client,
+    streamController,
+    admission: input.control.admission,
+    connectionSignal: input.connectionSignal,
+    sessionSignal: input.sessionSignal,
+  })
+  const stream = opened.stream
+  const closeStream = opened.close
 
   const control = input.control
   let started = false
@@ -173,6 +219,7 @@ export async function streamTurn(input: {
       if (!eventSessionID || (eventSessionID !== input.sessionID && !child)) continue
       if (matchesStart(event, input.start)) {
         started = true
+        control.admitted = true
         continue
       }
       if (!started) continue
@@ -335,34 +382,38 @@ export async function streamTurn(input: {
     return "interrupted" as const
   }
 
-  const completed = consume("turn")
-  const closeStream = async () => {
-    streamController.abort()
-    input.connectionSignal?.removeEventListener("abort", connectionAbort)
-    input.sessionSignal?.removeEventListener("abort", connectionAbort)
-    await stream.return?.(undefined).catch(() => {})
-  }
+  const completed = consume("turn").then(
+    (value) => ({ success: true as const, value }),
+    (error) => ({ success: false as const, error }),
+  )
+  const submitted = input.submit(control.admission.signal).then(
+    () => ({ success: true as const }),
+    (error) => ({ success: false as const, error }),
+  )
   try {
-    await input.submit(control.admission.signal).catch((error) => {
-      if (!control.cancelled) throw error
-    })
-    if (input.action) {
-      streamController.abort()
-      await completed.catch(() => {})
-      return response(undefined, undefined, "succeeded", control.cancelled, undefined)
-    }
-    if (control.cancelled) {
-      await input.client.session.interrupt({ sessionID: input.sessionID }).catch(() => {})
-      if (!started) {
-        streamController.abort()
-        await completed.catch(() => {})
-        return response(undefined, undefined, "interrupted", true, undefined)
+    const first = await Promise.race([
+      submitted.then((result) => ({ source: "admission" as const, result })),
+      completed.then((result) => ({ source: "stream" as const, result })),
+    ])
+    const completion = await (async () => {
+      if (first.source === "stream") {
+        control.admission.abort()
+        return first.result
       }
-    }
-    const terminal = await completed
+      if (!first.result.success && !control.cancelled) throw first.result.error
+      if (first.result.success) control.admitted = true
+      if (input.action) {
+        streamController.abort()
+        await completed
+        return { success: true as const, value: "succeeded" as const }
+      }
+      if (control.cancelled && !started) streamController.abort()
+      return completed
+    })()
+    if (!completion.success && !control.cancelled) throw completion.error
+    const terminal = completion.success ? completion.value : "interrupted"
     if (input.childSessionUpdate && openChildren.size > 0 && !input.sessionSignal?.aborted) {
       handedOff = true
-      input.sessionSignal?.addEventListener("abort", connectionAbort, { once: true })
       void consume("background")
         .catch(() => {})
         .finally(closeStream)
@@ -381,7 +432,6 @@ export async function streamTurn(input: {
     )
   } catch (error) {
     streamController.abort()
-    await completed.catch(() => {})
     throw error
   } finally {
     if (!handedOff) await closeStream()

packages/cli/src/acp/service.ts

@@ -9,6 +9,7 @@ import {
   type SkillInfo,
 } from "@opencode-ai/client/promise"
 import { withTimestampedFallback } from "@opencode-ai/util/session-title-fallback"
+import { Effect, Semaphore } from "effect"
 import type {
   AgentSideConnection,
   AuthenticateRequest,
@@ -78,6 +79,27 @@ type Attached = {
   modeID: string
 }
 
+type ActiveTurn = {
+  readonly state: Attached
+  readonly control: TurnControl
+  readonly stopped: Promise<void>
+  readonly resolveStopped: () => void
+}
+
+type RegisteredMcp = {
+  readonly server: string
+  readonly config: ReturnType<typeof mcpConfig>
+}
+
+class McpRollbackError extends AggregateError {
+  readonly servers: ReadonlyArray<string>
+
+  constructor(primary: unknown, rollback: unknown, servers: ReadonlyArray<string>) {
+    super([primary, rollback], "ACP attachment failed and MCP rollback did not complete", { cause: primary })
+    this.servers = servers
+  }
+}
+
 type PreparedPrompt = {
   readonly start: TurnStart
   readonly text: string
@@ -104,11 +126,42 @@ export interface Interface {
   cancel(input: CancelNotification): Promise<void>
 }
 
+type KeyedLock<Key> = <A>(key: Key, operation: () => Promise<A>) => Promise<A>
+
+function makeKeyedLock<Key>(): KeyedLock<Key> {
+  const entries = new Map<Key, { readonly semaphore: Semaphore.Semaphore; users: number }>()
+  return async <A>(key: Key, operation: () => Promise<A>) => {
+    const current = entries.get(key)
+    const entry = current ?? { semaphore: Semaphore.makeUnsafe(1), users: 0 }
+    if (!current) entries.set(key, entry)
+    // Count holders and waiters so cleanup cannot split one key across two locks.
+    entry.users++
+    const result = await Effect.runPromise(
+      entry.semaphore.withPermit(
+        Effect.promise(() =>
+          operation().then(
+            (value) => ({ success: true as const, value }),
+            (error) => ({ success: false as const, error }),
+          ),
+        ),
+      ),
+    ).finally(() => {
+      entry.users--
+      if (entry.users === 0) entries.delete(key)
+    })
+    if (!result.success) throw result.error
+    return result.value
+  }
+}
+
 export function make(input: { readonly client: OpenCodeClient; readonly connection: Connection }): Interface {
   const sessions = new Map<string, Attached>()
   const catalogs = new Map<string, Promise<Catalog>>()
-  const registeredMcp = new Map<string, Set<string>>()
-  const active = new Map<string, TurnControl>()
+  const registeredMcp = new Map<string, Map<string, RegisteredMcp>>()
+  const uncertainMcp = new Map<string, Set<string>>()
+  const active = new Map<string, ActiveTurn>()
+  const withSessionLock = makeKeyedLock<string>()
+  const withLocationLock = makeKeyedLock<string>()
   const capabilities = { writeTextFile: false, childSessionUpdates: false }
 
   const catalog = (cwd: string) => {
@@ -128,15 +181,50 @@ export function make(input: { readonly client: OpenCodeClient; readonly connecti
     throw new ACPError.SessionNotFoundError({ sessionId: sessionID })
   }
 
-  const detach = (sessionID: string) => {
-    sessions.get(sessionID)?.abort.abort()
-    sessions.delete(sessionID)
-    registeredMcp.delete(sessionID)
+  const retire = (state: Attached) => {
+    state.abort.abort()
+    const turn = active.get(state.id)
+    if (turn?.state !== state) return
+    turn.control.admission.abort()
+    active.delete(state.id)
   }
 
-  const attach = async (session: SessionInfo, cwd: string, mcpServers: readonly McpServer[]) => {
+  const detach = (sessionID: string) => {
+    const state = sessions.get(sessionID)
+    if (state) retire(state)
+    sessions.delete(sessionID)
+  }
+
+  const invalidateLocation = (cwd: string, servers: ReadonlyArray<string>) => {
+    sessions.forEach((state, sessionID) => {
+      if (state.cwd !== cwd) return
+      retire(state)
+      sessions.delete(sessionID)
+    })
+    const uncertain = new Set([...(registeredMcp.get(cwd)?.keys() ?? []), ...servers])
+    if (uncertain.size > 0) uncertainMcp.set(cwd, uncertain)
+    registeredMcp.delete(cwd)
+  }
+
+  const reconcileLocation = async (cwd: string) => {
+    const uncertain = uncertainMcp.get(cwd)
+    if (!uncertain) return
+    const removed = await Promise.allSettled(
+      [...uncertain].map((server) => input.client.mcp.remove({ server, location: { directory: cwd } })),
+    )
+    const failures = removed.flatMap((result) => (result.status === "rejected" ? [result.reason] : []))
+    if (failures.length > 0) throw new AggregateError(failures, "Failed to reconcile uncertain MCP configuration")
+    uncertainMcp.delete(cwd)
+  }
+
+  // Lifecycle operations acquire Session ID before entering this Location transaction.
+  const attach = async (
+    session: SessionInfo,
+    cwd: string,
+    mcpServers: readonly McpServer[],
+    replayHistory: boolean,
+  ) => {
     const currentCatalog = await catalog(cwd)
-    sessions.get(session.id)?.abort.abort()
     const state: Attached = {
       id: session.id,
       cwd,
@@ -145,25 +233,56 @@ export function make(input: { readonly client: OpenCodeClient; readonly connecti
       model: session.model ?? currentCatalog.defaultModel,
       modeID: session.agent ?? currentCatalog.defaultModeID,
     }
-    sessions.set(session.id, state)
-    await registerMcpServers(input.client, registeredMcp, state, mcpServers)
-    await input.connection.sessionUpdate({
-      sessionId: state.id,
-      update: {
-        sessionUpdate: "available_commands_update",
-        availableCommands: [
-          ...state.catalog.commands,
-          ...state.catalog.skills.filter(
-            (skill) => !state.catalog.commands.some((command) => command.name === skill.name),
-          ),
-        ].map((command) => ({ name: command.name, description: command.description ?? "" })),
-      },
+    return withLocationLock(cwd, async () => {
+      const history = replayHistory ? await messages(input.client, state.id) : undefined
+      await reconcileLocation(cwd)
+      const registration = await registerMcpServers(
+        input.client,
+        registeredMcp.get(cwd) ?? new Map(),
+        state,
+        mcpServers,
+      ).catch((error) => {
+        state.abort.abort()
+        if (error instanceof McpRollbackError) invalidateLocation(cwd, error.servers)
+        throw error
+      })
+      return input.connection
+        .sessionUpdate({
+          sessionId: state.id,
+          update: {
+            sessionUpdate: "available_commands_update",
+            availableCommands: [
+              ...state.catalog.commands,
+              ...state.catalog.skills.filter(
+                (skill) => !state.catalog.commands.some((command) => command.name === skill.name),
+              ),
+            ].map((command) => ({ name: command.name, description: command.description ?? "" })),
+          },
+        })
+        .then(async () => {
+          if (history) await replayMessages(input.connection, state.id, state.cwd, history)
+          const previous = sessions.get(session.id)
+          if (previous) retire(previous)
+          sessions.set(session.id, state)
+          registeredMcp.set(cwd, registration.registered)
+          return state
+        })
+        .catch(async (error) => {
+          state.abort.abort()
+          const rollback = await registration.rollback().then(
+            () => ({ success: true as const }),
+            (failure) => ({ success: false as const, failure }),
+          )
+          if (!rollback.success) {
+            invalidateLocation(cwd, registration.changed)
+            throw new McpRollbackError(error, rollback.failure, registration.changed)
+          }
+          throw error
+        })
+    }).catch((error) => {
+      state.abort.abort()
+      throw error
     })
-    return state
-  }
-
-  const replay = async (state: Attached) => {
-    await replayMessages(input.connection, state.id, state.cwd, await messages(input.client, state.id))
   }
 
   const configOptions = (state: Attached) =>
@@ -213,15 +332,15 @@ export function make(input: { readonly client: OpenCodeClient; readonly connecti
         agent: currentCatalog.defaultModeID,
         model: currentCatalog.defaultModel,
       })
-      const state = await attach(created, params.cwd, params.mcpServers)
+      const state = await withSessionLock(created.id, () => attach(created, params.cwd, params.mcpServers, false))
       return { sessionId: state.id, configOptions: configOptions(state) }
     },
-    loadSession: async (params) => {
-      const session = await getSession(input.client, params.sessionId)
-      const state = await attach(session, session.location.directory, params.mcpServers)
-      await replay(state)
-      return { configOptions: configOptions(state) }
-    },
+    loadSession: (params) =>
+      withSessionLock(params.sessionId, async () => {
+        const session = await getSession(input.client, params.sessionId)
+        const state = await attach(session, session.location.directory, params.mcpServers, true)
+        return { configOptions: configOptions(state) }
+      }),
     listSessions: async (params) => {
       const page = await input.client.session.list({
         ...(params.cwd ? { directory: params.cwd } : {}),
@@ -239,86 +358,109 @@ export function make(input: { readonly client: OpenCodeClient; readonly connecti
         ...(page.cursor.next ? { nextCursor: page.cursor.next } : {}),
       }
     },
-    deleteSession: async (params) => {
-      await input.client.session.remove({ sessionID: params.sessionId }).catch((error) => {
-        if (!isSessionNotFoundError(error)) throw error
-      })
-      detach(params.sessionId)
-      return {}
-    },
-    resumeSession: async (params) => {
-      const session = await getSession(input.client, params.sessionId)
-      const state = await attach(session, session.location.directory, params.mcpServers ?? [])
-      return { configOptions: configOptions(state) }
-    },
-    closeSession: async (params) => {
-      detach(params.sessionId)
-      const turn = active.get(params.sessionId)
-      if (turn) {
-        turn.cancelled = true
-        turn.admission.abort()
-      }
-      await input.client.session.interrupt({ sessionID: params.sessionId }).catch(() => {})
-      return {}
-    },
+    deleteSession: (params) =>
+      withSessionLock(params.sessionId, async () => {
+        await input.client.session.remove({ sessionID: params.sessionId }).catch((error) => {
+          if (!isSessionNotFoundError(error)) throw error
+        })
+        detach(params.sessionId)
+        return {}
+      }),
+    resumeSession: (params) =>
+      withSessionLock(params.sessionId, async () => {
+        const session = await getSession(input.client, params.sessionId)
+        const state = await attach(session, session.location.directory, params.mcpServers ?? [], false)
+        return { configOptions: configOptions(state) }
+      }),
+    closeSession: (params) =>
+      withSessionLock(params.sessionId, async () => {
+        const turn = active.get(params.sessionId)
+        if (turn) {
+          turn.control.cancelled = true
+          turn.control.interrupting = true
+        }
+        detach(params.sessionId)
+        await input.client.session.interrupt({ sessionID: params.sessionId }).catch(() => {})
+        return {}
+      }),
     forkSession: async (params) => {
-      const forked = await input.client.session.fork({
-        sessionID: params.sessionId,
-        boundary: { type: "through" },
+      const forked = await withSessionLock(params.sessionId, () =>
+        input.client.session.fork({
+          sessionID: params.sessionId,
+          boundary: { type: "through" },
+        }),
+      )
+      const state = await withSessionLock(forked.id, async () => {
+        return attach(forked, forked.location.directory, params.mcpServers ?? [], true)
       })
-      const state = await attach(forked, forked.location.directory, params.mcpServers ?? [])
-      await replay(state)
       return { sessionId: state.id, configOptions: configOptions(state) }
     },
     setSessionConfigOption: async (params) => {
-      const state = await requireSession(params.sessionId)
       if (typeof params.value !== "string") throw new ACPError.InvalidConfigOptionError({ configId: params.configId })
-      switch (params.configId) {
-        case "model": {
-          const selected = requireModel(state.catalog, params.value)
-          state.model = selected
-          await input.client.session.switchModel({ sessionID: state.id, model: selected })
-          break
+      return withSessionLock(params.sessionId, async () => {
+        const state = await requireSession(params.sessionId)
+        switch (params.configId) {
+          case "model": {
+            const selected = requireModel(state.catalog, params.value)
+            await input.client.session.switchModel({ sessionID: state.id, model: selected })
+            state.model = selected
+            break
+          }
+          case "effort": {
+            const model = state.catalog.models.find(
+              (item) => item.providerID === state.model.providerID && item.id === state.model.id,
+            )
+            if (!model?.variants.some((variant) => variant.id === params.value))
+              throw new ACPError.InvalidEffortError({ effort: params.value })
+            const selected = { ...state.model, variant: params.value }
+            await input.client.session.switchModel({ sessionID: state.id, model: selected })
+            state.model = selected
+            break
+          }
+          case "mode":
+            await selectMode(input.client, state, params.value)
+            break
+          default:
+            throw new ACPError.InvalidConfigOptionError({ configId: params.configId })
         }
-        case "effort": {
-          const model = state.catalog.models.find(
-            (item) => item.providerID === state.model.providerID && item.id === state.model.id,
-          )
-          if (!model?.variants.some((variant) => variant.id === params.value))
-            throw new ACPError.InvalidEffortError({ effort: params.value })
-          state.model = { ...state.model, variant: params.value }
-          await input.client.session.switchModel({ sessionID: state.id, model: state.model })
-          break
-        }
-        case "mode":
-          await selectMode(input.client, state, params.value)
-          break
-        default:
-          throw new ACPError.InvalidConfigOptionError({ configId: params.configId })
-      }
-      return { configOptions: configOptions(state) }
+        return { configOptions: configOptions(state) }
+      })
     },
     setSessionMode: async (params) => {
-      await selectMode(input.client, await requireSession(params.sessionId), params.modeId)
+      await withSessionLock(params.sessionId, async () => {
+        const state = await requireSession(params.sessionId)
+        await selectMode(input.client, state, params.modeId)
+      })
       return {}
     },
     prompt: async (params) => {
-      const state = await requireSession(params.sessionId)
-      if (active.has(state.id)) {
-        throw new ACPError.ServiceFailureError({
-          safeMessage: `Session already has an active ACP prompt: ${state.id}`,
-          service: "session",
-        })
-      }
-      const messageID = SessionMessage.ID.create()
-      const prepared = preparePrompt(state.catalog, params.prompt, messageID)
-      const control: TurnControl = { cancelled: false, admission: new AbortController() }
+      const acquired = await withSessionLock(params.sessionId, async () => {
+        const state = await requireSession(params.sessionId)
+        if (active.has(state.id)) {
+          throw new ACPError.ServiceFailureError({
+            safeMessage: `Session already has an active ACP prompt: ${state.id}`,
+            service: "session",
+          })
+        }
+        const prepared = preparePrompt(state.catalog, params.prompt, SessionMessage.ID.create())
+        const control: TurnControl = {
+          cancelled: false,
+          admission: new AbortController(),
+          stream: new AbortController(),
+        }
+        const stopped = Promise.withResolvers<void>()
+        const turn = { state, control, stopped: stopped.promise, resolveStopped: () => stopped.resolve() }
+        active.set(state.id, turn)
+        return { state, control, prepared, turn }
+      })
+      const state = acquired.state
+      const control = acquired.control
+      const prepared = acquired.prepared
       const extNotification = input.connection.extNotification
       const childSessionUpdate =
         capabilities.childSessionUpdates && extNotification
           ? (update: ChildSessionUpdate) => extNotification(ChildSessionUpdateMethod, update).then(() => {})
           : undefined
-      active.set(state.id, control)
       const response = await streamTurn({
         client: input.client,
         connection: input.connection,
@@ -333,18 +475,49 @@ export function make(input: { readonly client: OpenCodeClient; readonly connecti
         submit: (signal) => submitPrompt(input.client, state, prepared, signal),
         ...(childSessionUpdate ? { childSessionUpdate } : {}),
       }).finally(() => {
-        if (active.get(state.id) === control) active.delete(state.id)
+        if (active.get(state.id) === acquired.turn) active.delete(state.id)
+        acquired.turn.resolveStopped()
       })
       await sendUsageUpdate(input.client, input.connection, state, response.usage?.totalTokens).catch(() => {})
       return response
     },
     cancel: async (params) => {
-      const current = active.get(params.sessionId)
-      if (current) {
-        current.cancelled = true
-        current.admission.abort()
+      const cancellation = await withSessionLock(params.sessionId, async () => {
+        const current = active.get(params.sessionId)
+        if (!current) return undefined
+        current.control.cancelled = true
+        current.control.admission.abort()
+        if (!current.control.admitted) {
+          current.control.stream?.abort()
+          return { current, interrupt: false as const }
+        }
+        if (current.control.interrupting) return { current, interrupt: false as const }
+        current.control.interrupting = true
+        return { current, interrupt: true as const }
+      })
+      if (!cancellation) return
+      const current = cancellation.current
+      if (!cancellation.interrupt) {
+        await current.stopped
+        return
       }
-      await input.client.session.interrupt({ sessionID: params.sessionId }).catch(() => {})
+      const interrupted = await input.client.session.interrupt({ sessionID: params.sessionId }).catch(async (error) => {
+        await withSessionLock(params.sessionId, async () => {
+          if (active.get(params.sessionId) === current) current.control.interrupting = false
+        })
+        throw error
+      })
+      if (!interrupted.interrupted) {
+        await withSessionLock(params.sessionId, async () => {
+          if (active.get(params.sessionId) === current) current.control.interrupting = false
+        })
+        throw new ACPError.ServiceFailureError({
+          safeMessage: `Failed to interrupt active ACP prompt: ${params.sessionId}`,
+          service: "session",
+        })
+      }
+      current.control.stream?.abort()
+      await current.stopped
     },
   }
 }
@@ -364,16 +537,21 @@ function preparePrompt(catalog: Catalog, prompt: PromptRequest["prompt"], messag
 
 async function submitPrompt(client: OpenCodeClient, session: Attached, prompt: PreparedPrompt, signal: AbortSignal) {
   if (prompt.synthetic.length > 0) {
-    await client.session.synthetic({
-      sessionID: session.id,
-      text: prompt.synthetic.join("\n\n"),
-      description: "ACP embedded context",
-      delivery: "steer",
-      resume: false,
-    })
+    await client.session.synthetic(
+      {
+        sessionID: session.id,
+        text: prompt.synthetic.join("\n\n"),
+        description: "ACP embedded context",
+        delivery: "steer",
+        resume: false,
+      },
+      { signal },
+    )
   }
-  if (prompt.start.type === "compaction") return client.session.compact({ sessionID: session.id, id: prompt.start.id })
-  if (prompt.skill) return client.session.skill({ sessionID: session.id, id: prompt.start.id, skill: prompt.skill.id })
+  if (prompt.start.type === "compaction")
+    return client.session.compact({ sessionID: session.id, id: prompt.start.id }, { signal })
+  if (prompt.skill)
+    return client.session.skill({ sessionID: session.id, id: prompt.start.id, skill: prompt.skill.id }, { signal })
   if (prompt.command) {
     return client.session.command(
       {
@@ -461,8 +639,8 @@ function requireModel(catalog: Catalog, modelID: string): ModelRef {
 
 async function selectMode(client: OpenCodeClient, state: Attached, modeID: string) {
   if (!state.catalog.modes.some((mode) => mode.id === modeID)) throw new ACPError.InvalidModeError({ mode: modeID })
-  state.modeID = modeID
   await client.session.switchAgent({ sessionID: state.id, agent: modeID })
+  state.modeID = modeID
 }
 
 async function getSession(client: OpenCodeClient, sessionID: string) {
@@ -487,26 +665,59 @@ async function messages(client: OpenCodeClient, sessionID: string) {
 
 async function registerMcpServers(
   client: OpenCodeClient,
-  registered: Map<string, Set<string>>,
+  current: Map<string, RegisteredMcp>,
   session: Attached,
   servers: readonly McpServer[],
 ) {
-  const current = registered.get(session.id) ?? new Set<string>()
-  registered.set(session.id, current)
-  await Promise.all(
-    servers.flatMap((server) => {
+  const requested = new Map(
+    servers.map((server) => {
       const config = mcpConfig(server)
-      const key = `${server.name}:${stableStringify(config)}`
-      if (current.has(key)) return []
-      current.add(key)
-      return [
-        client.mcp.add({ server: server.name, location: { directory: session.cwd }, config }).catch((error) => {
-          current.delete(key)
-          throw error
-        }),
-      ]
+      return [server.name, { server: server.name, config }] as const
     }),
   )
+  const changed = [...requested.values()].filter(
+    (entry) => stableStringify(current.get(entry.server)?.config) !== stableStringify(entry.config),
+  )
+  const registered = new Map(current)
+  changed.forEach((entry) => registered.set(entry.server, entry))
+  const rollback = async () => {
+    const results = await Promise.allSettled(
+      changed.map((entry) => {
+        const previous = current.get(entry.server)
+        if (previous) {
+          return client.mcp.add({
+            server: previous.server,
+            location: { directory: session.cwd },
+            config: previous.config,
+          })
+        }
+        return client.mcp.remove({ server: entry.server, location: { directory: session.cwd } })
+      }),
+    )
+    const failures = results.flatMap((result) => (result.status === "rejected" ? [result.reason] : []))
+    if (failures.length > 0) throw new AggregateError(failures, "Failed to roll back MCP configuration")
+  }
+  const additions = await Promise.allSettled(
+    changed.map((entry) =>
+      client.mcp.add({ server: entry.server, location: { directory: session.cwd }, config: entry.config }),
+    ),
+  )
+  const failure = additions.find((result): result is PromiseRejectedResult => result.status === "rejected")
+  if (failure) {
+    const rollbackResult = await rollback().then(
+      () => ({ success: true as const }),
+      (error) => ({ success: false as const, error }),
+    )
+    if (!rollbackResult.success) {
+      throw new McpRollbackError(
+        failure.reason,
+        rollbackResult.error,
+        changed.map((entry) => entry.server),
+      )
+    }
+    throw failure.reason
+  }
+  return { registered, rollback, changed: changed.map((entry) => entry.server) }
 }
 
 function mcpConfig(server: McpServer) {

packages/cli/src/commands/commands.ts

@@ -375,6 +375,11 @@ const Root = Spec.make(typeof OPENCODE_CLI_NAME === "string" ? OPENCODE_CLI_NAME
       params: {
         hostname: Flag.string("hostname").pipe(Flag.optional),
         port: Flag.integer("port").pipe(Flag.optional),
+        cors: Flag.string("cors").pipe(
+          Flag.withSchema(Schema.NonEmptyString),
+          Flag.withDescription("Additional allowed CORS origin (repeat for multiple origins)"),
+          Flag.atLeast(0),
+        ),
         service: Flag.boolean("service").pipe(Flag.withDefault(false)),
         stdio: Flag.boolean("stdio").pipe(Flag.withDefault(false)),
       },

packages/cli/src/commands/handlers/serve.ts

@@ -11,6 +11,7 @@ export default Runtime.handler(
       mode: input.service ? "service" : input.stdio ? "stdio" : "default",
       hostname: Option.getOrUndefined(input.hostname),
       port: Option.getOrUndefined(input.port),
+      cors: input.cors.length > 0 ? input.cors : undefined,
     })
   }),
 )

packages/cli/src/server-process.ts

@@ -22,6 +22,7 @@ export type Options = {
   readonly mode: Mode
   readonly hostname?: string
   readonly port?: number
+  readonly cors?: readonly string[]
 }
 
 // The process effect lives until server shutdown; tracing it would parent every request to one process-lifetime trace.
@@ -88,6 +89,7 @@ const processEffect = Effect.fnUntraced(function* (options: Options) {
           },
           hostname,
           port,
+          cors: options.cors ?? config.cors,
           password,
           pty: { handoff },
           simulation: truthy(process.env.OPENCODE_SIMULATE),

packages/cli/src/services/service-config.ts

@@ -15,11 +15,12 @@ export const Info = Schema.Struct({
   hostname: Schema.optional(Schema.String),
   port: Schema.optional(Schema.Int.check(Schema.isGreaterThanOrEqualTo(1), Schema.isLessThanOrEqualTo(65_535))),
   password: Schema.optional(Schema.String),
+  cors: Schema.optional(Schema.Array(Schema.String)),
   env: Schema.optional(Schema.Record(Schema.String, Schema.String)),
 })
 export type Info = typeof Info.Type
 
-const keys = ["hostname", "port", "password", "env"] as const
+const keys = ["hostname", "port", "password", "cors", "env"] as const
 type Key = (typeof keys)[number]
 
 const decodeInfo = Schema.decodeUnknownEffect(Schema.fromJsonString(Info))
@@ -77,7 +78,7 @@ export const migrateConfig = Effect.fnUntraced(function* (legacy: string, file:
 })
 
 function configKey(key: string): Key {
-  if (key === "hostname" || key === "port" || key === "password" || key === "env") return key
+  if (key === "hostname" || key === "port" || key === "password" || key === "cors" || key === "env") return key
   throw new Error(`Unknown service config key: ${key}`)
 }
 
@@ -160,6 +161,9 @@ export const get = Effect.fn("cli.service-config.get")(function* (key?: string,
     case "password": {
       return yield* password()
     }
+    case "cors": {
+      return JSON.stringify((yield* read()).cors ?? [], null, 2)
+    }
     case "env": {
       const env = (yield* read()).env ?? {}
       return name === undefined ? JSON.stringify(env, null, 2) : (env[name] ?? "")
@@ -197,6 +201,19 @@ export const set = Effect.fn("cli.service-config.set")(function* (key: string, v
       yield* write({ ...existing, env: { ...existing.env, [value]: nestedValue } })
       return
     }
+    case "cors": {
+      const cors = value.split(",").map((origin) => origin.trim())
+      if (
+        cors.some((origin) => {
+          const url = URL.parse(origin)
+          return !url || (url.protocol !== "http:" && url.protocol !== "https:") || url.origin !== origin
+        })
+      )
+        throw new Error("CORS must be a comma-separated list of HTTP(S) origins without paths or trailing slashes")
+      yield* Service.stop(yield* options())
+      yield* write({ ...(yield* read()), cors })
+      return
+    }
   }
 })
 
@@ -231,6 +248,12 @@ export const unset = Effect.fn("cli.service-config.unset")(function* (key: strin
       yield* write(Object.keys(env).length === 0 ? rest : { ...rest, env })
       return
     }
+    case "cors": {
+      yield* Service.stop(yield* options())
+      const { cors: _cors, ...next } = yield* read()
+      yield* write(next)
+      return
+    }
   }
 })
 

packages/cli/test/acp/event-behavior.test.ts

@@ -624,6 +624,7 @@ describe("acp event behavior", () => {
     try {
       await withTimeout(submitted.promise, "cancel test prompt was not admitted")
       control.cancelled = true
+      control.interrupting = true
       control.admission.abort()
       expect(await fixture.client.session.interrupt({ sessionID: "ses_cancel" })).toEqual({ interrupted: true })
 
@@ -669,7 +670,7 @@ describe("acp event behavior", () => {
 
       const response = await withTimeout(result, "pre-admission cancellation did not terminate")
       expect(response).toMatchObject({ stopReason: "cancelled" })
-      expect(fixture.requests.filter((request) => request.path.endsWith("/interrupt"))).toHaveLength(1)
+      expect(fixture.requests.filter((request) => request.path.endsWith("/interrupt"))).toHaveLength(0)
     } finally {
       control.cancelled = true
       control.admission.abort()
@@ -678,6 +679,169 @@ describe("acp event behavior", () => {
     }
   })
 
+  test("observes stream failure while cancelled admission settles", async () => {
+    const fixture = createSseFixture()
+
+    try {
+      for (let index = 0; index < 20; index++) {
+        const submitted = Promise.withResolvers<void>()
+        const session = new AbortController()
+        const result = streamTurn({
+          client: fixture.client,
+          connection: recordingConnection([]),
+          sessionID: `ses_abort_stress_${index}`,
+          cwd: "/workspace",
+          start: { type: "input", id: `input_abort_stress_${index}` },
+          writeTextFile: false,
+          control: { cancelled: false, admission: new AbortController() },
+          sessionSignal: session.signal,
+          submit: (signal) =>
+            new Promise<void>((resolve) => {
+              submitted.resolve()
+              signal.addEventListener(
+                "abort",
+                () => {
+                  void Bun.sleep(5).then(resolve)
+                },
+                { once: true },
+              )
+            }),
+        })
+        const observed = result.catch((error: unknown) => error)
+
+        await submitted.promise
+        session.abort()
+        expect(await withTimeout(observed, "cancelled stress turn did not settle")).toBeInstanceOf(Error)
+      }
+    } finally {
+      await fixture.stop()
+    }
+  })
+
+  test("connection abort stops a turn with hanging admission", async () => {
+    const fixture = createSseFixture()
+    const submitted = Promise.withResolvers<void>()
+    const admissionAborted = Promise.withResolvers<void>()
+    const connection = new AbortController()
+    const result = streamTurn({
+      client: fixture.client,
+      connection: recordingConnection([]),
+      connectionSignal: connection.signal,
+      sessionID: "ses_connection_abort",
+      cwd: "/workspace",
+      start: { type: "input", id: "input_connection_abort" },
+      writeTextFile: false,
+      control: { cancelled: false, admission: new AbortController() },
+      submit: (signal) =>
+        new Promise<void>(() => {
+          submitted.resolve()
+          signal.addEventListener("abort", () => admissionAborted.resolve(), { once: true })
+        }),
+    })
+    const observed = result.catch((error: unknown) => error)
+
+    try {
+      await submitted.promise
+      connection.abort()
+
+      await withTimeout(admissionAborted.promise, "connection abort did not cancel admission")
+      expect(await withTimeout(observed, "connection-aborted turn did not settle")).toBeInstanceOf(Error)
+    } finally {
+      await fixture.stop()
+    }
+  })
+
+  test("cleans stream setup when attachment is already aborted", async () => {
+    const fixture = createSseFixture()
+    const session = new AbortController()
+    let submitted = false
+    session.abort()
+
+    try {
+      const failure = await streamTurn({
+        client: fixture.client,
+        connection: recordingConnection([]),
+        sessionSignal: session.signal,
+        sessionID: "ses_preaborted",
+        cwd: "/workspace",
+        start: { type: "input", id: "input_preaborted" },
+        writeTextFile: false,
+        control: { cancelled: false, admission: new AbortController() },
+        submit: async () => {
+          submitted = true
+        },
+      }).catch((error: unknown) => error)
+
+      expect(failure).toBeInstanceOf(Error)
+      expect(submitted).toBe(false)
+      expect(fixture.streamCount()).toBe(0)
+    } finally {
+      await fixture.stop()
+    }
+  })
+
+  test("preserves admission failure when admission settles first", async () => {
+    const fixture = createSseFixture()
+    const expected = new Error("admission failed first")
+
+    try {
+      const failure = await streamTurn({
+        client: fixture.client,
+        connection: recordingConnection([]),
+        sessionID: "ses_admission_first",
+        cwd: "/workspace",
+        start: { type: "input", id: "input_admission_first" },
+        writeTextFile: false,
+        control: { cancelled: false, admission: new AbortController() },
+        submit: () => Promise.reject(expected),
+      }).catch((error: unknown) => error)
+
+      expect(failure).toBe(expected)
+    } finally {
+      await fixture.stop()
+    }
+  })
+
+  test("preserves stream failure when stream settles before admission", async () => {
+    const fixture = createSseFixture()
+    const connection = new AbortController()
+    const submitted = Promise.withResolvers<void>()
+    const lateAdmission = new Error("admission failed later")
+    const result = streamTurn({
+      client: fixture.client,
+      connection: recordingConnection([]),
+      connectionSignal: connection.signal,
+      sessionID: "ses_stream_first",
+      cwd: "/workspace",
+      start: { type: "input", id: "input_stream_first" },
+      writeTextFile: false,
+      control: { cancelled: false, admission: new AbortController() },
+      submit: (signal) =>
+        new Promise<void>((_, reject) => {
+          submitted.resolve()
+          signal.addEventListener(
+            "abort",
+            () => {
+              void Bun.sleep(20).then(() => reject(lateAdmission))
+            },
+            { once: true },
+          )
+        }),
+    })
+    const observed = result.catch((error: unknown) => error)
+
+    try {
+      await submitted.promise
+      connection.abort()
+
+      const failure = await withTimeout(observed, "stream-first failure did not settle")
+      expect(failure).toBeInstanceOf(Error)
+      expect(failure).not.toBe(lateAdmission)
+    } finally {
+      await fixture.stop()
+    }
+  })
+
   test("cancels unsupported session forms so execution can continue", async () => {
     const fixture = createSseFixture({
       onPrompt({ id, send }) {

packages/cli/test/acp/service-directory.test.ts

@@ -181,6 +181,180 @@ describe("acp service directory behavior", () => {
     expect(invalidConfig).toMatchObject({ _tag: "ACPInvalidConfigOptionError" })
   })
 
+  test("keeps the last confirmed config after switch requests are rejected", async () => {
+    let rejected: "model" | "effort" | "config-mode" | "mode" | undefined
+    await using fixture = makeACPFixture({
+      fetch(request) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_rejected_config") })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_rejected_config/model") {
+          if (rejected === "model" || rejected === "effort") return new Response(null, { status: 409 })
+          return new Response(null, { status: 204 })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_rejected_config/agent") {
+          if (rejected === "config-mode" || rejected === "mode") return new Response(null, { status: 409 })
+          return new Response(null, { status: 204 })
+        }
+        return undefined
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+
+    rejected = "model"
+    const modelFailure = await fixture.service
+      .setSessionConfigOption({ sessionId: session.sessionId, configId: "model", value: "test/second-model" })
+      .catch((error: unknown) => error)
+    rejected = undefined
+    const afterModelFailure = await fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "effort",
+      value: "high",
+    })
+
+    rejected = "effort"
+    const effortFailure = await fixture.service
+      .setSessionConfigOption({ sessionId: session.sessionId, configId: "effort", value: "default" })
+      .catch((error: unknown) => error)
+    rejected = undefined
+    const afterEffortFailure = await fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "mode",
+      value: "plan",
+    })
+
+    rejected = "config-mode"
+    const configModeFailure = await fixture.service
+      .setSessionConfigOption({ sessionId: session.sessionId, configId: "mode", value: "build" })
+      .catch((error: unknown) => error)
+    rejected = undefined
+    const afterConfigModeFailure = await fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "model",
+      value: "test/test-model",
+    })
+
+    rejected = "mode"
+    const modeFailure = await fixture.service
+      .setSessionMode({ sessionId: session.sessionId, modeId: "build" })
+      .catch((error: unknown) => error)
+    rejected = undefined
+    const afterModeFailure = await fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "effort",
+      value: "high",
+    })
+
+    expect([modelFailure, effortFailure, configModeFailure, modeFailure]).toEqual([
+      expect.any(Error),
+      expect.any(Error),
+      expect.any(Error),
+      expect.any(Error),
+    ])
+    expect(currentValue(afterModelFailure, "model")).toBe("test/test-model")
+    expect(currentValue(afterModelFailure, "effort")).toBe("high")
+    expect(currentValue(afterEffortFailure, "effort")).toBe("high")
+    expect(currentValue(afterConfigModeFailure, "mode")).toBe("plan")
+    expect(currentValue(afterModeFailure, "mode")).toBe("plan")
+  })
+
+  test("orders overlapping model and effort switches for one session", async () => {
+    const modelStarted = Promise.withResolvers<void>()
+    const releaseModel = Promise.withResolvers<void>()
+    let serverModel = "test/test-model/default"
+    await using fixture = makeACPFixture({
+      fetch(request) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_ordered_model") })
+        }
+        if (request.method !== "POST" || request.path !== "/api/session/ses_ordered_model/model") return undefined
+        if (serverModel === "test/test-model/default") {
+          serverModel = "test/second-model"
+          modelStarted.resolve()
+          return releaseModel.promise.then(() => new Response(null, { status: 204 }))
+        }
+        serverModel = "test/second-model/medium"
+        return new Response(null, { status: 204 })
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+
+    const model = fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "model",
+      value: "test/second-model",
+    })
+    await modelStarted.promise
+    const effort = fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "effort",
+      value: "medium",
+    })
+    releaseModel.resolve()
+    await model
+    const result = await effort
+
+    expect(serverModel).toBe("test/second-model/medium")
+    expect(currentValue(result, "model")).toBe("test/second-model")
+    expect(currentValue(result, "effort")).toBe("medium")
+    expect(
+      fixture.requests
+        .filter((request) => request.path === "/api/session/ses_ordered_model/model")
+        .map((request) => request.body),
+    ).toEqual([
+      { model: { providerID: "test", id: "second-model" } },
+      { model: { providerID: "test", id: "second-model", variant: "medium" } },
+    ])
+  })
+
+  test("orders overlapping config-mode and setSessionMode switches for one session", async () => {
+    const configModeStarted = Promise.withResolvers<void>()
+    const releaseConfigMode = Promise.withResolvers<void>()
+    let serverMode = "build"
+    await using fixture = makeACPFixture({
+      fetch(request) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_ordered_mode") })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_ordered_mode/model") {
+          return new Response(null, { status: 204 })
+        }
+        if (request.method !== "POST" || request.path !== "/api/session/ses_ordered_mode/agent") return undefined
+        if (serverMode !== "build") {
+          serverMode = "build"
+          return new Response(null, { status: 204 })
+        }
+        serverMode = "plan"
+        configModeStarted.resolve()
+        return releaseConfigMode.promise.then(() => new Response(null, { status: 204 }))
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+
+    const configMode = fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "mode",
+      value: "plan",
+    })
+    await configModeStarted.promise
+    const mode = fixture.service.setSessionMode({ sessionId: session.sessionId, modeId: "build" })
+    releaseConfigMode.resolve()
+    await Promise.all([configMode, mode])
+    const result = await fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "model",
+      value: "test/test-model",
+    })
+
+    expect(serverMode).toBe("build")
+    expect(currentValue(result, "mode")).toBe("build")
+    expect(
+      fixture.requests
+        .filter((request) => request.path === "/api/session/ses_ordered_mode/agent")
+        .map((request) => request.body),
+    ).toEqual([{ agent: "plan" }, { agent: "build" }])
+  })
+
   test("converts MCP configs and deduplicates registrations per session and config", async () => {
     const local: McpServer = {
       name: "tools",

packages/cli/test/acp/service-fixture.ts

@@ -30,6 +30,8 @@ type FixtureHandler = (
 
 type FixtureOptions = {
   readonly fetch?: FixtureHandler
+  readonly clientFetch?: (...args: Parameters<typeof fetch>) => ReturnType<typeof fetch>
+  readonly sessionUpdate?: AgentSideConnection["sessionUpdate"]
   readonly models?: readonly ModelInfo[]
   readonly defaultModel?: ModelInfo
   readonly agents?: readonly AgentInfo[]
@@ -127,13 +129,15 @@ export function makeACPFixture(options: FixtureOptions = {}) {
   const requests: FixtureRequest[] = []
   const updates: Parameters<AgentSideConnection["sessionUpdate"]>[0][] = []
   const encoder = new TextEncoder()
-  let eventController: ReadableStreamDefaultController<Uint8Array> | undefined
+  const eventControllers = new Set<ReadableStreamDefaultController<Uint8Array>>()
   const models = options.models ?? [testModel, secondModel]
   const context: FixtureContext = {
     requests,
     send(event) {
-      if (!eventController) throw new Error("ACP fixture has no active event stream")
-      eventController.enqueue(encoder.encode(`data: ${JSON.stringify(event)}\n\n`))
+      if (eventControllers.size === 0) throw new Error("ACP fixture has no active event stream")
+      eventControllers.forEach((controller) => {
+        controller.enqueue(encoder.encode(`data: ${JSON.stringify(event)}\n\n`))
+      })
     },
   }
   const server = Bun.serve({
@@ -158,11 +162,11 @@ export function makeACPFixture(options: FixtureOptions = {}) {
           new ReadableStream<Uint8Array>({
             start(value) {
               controller = value
-              eventController = value
+              eventControllers.add(value)
               context.send({ id: "evt_connected", type: "server.connected", data: {} })
             },
             cancel() {
-              if (eventController === controller) eventController = undefined
+              if (controller) eventControllers.delete(controller)
             },
           }),
           { headers: { "content-type": "text/event-stream" } },
@@ -185,10 +189,14 @@ export function makeACPFixture(options: FixtureOptions = {}) {
     },
   })
   const service = ACPService.make({
-    client: OpenCode.make({ baseUrl: server.url.toString() }),
+    client: OpenCode.make({
+      baseUrl: server.url.toString(),
+      ...(options.clientFetch ? { fetch: Object.assign(options.clientFetch, { preconnect: fetch.preconnect }) } : {}),
+    }),
     connection: {
       sessionUpdate: async (update) => {
         updates.push(update)
+        await options.sessionUpdate?.(update)
       },
       requestPermission: async () => ({ outcome: { outcome: "cancelled" } }),
     },
@@ -198,8 +206,10 @@ export function makeACPFixture(options: FixtureOptions = {}) {
     service,
     requests,
     updates,
+    send: (event: unknown) => context.send(event),
     async [Symbol.asyncDispose]() {
-      eventController?.close()
+      eventControllers.forEach((controller) => controller.close())
+      eventControllers.clear()
       await server.stop(true)
     },
   }

packages/cli/test/acp/service-lifecycle.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, test } from "bun:test"
 import type { SessionConfigOption } from "@agentclientprotocol/sdk"
 import { makeACPFixture, makeSession, secondModel } from "./service-fixture"
+import { withTimeout } from "./sse-fixture"
 
 describe("acp service lifecycle", () => {
   test("does not persist the first catalog variant when no explicit default exists", async () => {
@@ -172,6 +173,833 @@ describe("acp service lifecycle", () => {
     })
   })
 
+  test("loads authoritative config after an overlapping switch completes", async () => {
+    const switchStarted = Promise.withResolvers<void>()
+    const releaseSwitch = Promise.withResolvers<void>()
+    const nativeFetch = fetch
+    let switching = true
+    let serverModel = makeSession("server").model
+    await using fixture = makeACPFixture({
+      clientFetch(input, init) {
+        const url = new URL(input instanceof Request ? input.url : input.toString())
+        if (init?.method !== "GET" || url.pathname !== "/api/session/ses_load_during_switch") {
+          return nativeFetch(input, init)
+        }
+        return Promise.resolve(Response.json({ data: makeSession("ses_load_during_switch", { model: serverModel }) }))
+      },
+      fetch(request) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_load_during_switch", { model: serverModel }) })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_load_during_switch/model") {
+          if (!switching) return new Response(null, { status: 204 })
+          switching = false
+          switchStarted.resolve()
+          return releaseSwitch.promise.then(() => {
+            serverModel = { providerID: "test", id: secondModel.id }
+            return new Response(null, { status: 204 })
+          })
+        }
+        if (request.method === "GET" && request.path === "/api/session/ses_load_during_switch/message") {
+          return Response.json({ data: [], cursor: {} })
+        }
+        return undefined
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+
+    const switched = fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "model",
+      value: "test/second-model",
+    })
+    await switchStarted.promise
+    const loaded = fixture.service.loadSession({ cwd: "/workspace", sessionId: session.sessionId, mcpServers: [] })
+    releaseSwitch.resolve()
+    await switched
+    const result = await loaded
+    const effort = await fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "effort",
+      value: "medium",
+    })
+
+    expect(currentValue(result, "model")).toBe("test/second-model")
+    expect(currentValue(effort, "effort")).toBe("medium")
+  })
+
+  test("detaches and resumes after an overlapping switch completes", async () => {
+    const switchStarted = Promise.withResolvers<void>()
+    const releaseSwitch = Promise.withResolvers<void>()
+    const nativeFetch = fetch
+    let switching = true
+    let serverModel = makeSession("server").model
+    await using fixture = makeACPFixture({
+      clientFetch(input, init) {
+        const url = new URL(input instanceof Request ? input.url : input.toString())
+        if (init?.method !== "GET" || url.pathname !== "/api/session/ses_resume_during_switch") {
+          return nativeFetch(input, init)
+        }
+        return Promise.resolve(Response.json({ data: makeSession("ses_resume_during_switch", { model: serverModel }) }))
+      },
+      fetch(request) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_resume_during_switch", { model: serverModel }) })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_resume_during_switch/model") {
+          if (!switching) return new Response(null, { status: 204 })
+          switching = false
+          switchStarted.resolve()
+          return releaseSwitch.promise.then(() => {
+            serverModel = { providerID: "test", id: secondModel.id }
+            return new Response(null, { status: 204 })
+          })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_resume_during_switch/interrupt") {
+          return new Response(null, { status: 204 })
+        }
+        return undefined
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+
+    const switched = fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "model",
+      value: "test/second-model",
+    })
+    await switchStarted.promise
+    const closed = fixture.service.closeSession({ sessionId: session.sessionId })
+    const resumed = fixture.service.resumeSession({ cwd: "/workspace", sessionId: session.sessionId, mcpServers: [] })
+    releaseSwitch.resolve()
+    await Promise.all([switched, closed])
+    const result = await resumed
+    const effort = await fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "effort",
+      value: "medium",
+    })
+
+    expect(currentValue(result, "model")).toBe("test/second-model")
+    expect(currentValue(effort, "effort")).toBe("medium")
+  })
+
+  test("forks from authoritative parent config after an overlapping switch completes", async () => {
+    const switchStarted = Promise.withResolvers<void>()
+    const releaseSwitch = Promise.withResolvers<void>()
+    const nativeFetch = fetch
+    let serverModel = makeSession("server").model
+    await using fixture = makeACPFixture({
+      clientFetch(input, init) {
+        const url = new URL(input instanceof Request ? input.url : input.toString())
+        if (init?.method !== "POST" || url.pathname !== "/api/session/ses_fork_parent/fork") {
+          return nativeFetch(input, init)
+        }
+        return Promise.resolve(
+          Response.json({ data: makeSession("ses_fork_child", { model: serverModel, agent: "build" }) }),
+        )
+      },
+      fetch(request) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_fork_parent", { model: serverModel }) })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_fork_parent/model") {
+          switchStarted.resolve()
+          return releaseSwitch.promise.then(() => {
+            serverModel = { providerID: "test", id: secondModel.id }
+            return new Response(null, { status: 204 })
+          })
+        }
+        if (request.method === "GET" && request.path === "/api/session/ses_fork_child/message") {
+          return Response.json({ data: [], cursor: {} })
+        }
+        return undefined
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+
+    const switched = fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "model",
+      value: "test/second-model",
+    })
+    await switchStarted.promise
+    const forked = fixture.service.forkSession({ cwd: "/workspace", sessionId: session.sessionId, mcpServers: [] })
+    releaseSwitch.resolve()
+    await switched
+    const result = await forked
+
+    expect(result.sessionId).toBe("ses_fork_child")
+    expect(currentValue(result, "model")).toBe("test/second-model")
+  })
+
+  test("keeps the prior attachment when staged MCP, command, or replay setup fails", async () => {
+    let phase: "mcp" | "commands" | "replay" | "success" = "mcp"
+    await using fixture = makeACPFixture({
+      sessionUpdate: async () => {
+        if (phase === "commands") throw new Error("command publication failed")
+      },
+      fetch(request) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_attach_transaction") })
+        }
+        if (request.method === "GET" && request.path === "/api/session/ses_attach_transaction") {
+          return Response.json({
+            data: makeSession("ses_attach_transaction", {
+              model: { providerID: secondModel.providerID, id: secondModel.id },
+            }),
+          })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_attach_transaction/model") {
+          return new Response(null, { status: 204 })
+        }
+        if (request.method === "GET" && request.path === "/api/session/ses_attach_transaction/message") {
+          if (phase === "replay") return new Response(null, { status: 500 })
+          return Response.json({ data: [], cursor: {} })
+        }
+        if (request.method === "PUT" && request.path === "/api/mcp/docs" && phase === "mcp") {
+          return new Response(null, { status: 500 })
+        }
+        if (request.method === "PUT" && request.path.startsWith("/api/mcp/")) {
+          return new Response(null, { status: 204 })
+        }
+        if (request.method === "DELETE" && request.path.startsWith("/api/mcp/")) {
+          return new Response(null, { status: 204 })
+        }
+        return undefined
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+    const tools = { name: "tools", command: "bun", args: ["tools.ts"], env: [] }
+    const docs = { name: "docs", command: "bun", args: ["docs.ts"], env: [] }
+
+    const mcpFailure = await fixture.service
+      .loadSession({ cwd: "/workspace", sessionId: session.sessionId, mcpServers: [tools, docs] })
+      .catch((error: unknown) => error)
+    const afterMcpFailure = await fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "effort",
+      value: "high",
+    })
+
+    phase = "commands"
+    const commandFailure = await fixture.service
+      .resumeSession({ cwd: "/workspace", sessionId: session.sessionId, mcpServers: [tools] })
+      .catch((error: unknown) => error)
+    const afterCommandFailure = await fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "effort",
+      value: "default",
+    })
+
+    phase = "replay"
+    const replayFailure = await fixture.service
+      .loadSession({ cwd: "/workspace", sessionId: session.sessionId, mcpServers: [tools] })
+      .catch((error: unknown) => error)
+    const afterReplayFailure = await fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "effort",
+      value: "high",
+    })
+
+    phase = "success"
+    const attached = await fixture.service.resumeSession({
+      cwd: "/workspace",
+      sessionId: session.sessionId,
+      mcpServers: [tools],
+    })
+
+    expect([mcpFailure, commandFailure, replayFailure]).toEqual([
+      expect.any(Error),
+      expect.any(Error),
+      expect.any(Error),
+    ])
+    expect(currentValue(afterMcpFailure, "model")).toBe("test/test-model")
+    expect(currentValue(afterCommandFailure, "model")).toBe("test/test-model")
+    expect(currentValue(afterReplayFailure, "model")).toBe("test/test-model")
+    expect(currentValue(attached, "model")).toBe("test/second-model")
+    expect(
+      fixture.requests
+        .filter((request) => request.path.startsWith("/api/mcp/"))
+        .map((request) => `${request.method} ${request.path}`),
+    ).toEqual([
+      "PUT /api/mcp/tools",
+      "PUT /api/mcp/docs",
+      "DELETE /api/mcp/tools",
+      "DELETE /api/mcp/docs",
+      "PUT /api/mcp/tools",
+      "DELETE /api/mcp/tools",
+      "PUT /api/mcp/tools",
+    ])
+  })
+
+  test("serializes MCP attachment transactions for sessions in the same location", async () => {
+    const firstStaged = Promise.withResolvers<void>()
+    const releaseFirst = Promise.withResolvers<void>()
+    let racing = false
+    let created = 0
+    let installed: unknown
+    await using fixture = makeACPFixture({
+      sessionUpdate: async (update) => {
+        if (!racing || update.sessionId !== "ses_location_1") return
+        firstStaged.resolve()
+        await releaseFirst.promise
+        throw new Error("first publication failed")
+      },
+      fetch(request) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          created++
+          return Response.json({ data: makeSession(`ses_location_${created}`) })
+        }
+        if (request.method === "GET" && request.path.startsWith("/api/session/ses_location_")) {
+          return Response.json({ data: makeSession(request.path.split("/").at(-1) ?? "missing") })
+        }
+        if (request.method === "PUT" && request.path === "/api/mcp/shared") {
+          installed = request.body
+          return new Response(null, { status: 204 })
+        }
+        if (request.method === "DELETE" && request.path === "/api/mcp/shared") {
+          installed = undefined
+          return new Response(null, { status: 204 })
+        }
+        return undefined
+      },
+    })
+    const first = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+    const second = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+    racing = true
+
+    const failed = fixture.service
+      .resumeSession({
+        cwd: "/workspace",
+        sessionId: first.sessionId,
+        mcpServers: [{ name: "shared", command: "bun", args: ["first.ts"], env: [] }],
+      })
+      .catch((error: unknown) => error)
+    await firstStaged.promise
+    const succeeded = fixture.service.resumeSession({
+      cwd: "/workspace",
+      sessionId: second.sessionId,
+      mcpServers: [{ name: "shared", command: "bun", args: ["second.ts"], env: [] }],
+    })
+    releaseFirst.resolve()
+
+    expect(await failed).toBeInstanceOf(Error)
+    await succeeded
+    expect(installed).toEqual({
+      config: { type: "local", command: ["bun", "second.ts"], environment: {} },
+    })
+    expect(
+      fixture.requests
+        .filter((request) => request.path === "/api/mcp/shared")
+        .map((request) => ({ method: request.method, body: request.body })),
+    ).toEqual([
+      {
+        method: "PUT",
+        body: { config: { type: "local", command: ["bun", "first.ts"], environment: {} } },
+      },
+      { method: "DELETE", body: undefined },
+      {
+        method: "PUT",
+        body: { config: { type: "local", command: ["bun", "second.ts"], environment: {} } },
+      },
+    ])
+  })
+
+  test("invalidates a location when MCP rollback fails", async () => {
+    let failing = false
+    let created = 0
+    await using fixture = makeACPFixture({
+      sessionUpdate: async (update) => {
+        if (failing && update.sessionId === "ses_rollback_1") throw new Error("command publication failed")
+      },
+      fetch(request) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          created++
+          return Response.json({ data: makeSession(`ses_rollback_${created}`) })
+        }
+        if (request.method === "GET" && request.path.startsWith("/api/session/ses_rollback_")) {
+          return Response.json({ data: makeSession(request.path.split("/").at(-1) ?? "missing") })
+        }
+        if (request.method === "PUT" && request.path === "/api/mcp/tools") {
+          return new Response(null, { status: 204 })
+        }
+        if (request.method === "DELETE" && request.path === "/api/mcp/tools") {
+          return new Response(null, { status: failing ? 500 : 204 })
+        }
+        if (request.method === "POST" && request.path.endsWith("/model")) {
+          return new Response(null, { status: 204 })
+        }
+        return undefined
+      },
+    })
+    const first = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+    const second = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+    failing = true
+
+    const failure = await fixture.service
+      .resumeSession({
+        cwd: "/workspace",
+        sessionId: first.sessionId,
+        mcpServers: [{ name: "tools", command: "bun", args: ["tools.ts"], env: [] }],
+      })
+      .catch((error: unknown) => error)
+    const missing = await Promise.all(
+      [first, second].map((session) =>
+        fixture.service
+          .setSessionConfigOption({ sessionId: session.sessionId, configId: "effort", value: "high" })
+          .catch((error: unknown) => error),
+      ),
+    )
+
+    expect(failure).toBeInstanceOf(AggregateError)
+    expect(failure).toMatchObject({ message: "ACP attachment failed and MCP rollback did not complete" })
+    expect(missing).toEqual([
+      expect.objectContaining({ _tag: "ACPSessionNotFoundError" }),
+      expect.objectContaining({ _tag: "ACPSessionNotFoundError" }),
+    ])
+
+    failing = false
+    const recovered = await fixture.service.resumeSession({
+      cwd: "/workspace",
+      sessionId: first.sessionId,
+      mcpServers: [],
+    })
+
+    expect(currentValue(recovered, "model")).toBe("test/test-model")
+    expect(
+      fixture.requests.filter((request) => request.path === "/api/mcp/tools").map((request) => request.method),
+    ).toEqual(["PUT", "DELETE", "DELETE"])
+  })
+
+  test("allows MCP attachment transactions in distinct locations to proceed concurrently", async () => {
+    const firstStaged = Promise.withResolvers<void>()
+    const releaseFirst = Promise.withResolvers<void>()
+    let racing = false
+    let created = 0
+    await using fixture = makeACPFixture({
+      sessionUpdate: async (update) => {
+        if (!racing || update.sessionId !== "ses_distinct_1") return
+        firstStaged.resolve()
+        await releaseFirst.promise
+      },
+      fetch(request) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          created++
+          const cwd = created === 1 ? "/first" : "/second"
+          return Response.json({ data: makeSession(`ses_distinct_${created}`, { cwd }) })
+        }
+        if (request.method === "GET" && request.path.startsWith("/api/session/ses_distinct_")) {
+          const id = request.path.split("/").at(-1) ?? "missing"
+          return Response.json({ data: makeSession(id, { cwd: id.endsWith("1") ? "/first" : "/second" }) })
+        }
+        if (request.method === "PUT" && request.path === "/api/mcp/shared") {
+          return new Response(null, { status: 204 })
+        }
+        return undefined
+      },
+    })
+    const first = await fixture.service.newSession({ cwd: "/first", mcpServers: [] })
+    const second = await fixture.service.newSession({ cwd: "/second", mcpServers: [] })
+    racing = true
+
+    const blocked = fixture.service.resumeSession({
+      cwd: "/first",
+      sessionId: first.sessionId,
+      mcpServers: [{ name: "shared", command: "bun", args: ["first.ts"], env: [] }],
+    })
+    await firstStaged.promise
+    const concurrent = fixture.service.resumeSession({
+      cwd: "/second",
+      sessionId: second.sessionId,
+      mcpServers: [{ name: "shared", command: "bun", args: ["second.ts"], env: [] }],
+    })
+
+    await withTimeout(concurrent, "distinct location transaction was blocked")
+    releaseFirst.resolve()
+    await blocked
+  })
+
+  test("allows config switches for distinct sessions to proceed concurrently", async () => {
+    const firstStarted = Promise.withResolvers<void>()
+    const releaseFirst = Promise.withResolvers<void>()
+    let created = 0
+    await using fixture = makeACPFixture({
+      fetch(request) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          created++
+          return Response.json({ data: makeSession(`ses_concurrent_${created}`) })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_concurrent_1/model") {
+          firstStarted.resolve()
+          return releaseFirst.promise.then(() => new Response(null, { status: 204 }))
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_concurrent_2/model") {
+          return new Response(null, { status: 204 })
+        }
+        return undefined
+      },
+    })
+    const first = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+    const second = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+
+    const blocked = fixture.service.setSessionConfigOption({
+      sessionId: first.sessionId,
+      configId: "effort",
+      value: "high",
+    })
+    await firstStarted.promise
+    const concurrent = await fixture.service.setSessionConfigOption({
+      sessionId: second.sessionId,
+      configId: "effort",
+      value: "high",
+    })
+    releaseFirst.resolve()
+    await blocked
+
+    expect(currentValue(concurrent, "effort")).toBe("high")
+  })
+
+  test("load replacement cancels prompt ownership acquired before streaming", async () => {
+    await using fixture = makeACPFixture({
+      fetch(request, context) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_prompt_load") })
+        }
+        if (request.method === "GET" && request.path === "/api/session/ses_prompt_load") {
+          return Response.json({ data: makeSession("ses_prompt_load") })
+        }
+        if (request.method === "GET" && request.path === "/api/session/ses_prompt_load/message") {
+          return Response.json({ data: [], cursor: {} })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_prompt_load/prompt") {
+          const id = requestField(request.body, "id")
+          context.send({
+            id: `evt_${id}`,
+            type: "session.inbox.delivered",
+            data: { sessionID: "ses_prompt_load", inboxID: id },
+          })
+          if (requestField(request.body, "text") === "second") {
+            context.send({
+              id: "evt_second_complete",
+              type: "session.execution.succeeded",
+              data: { sessionID: "ses_prompt_load" },
+            })
+          }
+          return Response.json({ data: {} })
+        }
+        return undefined
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+
+    const prompt = fixture.service.prompt({
+      sessionId: session.sessionId,
+      prompt: [{ type: "text", text: "first" }],
+    })
+    const stoppedPrompt = prompt.then(
+      () => "resolved",
+      () => "rejected",
+    )
+    const loaded = fixture.service.loadSession({ cwd: "/workspace", sessionId: session.sessionId, mcpServers: [] })
+    await loaded
+    const stopped = await withTimeout(stoppedPrompt, "replaced prompt did not stop")
+    const second = await fixture.service.prompt({
+      sessionId: session.sessionId,
+      prompt: [{ type: "text", text: "second" }],
+    })
+
+    expect(stopped).toBe("rejected")
+    expect(second.stopReason).toBe("end_turn")
+  })
+
+  test("replacement permits a new prompt while the retired request does not settle", async () => {
+    const firstStarted = Promise.withResolvers<void>()
+    const firstAborted = Promise.withResolvers<void>()
+    const nativeFetch = fetch
+    let prompts = 0
+    await using fixture = makeACPFixture({
+      clientFetch(input, init) {
+        const url = new URL(input instanceof Request ? input.url : input.toString())
+        if (init?.method !== "POST" || url.pathname !== "/api/session/ses_prompt_handoff/prompt") {
+          return nativeFetch(input, init)
+        }
+        prompts++
+        if (prompts > 1) return nativeFetch(input, init)
+        firstStarted.resolve()
+        init.signal?.addEventListener("abort", () => firstAborted.resolve(), { once: true })
+        return new Promise<Response>(() => {})
+      },
+      fetch(request, context) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_prompt_handoff") })
+        }
+        if (request.method === "GET" && request.path === "/api/session/ses_prompt_handoff") {
+          return Response.json({ data: makeSession("ses_prompt_handoff") })
+        }
+        if (request.method === "GET" && request.path === "/api/session/ses_prompt_handoff/message") {
+          return Response.json({ data: [], cursor: {} })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_prompt_handoff/prompt") {
+          const id = requestField(request.body, "id")
+          context.send({
+            id: `evt_${id}`,
+            type: "session.inbox.delivered",
+            data: { sessionID: "ses_prompt_handoff", inboxID: id },
+          })
+          context.send({
+            id: "evt_handoff_complete",
+            type: "session.execution.succeeded",
+            data: { sessionID: "ses_prompt_handoff" },
+          })
+          return Response.json({ data: {} })
+        }
+        return undefined
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+    void fixture.service
+      .prompt({ sessionId: session.sessionId, prompt: [{ type: "text", text: "never settles" }] })
+      .catch(() => undefined)
+    await firstStarted.promise
+
+    await fixture.service.loadSession({ cwd: "/workspace", sessionId: session.sessionId, mcpServers: [] })
+    await firstAborted.promise
+    const current = await fixture.service.prompt({
+      sessionId: session.sessionId,
+      prompt: [{ type: "text", text: "new owner" }],
+    })
+
+    expect(current.stopReason).toBe("end_turn")
+    expect(prompts).toBe(2)
+  })
+
+  test("cancel permits a new prompt while the cancelled request does not settle", async () => {
+    const firstStarted = Promise.withResolvers<void>()
+    const firstAborted = Promise.withResolvers<void>()
+    const nativeFetch = fetch
+    let prompts = 0
+    await using fixture = makeACPFixture({
+      clientFetch(input, init) {
+        const url = new URL(input instanceof Request ? input.url : input.toString())
+        if (init?.method !== "POST" || url.pathname !== "/api/session/ses_prompt_cancel_handoff/prompt") {
+          return nativeFetch(input, init)
+        }
+        prompts++
+        if (prompts > 1) return nativeFetch(input, init)
+        firstStarted.resolve()
+        init.signal?.addEventListener("abort", () => firstAborted.resolve(), { once: true })
+        return new Promise<Response>(() => {})
+      },
+      fetch(request, context) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_prompt_cancel_handoff") })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_prompt_cancel_handoff/interrupt") {
+          return Response.json({ interrupted: true })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_prompt_cancel_handoff/prompt") {
+          const id = requestField(request.body, "id")
+          context.send({
+            id: `evt_${id}`,
+            type: "session.inbox.delivered",
+            data: { sessionID: "ses_prompt_cancel_handoff", inboxID: id },
+          })
+          context.send({
+            id: "evt_cancel_handoff_complete",
+            type: "session.execution.succeeded",
+            data: { sessionID: "ses_prompt_cancel_handoff" },
+          })
+          return Response.json({ data: {} })
+        }
+        return undefined
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+    void fixture.service
+      .prompt({ sessionId: session.sessionId, prompt: [{ type: "text", text: "never settles" }] })
+      .catch(() => undefined)
+    await firstStarted.promise
+
+    await fixture.service.cancel({ sessionId: session.sessionId })
+    await firstAborted.promise
+    const current = await fixture.service.prompt({
+      sessionId: session.sessionId,
+      prompt: [{ type: "text", text: "new owner" }],
+    })
+
+    expect(current.stopReason).toBe("end_turn")
+    expect(prompts).toBe(2)
+  })
+
+  test("failed authoritative interruption retains sole prompt ownership", async () => {
+    const admitted = Promise.withResolvers<void>()
+    const afterFailure = Promise.withResolvers<void>()
+    let interruptFails = true
+    let prompts = 0
+    await using fixture = makeACPFixture({
+      sessionUpdate: async (update) => {
+        if (
+          update.update.sessionUpdate === "agent_message_chunk" &&
+          update.update.content.type === "text" &&
+          update.update.content.text === "before cancel"
+        ) {
+          admitted.resolve()
+        }
+        if (
+          update.update.sessionUpdate === "agent_message_chunk" &&
+          update.update.content.type === "text" &&
+          update.update.content.text === "after failure"
+        ) {
+          afterFailure.resolve()
+        }
+      },
+      fetch(request, context) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_interrupt_owner") })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_interrupt_owner/prompt") {
+          prompts++
+          const id = requestField(request.body, "id")
+          context.send({
+            id: `evt_${id}`,
+            type: "session.inbox.delivered",
+            data: { sessionID: "ses_interrupt_owner", inboxID: id },
+          })
+          context.send({
+            id: `evt_text_${prompts}`,
+            type: "session.text.delta",
+            data: {
+              sessionID: "ses_interrupt_owner",
+              assistantMessageID: `msg_assistant_${prompts}`,
+              ordinal: 0,
+              delta: prompts === 1 ? "before cancel" : "replacement",
+            },
+          })
+          if (prompts > 1) {
+            context.send({
+              id: "evt_replacement_complete",
+              type: "session.execution.succeeded",
+              data: { sessionID: "ses_interrupt_owner" },
+            })
+          }
+          return Response.json({ data: {} })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_interrupt_owner/interrupt") {
+          if (interruptFails) return new Response(null, { status: 500 })
+          context.send({
+            id: "evt_owner_interrupted",
+            type: "session.execution.interrupted",
+            data: { sessionID: "ses_interrupt_owner", reason: "user" },
+          })
+          return Response.json({ interrupted: true })
+        }
+        return undefined
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+    const first = fixture.service
+      .prompt({ sessionId: session.sessionId, prompt: [{ type: "text", text: "first" }] })
+      .catch((error: unknown) => error)
+    await admitted.promise
+
+    const interruptionFailure = await fixture.service.cancel({ sessionId: session.sessionId }).catch((error) => error)
+    const replacementFailure = await fixture.service
+      .prompt({ sessionId: session.sessionId, prompt: [{ type: "text", text: "must wait" }] })
+      .catch((error: unknown) => error)
+    fixture.updates.length = 0
+    fixture.send({
+      id: "evt_after_failed_interrupt",
+      type: "session.text.delta",
+      data: {
+        sessionID: "ses_interrupt_owner",
+        assistantMessageID: "msg_assistant_1",
+        ordinal: 1,
+        delta: "after failure",
+      },
+    })
+    await afterFailure.promise
+    const activeStream = fixture.requests.filter((request) => request.path === "/api/event").length
+
+    expect(interruptionFailure).toBeInstanceOf(Error)
+    expect(replacementFailure).toMatchObject({ _tag: "ACPServiceFailureError" })
+    expect(activeStream).toBe(1)
+    expect(
+      fixture.updates.flatMap((update) =>
+        update.update.sessionUpdate === "agent_message_chunk" && update.update.content.type === "text"
+          ? [update.update.content.text]
+          : [],
+      ),
+    ).toEqual(["after failure"])
+
+    interruptFails = false
+    await fixture.service.cancel({ sessionId: session.sessionId })
+    await first
+    const replacement = await fixture.service.prompt({
+      sessionId: session.sessionId,
+      prompt: [{ type: "text", text: "replacement" }],
+    })
+
+    expect(replacement.stopReason).toBe("end_turn")
+    expect(prompts).toBe(2)
+    expect(
+      fixture.updates.flatMap((update) =>
+        update.update.sessionUpdate === "agent_message_chunk" && update.update.content.type === "text"
+          ? [update.update.content.text]
+          : [],
+      ),
+    ).toEqual(["after failure", "replacement"])
+  })
+
+  test("delete detaches and cancels an active foreground prompt", async () => {
+    const promptStarted = Promise.withResolvers<void>()
+    await using fixture = makeACPFixture({
+      fetch(request, context) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_prompt_delete") })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_prompt_delete/prompt") {
+          const id = requestField(request.body, "id")
+          context.send({
+            id: `evt_${id}`,
+            type: "session.inbox.delivered",
+            data: { sessionID: "ses_prompt_delete", inboxID: id },
+          })
+          promptStarted.resolve()
+          return Response.json({ data: {} })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_prompt_delete/model") {
+          return new Response(null, { status: 204 })
+        }
+        if (request.method === "DELETE" && request.path === "/api/session/ses_prompt_delete") {
+          return new Response(null, { status: 204 })
+        }
+        return undefined
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+    const prompt = fixture.service.prompt({
+      sessionId: session.sessionId,
+      prompt: [{ type: "text", text: "running" }],
+    })
+    const stoppedPrompt = prompt.then(
+      () => "resolved",
+      () => "rejected",
+    )
+    await promptStarted.promise
+
+    const configured = await fixture.service.setSessionConfigOption({
+      sessionId: session.sessionId,
+      configId: "effort",
+      value: "high",
+    })
+    await fixture.service.deleteSession({ sessionId: session.sessionId })
+    const stopped = await withTimeout(stoppedPrompt, "deleted session prompt did not stop")
+
+    expect(currentValue(configured, "effort")).toBe("high")
+    expect(stopped).toBe("rejected")
+  })
+
   test("lists server-backed pages and forwards cwd and cursor", async () => {
     const firstPage = Array.from({ length: 100 }, (_, index) =>
       makeSession(`ses_${100 - index}`, {
@@ -251,11 +1079,7 @@ describe("acp service lifecycle", () => {
     expect(await fixture.service.closeSession({ sessionId: "missing" })).toEqual({})
     expect(
       fixture.requests.filter((request) => request.path.endsWith("/interrupt")).map((request) => request.path),
-    ).toEqual([
-      "/api/session/ses_lifecycle/interrupt",
-      "/api/session/ses_lifecycle/interrupt",
-      "/api/session/missing/interrupt",
-    ])
+    ).toEqual(["/api/session/ses_lifecycle/interrupt", "/api/session/missing/interrupt"])
   })
 
   test("deletes sessions from backing and local storage", async () => {
@@ -289,3 +1113,10 @@ describe("acp service lifecycle", () => {
 function currentValue(result: { readonly configOptions?: readonly SessionConfigOption[] | null }, id: string) {
   return result.configOptions?.find((option) => option.id === id)?.currentValue
 }
+
+function requestField(value: unknown, key: string) {
+  if (!value || typeof value !== "object") throw new Error(`Missing request ${key}`)
+  const field = Reflect.get(value, key)
+  if (typeof field !== "string") throw new Error(`Missing request ${key}`)
+  return field
+}

packages/cli/test/acp/service-usage.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, test } from "bun:test"
 import { makeACPFixture, makeSession, secondModel, type FixtureContext, type FixtureRequest } from "./service-fixture"
+import { withTimeout } from "./sse-fixture"
 
 describe("acp service prompt routing and usage", () => {
   test("routes slash commands, skills, and compact through their session endpoints", async () => {
@@ -69,6 +70,87 @@ describe("acp service prompt routing and usage", () => {
     expect(fixture.requests.some((request) => request.path === "/api/session/ses_routes/prompt")).toBe(false)
   })
 
+  test("forwards admission signals through every prompt route", async () => {
+    const nativeFetch = fetch
+    const signalled: string[] = []
+    await using fixture = makeACPFixture({
+      clientFetch(input, init) {
+        const url = new URL(input instanceof Request ? input.url : input.toString())
+        if (
+          ["synthetic", "prompt", "skill", "compact", "command"].some((suffix) => url.pathname.endsWith(`/${suffix}`))
+        ) {
+          if (init?.signal instanceof AbortSignal) signalled.push(url.pathname.split("/").at(-1) ?? "")
+        }
+        return nativeFetch(input, init)
+      },
+      fetch(request, context) {
+        if (request.method === "POST" && request.path === "/api/session") {
+          return Response.json({ data: makeSession("ses_signals") })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_signals/synthetic") {
+          return Response.json({ data: {} })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_signals/prompt") {
+          const id = requestID(request)
+          completeTurn(context, "ses_signals", {
+            id: id.replace(/^msg_/, "evt_"),
+            type: "session.inbox.delivered",
+            data: { sessionID: "ses_signals", inboxID: id },
+          })
+          return Response.json({ data: {} })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_signals/skill") {
+          const id = requestID(request)
+          completeTurn(context, "ses_signals", {
+            id: id.replace(/^msg_/, "evt_"),
+            type: "session.skill.activated",
+            data: { sessionID: "ses_signals", skill: "verify" },
+          })
+          return new Response(null, { status: 204 })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_signals/compact") {
+          const id = requestID(request)
+          completeTurn(context, "ses_signals", {
+            id: `evt_${id}`,
+            type: "session.inbox.delivered",
+            data: { sessionID: "ses_signals", inboxID: id },
+          })
+          return Response.json({ data: {} })
+        }
+        if (request.method === "POST" && request.path === "/api/session/ses_signals/command") {
+          return new Response(null, { status: 204 })
+        }
+        return undefined
+      },
+    })
+    const session = await fixture.service.newSession({ cwd: "/workspace", mcpServers: [] })
+
+    await withTimeout(
+      fixture.service.prompt({
+        sessionId: session.sessionId,
+        prompt: [
+          { type: "text", text: "context", annotations: { audience: ["assistant"] } },
+          { type: "text", text: "hello" },
+        ],
+      }),
+      "synthetic prompt did not complete",
+    )
+    await withTimeout(
+      fixture.service.prompt({ sessionId: session.sessionId, prompt: [{ type: "text", text: "/verify" }] }),
+      "skill prompt did not complete",
+    )
+    await withTimeout(
+      fixture.service.prompt({ sessionId: session.sessionId, prompt: [{ type: "text", text: "/compact" }] }),
+      "compact prompt did not complete",
+    )
+    await withTimeout(
+      fixture.service.prompt({ sessionId: session.sessionId, prompt: [{ type: "text", text: "/review" }] }),
+      "command prompt did not complete",
+    )
+
+    expect(signalled).toEqual(["synthetic", "prompt", "skill", "compact", "command"])
+  })
+
   test("returns turn usage and publishes current context usage with cumulative session cost", async () => {
     const assistantTokens = {
       input: 100,

packages/cli/test/acp/sse-fixture.ts

@@ -166,6 +166,7 @@ export function createSseFixture(options: FixtureOptions = {}) {
     messages,
     requests,
     send,
+    streamCount: () => streams.size,
     async stop() {
       for (const stream of streams) {
         try {

packages/cli/test/cors.test.ts

@@ -0,0 +1,124 @@
+import { NodeServices } from "@effect/platform-node"
+import { Global } from "@opencode-ai/util/global"
+import { expect, test } from "bun:test"
+import { Effect, Exit, FileSystem } from "effect"
+import { Command } from "effect/unstable/cli"
+import path from "node:path"
+import { Commands } from "../src/commands/commands"
+import { ServiceConfig } from "../src/services/service-config"
+import { it } from "../../core/test/lib/effect"
+
+it.live("service CORS config persists multiple origins and preserves other settings on set and unset", () =>
+  Effect.gen(function* () {
+    const fs = yield* FileSystem.FileSystem
+    const root = yield* fs.makeTempDirectoryScoped({ prefix: "opencode-cors-" })
+    const config = path.join(root, "config")
+    const state = path.join(root, "state")
+    const file = path.join(config, ServiceConfig.filename())
+    const existing = { hostname: "127.0.0.1", port: 4321, password: "test-secret", env: { TEST: "value" } }
+    yield* fs.makeDirectory(config)
+    yield* fs.makeDirectory(state)
+    yield* fs.writeFileString(file, JSON.stringify(existing))
+    yield* Effect.gen(function* () {
+      expect(yield* ServiceConfig.get("cors")).toBe("[]")
+      yield* ServiceConfig.set("cors", " http://192.0.2.10:3001, https://app.example.com ")
+      const cors = ["http://192.0.2.10:3001", "https://app.example.com"]
+      expect(yield* ServiceConfig.read()).toEqual({ ...existing, cors })
+      expect(yield* ServiceConfig.get("cors")).toBe(JSON.stringify(cors, null, 2))
+      expect(JSON.parse(yield* ServiceConfig.get())).toEqual({
+        hostname: existing.hostname,
+        port: existing.port,
+        env: existing.env,
+        cors,
+      })
+      expect(JSON.parse(yield* fs.readFileString(file))).toEqual({ ...existing, cors })
+      yield* ServiceConfig.set("cors", "https://replacement.example.com")
+      expect((yield* ServiceConfig.read()).cors).toEqual(["https://replacement.example.com"])
+      yield* ServiceConfig.unset("cors")
+      expect(yield* ServiceConfig.get("cors")).toBe("[]")
+      expect(JSON.parse(yield* fs.readFileString(file))).toEqual(existing)
+    }).pipe(Effect.provideService(Global.Service, Global.make({ config, state })))
+  }).pipe(Effect.provide(NodeServices.layer)),
+)
+
+it.live("service CORS config rejects empty lists, invalid origins, and extra arguments without changing config", () =>
+  Effect.gen(function* () {
+    const fs = yield* FileSystem.FileSystem
+    const root = yield* fs.makeTempDirectoryScoped({ prefix: "opencode-cors-invalid-" })
+    const config = path.join(root, "config")
+    const state = path.join(root, "state")
+    const file = path.join(config, ServiceConfig.filename())
+    const existing = { port: 4321, cors: ["https://app.example.com"] }
+    yield* fs.makeDirectory(config)
+    yield* fs.makeDirectory(state)
+    yield* fs.writeFileString(file, JSON.stringify(existing))
+    yield* Effect.gen(function* () {
+      yield* Effect.forEach(
+        [
+          "",
+          " ",
+          ",",
+          "https://app.example.com,",
+          ",https://app.example.com",
+          "https://app.example.com,,https://other.example.com",
+          "not-a-url",
+          "*",
+          "null",
+          "ftp://app.example.com",
+          "https://app.example.com/",
+          "https://app.example.com/path",
+          "https://app.example.com?query=1",
+          "https://app.example.com#fragment",
+          "https://user:password@app.example.com",
+        ],
+        (value) =>
+          Effect.gen(function* () {
+            expect(Exit.isFailure(yield* ServiceConfig.set("cors", value).pipe(Effect.exit))).toBe(true)
+            expect(yield* ServiceConfig.read()).toEqual(existing)
+          }),
+      )
+      yield* Effect.forEach(
+        [
+          ServiceConfig.get("cors", "extra"),
+          ServiceConfig.set("cors", "https://app.example.com", "extra"),
+          ServiceConfig.unset("cors", "extra"),
+        ],
+        (operation) =>
+          Effect.gen(function* () {
+            expect(Exit.isFailure(yield* operation.pipe(Effect.exit))).toBe(true)
+          }),
+      )
+      expect(JSON.parse(yield* fs.readFileString(file))).toEqual(existing)
+    }).pipe(Effect.provideService(Global.Service, Global.make({ config, state })))
+  }).pipe(Effect.provide(NodeServices.layer)),
+)
+
+test.each([
+  { args: [], cors: [] },
+  { args: ["--cors", "https://app.example.com"], cors: ["https://app.example.com"] },
+  {
+    args: ["--service", "--cors", "http://192.0.2.10:3001", "--cors", "https://app.example.com"],
+    cors: ["http://192.0.2.10:3001", "https://app.example.com"],
+  },
+])("serve parses CORS flags: $args", async ({ args, cors }) => {
+  const received: (readonly string[])[] = []
+  const command = Commands.commands.serve.spec.pipe(
+    Command.withHandler((input) => Effect.sync(() => void received.push(input.cors))),
+  )
+  await Effect.runPromise(Command.runWith(command, { version: "test" })(args).pipe(Effect.provide(NodeServices.layer)))
+  expect(received).toEqual([cors])
+})
+
+test.each([{ args: ["--cors"] }, { args: ["--cors", ""] }])(
+  "serve rejects a missing or empty CORS flag value: $args",
+  async ({ args }) => {
+    const command = Commands.commands.serve.spec.pipe(Command.withHandler(() => Effect.void))
+    const result = await Effect.runPromise(
+      Command.runWith(command, { version: "test", renderErrors: false })(args).pipe(
+        Effect.exit,
+        Effect.provide(NodeServices.layer),
+      ),
+    )
+    expect(Exit.isFailure(result)).toBe(true)
+  },
+)

packages/cli/test/service.test.ts

@@ -9,6 +9,7 @@ import os from "node:os"
 import path from "node:path"
 import { ServiceConfig } from "../src/services/service-config"
 import { ServiceRegistration } from "../src/services/service-registration"
+import { isolatedEnv } from "./fixture/environment"
 
 test("managed service ports are stable per installation channel", () => {
   expect(ServiceConfig.defaultPort("latest")).toBe(0xc0de)
@@ -313,6 +314,48 @@ test("configured managed service port overrides the channel default", async () =
   }
 }, 30_000)
 
+test.each([
+  { args: [], origins: ["http://192.0.2.10:3001", "https://configured.example.com"] },
+  {
+    args: ["--cors", "http://192.0.2.20:3001", "--cors", "https://override.example.com"],
+    origins: ["http://192.0.2.20:3001", "https://override.example.com"],
+  },
+])(
+  "managed service applies CORS configuration with flag overrides: $args",
+  async ({ args, origins }) => {
+    const root = await fs.mkdtemp(path.join(os.tmpdir(), "opencode-service-cors-"))
+    const config = path.join(root, "config", ServiceConfig.filename())
+    const registration = path.join(root, "state", "opencode", ServiceConfig.filename())
+    const cors = ["http://192.0.2.10:3001", "https://configured.example.com"]
+    await fs.mkdir(path.dirname(config), { recursive: true })
+    await fs.writeFile(config, JSON.stringify({ cors }))
+    const owner = Bun.spawn(
+      [process.execPath, path.join(import.meta.dir, "../src/index.ts"), "serve", "--service", "--port", "0", ...args],
+      { env: isolatedEnv(root), stderr: "pipe", stdout: "ignore" },
+    )
+    try {
+      const info = await waitForInfo(registration)
+      await Promise.all(
+        [...new Set([...cors, ...origins, "https://unlisted.example.com"])].map(async (origin) => {
+          const response = await fetch(new URL("/api/health", info.url), {
+            method: "OPTIONS",
+            headers: { Origin: origin, "Access-Control-Request-Method": "GET" },
+          })
+          expect(response.headers.get("access-control-allow-origin")).toBe(
+            origins.some((value) => value === origin) ? origin : null,
+          )
+        }),
+      )
+      expect((await Bun.file(config).json()).cors).toEqual(cors)
+    } finally {
+      owner.kill("SIGTERM")
+      await owner.exited
+      await fs.rm(root, { recursive: true, force: true })
+    }
+  },
+  30_000,
+)
+
 test("unrelated managed port occupancy reports an actionable conflict", async () => {
   const root = await fs.mkdtemp(path.join(os.tmpdir(), "opencode-service-conflict-"))
   const listener = Bun.serve({ hostname: "127.0.0.1", port: 0, fetch: () => new Response("unrelated") })

packages/client/src/effect/api/api.ts

@@ -1950,6 +1950,12 @@ export type VcsGetInput = {
 export type VcsGetOutput = { readonly location: Location.Info; readonly data: Vcs.Info }
 export type VcsGetOperation<E = never> = (input?: VcsGetInput) => Effect.Effect<VcsGetOutput, E>
 
+export type VcsBaseInput = {
+  readonly location?: { readonly directory?: string | undefined; readonly workspace?: string | undefined } | undefined
+}
+export type VcsBaseOutput = { readonly location: Location.Info; readonly data: Vcs.Base | null }
+export type VcsBaseOperation<E = never> = (input?: VcsBaseInput) => Effect.Effect<VcsBaseOutput, E>
+
 export type VcsStatusInput = {
   readonly location?: { readonly directory?: string | undefined; readonly workspace?: string | undefined } | undefined
 }
@@ -1967,6 +1973,7 @@ export type VcsBranchesOperation<E = never> = (input?: VcsBranchesInput) => Effe
 export type VcsDiffInput = {
   readonly location?: { readonly directory?: string | undefined; readonly workspace?: string | undefined } | undefined
   readonly mode: Vcs.Mode
+  readonly base?: string | undefined
   readonly context?: number | undefined
 }
 export type VcsDiffOutput = { readonly location: Location.Info; readonly data: ReadonlyArray<FileDiff.Info> }
@@ -1974,6 +1981,7 @@ export type VcsDiffOperation<E = never> = (input: VcsDiffInput) => Effect.Effect
 
 export interface VcsApi<E = never> {
   readonly get: VcsGetOperation<E>
+  readonly base: VcsBaseOperation<E>
   readonly status: VcsStatusOperation<E>
   readonly branches: VcsBranchesOperation<E>
   readonly diff: VcsDiffOperation<E>

packages/client/src/effect/generated/client.ts

@@ -244,6 +244,8 @@ import type {
   WorkspaceDestroyOutput,
   VcsGetInput,
   VcsGetOutput,
+  VcsBaseInput,
+  VcsBaseOutput,
   VcsStatusInput,
   VcsStatusOutput,
   VcsBranchesInput,
@@ -1468,6 +1470,11 @@ const EndpointVcsGet = (raw: RawClient["server.vcs"]) => (input?: VcsGetInput) =
     raw["vcs.get"]({ query: { location: input?.["location"] } }).pipe(Effect.mapError(mapClientError)),
   )
 
+const EndpointVcsBase = (raw: RawClient["server.vcs"]) => (input?: VcsBaseInput) =>
+  preserveEffect<VcsBaseOutput>()(
+    raw["vcs.base"]({ query: { location: input?.["location"] } }).pipe(Effect.mapError(mapClientError)),
+  )
+
 const EndpointVcsStatus = (raw: RawClient["server.vcs"]) => (input?: VcsStatusInput) =>
   preserveEffect<VcsStatusOutput>()(
     raw["vcs.status"]({ query: { location: input?.["location"] } }).pipe(Effect.mapError(mapClientError)),
@@ -1482,13 +1489,14 @@ const EndpointVcsBranches = (raw: RawClient["server.vcs"]) => (input?: VcsBranch
 
 const EndpointVcsDiff = (raw: RawClient["server.vcs"]) => (input: VcsDiffInput) =>
   preserveEffect<VcsDiffOutput>()(
-    raw["vcs.diff"]({ query: { location: input["location"], mode: input["mode"], context: input["context"] } }).pipe(
-      Effect.mapError(mapClientError),
-    ),
+    raw["vcs.diff"]({
+      query: { location: input["location"], mode: input["mode"], base: input["base"], context: input["context"] },
+    }).pipe(Effect.mapError(mapClientError)),
   )
 
 const adaptGroupVcs = (raw: RawClient["server.vcs"]) => ({
   get: EndpointVcsGet(raw),
+  base: EndpointVcsBase(raw),
   status: EndpointVcsStatus(raw),
   branches: EndpointVcsBranches(raw),
   diff: EndpointVcsDiff(raw),

packages/client/src/effect/index.ts

@@ -34,6 +34,7 @@ export { Permission } from "@opencode-ai/schema/permission"
 export { PermissionSaved } from "@opencode-ai/schema/permission-saved"
 export { Project } from "@opencode-ai/schema/project"
 export { Worktree } from "@opencode-ai/schema/worktree"
+export { Vcs } from "@opencode-ai/schema/vcs"
 export { Provider } from "@opencode-ai/schema/provider"
 export { Pty } from "@opencode-ai/schema/pty"
 export { Question } from "@opencode-ai/schema/question"

packages/client/src/promise/generated/client.ts

@@ -240,6 +240,8 @@ import type {
   WorkspaceDestroyOutput,
   VcsGetInput,
   VcsGetOutput,
+  VcsBaseInput,
+  VcsBaseOutput,
   VcsStatusInput,
   VcsStatusOutput,
   VcsBranchesInput,
@@ -1367,7 +1369,7 @@ export function make(options: ClientOptions) {
             method: "GET",
             path: `/api/session/${encodeURIComponent(input.sessionID)}/form`,
             successStatus: 200,
-            declaredStatuses: [404, 400, 401],
+            declaredStatuses: [404, 401, 400],
             empty: false,
           },
           requestOptions,
@@ -1496,7 +1498,7 @@ export function make(options: ClientOptions) {
             method: "GET",
             path: `/api/session/${encodeURIComponent(input.sessionID)}/permission`,
             successStatus: 200,
-            declaredStatuses: [404, 400, 401],
+            declaredStatuses: [404, 401, 400],
             empty: false,
           },
           requestOptions,
@@ -1996,6 +1998,18 @@ export function make(options: ClientOptions) {
           },
           requestOptions,
         ),
+      base: (input?: VcsBaseInput, requestOptions?: RequestOptions) =>
+        request<VcsBaseOutput>(
+          {
+            method: "GET",
+            path: `/api/vcs/base`,
+            query: { location: input?.["location"] },
+            successStatus: 200,
+            declaredStatuses: [503, 401, 400],
+            empty: false,
+          },
+          requestOptions,
+        ),
       status: (input?: VcsStatusInput, requestOptions?: RequestOptions) =>
         request<VcsStatusOutput>(
           {
@@ -2025,9 +2039,9 @@ export function make(options: ClientOptions) {
           {
             method: "GET",
             path: `/api/vcs/diff`,
-            query: { location: input["location"], mode: input["mode"], context: input["context"] },
+            query: { location: input["location"], mode: input["mode"], base: input["base"], context: input["context"] },
             successStatus: 200,
-            declaredStatuses: [401, 400],
+            declaredStatuses: [503, 401, 400],
             empty: false,
           },
           requestOptions,

packages/client/src/promise/generated/types.ts

@@ -419,6 +419,8 @@ export type WorkspaceDestroyResult = { destroyed: boolean }
 
 export type VcsBranch = { current?: string; default?: string }
 
+export type VcsBase = { name: string; ref: string; source: "reflog" | "default" }
+
 export type VcsFileStatus = {
   file: string
   additions: number
@@ -6073,6 +6075,17 @@ export type VcsGetOutput = {
   data: VcsInfo
 }
 
+export type VcsBaseInput = {
+  readonly location?: {
+    readonly location?: { readonly directory?: string | undefined; readonly workspace?: string | undefined } | undefined
+  }["location"]
+}
+
+export type VcsBaseOutput = {
+  location: { directory: string; workspaceID?: string; project: { id: string; directory: string; canonical: string } }
+  data: VcsBase | null
+}
+
 export type VcsStatusInput = {
   readonly location?: {
     readonly location?: { readonly directory?: string | undefined; readonly workspace?: string | undefined } | undefined
@@ -6110,17 +6123,26 @@ export type VcsBranchesOutput = {
 export type VcsDiffInput = {
   readonly location?: {
     readonly location?: { readonly directory?: string | undefined; readonly workspace?: string | undefined } | undefined
-    readonly mode: "working" | "branch"
+    readonly mode: "working" | "branch" | "committed"
+    readonly base?: string | undefined
     readonly context?: number | undefined
   }["location"]
   readonly mode: {
     readonly location?: { readonly directory?: string | undefined; readonly workspace?: string | undefined } | undefined
-    readonly mode: "working" | "branch"
+    readonly mode: "working" | "branch" | "committed"
+    readonly base?: string | undefined
     readonly context?: number | undefined
   }["mode"]
+  readonly base?: {
+    readonly location?: { readonly directory?: string | undefined; readonly workspace?: string | undefined } | undefined
+    readonly mode: "working" | "branch" | "committed"
+    readonly base?: string | undefined
+    readonly context?: number | undefined
+  }["base"]
   readonly context?: {
     readonly location?: { readonly directory?: string | undefined; readonly workspace?: string | undefined } | undefined
-    readonly mode: "working" | "branch"
+    readonly mode: "working" | "branch" | "committed"
+    readonly base?: string | undefined
     readonly context?: number | undefined
   }["context"]
 }

packages/client/src/solid/data.ts

@@ -750,7 +750,8 @@ export function createData(config: CreateDataInput) {
             command: event.data.shell.command,
             status: event.data.shell.status,
             exit: event.data.shell.exit,
-            metadata: event.metadata,
+            metadata:
+              event.data.shell.metadata.background === true ? { ...event.metadata, background: true } : event.metadata,
             time: { created: event.created },
           })
         })

packages/client/test/contract-identity.test.ts

@@ -6,6 +6,7 @@ import { Model } from "@opencode-ai/schema/model"
 import { Prompt } from "@opencode-ai/schema/prompt"
 import { Session } from "@opencode-ai/schema/session"
 import { SessionMessage } from "@opencode-ai/schema/session-message"
+import { Vcs } from "@opencode-ai/schema/vcs"
 
 const Client = await import("../src/effect")
 
@@ -14,6 +15,7 @@ test("effect entrypoint exposes canonical Schema contracts", () => {
   expect(Client.Config).toBe(Config)
   expect(Client.Model).toBe(Model)
   expect(Client.Session).toBe(Session)
+  expect(Client.Vcs.Base).toBe(Vcs.Base)
 })
 
 test("generated Effect API names canonical and composed outputs", async () => {

packages/client/test/effect.test.ts

@@ -27,6 +27,26 @@ test("health.get decodes the readiness response", async () => {
   expect(result).toEqual({ healthy: true, version: "old", pid: 123 })
 })
 
+test("vcs.base decodes nullable review-base metadata", async () => {
+  const location = { directory: "/repo", project: { id: "global", directory: "/repo", canonical: "/repo" } }
+  const base = {
+    name: "release",
+    ref: "refs/remotes/origin/release",
+    source: "reflog",
+  }
+  for (const data of [base, null]) {
+    const httpClient = HttpClient.make((request) =>
+      Effect.succeed(HttpClientResponse.fromWeb(request, Response.json({ location, data }))),
+    )
+    const result = await Effect.gen(function* () {
+      const client = yield* OpenCode.make({ baseUrl: "http://localhost:3000" })
+      return yield* client.vcs.base({ location: { directory: AbsolutePath.make("/repo") } })
+    }).pipe(Effect.provideService(HttpClient.HttpClient, httpClient), Effect.runPromise)
+    expect(result.data).toEqual(data)
+    expect(result.location.directory).toBe("/repo")
+  }
+})
+
 test("session.get returns the decoded Effect projection", async () => {
   const httpClient = HttpClient.make((request) =>
     Effect.succeed(HttpClientResponse.fromWeb(request, Response.json(session))),

packages/client/test/promise.test.ts

@@ -47,7 +47,7 @@ test("exposes every standard HTTP API group", () => {
   expect(Object.keys(client.integration.command)).toEqual(["connect", "status", "cancel"])
   expect(Object.keys(client.websearch)).toEqual(["providers", "query"])
   expect(Object.keys(client.file)).toEqual(["read", "list", "find"])
-  expect(Object.keys(client.vcs)).toEqual(["get", "status", "branches", "diff"])
+  expect(Object.keys(client.vcs)).toEqual(["get", "base", "status", "branches", "diff"])
   expect(Object.keys(client.pty)).toEqual(["list", "create", "get", "update", "remove", "connect"])
   expect(Object.keys(client.pty.connect)).toEqual(["token"])
   expect(Object.keys(client.experimental)).toEqual(["persistentPty"])
@@ -84,6 +84,46 @@ test("config.get returns ordered config entries for a location", async () => {
   expect(request?.url).toBe("http://localhost:3000/api/config?location%5Bdirectory%5D=%2Ftmp%2Fproject")
 })
 
+test("vcs.base and committed diffs preserve location and explicit base on the wire", async () => {
+  const requests: Request[] = []
+  const location = { directory: "/repo", project: { id: "global", directory: "/repo", canonical: "/repo" } }
+  const base = { name: "release", ref: "refs/remotes/origin/release", source: "reflog" }
+  const client = OpenCode.make({
+    baseUrl: "http://localhost:3000",
+    fetch: async (input, init) => {
+      const request = input instanceof Request ? input : new Request(input, init)
+      requests.push(request)
+      return Response.json({ location, data: new URL(request.url).pathname.endsWith("/base") ? base : [] })
+    },
+  })
+  expect(await client.vcs.base({ location: { directory: "/repo" } })).toEqual({ location, data: base })
+  expect(
+    await client.vcs.diff({ location: { directory: "/repo" }, mode: "committed", base: base.ref, context: 1 }),
+  ).toEqual({ location, data: [] })
+  expect(new URL(requests[0].url).pathname).toBe("/api/vcs/base")
+  const query = new URL(requests[1].url).searchParams
+  expect(query.get("location[directory]")).toBe("/repo")
+  expect(query.get("mode")).toBe("committed")
+  expect(query.get("base")).toBe(base.ref)
+  expect(query.get("context")).toBe("1")
+})
+
+test("vcs.diff exposes unavailable comparisons as errors, not empty diffs", async () => {
+  const client = OpenCode.make({
+    baseUrl: "http://localhost:3000",
+    fetch: async () =>
+      Response.json(
+        { _tag: "ServiceUnavailableError", service: "vcs", message: "No review base available" },
+        { status: 503 },
+      ),
+  })
+  await expect(client.vcs.diff({ mode: "committed" })).rejects.toMatchObject({
+    _tag: "ServiceUnavailableError",
+    service: "vcs",
+    message: "No review base available",
+  })
+})
+
 test("project.update uses the global project contract", async () => {
   let request: Request | undefined
   const project = {

packages/client/test/solid-data.test.ts

@@ -666,6 +666,36 @@ test("ignores activity snapshots from an older connection", async () => {
   }
 })
 
+test("projects background user shell metadata from durable shell data", () => {
+  const setup = activityFixture(() => Response.json({ data: {} }))
+  try {
+    setup.emit({
+      id: "evt_user_shell",
+      created: 1,
+      type: "session.shell.started",
+      durable: { aggregateID: "ses_refresh", seq: 1, version: 1 },
+      data: {
+        sessionID: "ses_refresh",
+        shell: {
+          id: "sh_user",
+          status: "running",
+          command: "pwd",
+          cwd: "/project",
+          shell: "/bin/sh",
+          file: "/project/shell.out",
+          metadata: { sessionID: "ses_refresh", background: true },
+          time: { started: 1 },
+        },
+      },
+    })
+    expect(setup.data.session.message.list("ses_refresh")).toMatchObject([
+      { type: "shell", shellID: "sh_user", status: "running", metadata: { background: true } },
+    ])
+  } finally {
+    setup.dispose()
+  }
+})
+
 function activityFixture(read: () => Response | Promise<Response>) {
   const listeners = new Set<Parameters<CreateDataInput["event"]["listen"]>[0]>()
   const api = OpenCode.make({

packages/codemode/src/openapi/runtime.ts

@@ -24,8 +24,8 @@ export const invoke = (plan: Plan, input: unknown): Effect.Effect<unknown, unkno
     const response = yield* client
       .execute(request)
       .pipe(
-        Effect.catch((cause) =>
-          Effect.fail(toolError(`${plan.operation.method} ${plan.operation.path} failed: transport error`, cause)),
+        Effect.mapError((cause) =>
+          toolError(`${plan.operation.method} ${plan.operation.path} failed: transport error`, cause),
         ),
       )
     const text = yield* readResponseBody(response, plan)

packages/console/app/src/global.d.ts

@@ -1,5 +1,7 @@
 /// <reference types="@solidjs/start/env" />
 
+import "@solidjs/start"
+
 export declare module "@solidjs/start/server" {
   export type APIEvent = { request: Request }
 }

packages/core/src/aisdk.ts

@@ -482,8 +482,7 @@ function toolMessage(input: LLMRequest["messages"][number]) {
     const value = part.result.value.filter((item) => {
       if (item.type !== "file") return true
       if (!item.mime.startsWith("image/") && item.mime !== "application/pdf") return true
-      const data = /^data:[^;,]+(?:;[^,]*)*;base64,(.*)$/s.exec(item.uri)?.[1] ?? item.uri
-      media.push({ type: "file", mediaType: item.mime, data, filename: item.name })
+      media.push({ type: "file", mediaType: item.mime, data: fileData(item.uri), filename: item.name })
       return false
     })
     return toolResultPart({
@@ -507,7 +506,7 @@ function text(part: ContentPart) {
 function userPart(part: ContentPart): UserContent {
   if (part.type === "text") return [{ type: "text", text: part.text }]
   if (part.type === "media")
-    return [{ type: "file", mediaType: part.mediaType, data: part.data, filename: part.filename }]
+    return [{ type: "file", mediaType: part.mediaType, data: fileData(part.data), filename: part.filename }]
   return []
 }
 
@@ -516,7 +515,7 @@ function assistantPart(part: ContentPart): AssistantContent {
     case "text":
       return [{ type: "text", text: part.text, providerOptions: metadataProviderOptions(part.providerMetadata) }]
     case "media":
-      return [{ type: "file", mediaType: part.mediaType, data: part.data, filename: part.filename }]
+      return [{ type: "file", mediaType: part.mediaType, data: fileData(part.data), filename: part.filename }]
     case "reasoning":
       return [{ type: "reasoning", text: part.text, providerOptions: metadataProviderOptions(part.providerMetadata) }]
     case "tool-call":
@@ -535,6 +534,15 @@ function assistantPart(part: ContentPart): AssistantContent {
   }
 }
 
+function fileData(data: Extract<ContentPart, { type: "media" }>["data"]) {
+  if (typeof data !== "string") return data
+  const base64 = /^data:[^;,]+(?:;[^,]*)*;base64,(.*)$/s.exec(data)?.[1]
+  if (base64 !== undefined) return base64
+  if (!URL.canParse(data)) return data
+  const url = new URL(data)
+  return url.protocol === "http:" || url.protocol === "https:" ? url : data
+}
+
 function toolResultPart(part: ContentPart): ToolResultContent[] {
   if (part.type !== "tool-result") return []
   return [

packages/core/src/bus.ts

@@ -859,16 +859,12 @@ export function configured(options?: Options) {
                 aggregateID: input.aggregateID,
                 ...(target >= 0 ? { seq: Event.Seq.make(target) } : {}),
               }
-              const replay: Stream.Stream<LogItem> = readThrough(target).pipe(
-                Stream.map((event): LogItem => event),
-                Stream.concat(Stream.make(marker)),
-              )
+              const replay: Stream.Stream<LogItem> = readThrough(target).pipe(Stream.concat(Stream.make(marker)))
               if (!wakes) return replay
               const live: Stream.Stream<LogItem> = Stream.fromSubscription(wakes).pipe(
                 Stream.mapEffect(() => latestSequence(db, input.aggregateID)),
                 Stream.filter((target) => target > sequence),
                 Stream.flatMap((target) => readThrough(target)),
-                Stream.map((event): LogItem => event),
               )
               return Stream.concat(replay, live)
             }),

packages/core/src/config.ts

@@ -316,16 +316,15 @@ export const layer = (options?: Options) =>
         }
       })
 
-      const reload = Effect.fn("Config.reload")(() =>
-        reloadLock.withPermit(
-          Effect.gen(function* () {
-            const next = yield* discover()
-            yield* reconcile(next)
-            if (isDeepStrictEqual(configs, next)) return
-            configs = next
-            yield* bus.publish(Event.Updated, {})
-          }),
-        ),
+      const reload = Effect.fn("Config.reload")(
+        function* () {
+          const next = yield* discover()
+          yield* reconcile(next)
+          if (isDeepStrictEqual(configs, next)) return
+          configs = next
+          yield* bus.publish(Event.Updated, {})
+        },
+        (effect) => reloadLock.withPermit(effect),
       )
 
       yield* Stream.fromPubSub(updates).pipe(

packages/core/src/config/normalize.ts

@@ -292,18 +292,13 @@ function normalizeMcpTimeout(
     invalid(path, diagnostics)
     return
   }
-  const recognized = ["startup", "catalog", "execution"].filter((key) => own(value, key))
+  const recognized = Object.entries(ConfigMCP.Timeout.fields).filter(([key]) => own(value, key))
   if (Object.keys(value).length && !recognized.length) {
     invalid(path, diagnostics)
     return
   }
-  recognized.forEach((key) => {
-    const leaf = decodeEncoded(
-      ConfigMCP.Timeout.fields[key as keyof typeof ConfigMCP.Timeout.fields],
-      value[key],
-      [...path, key],
-      diagnostics,
-    )
+  recognized.forEach(([key, field]) => {
+    const leaf = decodeEncoded(field, value[key], [...path, key], diagnostics)
     if (leaf === undefined) return
     overlay(timeout, key, leaf, [...path, key], diagnostics)
   })

packages/core/src/config/plugin/agent.ts

@@ -32,19 +32,7 @@ type PathAction =
   | typeof ReadTool.name
   | typeof EditTool.name
 const pathActions = ["external_directory", "read", "edit"] as const satisfies readonly PathAction[]
-const agentKeys = new Set([
-  "model",
-  "variant",
-  "request",
-  "system",
-  "description",
-  "mode",
-  "hidden",
-  "color",
-  "steps",
-  "disabled",
-  "permissions",
-])
+const agentKeys = new Set(["variant", ...Object.keys(ConfigAgent.Info.fields)])
 
 export const Plugin = define({
   id: "opencode.config.agent",

packages/core/src/config/plugin/instruction.ts

@@ -83,26 +83,25 @@ export const Plugin = define({
           ),
         )
 
-      const refresh = Effect.fn("ConfigInstructionPlugin.refresh")(function* (file?: string) {
-        yield* lock.withPermit(
-          Effect.gen(function* () {
-            const sources = yield* Effect.all({
-              global: isolate("global", globalSource()),
-              project: isolate("project", projectSource()),
-            })
-            loaded.current =
-              Array.isArray(sources.global) && Array.isArray(sources.project)
-                ? { type: "available", files: [...sources.global, ...sources.project] }
-                : { type: "unavailable" }
-            if (!file) return
-            yield* Effect.logDebug("instructions rescanned", {
-              file,
-              instructions:
-                loaded.current.type === "available" ? loaded.current.files.map((item) => item.path) : "unavailable",
-            })
-          }),
-        )
-      })
+      const refresh = Effect.fn("ConfigInstructionPlugin.refresh")(
+        function* (file?: string) {
+          const sources = yield* Effect.all({
+            global: isolate("global", globalSource()),
+            project: isolate("project", projectSource()),
+          })
+          loaded.current =
+            Array.isArray(sources.global) && Array.isArray(sources.project)
+              ? { type: "available", files: [...sources.global, ...sources.project] }
+              : { type: "unavailable" }
+          if (!file) return
+          yield* Effect.logDebug("instructions rescanned", {
+            file,
+            instructions:
+              loaded.current.type === "available" ? loaded.current.files.map((item) => item.path) : "unavailable",
+          })
+        },
+        (effect, ..._args: [file?: string]) => lock.withPermit(effect),
+      )
 
       yield* Stream.fromPubSub(changes).pipe(
         Stream.runForEach((file) => refresh(file).pipe(Effect.andThen(discovery.reload()))),

packages/core/src/config/plugin/reference.ts

@@ -20,14 +20,13 @@ export const Plugin = define({
     const global = yield* Global.Service
     const loaded = yield* ConfigEntryObserver.observe(config, ctx.event, ctx.reference.reload())
     yield* ctx.reference.transform((draft) => {
-      const entries = new Map<string, Reference.Source>()
       for (const doc of loaded.entries.filter((entry): entry is Document => entry.type === "document")) {
         const directory = doc.path ? path.dirname(doc.path) : location.directory
         for (const [name, entry] of Object.entries(doc.info.references ?? {})) {
           if (!validAlias(name)) continue
           const description = typeof entry === "string" ? undefined : entry.description
           const hidden = typeof entry === "string" ? undefined : entry.hidden
-          entries.set(
+          draft.add(
             name,
             local(entry)
               ? Reference.LocalSource.make({
@@ -48,7 +47,6 @@ export const Plugin = define({
           )
         }
       }
-      for (const [name, source] of entries) draft.add(name, source)
     })
   }),
 })

packages/core/src/config/plugin/skill.ts

@@ -151,26 +151,25 @@ export const Plugin = define({
       return skills
     })
 
-    const refresh = Effect.fn("ConfigSkillPlugin.refresh")(function* (file?: string) {
-      yield* lock.withPermit(
-        Effect.gen(function* () {
-          yield* FiberMap.clear(watches)
-          const skills = new Map<Skill.ID, Skill.Info>()
-          const current = sources()
-          for (const source of current) {
-            for (const skill of yield* load(source)) skills.set(skill.id, skill)
-          }
-          loaded.skills = Array.from(skills.values())
-          if (file) {
-            yield* Effect.logInfo("skills rescanned", {
-              file,
-              sources: current.map(Skill.Source.key),
-              skills: loaded.skills.map((skill) => skill.id),
-            })
-          }
-        }),
-      )
-    })
+    const refresh = Effect.fn("ConfigSkillPlugin.refresh")(
+      function* (file?: string) {
+        yield* FiberMap.clear(watches)
+        const skills = new Map<Skill.ID, Skill.Info>()
+        const current = sources()
+        for (const source of current) {
+          for (const skill of yield* load(source)) skills.set(skill.id, skill)
+        }
+        loaded.skills = Array.from(skills.values())
+        if (file) {
+          yield* Effect.logInfo("skills rescanned", {
+            file,
+            sources: current.map(Skill.Source.key),
+            skills: loaded.skills.map((skill) => skill.id),
+          })
+        }
+      },
+      (effect, ..._args: [file?: string]) => lock.withPermit(effect),
+    )
 
     yield* Stream.fromPubSub(changes).pipe(
       Stream.runForEach((file) => refresh(file).pipe(Effect.andThen(ctx.skill.reload()))),

packages/core/src/database/drizzle/README.md

@@ -0,0 +1,35 @@
+# Effect Drizzle SQLite Adapter
+
+This subtree is an upstream-derived Drizzle ORM fork adapted to run SQLite query
+builders over Effect's generic `SqlClient`. It is maintained source, not
+generated output.
+
+## Provenance
+
+The implementation is derived from Drizzle ORM's Effect SQLite driver/session,
+SQLite Effect query builders, and shared query-builder utilities. The
+corresponding upstream source families are `drizzle-orm/src/effect-sqlite`,
+`drizzle-orm/src/sqlite-core`, and `drizzle-orm/src/utils.ts`.
+
+The exact upstream revision originally copied into this repository is unknown.
+The currently pinned `drizzle-orm` version is a compatibility dependency, not
+copy provenance.
+
+## Local Boundary
+
+The supported local entrypoint is `@opencode-ai/core/database/drizzle`, exposed
+as the `EffectDrizzleSqlite` namespace. OpenCode's database service consumes that
+facade from `database/database.ts`.
+
+Material local adaptations include:
+
+- a runtime-independent driver over Effect's generic `SqlClient`
+- local cache, mapping, and runtime-inspection helpers
+- suppressed statement tracing beneath the database operation boundary
+- explicit SQLite transactions and savepoints
+- native transaction delegation for Durable Object SQLite
+- deliberate query-builder variance annotations
+
+Preserve these adaptations when comparing or synchronizing upstream code.
+Focused regression coverage is in `test/database-drizzle.test.ts` and
+`test/sqlite-workerd.test.ts`.

packages/core/src/database/drizzle/effect-sqlite/driver.ts

@@ -36,14 +36,14 @@ export const DefaultServices = Layer.merge(EffectCache.Default, EffectLogger.Def
  *
  * @example
  * ```ts
- * import { SqliteClient } from '@effect/sql-sqlite-node';
- * import * as SQLiteDrizzle from 'drizzle-orm/effect-sqlite';
- * import * as Effect from 'effect/Effect';
+ * import { SqliteClient } from "@effect/sql-sqlite-node"
+ * import { EffectDrizzleSqlite } from "@opencode-ai/core/database/drizzle"
+ * import { Effect } from "effect"
  *
- * const db = yield* SQLiteDrizzle.make({ relations }).pipe(
- *   Effect.provide(SQLiteDrizzle.DefaultServices),
- *   Effect.provide(SqliteClient.layer({ filename: 'sqlite.db' })),
- * );
+ * const db = yield* EffectDrizzleSqlite.make({ relations }).pipe(
+ *   Effect.provide(EffectDrizzleSqlite.DefaultServices),
+ *   Effect.provide(SqliteClient.layer({ filename: "sqlite.db" })),
+ * )
  * ```
  */
 export const make = Effect.fn("SQLiteDrizzle.make")(function* <TRelations extends AnyRelations = EmptyRelations>(

packages/core/src/database/drizzle/sqlite-core/effect/insert.ts

@@ -227,7 +227,7 @@ export class SQLiteEffectInsertBase<
   config: SQLiteInsertConfig<TTable>
 
   constructor(
-    private table: TTable,
+    table: TTable,
     values: SQLiteInsertConfig["values"],
     private effectSession: SQLiteEffectSession<TEffectHKT, TRunResult, any>,
     private effectDialect: SQLiteDialect,

packages/core/src/database/drizzle/sqlite-core/effect/session.ts

@@ -277,11 +277,7 @@ export class SQLiteEffectPreparedQuery<
       }
 
       assertUnreachable(cacheStrat)
-    }).pipe(
-      Effect.catch((e) => {
-        return Effect.fail(new EffectDrizzleQueryError({ query: queryString, params, cause: Cause.fail(e) }))
-      }),
-    )
+    }).pipe(Effect.mapError((e) => new EffectDrizzleQueryError({ query: queryString, params, cause: Cause.fail(e) })))
   }
 
   getQuery(): Query {

packages/core/src/database/drizzle/sqlite-core/effect/update.ts

@@ -279,7 +279,7 @@ export class SQLiteEffectUpdateBase<
           : undefined
         on = on(
           new Proxy(
-            this.config.table._.columns,
+            getTableColumnsRuntime(this.config.table),
             new SelectionProxyHandler({ sqlAliasedBehavior: "sql", sqlBehavior: "sql" }),
           ) as any,
           from &&

packages/core/src/database/v1-migration.bun.ts

@@ -481,7 +481,7 @@ export function status(): Effect.Effect<Status, never, Database.Service> {
     if (runtimeState.status === "error") return runtimeState
     if (state?.phase === "completed") return { status: "completed" as const }
     return { status: "required" as const }
-  }).pipe(Effect.orDie)
+  })
 }
 
 export const layer = Layer.effectDiscard(
@@ -521,76 +521,75 @@ export function run(options: Options = {}): Effect.Effect<RunResult, never, Data
       const state = yield* readState(db)
       if (state?.phase === "completed") return { status: "completed" as const }
       if (!(yield* hasLegacySessions(db))) return { status: "completed" as const }
-      const migrate = Effect.gen(function* () {
-        const now = Date.now()
-        yield* db.run(sql`
+      const now = Date.now()
+      yield* db.run(sql`
           INSERT OR IGNORE INTO project (id, worktree, time_created, time_updated, sandboxes)
           VALUES (${Project.ID.global}, ${path.parse(global.data).root}, ${now}, ${now}, '[]')
         `)
-        if (state === undefined)
-          yield* db
-            .transaction((tx) =>
-              Effect.gen(function* () {
-                while (true) {
-                  yield* tx.run(sql`
+      if (state === undefined)
+        yield* db
+          .transaction((tx) =>
+            Effect.gen(function* () {
+              while (true) {
+                yield* tx.run(sql`
                     DELETE FROM event
                     WHERE rowid IN (SELECT rowid FROM event LIMIT ${EVENT_DELETE_BATCH_SIZE})
                   `)
-                  const deleted = (yield* tx.get<{ value: number }>(sql`SELECT changes() AS value`))?.value ?? 0
-                  if (deleted < EVENT_DELETE_BATCH_SIZE) break
-                  yield* Effect.yieldNow
-                }
-                yield* tx
-                  .insert(KVTable)
-                  .values({ key: MIGRATION_STATE_KEY, value: { phase: "sessions" } })
-                  .run()
-              }),
-            )
-            .pipe(Effect.orDie)
-        const sourceTotal = yield* countNextSessions(nextPath(options, global.data))
-        const legacyTotal = (yield* db.get<{ value: number }>(sql`SELECT COUNT(*) AS value FROM session`))?.value ?? 0
-        const cursor = state?.phase === "sessions" ? state.cursor : undefined
-        const migrated =
-          cursor !== undefined
-            ? ((yield* db.get<{ value: number }>(sql`SELECT COUNT(*) AS value FROM session WHERE id >= ${cursor}`))
-                ?.value ?? 0)
-            : 0
-        const denominator = sourceTotal + legacyTotal
-        updateProgress({ label: "Migrating sessions", numerator: migrated, denominator })
-        yield* importNextDatabase(db, nextPath(options, global.data), (completed) => {
-          updateProgress({ label: "Migrating sessions", numerator: migrated + completed, denominator })
-        })
-        updateProgress({ label: "Migrating sessions", numerator: migrated + sourceTotal, denominator })
-        const projects = new Set(
-          (yield* db.all<{ id: string }>(sql`SELECT id FROM project`)).map((project) => project.id),
-        )
-        while (true) {
-          const state = yield* readState(db)
-          const cursorValue = state?.phase === "sessions" ? state.cursor : undefined
-          const nextID = yield* db.get<{ id: string; project_id: string }>(
-            cursorValue === undefined
-              ? sql`SELECT id, project_id FROM session ORDER BY id DESC LIMIT 1`
-              : sql`SELECT id, project_id FROM session WHERE id < ${cursorValue} ORDER BY id DESC LIMIT 1`,
+                const deleted = (yield* tx.get<{ value: number }>(sql`SELECT changes() AS value`))?.value ?? 0
+                if (deleted < EVENT_DELETE_BATCH_SIZE) break
+                yield* Effect.yieldNow
+              }
+              yield* tx
+                .insert(KVTable)
+                .values({ key: MIGRATION_STATE_KEY, value: { phase: "sessions" } })
+                .run()
+            }),
           )
-          if (!nextID) break
-          yield* db
-            .transaction((tx) =>
-              Effect.gen(function* () {
-                yield* tx
-                  .insert(KVTable)
-                  .values({ key: MIGRATION_STATE_KEY, value: { phase: "sessions", cursor: nextID.id } })
-                  .onConflictDoUpdate({
-                    target: KVTable.key,
-                    set: { value: { phase: "sessions", cursor: nextID.id }, time_updated: Date.now() },
-                  })
-                  .run()
-                const projectID = projects.has(nextID.project_id) ? nextID.project_id : Project.ID.global
-                if (projectID !== nextID.project_id)
-                  yield* Effect.logWarning("Reassigned V1 session with missing project", {
-                    sessionID: nextID.id,
-                    projectID: nextID.project_id,
-                  })
-                yield* tx.run(sql`
+          .pipe(Effect.orDie)
+      const sourceTotal = yield* countNextSessions(nextPath(options, global.data))
+      const legacyTotal = (yield* db.get<{ value: number }>(sql`SELECT COUNT(*) AS value FROM session`))?.value ?? 0
+      const cursor = state?.phase === "sessions" ? state.cursor : undefined
+      const migrated =
+        cursor !== undefined
+          ? ((yield* db.get<{ value: number }>(sql`SELECT COUNT(*) AS value FROM session WHERE id >= ${cursor}`))
+              ?.value ?? 0)
+          : 0
+      const denominator = sourceTotal + legacyTotal
+      updateProgress({ label: "Migrating sessions", numerator: migrated, denominator })
+      yield* importNextDatabase(db, nextPath(options, global.data), (completed) => {
+        updateProgress({ label: "Migrating sessions", numerator: migrated + completed, denominator })
+      })
+      updateProgress({ label: "Migrating sessions", numerator: migrated + sourceTotal, denominator })
+      const projects = new Set(
+        (yield* db.all<{ id: string }>(sql`SELECT id FROM project`)).map((project) => project.id),
+      )
+      while (true) {
+        const state = yield* readState(db)
+        const cursorValue = state?.phase === "sessions" ? state.cursor : undefined
+        const nextID = yield* db.get<{ id: string; project_id: string }>(
+          cursorValue === undefined
+            ? sql`SELECT id, project_id FROM session ORDER BY id DESC LIMIT 1`
+            : sql`SELECT id, project_id FROM session WHERE id < ${cursorValue} ORDER BY id DESC LIMIT 1`,
+        )
+        if (!nextID) break
+        yield* db
+          .transaction((tx) =>
+            Effect.gen(function* () {
+              yield* tx
+                .insert(KVTable)
+                .values({ key: MIGRATION_STATE_KEY, value: { phase: "sessions", cursor: nextID.id } })
+                .onConflictDoUpdate({
+                  target: KVTable.key,
+                  set: { value: { phase: "sessions", cursor: nextID.id }, time_updated: Date.now() },
+                })
+                .run()
+              const projectID = projects.has(nextID.project_id) ? nextID.project_id : Project.ID.global
+              if (projectID !== nextID.project_id)
+                yield* Effect.logWarning("Reassigned V1 session with missing project", {
+                  sessionID: nextID.id,
+                  projectID: nextID.project_id,
+                })
+              yield* tx.run(sql`
                   INSERT OR IGNORE INTO session_v2 (
                     id, project_id, workspace_id, parent_id, slug, directory, path, title, version, share_url,
                     summary_additions, summary_deletions, summary_files, summary_diffs, metadata, cost,
@@ -605,81 +604,79 @@ export function run(options: Options = {}): Effect.Effect<RunResult, never, Data
                   FROM session
                   WHERE id = ${nextID.id}
                 `)
-                const next = yield* tx
-                  .select()
-                  .from(SessionTable)
-                  .where(eq(SessionTable.id, SessionSchema.ID.make(nextID.id)))
-                  .get()
-                if (!next) return yield* Effect.die(new Error(`Failed to copy V1 session ${nextID.id}`))
-                const sourceMessages = yield* tx.all<SourceMessage>(
-                  sql`SELECT id, session_id, time_created, time_updated, data FROM message WHERE session_id = ${next.id}`,
-                )
-                const sourceParts = yield* tx.all<SourcePart>(
-                  sql`SELECT id, message_id, session_id, time_created, time_updated, data FROM part WHERE session_id = ${next.id}`,
-                )
-                const transformed = transformSession({ session: next, messages: sourceMessages, parts: sourceParts })
-                yield* Effect.forEach(transformed.warnings, (warning) =>
-                  Effect.logWarning("Skipped V1 migration row", warning),
-                )
-                yield* tx.delete(SessionMessageTable).where(eq(SessionMessageTable.session_id, next.id)).run()
-                yield* Effect.forEach(transformed.messages, (message) =>
-                  tx
-                    .insert(SessionMessageTable)
-                    .values({
-                      id: SessionMessage.ID.make(message.id),
-                      session_id: SessionSchema.ID.make(message.session_id),
-                      type: message.type,
-                      seq: message.seq,
-                      time_created: message.time_created,
-                      time_updated: message.time_updated,
-                      data: sql`${JSON.stringify(message.data)}`,
-                    })
-                    .run(),
-                )
-                yield* tx
-                  .update(SessionTable)
-                  .set({ ...transformed.session, time_updated: next.time_updated })
-                  .where(eq(SessionTable.id, next.id))
-                  .run()
-                yield* tx
-                  .insert(EventSequenceTable)
-                  .values({ aggregate_id: next.id, seq: transformed.watermark })
-                  .onConflictDoUpdate({
-                    target: EventSequenceTable.aggregate_id,
-                    set: { seq: transformed.watermark, owner_id: null },
+              const next = yield* tx
+                .select()
+                .from(SessionTable)
+                .where(eq(SessionTable.id, SessionSchema.ID.make(nextID.id)))
+                .get()
+              if (!next) return yield* Effect.die(new Error(`Failed to copy V1 session ${nextID.id}`))
+              const sourceMessages = yield* tx.all<SourceMessage>(
+                sql`SELECT id, session_id, time_created, time_updated, data FROM message WHERE session_id = ${next.id}`,
+              )
+              const sourceParts = yield* tx.all<SourcePart>(
+                sql`SELECT id, message_id, session_id, time_created, time_updated, data FROM part WHERE session_id = ${next.id}`,
+              )
+              const transformed = transformSession({ session: next, messages: sourceMessages, parts: sourceParts })
+              yield* Effect.forEach(transformed.warnings, (warning) =>
+                Effect.logWarning("Skipped V1 migration row", warning),
+              )
+              yield* tx.delete(SessionMessageTable).where(eq(SessionMessageTable.session_id, next.id)).run()
+              yield* Effect.forEach(transformed.messages, (message) =>
+                tx
+                  .insert(SessionMessageTable)
+                  .values({
+                    id: SessionMessage.ID.make(message.id),
+                    session_id: SessionSchema.ID.make(message.session_id),
+                    type: message.type,
+                    seq: message.seq,
+                    time_created: message.time_created,
+                    time_updated: message.time_updated,
+                    data: sql`${JSON.stringify(message.data)}`,
                   })
-                  .run()
-              }),
-            )
-            .pipe(Effect.orDie)
-          if (runtimeState.status === "running")
-            runtimeState = {
-              status: "running",
-              progress: {
-                label: "Migrating sessions",
-                numerator: (runtimeState.progress.numerator ?? 0) + 1,
-                denominator,
-              },
-            }
-          yield* Effect.yieldNow
-        }
-        yield* db
-          .transaction((tx) =>
-            Effect.gen(function* () {
+                  .run(),
+              )
               yield* tx
-                .insert(KVTable)
-                .values({ key: MIGRATION_STATE_KEY, value: { phase: "completed" } })
+                .update(SessionTable)
+                .set({ ...transformed.session, time_updated: next.time_updated })
+                .where(eq(SessionTable.id, next.id))
+                .run()
+              yield* tx
+                .insert(EventSequenceTable)
+                .values({ aggregate_id: next.id, seq: transformed.watermark })
                 .onConflictDoUpdate({
-                  target: KVTable.key,
-                  set: { value: { phase: "completed" }, time_updated: Date.now() },
+                  target: EventSequenceTable.aggregate_id,
+                  set: { seq: transformed.watermark, owner_id: null },
                 })
                 .run()
             }),
           )
           .pipe(Effect.orDie)
-        return { status: "completed" as const }
-      })
-      return yield* migrate
+        if (runtimeState.status === "running")
+          runtimeState = {
+            status: "running",
+            progress: {
+              label: "Migrating sessions",
+              numerator: (runtimeState.progress.numerator ?? 0) + 1,
+              denominator,
+            },
+          }
+        yield* Effect.yieldNow
+      }
+      yield* db
+        .transaction((tx) =>
+          Effect.gen(function* () {
+            yield* tx
+              .insert(KVTable)
+              .values({ key: MIGRATION_STATE_KEY, value: { phase: "completed" } })
+              .onConflictDoUpdate({
+                target: KVTable.key,
+                set: { value: { phase: "completed" }, time_updated: Date.now() },
+              })
+              .run()
+          }),
+        )
+        .pipe(Effect.orDie)
+      return { status: "completed" as const }
     }).pipe(Effect.orDie),
   )
 }
@@ -708,7 +705,7 @@ function countNextSessions(sourcePath: string | undefined) {
       if (!isNextDatabase(source)) return 0
       return source.query<{ value: number }, []>("SELECT COUNT(*) AS value FROM session").get()?.value ?? 0
     }),
-  ).pipe(Effect.orElseSucceed(() => 0))
+  )
 }
 
 function importNextDatabase(

packages/core/src/environment/memory.ts

@@ -61,21 +61,23 @@ export const makeMemoryDriver = (): MemoryDriver => {
   }
   const failed = (value: string, cause: unknown) => new Failed({ path: value, cause })
   const overrides: FilesImpl = {
-    stat: (value) => {
-      const node = lookup(value)
-      return node ? Effect.succeed(info(node)) : Effect.fail(new NotFound({ path: value }))
-    },
-    read: (value, range) => {
-      const original = lookup(value)
-      if (!original) return Effect.fail(new NotFound({ path: value }))
-      if (original.type === "directory") return Effect.fail(new WrongKind({ path: value, actual: "directory" }))
-      const resolved = resolveKey(value, true)
-      const node = resolved === undefined ? undefined : nodes.get(resolved)
-      if (!node) return Effect.fail(new NotFound({ path: value }))
-      if (node.type !== "file") return Effect.fail(new WrongKind({ path: value, actual: node.type }))
-      const bytes = range === undefined ? node.bytes : node.bytes.subarray(range.offset, range.offset + range.length)
-      return Effect.succeed({ info: info(node), bytes: bytes.slice() })
-    },
+    stat: (value) =>
+      Effect.suspend(() => {
+        const node = lookup(value)
+        return node ? Effect.succeed(info(node)) : Effect.fail(new NotFound({ path: value }))
+      }),
+    read: (value, range) =>
+      Effect.gen(function* () {
+        const original = lookup(value)
+        if (!original) return yield* new NotFound({ path: value })
+        if (original.type === "directory") return yield* new WrongKind({ path: value, actual: "directory" })
+        const resolved = resolveKey(value, true)
+        const node = resolved === undefined ? undefined : nodes.get(resolved)
+        if (!node) return yield* new NotFound({ path: value })
+        if (node.type !== "file") return yield* new WrongKind({ path: value, actual: node.type })
+        const bytes = range === undefined ? node.bytes : node.bytes.subarray(range.offset, range.offset + range.length)
+        return { info: info(node), bytes: bytes.slice() }
+      }),
     write: (value, bytes) =>
       Effect.try({
         try: () => {
@@ -89,17 +91,17 @@ export const makeMemoryDriver = (): MemoryDriver => {
         },
         catch: (cause) => failed(value, cause),
       }),
-    list: (value) => {
-      const target = resolveKey(value, true) ?? key(value)
-      const node = nodes.get(target)
-      if (!node) return Effect.fail(new NotFound({ path: value }))
-      if (node.type !== "directory") return Effect.fail(new WrongKind({ path: value, actual: node.type }))
-      const entries = [...nodes.entries()]
-        .filter(([entry]) => entry !== target && path.posix.dirname(entry) === target)
-        .map(([entry, child]) => ({ name: path.posix.basename(entry), type: child.type satisfies FileType }))
-        .sort((a, b) => a.name.localeCompare(b.name))
-      return Effect.succeed(entries)
-    },
+    list: (value) =>
+      Effect.gen(function* () {
+        const target = resolveKey(value, true) ?? key(value)
+        const node = nodes.get(target)
+        if (!node) return yield* new NotFound({ path: value })
+        if (node.type !== "directory") return yield* new WrongKind({ path: value, actual: node.type })
+        return [...nodes.entries()]
+          .filter(([entry]) => entry !== target && path.posix.dirname(entry) === target)
+          .map(([entry, child]) => ({ name: path.posix.basename(entry), type: child.type satisfies FileType }))
+          .sort((a, b) => a.name.localeCompare(b.name))
+      }),
     remove: (value) =>
       Effect.sync(() => {
         const target = resolveKey(value, false) ?? key(value)
@@ -107,32 +109,33 @@ export const makeMemoryDriver = (): MemoryDriver => {
           if (entry === target || entry.startsWith(`${target}/`)) nodes.delete(entry)
         }
       }),
-    move: (from, to) => {
-      const source = resolveKey(from, false) ?? key(from)
-      const node = nodes.get(source)
-      if (!node) return Effect.fail(new NotFound({ path: from }))
-      return Effect.try({
-        try: () => {
-          const requested = resolveKey(to, false) ?? key(to)
-          const destination =
-            nodes.get(requested)?.type === "directory"
-              ? path.posix.join(requested, path.posix.basename(source))
-              : requested
-          if (node.type === "directory" && destination.startsWith(`${source}/`)) {
-            throw new Error(`Cannot move a directory into itself: ${from}`)
-          }
-          const existing = nodes.get(destination)
-          if (node.type === "directory" && existing && existing.type !== "directory") {
-            throw new Error(`Cannot overwrite a non-directory with a directory: ${to}`)
-          }
-          requireParent(destination)
-          const moved = [...nodes.entries()].filter(([entry]) => entry === source || entry.startsWith(`${source}/`))
-          for (const [entry] of moved) nodes.delete(entry)
-          for (const [entry, child] of moved) nodes.set(`${destination}${entry.slice(source.length)}`, child)
-        },
-        catch: (cause) => failed(from, cause),
-      })
-    },
+    move: (from, to) =>
+      Effect.gen(function* () {
+        const source = resolveKey(from, false) ?? key(from)
+        const node = nodes.get(source)
+        if (!node) return yield* new NotFound({ path: from })
+        yield* Effect.try({
+          try: () => {
+            const requested = resolveKey(to, false) ?? key(to)
+            const destination =
+              nodes.get(requested)?.type === "directory"
+                ? path.posix.join(requested, path.posix.basename(source))
+                : requested
+            if (node.type === "directory" && destination.startsWith(`${source}/`)) {
+              throw new Error(`Cannot move a directory into itself: ${from}`)
+            }
+            const existing = nodes.get(destination)
+            if (node.type === "directory" && existing && existing.type !== "directory") {
+              throw new Error(`Cannot overwrite a non-directory with a directory: ${to}`)
+            }
+            requireParent(destination)
+            const moved = [...nodes.entries()].filter(([entry]) => entry === source || entry.startsWith(`${source}/`))
+            for (const [entry] of moved) nodes.delete(entry)
+            for (const [entry, child] of moved) nodes.set(`${destination}${entry.slice(source.length)}`, child)
+          },
+          catch: (cause) => failed(from, cause),
+        })
+      }),
     mkdir: (value) => Effect.try({ try: () => mkdirSync(value), catch: (cause) => failed(value, cause) }),
   }
 

packages/core/src/git.ts

@@ -177,7 +177,7 @@ const layer = Layer.effect(
       if (!dotgit) return undefined
 
       const cwd = path.dirname(dotgit)
-      const result = yield* run(cwd, proc)(["rev-parse", "--git-dir", "--git-common-dir", "--show-toplevel"])
+      const result = yield* run(cwd, proc, ["rev-parse", "--git-dir", "--git-common-dir", "--show-toplevel"])
       const [gitDir, commonDir, topLevel] = result.text.split(/\r?\n/)
       if (!gitDir || !commonDir) return undefined
 
@@ -189,13 +189,13 @@ const layer = Layer.effect(
     })
 
     const remote = Effect.fn("Git.remote.get")(function* (repository: Repository, name = "origin") {
-      const result = yield* run(repository.worktree, proc)(["remote", "get-url", name])
+      const result = yield* run(repository.worktree, proc, ["remote", "get-url", name])
       if (result.exitCode !== 0) return undefined
       return result.text.trim() || undefined
     })
 
     const roots = Effect.fn("Git.history.rootCommits")(function* (repository: Repository) {
-      const result = yield* run(repository.worktree, proc)(["rev-list", "--max-parents=0", "HEAD"])
+      const result = yield* run(repository.worktree, proc, ["rev-list", "--max-parents=0", "HEAD"])
       if (result.exitCode !== 0) return []
       return result.text
         .split("\n")
@@ -205,13 +205,13 @@ const layer = Layer.effect(
     })
 
     const head = Effect.fn("Git.history.head")(function* (repository: Repository) {
-      const result = yield* run(repository.worktree, proc)(["rev-parse", "HEAD"])
+      const result = yield* run(repository.worktree, proc, ["rev-parse", "HEAD"])
       if (result.exitCode !== 0) return undefined
       return result.text.trim() || undefined
     })
 
     const branch = Effect.fn("Git.history.branch")(function* (repository: Repository) {
-      const result = yield* run(repository.worktree, proc)(["symbolic-ref", "--quiet", "--short", "HEAD"])
+      const result = yield* run(repository.worktree, proc, ["symbolic-ref", "--quiet", "--short", "HEAD"])
       if (result.exitCode !== 0) return undefined
       return result.text.trim() || undefined
     })
@@ -220,7 +220,7 @@ const layer = Layer.effect(
       repository: Repository,
       remoteName = "origin",
     ) {
-      const result = yield* run(repository.worktree, proc)(["symbolic-ref", `refs/remotes/${remoteName}/HEAD`])
+      const result = yield* run(repository.worktree, proc, ["symbolic-ref", `refs/remotes/${remoteName}/HEAD`])
       if (result.exitCode !== 0) return undefined
       return result.text.trim().replace(new RegExp(`^refs/remotes/${remoteName}/`), "") || undefined
     })
@@ -230,10 +230,7 @@ const layer = Layer.effect(
       directory: AbsolutePath,
       args: string[],
     ) {
-      const result = yield* execute(
-        directory,
-        proc,
-      )(args).pipe(
+      const result = yield* execute(directory, proc, args).pipe(
         Effect.mapError((cause) => new OperationError({ operation, directory, message: cause.message, cause })),
       )
       if (result.exitCode === 0) return
@@ -711,31 +708,29 @@ interface Result {
   readonly stderr: string
 }
 
-function run(cwd: string, proc: AppProcess.Interface) {
-  return (args: string[]) =>
-    execute(cwd, proc)(args).pipe(Effect.orElseSucceed(() => ({ exitCode: 1, text: "", stderr: "" })))
+function run(cwd: string, proc: AppProcess.Interface, args: string[]) {
+  return execute(cwd, proc, args).pipe(Effect.orElseSucceed(() => ({ exitCode: 1, text: "", stderr: "" })))
 }
 
-function execute(cwd: string, proc: AppProcess.Interface) {
-  return (args: string[]) =>
-    proc
-      .run(
-        ChildProcess.make("git", args, {
-          cwd,
-          extendEnv: true,
-          stdin: "ignore",
-        }),
-      )
-      .pipe(
-        Effect.map(
-          (result) =>
-            ({
-              exitCode: result.exitCode,
-              text: result.stdout.toString("utf8"),
-              stderr: result.stderr.toString("utf8"),
-            }) satisfies Result,
-        ),
-      )
+function execute(cwd: string, proc: AppProcess.Interface, args: string[]) {
+  return proc
+    .run(
+      ChildProcess.make("git", args, {
+        cwd,
+        extendEnv: true,
+        stdin: "ignore",
+      }),
+    )
+    .pipe(
+      Effect.map(
+        (result) =>
+          ({
+            exitCode: result.exitCode,
+            text: result.stdout.toString("utf8"),
+            stderr: result.stderr.toString("utf8"),
+          }) satisfies Result,
+      ),
+    )
 }
 
 function resolvePath(cwd: string, value: string) {

packages/core/src/github-copilot/README.md

@@ -1,5 +1,38 @@
-This is a temporary package used primarily for GitHub Copilot compatibility.
+# GitHub Copilot AI SDK Adapters
 
-These DO NOT apply for openai-compatible providers or majority of providers supporting completions/responses apis. THIS IS ONLY FOR GITHUB COPILOT!!!
+This directory contains upstream-derived AI SDK implementations adapted for
+GitHub Copilot. It is not a generic OpenAI-compatible provider.
 
-Avoid making edits to these files
+## Provenance
+
+- `chat/` is derived from the Vercel AI SDK
+  `@ai-sdk/openai-compatible` chat implementation.
+- `responses/` is derived from the Vercel AI SDK `@ai-sdk/openai` Responses
+  implementation.
+- The exact upstream revisions originally copied into this repository are
+  unknown. Current dependency versions and the `VERSION` constant in
+  `copilot-provider.ts` are not copy provenance.
+
+## Ownership
+
+Keep `chat/` and `responses/` structurally close to their upstream modules, but
+preserve the intentional Copilot adaptations: the `copilot` options and metadata
+namespace, `thinking_budget`, reasoning text and opaque reasoning, stateless
+Responses requests with encrypted reasoning, rotating response item IDs, and
+explicit function-tool strictness taking precedence over the global fallback.
+
+`copilot-provider.ts` is the local adapter assembly entrypoint used by
+`plugin/provider/github-copilot.ts`. `models.ts` is OpenCode-owned catalog
+reconciliation, not vendored SDK code. Authentication, request headers, model
+routing, and integration lifecycle are also owned by the provider plugin.
+
+When updating the upstream-shaped modules, compare against both source packages
+and reapply the documented Copilot adaptations. Focused regression coverage is
+in:
+
+- `test/github-copilot/copilot-chat-model.test.ts`
+- `test/github-copilot/convert-to-copilot-messages.test.ts`
+- `test/github-copilot/openai-responses-language-model.test.ts`
+- `test/github-copilot/openai-responses-prepare-tools.test.ts`
+- `test/github-copilot/models.test.ts`
+- `test/plugin/provider-github-copilot.test.ts`

packages/core/src/github-copilot/chat/openai-compatible-chat-language-model.ts

@@ -653,7 +653,11 @@ export class OpenAICompatibleChatLanguageModel implements LanguageModelV3 {
             }
 
             if (isActiveText) {
-              controller.enqueue({ type: "text-end", id: "txt-0" })
+              controller.enqueue({
+                type: "text-end",
+                id: "txt-0",
+                providerMetadata: reasoningOpaque ? { copilot: { reasoningOpaque } } : undefined,
+              })
             }
 
             // go through all tool calls and send the ones that are not finished

packages/core/src/github-copilot/responses/openai-responses-language-model.ts

@@ -4,7 +4,6 @@ import {
   type LanguageModelV3,
   type LanguageModelV3CallOptions,
   type LanguageModelV3Content,
-  type LanguageModelV3ProviderTool,
   type LanguageModelV3StreamPart,
   type SharedV3ProviderMetadata,
   type SharedV3Warning,
@@ -27,7 +26,7 @@ import { imageGenerationOutputSchema } from "./tool/image-generation.js"
 import { convertToOpenAIResponsesInput } from "./convert-to-openai-responses-input.js"
 import { mapOpenAIResponseFinishReason } from "./map-openai-responses-finish-reason.js"
 import type { OpenAIResponsesIncludeOptions, OpenAIResponsesIncludeValue } from "./openai-responses-api-types.js"
-import { prepareResponsesTools } from "./openai-responses-prepare-tools.js"
+import { prepareResponsesTools, type ResponsesHostedTool } from "./openai-responses-prepare-tools.js"
 import type { OpenAIResponsesModelId } from "./openai-responses-settings.js"
 
 const webSearchCallItem = z.object({
@@ -221,15 +220,23 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
       addInclude("message.output_text.logprobs")
     }
 
-    // when a web search tool is present, automatically include the sources:
-    const webSearchToolName = (
-      tools?.find(
-        (tool) =>
-          tool.type === "provider" && (tool.id === "openai.web_search" || tool.id === "openai.web_search_preview"),
-      ) as LanguageModelV3ProviderTool | undefined
-    )?.name
+    const {
+      tools: openaiTools,
+      toolChoice: openaiToolChoice,
+      hostedTools,
+      selectedHostedTool,
+      toolWarnings,
+    } = prepareResponsesTools({
+      tools,
+      toolChoice,
+      strictJsonSchema,
+    })
+    const getHostedToolName = (responseType: ResponsesHostedTool["responseType"]) => {
+      if (selectedHostedTool?.responseType === responseType) return selectedHostedTool.name
+      return hostedTools.find((tool) => tool.responseType === responseType)?.name ?? responseType
+    }
 
-    if (webSearchToolName) {
+    if (hostedTools.some((tool) => tool.responseType === "web_search")) {
       addInclude("web_search_call.action.sources")
     }
 
@@ -357,18 +364,8 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
       baseArgs.service_tier = undefined
     }
 
-    const {
-      tools: openaiTools,
-      toolChoice: openaiToolChoice,
-      toolWarnings,
-    } = prepareResponsesTools({
-      tools,
-      toolChoice,
-      strictJsonSchema,
-    })
-
     return {
-      webSearchToolName,
+      getHostedToolName,
       args: {
         ...baseArgs,
         tools: openaiTools,
@@ -379,7 +376,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
   }
 
   async doGenerate(options: LanguageModelV3CallOptions) {
-    const { args: body, warnings, webSearchToolName } = await this.getArgs(options)
+    const { args: body, warnings, getHostedToolName } = await this.getArgs(options)
     const url = this.config.url({
       path: "/responses",
       modelId: this.modelId,
@@ -526,7 +523,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
           content.push({
             type: "tool-call",
             toolCallId: part.id,
-            toolName: "image_generation",
+            toolName: getHostedToolName("image_generation"),
             input: "{}",
             providerExecuted: true,
           })
@@ -534,7 +531,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
           content.push({
             type: "tool-result",
             toolCallId: part.id,
-            toolName: "image_generation",
+            toolName: getHostedToolName("image_generation"),
             result: {
               result: part.result,
             } satisfies z.infer<typeof imageGenerationOutputSchema>,
@@ -605,7 +602,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
           content.push({
             type: "tool-call",
             toolCallId: part.id,
-            toolName: webSearchToolName ?? "web_search",
+            toolName: getHostedToolName("web_search"),
             input: JSON.stringify({ action: part.action }),
             providerExecuted: true,
           })
@@ -613,7 +610,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
           content.push({
             type: "tool-result",
             toolCallId: part.id,
-            toolName: webSearchToolName ?? "web_search",
+            toolName: getHostedToolName("web_search"),
             result: { status: part.status },
           })
 
@@ -645,7 +642,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
           content.push({
             type: "tool-call",
             toolCallId: part.id,
-            toolName: "file_search",
+            toolName: getHostedToolName("file_search"),
             input: "{}",
             providerExecuted: true,
           })
@@ -653,7 +650,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
           content.push({
             type: "tool-result",
             toolCallId: part.id,
-            toolName: "file_search",
+            toolName: getHostedToolName("file_search"),
             result: {
               queries: part.queries,
               results:
@@ -673,7 +670,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
           content.push({
             type: "tool-call",
             toolCallId: part.id,
-            toolName: "code_interpreter",
+            toolName: getHostedToolName("code_interpreter"),
             input: JSON.stringify({
               code: part.code,
               containerId: part.container_id,
@@ -684,7 +681,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
           content.push({
             type: "tool-result",
             toolCallId: part.id,
-            toolName: "code_interpreter",
+            toolName: getHostedToolName("code_interpreter"),
             result: {
               outputs: part.outputs,
             } satisfies z.infer<typeof codeInterpreterOutputSchema>,
@@ -746,7 +743,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
   }
 
   async doStream(options: LanguageModelV3CallOptions) {
-    const { args: body, warnings, webSearchToolName } = await this.getArgs(options)
+    const { args: body, warnings, getHostedToolName } = await this.getArgs(options)
 
     const { responseHeaders, value: response } = await postJsonToApi({
       url: this.config.url({
@@ -866,7 +863,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
                 controller.enqueue({
                   type: "tool-input-start",
                   id: value.item.id,
-                  toolName: webSearchToolName ?? "web_search",
+                  toolName: getHostedToolName("web_search"),
                 })
               } else if (value.item.type === "computer_call") {
                 ongoingToolCalls[value.output_index] = {
@@ -889,7 +886,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
                 controller.enqueue({
                   type: "tool-input-start",
                   id: value.item.id,
-                  toolName: "code_interpreter",
+                  toolName: getHostedToolName("code_interpreter"),
                 })
 
                 controller.enqueue({
@@ -901,7 +898,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
                 controller.enqueue({
                   type: "tool-call",
                   toolCallId: value.item.id,
-                  toolName: "file_search",
+                  toolName: getHostedToolName("file_search"),
                   input: "{}",
                   providerExecuted: true,
                 })
@@ -909,7 +906,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
                 controller.enqueue({
                   type: "tool-call",
                   toolCallId: value.item.id,
-                  toolName: "image_generation",
+                  toolName: getHostedToolName("image_generation"),
                   input: "{}",
                   providerExecuted: true,
                 })
@@ -980,7 +977,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
                 controller.enqueue({
                   type: "tool-call",
                   toolCallId: value.item.id,
-                  toolName: "web_search",
+                  toolName: getHostedToolName("web_search"),
                   input: JSON.stringify({ action: value.item.action }),
                   providerExecuted: true,
                 })
@@ -988,7 +985,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
                 controller.enqueue({
                   type: "tool-result",
                   toolCallId: value.item.id,
-                  toolName: "web_search",
+                  toolName: getHostedToolName("web_search"),
                   result: { status: value.item.status },
                 })
               } else if (value.item.type === "computer_call") {
@@ -1022,7 +1019,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
                 controller.enqueue({
                   type: "tool-result",
                   toolCallId: value.item.id,
-                  toolName: "file_search",
+                  toolName: getHostedToolName("file_search"),
                   result: {
                     queries: value.item.queries,
                     results:
@@ -1041,7 +1038,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
                 controller.enqueue({
                   type: "tool-result",
                   toolCallId: value.item.id,
-                  toolName: "code_interpreter",
+                  toolName: getHostedToolName("code_interpreter"),
                   result: {
                     outputs: value.item.outputs,
                   } satisfies z.infer<typeof codeInterpreterOutputSchema>,
@@ -1050,7 +1047,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
                 controller.enqueue({
                   type: "tool-result",
                   toolCallId: value.item.id,
-                  toolName: "image_generation",
+                  toolName: getHostedToolName("image_generation"),
                   result: {
                     result: value.item.result,
                   } satisfies z.infer<typeof imageGenerationOutputSchema>,
@@ -1099,7 +1096,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
               controller.enqueue({
                 type: "tool-result",
                 toolCallId: value.item_id,
-                toolName: "image_generation",
+                toolName: getHostedToolName("image_generation"),
                 result: {
                   result: value.partial_image_b64,
                 } satisfies z.infer<typeof imageGenerationOutputSchema>,
@@ -1135,7 +1132,7 @@ export class OpenAIResponsesLanguageModel implements LanguageModelV3 {
                 controller.enqueue({
                   type: "tool-call",
                   toolCallId: toolCall.toolCallId,
-                  toolName: "code_interpreter",
+                  toolName: getHostedToolName("code_interpreter"),
                   input: JSON.stringify({
                     code: value.code,
                     containerId: toolCall.codeInterpreter!.containerId,

packages/core/src/github-copilot/responses/openai-responses-prepare-tools.ts

@@ -1,4 +1,9 @@
-import { type LanguageModelV3CallOptions, type SharedV3Warning, UnsupportedFunctionalityError } from "@ai-sdk/provider"
+import {
+  type LanguageModelV3CallOptions,
+  type LanguageModelV3ProviderTool,
+  type SharedV3Warning,
+  UnsupportedFunctionalityError,
+} from "@ai-sdk/provider"
 import { codeInterpreterArgsSchema } from "./tool/code-interpreter.js"
 import { fileSearchArgsSchema } from "./tool/file-search.js"
 import { webSearchArgsSchema } from "./tool/web-search.js"
@@ -6,6 +11,28 @@ import { webSearchPreviewArgsSchema } from "./tool/web-search-preview.js"
 import { imageGenerationArgsSchema } from "./tool/image-generation.js"
 import type { OpenAIResponsesTool } from "./openai-responses-api-types.js"
 
+export type ResponsesHostedTool = {
+  name: string
+  type: "file_search" | "web_search_preview" | "web_search" | "code_interpreter" | "image_generation"
+  responseType: "file_search" | "web_search" | "code_interpreter" | "image_generation"
+}
+
+export function getResponsesHostedTool(tool: LanguageModelV3ProviderTool): ResponsesHostedTool | undefined {
+  switch (tool.id) {
+    case "openai.file_search":
+      return { name: tool.name, type: "file_search", responseType: "file_search" }
+    case "openai.web_search_preview":
+      return { name: tool.name, type: "web_search_preview", responseType: "web_search" }
+    case "openai.web_search":
+      return { name: tool.name, type: "web_search", responseType: "web_search" }
+    case "openai.code_interpreter":
+      return { name: tool.name, type: "code_interpreter", responseType: "code_interpreter" }
+    case "openai.image_generation":
+      return { name: tool.name, type: "image_generation", responseType: "image_generation" }
+  }
+  return undefined
+}
+
 export function prepareResponsesTools({
   tools,
   toolChoice,
@@ -26,6 +53,8 @@ export function prepareResponsesTools({
     | { type: "function"; name: string }
     | { type: "code_interpreter" }
     | { type: "image_generation" }
+  hostedTools: ResponsesHostedTool[]
+  selectedHostedTool?: ResponsesHostedTool
   toolWarnings: SharedV3Warning[]
 } {
   // when the tools array is empty, change it to undefined to prevent errors:
@@ -34,7 +63,49 @@ export function prepareResponsesTools({
   const toolWarnings: SharedV3Warning[] = []
 
   if (tools == null) {
-    return { tools: undefined, toolChoice: undefined, toolWarnings }
+    return { tools: undefined, toolChoice: undefined, hostedTools: [], toolWarnings }
+  }
+
+  const hostedTools = tools.flatMap((tool) => {
+    if (tool.type !== "provider") return []
+    const hostedTool = getResponsesHostedTool(tool)
+    return hostedTool ? [hostedTool] : []
+  })
+  const selectedToolName = toolChoice?.type === "tool" ? toolChoice.toolName : undefined
+  const selectedTools = selectedToolName === undefined ? [] : tools.filter((tool) => tool.name === selectedToolName)
+  if (selectedTools.length > 1) {
+    throw new UnsupportedFunctionalityError({
+      functionality: `ambiguous tool choice '${selectedToolName}': multiple tool definitions share this name`,
+    })
+  }
+  const selectedHostedTool =
+    selectedTools[0]?.type === "provider" ? getResponsesHostedTool(selectedTools[0]) : undefined
+
+  const ambiguousHostedResponse =
+    toolChoice?.type === "none" || toolChoice?.type === "tool"
+      ? undefined
+      : hostedTools.find(
+          (tool) =>
+            new Set(
+              hostedTools.filter((candidate) => candidate.responseType === tool.responseType).map((item) => item.name),
+            ).size > 1,
+        )
+  if (ambiguousHostedResponse) {
+    const names = new Set(
+      hostedTools.filter((tool) => tool.responseType === ambiguousHostedResponse.responseType).map((tool) => tool.name),
+    )
+    throw new UnsupportedFunctionalityError({
+      functionality: `ambiguous ${ambiguousHostedResponse.responseType} response for hosted tools: ${[...names].join(", ")}`,
+    })
+  }
+
+  if (selectedHostedTool) {
+    const names = new Set(hostedTools.filter((tool) => tool.type === selectedHostedTool.type).map((tool) => tool.name))
+    if (names.size > 1) {
+      throw new UnsupportedFunctionalityError({
+        functionality: `ambiguous ${selectedHostedTool.type} tool choice for hosted tools: ${[...names].join(", ")}`,
+      })
+    }
   }
 
   const openaiTools: Array<OpenAIResponsesTool> = []
@@ -134,7 +205,7 @@ export function prepareResponsesTools({
   }
 
   if (toolChoice == null) {
-    return { tools: openaiTools, toolChoice: undefined, toolWarnings }
+    return { tools: openaiTools, toolChoice: undefined, hostedTools, selectedHostedTool, toolWarnings }
   }
 
   const type = toolChoice.type
@@ -143,20 +214,18 @@ export function prepareResponsesTools({
     case "auto":
     case "none":
     case "required":
-      return { tools: openaiTools, toolChoice: type, toolWarnings }
-    case "tool":
+      return { tools: openaiTools, toolChoice: type, hostedTools, selectedHostedTool, toolWarnings }
+    case "tool": {
       return {
         tools: openaiTools,
-        toolChoice:
-          toolChoice.toolName === "code_interpreter" ||
-          toolChoice.toolName === "file_search" ||
-          toolChoice.toolName === "image_generation" ||
-          toolChoice.toolName === "web_search_preview" ||
-          toolChoice.toolName === "web_search"
-            ? { type: toolChoice.toolName }
-            : { type: "function", name: toolChoice.toolName },
+        toolChoice: selectedHostedTool
+          ? { type: selectedHostedTool.type }
+          : { type: "function", name: toolChoice.toolName },
+        hostedTools,
+        selectedHostedTool,
         toolWarnings,
       }
+    }
     default: {
       const _exhaustiveCheck: never = type
       throw new UnsupportedFunctionalityError({

packages/core/src/image/photon.ts

@@ -3,7 +3,7 @@ import { Effect } from "effect"
 import path from "node:path"
 import { fileURLToPath } from "node:url"
 import { FileSystem } from "../filesystem.js"
-import { DecodeError, ResizerUnavailableError, SizeError } from "../image.js"
+import { DecodeError, ResizerUnavailableError, SizeError, type Limits } from "../image.js"
 
 const JPEG_QUALITIES = [80, 85, 70, 55, 40]
 
@@ -33,12 +33,7 @@ export const make = Effect.gen(function* () {
   return Effect.fn("Image.Photon.normalize")(function* (
     resource: string,
     content: FileSystem.Content & { readonly encoding: "base64" },
-    limits: {
-      readonly autoResize: boolean
-      readonly maxWidth: number
-      readonly maxHeight: number
-      readonly maxBase64Bytes: number
-    },
+    limits: Readonly<Limits>,
   ) {
     const photon = yield* loadPhoton
     const decoded = yield* Effect.try({

packages/core/src/instructions/builtins.ts

@@ -2,13 +2,13 @@ export * as InstructionBuiltIns from "./builtins.js"
 
 import { makeLocationNode } from "@opencode-ai/util/effect/app-node"
 import { Context, DateTime, Effect, Layer, Schema } from "effect"
+import type { Session } from "@opencode-ai/schema/session"
 import { Global } from "@opencode-ai/util/global"
 import { Location } from "../location.js"
-import { SessionSchema } from "../session/schema.js"
 import { Instructions } from "./index.js"
 
 export interface Interface {
-  readonly load: (sessionID: SessionSchema.ID) => Effect.Effect<Instructions.List>
+  readonly load: (sessionID: Session.ID) => Effect.Effect<Instructions.List>
 }
 
 export class Service extends Context.Service<Service, Interface>()("@opencode/InstructionBuiltIns") {}

packages/core/src/integration.ts

@@ -378,117 +378,109 @@ const layer = Layer.effect(
     }
 
     const settle = Effect.fnUntraced(function* (attemptID: AttemptID, exit: Exit.Exit<Credential.OAuth, unknown>) {
-      return yield* Effect.uninterruptible(
-        Effect.gen(function* () {
-          const now = yield* Clock.currentTimeMillis
-          const attempt = yield* SynchronizedRef.modify(attempts, (current) => {
-            const match = current.get(attemptID)
-            if (!match || match.status !== "pending" || match.persisting) return [undefined, current]
-            const next = Exit.isSuccess(exit)
-              ? { ...match, persisting: true }
-              : {
-                  status: "failed" as const,
-                  integrationID: match.integrationID,
-                  message: message(exit.cause),
-                  time: match.time,
-                  removeAt: now + terminalRetention,
-                }
-            return [match, new Map(current).set(attemptID, next)]
-          })
-          if (!attempt) return
-          if (Exit.isFailure(exit)) {
-            yield* close(attempt.scope)
-            return
-          }
+      const now = yield* Clock.currentTimeMillis
+      const attempt = yield* SynchronizedRef.modify(attempts, (current) => {
+        const match = current.get(attemptID)
+        if (!match || match.status !== "pending" || match.persisting) return [undefined, current]
+        const next = Exit.isSuccess(exit)
+          ? { ...match, persisting: true }
+          : {
+              status: "failed" as const,
+              integrationID: match.integrationID,
+              message: message(exit.cause),
+              time: match.time,
+              removeAt: now + terminalRetention,
+            }
+        return [match, new Map(current).set(attemptID, next)]
+      })
+      if (!attempt) return
+      if (Exit.isFailure(exit)) {
+        yield* close(attempt.scope)
+        return
+      }
 
-          yield* Effect.gen(function* () {
-            const implementation = state
-              .get()
-              .integrations.get(attempt.integrationID)
-              ?.implementations.get(attempt.methodID)
-            const persistence = yield* Effect.sync(() => attempt.label ?? implementation?.label?.(exit.value)).pipe(
-              Effect.flatMap((label) =>
-                createCredential({
-                  integrationID: attempt.integrationID,
-                  label,
-                  value: exit.value,
-                }),
-              ),
-              Effect.asVoid,
-              Effect.exit,
-            )
-            const settledAt = yield* Clock.currentTimeMillis
-            const terminal: TerminalAttempt = Exit.isSuccess(persistence)
-              ? {
-                  status: "complete",
-                  integrationID: attempt.integrationID,
-                  time: attempt.time,
-                  removeAt: settledAt + terminalRetention,
-                }
-              : {
-                  status: "failed",
-                  integrationID: attempt.integrationID,
-                  message: message(persistence.cause),
-                  time: attempt.time,
-                  removeAt: settledAt + terminalRetention,
-                }
-            // Persisting attempts cannot be cancelled, expired, or claimed again.
-            yield* SynchronizedRef.update(attempts, (current) => new Map(current).set(attemptID, terminal))
-            if (Exit.isFailure(persistence)) yield* Effect.failCause(persistence.cause)
-          }).pipe(Effect.ensuring(close(attempt.scope)))
-        }),
-      )
-    })
+      yield* Effect.gen(function* () {
+        const implementation = state
+          .get()
+          .integrations.get(attempt.integrationID)
+          ?.implementations.get(attempt.methodID)
+        const persistence = yield* Effect.sync(() => attempt.label ?? implementation?.label?.(exit.value)).pipe(
+          Effect.flatMap((label) =>
+            createCredential({
+              integrationID: attempt.integrationID,
+              label,
+              value: exit.value,
+            }),
+          ),
+          Effect.asVoid,
+          Effect.exit,
+        )
+        const settledAt = yield* Clock.currentTimeMillis
+        const terminal: TerminalAttempt = Exit.isSuccess(persistence)
+          ? {
+              status: "complete",
+              integrationID: attempt.integrationID,
+              time: attempt.time,
+              removeAt: settledAt + terminalRetention,
+            }
+          : {
+              status: "failed",
+              integrationID: attempt.integrationID,
+              message: message(persistence.cause),
+              time: attempt.time,
+              removeAt: settledAt + terminalRetention,
+            }
+        // Persisting attempts cannot be cancelled, expired, or claimed again.
+        yield* SynchronizedRef.update(attempts, (current) => new Map(current).set(attemptID, terminal))
+        if (Exit.isFailure(persistence)) yield* Effect.failCause(persistence.cause)
+      }).pipe(Effect.ensuring(close(attempt.scope)))
+    }, Effect.uninterruptible)
 
     const settleCommand = Effect.fnUntraced(function* (attemptID: AttemptID, exit: Exit.Exit<string, unknown>) {
-      return yield* Effect.uninterruptible(
-        Effect.gen(function* () {
-          const now = yield* Clock.currentTimeMillis
-          const attempt = yield* SynchronizedRef.modify(commandAttempts, (current) => {
-            const match = current.get(attemptID)
-            if (!match || match.status !== "pending" || match.persisting) return [undefined, current]
-            const next = Exit.isSuccess(exit)
-              ? { ...match, persisting: true }
-              : {
-                  status: "failed" as const,
-                  integrationID: match.integrationID,
-                  message: message(exit.cause),
-                  time: match.time,
-                  removeAt: now + terminalRetention,
-                }
-            return [match, new Map(current).set(attemptID, next)]
-          })
-          if (!attempt) return
-          if (Exit.isFailure(exit)) {
-            yield* close(attempt.scope)
-            return
-          }
+      const now = yield* Clock.currentTimeMillis
+      const attempt = yield* SynchronizedRef.modify(commandAttempts, (current) => {
+        const match = current.get(attemptID)
+        if (!match || match.status !== "pending" || match.persisting) return [undefined, current]
+        const next = Exit.isSuccess(exit)
+          ? { ...match, persisting: true }
+          : {
+              status: "failed" as const,
+              integrationID: match.integrationID,
+              message: message(exit.cause),
+              time: match.time,
+              removeAt: now + terminalRetention,
+            }
+        return [match, new Map(current).set(attemptID, next)]
+      })
+      if (!attempt) return
+      if (Exit.isFailure(exit)) {
+        yield* close(attempt.scope)
+        return
+      }
 
-          const persistence = yield* createCredential({
+      const persistence = yield* createCredential({
+        integrationID: attempt.integrationID,
+        label: attempt.label,
+        value: Credential.Key.make({ type: "key", key: exit.value }),
+      }).pipe(Effect.asVoid, Effect.exit)
+      const settledAt = yield* Clock.currentTimeMillis
+      const terminal: TerminalCommandAttempt = Exit.isSuccess(persistence)
+        ? {
+            status: "complete",
             integrationID: attempt.integrationID,
-            label: attempt.label,
-            value: Credential.Key.make({ type: "key", key: exit.value }),
-          }).pipe(Effect.asVoid, Effect.exit)
-          const settledAt = yield* Clock.currentTimeMillis
-          const terminal: TerminalCommandAttempt = Exit.isSuccess(persistence)
-            ? {
-                status: "complete",
-                integrationID: attempt.integrationID,
-                time: attempt.time,
-                removeAt: settledAt + terminalRetention,
-              }
-            : {
-                status: "failed",
-                integrationID: attempt.integrationID,
-                message: message(persistence.cause),
-                time: attempt.time,
-                removeAt: settledAt + terminalRetention,
-              }
-          yield* SynchronizedRef.update(commandAttempts, (current) => new Map(current).set(attemptID, terminal))
-          yield* close(attempt.scope)
-        }),
-      )
-    })
+            time: attempt.time,
+            removeAt: settledAt + terminalRetention,
+          }
+        : {
+            status: "failed",
+            integrationID: attempt.integrationID,
+            message: message(persistence.cause),
+            time: attempt.time,
+            removeAt: settledAt + terminalRetention,
+          }
+      yield* SynchronizedRef.update(commandAttempts, (current) => new Map(current).set(attemptID, terminal))
+      yield* close(attempt.scope)
+    }, Effect.uninterruptible)
 
     const scrub = Effect.fnUntraced(function* () {
       const now = yield* Clock.currentTimeMillis

packages/core/src/location-services.ts

@@ -37,6 +37,7 @@ export function buildLocationServiceMap(
         ...inner,
         get: (ref: Location.Ref) => inner.get(canonical(ref)),
         contextEffect: (ref: Location.Ref) => inner.contextEffect(canonical(ref)),
+        contextEffectOption: (ref: Location.Ref) => inner.contextEffectOption(canonical(ref)),
         invalidate: (ref: Location.Ref) => inner.invalidate(canonical(ref)),
       }),
     ),

packages/core/src/mcp/client.ts

@@ -26,6 +26,7 @@ import {
 } from "@modelcontextprotocol/sdk/types.js"
 import { Cause, Effect, Exit, Schema } from "effect"
 import { ConfigMCP } from "@opencode-ai/schema/config/mcp"
+import type { Session } from "@opencode-ai/schema/session"
 import { McpStdio } from "./stdio.js"
 
 const DEFAULT_STARTUP_TIMEOUT = 30_000
@@ -156,6 +157,7 @@ export interface Connection {
   readonly callTool: (input: {
     readonly name: string
     readonly args?: Record<string, unknown>
+    readonly sessionID?: Session.ID
   }) => Effect.Effect<CallToolResult, Error>
   readonly onClose: (callback: () => void) => void
   /** Registers a callback fired when the server emits an MCP logging notification. */
@@ -396,7 +398,11 @@ export const connect = Effect.fnUntraced(function* (
         Effect.tryPromise({
           try: (signal) =>
             client.callTool(
-              { name: input.name, arguments: input.args ?? {} },
+              {
+                name: input.name,
+                arguments: input.args ?? {},
+                ...(input.sessionID === undefined ? {} : { _meta: { sessionID: input.sessionID } }),
+              },
               CallToolResultSchema,
               // Keep progress tokens available while enforcing a hard wall-clock execution timeout.
               { signal, timeout: executionTimeout, onprogress: () => {} },

packages/core/src/mcp/index.ts

@@ -3,6 +3,7 @@ export * as Mcp from "./index.js"
 import { Mcp } from "@opencode-ai/schema/mcp"
 import { McpEvent } from "@opencode-ai/schema/mcp-event"
 import { ephemeral } from "@opencode-ai/schema/event"
+import type { Session } from "@opencode-ai/schema/session"
 import { createHash } from "node:crypto"
 import { isDeepStrictEqual } from "node:util"
 import { Cause, Context, Effect, Exit, FiberSet, Latch, Layer, Schema, Scope, Stream, Types } from "effect"
@@ -153,6 +154,7 @@ export interface Interface extends State.Transformable<Draft> {
     readonly server: ServerName | string
     readonly name: string
     readonly args?: Record<string, unknown>
+    readonly sessionID?: Session.ID
   }) => Effect.Effect<ToolResult, NotFoundError | ToolCallError>
   readonly instructions: () => Effect.Effect<ServerInstructions[]>
   readonly prompts: () => Effect.Effect<Prompt[]>
@@ -762,7 +764,7 @@ export const layer = (options?: Options) =>
               message: "MCP server is not connected",
             })
           const result = yield* target.entry.client
-            .callTool({ name: input.name, args: input.args })
+            .callTool({ name: input.name, args: input.args, sessionID: input.sessionID })
             .pipe(
               Effect.mapError(
                 (error) => new ToolCallError({ server: target.name, tool: input.name, message: error.message }),

packages/core/src/permission.ts

@@ -292,20 +292,11 @@ const layer = Layer.effect(
           pending.delete(input.requestID)
           if (input.reply !== "always" || !existing.request.save?.length) return
 
-          const rememberedRules = yield* savedRules()
           for (const [id, item] of pending) {
-            const rules = yield* configured(item.request.sessionID, item.agent).pipe(
+            const result = yield* evaluateInput({ ...item.request, agent: item.agent }).pipe(
               Effect.catchTag("Session.NotFoundError", () => Effect.undefined),
             )
-            if (!rules) continue
-            if (denied(item.request, rules)) continue
-            const effective = [...rules, ...rememberedRules]
-            if (
-              !item.request.resources.every(
-                (resource) => evaluate(item.request.action, resource, effective).effect === "allow",
-              )
-            )
-              continue
+            if (result?.effect !== "allow") continue
             yield* bus.publish(Permission.Event.Replied, {
               sessionID: item.request.sessionID,
               requestID: item.request.id,

packages/core/src/permission/saved.ts

@@ -2,9 +2,9 @@ export * as PermissionSaved from "./saved.js"
 
 import { eq } from "drizzle-orm"
 import { Context, Effect, Layer, Schema } from "effect"
+import { Project } from "@opencode-ai/schema/project"
 import { Database } from "../database/database.js"
 import { makeGlobalNode } from "@opencode-ai/util/effect/app-node"
-import { Project } from "../project.js"
 import { PermissionTable } from "./sql.js"
 import { PermissionSaved } from "@opencode-ai/schema/permission-saved"
 

packages/core/src/permission/sql.ts

@@ -1,6 +1,6 @@
 import { sqliteTable, text, uniqueIndex } from "drizzle-orm/sqlite-core"
+import type { Project } from "@opencode-ai/schema/project"
 import { Timestamps } from "../database/schema.sql.js"
-import { Project } from "../project.js"
 import { ProjectTable } from "../project/sql.js"
 import type { PermissionSaved } from "./saved.js"
 

packages/core/src/persistent-pty/index.ts

@@ -4,7 +4,7 @@ import os from "node:os"
 import path from "node:path"
 import { Context, Effect, Layer, Schema } from "effect"
 import { makeGlobalNode } from "@opencode-ai/util/effect/app-node"
-import { Added, Handoff, ReadLines, Removed, type ReadResult } from "@opencode-ai/schema/persistent-pty"
+import { Added, Handoff, PersistentPty, ReadLines, Removed, type ReadResult } from "@opencode-ai/schema/persistent-pty"
 import { Session } from "@opencode-ai/schema/session"
 import { Bus } from "../bus.js"
 import { Pty } from "@opencode-ai/schema/pty"
@@ -26,19 +26,9 @@ export { Handoff } from "@opencode-ai/schema/persistent-pty"
 export const Options = Schema.Struct({ handoff: Schema.optional(Handoff) })
 export type Options = typeof Options.Type
 
-export type Info = Pty.Info & {
-  readonly sessionID: Session.ID
-  readonly foregroundProcess: string | null
-  readonly size: { readonly cols: number; readonly rows: number }
-  readonly output: { readonly head: number; readonly tail: number }
-}
+export type Info = PersistentPty.Info
 
-export type Snapshot = {
-  readonly info: Info
-  readonly text: string
-  readonly checkpoint: Uint8Array
-  readonly cursor: { readonly x: number; readonly y: number }
-}
+export type Snapshot = PersistentPty.Snapshot
 
 export type Attachment = {
   readonly info: Info
@@ -161,15 +151,7 @@ export const configured = (options: Options = {}) =>
 
       const create = Effect.fn("PersistentPty.create")(function* (
         sessionID: Session.ID,
-        input: {
-          readonly command?: string
-          readonly args: readonly string[]
-          readonly cwd?: string
-          readonly title: string
-          readonly env: Readonly<Record<string, string>>
-          readonly cols?: number
-          readonly rows?: number
-        },
+        input: Parameters<Interface["create"]>[1],
       ) {
         const response = yield* request(
           daemon,
@@ -338,14 +320,7 @@ export const configured = (options: Options = {}) =>
 
       const attach = Effect.fn("PersistentPty.attach")(function* (
         id: Pty.ID,
-        input: {
-          readonly cursor: number
-          readonly attachmentID: string
-          readonly role: Role
-          readonly takeover?: boolean
-          readonly onEvent: (event: StreamEvent) => void
-          readonly onEnd: () => void
-        },
+        input: Parameters<Interface["attach"]>[1],
       ) {
         yield* get(id)
         const attachment = yield* daemon

packages/core/src/plugin/command.ts

@@ -84,7 +84,9 @@ export const Plugin = define({
 })
 
 function append(template: string, input: string) {
-  return [template, input.trim()].filter(Boolean).join("\n\n")
+  const value = input.trim()
+  if (template.includes("$ARGUMENTS")) return template.replaceAll("$ARGUMENTS", () => value)
+  return [template, value].filter(Boolean).join("\n\n")
 }
 
 function parseArguments(input: string) {

packages/core/src/plugin/host.ts

@@ -369,9 +369,10 @@ export const make = Effect.fn("PluginHost.make")(function* (plugin: Interface, p
     },
     vcs: {
       get: () => response(vcs.info()),
+      base: () => response(vcs.base()),
       branches: (input) => response(vcs.branches({ search: input?.search, limit: input?.limit })),
       status: () => response(vcs.status()),
-      diff: (input) => response(vcs.diff(input.mode, { context: input.context })),
+      diff: (input) => response(vcs.diff(input.mode, { context: input.context, base: input.base })),
       transform: vcs.transform,
       reload: vcs.reload,
     },

packages/core/src/plugin/models-dev.ts

@@ -1,9 +1,9 @@
 import { define } from "@opencode-ai/plugin/effect/plugin"
 import { Integration } from "@opencode-ai/schema/integration"
+import { Provider } from "@opencode-ai/schema/provider"
 import { Effect, Stream } from "effect"
 import { Bus } from "../bus.js"
 import { ModelsDev } from "../models-dev.js"
-import { Provider } from "../provider.js"
 
 export const ModelsDevPlugin = define({
   id: "opencode.models.dev",
@@ -37,7 +37,7 @@ export const ModelsDevPlugin = define({
         })
         for (const model of provider.models) {
           if (model.status === "deprecated") continue
-          catalog.model.update(provider.info.id, model.id, (draft) => Object.assign(draft, model))
+          catalog.model.update(provider.info.id, model.id, (draft) => Object.assign(draft, structuredClone(model)))
         }
       }
     })

packages/core/src/plugin/module.ts

@@ -40,7 +40,7 @@ export const load = Effect.fn("PluginModule.load")(function* (
   const npm = yield* Npm.Service
   const entrypoint = path.isAbsolute(operation.target)
     ? pathToFileURL(operation.target).href
-    : (yield* npm.add(operation.target, { subpaths: ["server", ""], refresh: true })).entrypoint
+    : (yield* npm.add(operation.target, { subpaths: ["server", ""] })).entrypoint
   if (!entrypoint) return yield* Effect.fail(new Error(`Plugin entrypoint not found: ${operation.target}`))
   // Bun currently ignores query parameters when caching file:// imports.
   const target = typeof Bun !== "undefined" ? operation.target.replaceAll("\\", "/") : entrypoint

packages/core/src/plugin/plan.ts

@@ -2,12 +2,12 @@ export * as PlanPlugin from "./plan.js"
 
 import { Message, ToolFailure } from "@opencode-ai/ai"
 import { define } from "@opencode-ai/plugin/effect/plugin"
+import { Agent } from "@opencode-ai/schema/agent"
+import type { SessionEvent } from "@opencode-ai/schema/session-event"
 import { Global } from "@opencode-ai/util/global"
 import { Effect, Stream } from "effect"
 import path from "path"
-import { Agent } from "../agent.js"
 import { Permission } from "../permission.js"
-import { SessionEvent } from "../session/event.js"
 
 const plan = Agent.ID.make("plan")
 

packages/core/src/plugin/skill/opencode.md

@@ -76,11 +76,13 @@ to every project for that user. Project configuration can live in any directory
 as `opencode.json(c)` or `.opencode/opencode.json(c)`, including nested packages
 in a monorepo.
 
-When OpenCode starts, it searches from the current directory up to the project
-root. It merges direct `opencode.json(c)` files from root to current directory,
+During ordinary project discovery, OpenCode searches the current Location
+directory and every ancestor through the filesystem root, including directories
+above the detected project or repository root. It merges direct
+`opencode.json(c)` files from the farthest ancestor to the current directory,
 then does the same for `.opencode/opencode.json(c)` files. This means every
-`.opencode` config overrides every direct config. Global configuration has the
-lowest precedence.
+discovered `.opencode` config overrides every discovered direct config. Global
+filesystem configuration has lower precedence than these discovered documents.
 
 Common configuration fields include `model`, `default_agent`, `permissions`,
 `agents`, `commands`, `plugins`, `providers`, `mcp`, `skills`, `instructions`,

packages/core/src/plugin/supervisor.ts

@@ -78,6 +78,9 @@ const resolve = Effect.fn("PluginSupervisor.resolve")(function* (
       ...post.filter((plugin) => enabled.has(plugin.id)),
     ],
     failures: [...failures.values()],
+    refreshes: [...packages.entries()].flatMap(([target, plugin]) =>
+      !path.isAbsolute(target) && enabled.has(plugin.id) ? [target] : [],
+    ),
   }
 })
 
@@ -89,6 +92,7 @@ export const layer = Layer.effect(
     const instance = yield* InstancePlugins.Service
     const sources = yield* ConfigPluginSource.Service
     const bus = yield* Bus.Service
+    const npm = yield* Npm.Service
     const ready = yield* Latch.make()
     let observed = 0
 
@@ -113,6 +117,18 @@ export const layer = Layer.effect(
       const resolved = yield* resolve(pre, post, operations)
       // Replace the active generation in one scoped, batched activation.
       yield* registry.activate(resolved.plugins, resolved.failures)
+      if (resolved.refreshes.length) {
+        yield* Effect.forEach(
+          resolved.refreshes,
+          (target) =>
+            npm
+              .add(target, { subpaths: ["server", ""], refresh: true })
+              .pipe(
+                Effect.catchCause((cause) => Effect.logWarning("failed to refresh package plugin", { target, cause })),
+              ),
+          { concurrency: "unbounded", discard: true },
+        ).pipe(Effect.forkDetach)
+      }
     })
     const updates = Stream.merge(sources.changes(), bus.subscribe([Event.Updated, SdkPlugins.Updated])).pipe(
       // Make accepted work visible to flush before coalescing the burst.

packages/core/src/plugin/variant.ts

@@ -2,7 +2,7 @@ export * as VariantPlugin from "./variant.js"
 
 import { Effect } from "effect"
 import { define } from "@opencode-ai/plugin/effect/plugin"
-import { Model } from "../model.js"
+import { Model } from "@opencode-ai/schema/model"
 import { Provider } from "../provider.js"
 
 export const Plugin = define({

packages/core/src/plugin/vcs/git.ts

@@ -4,10 +4,11 @@ import { define } from "@opencode-ai/plugin/effect/plugin"
 import { Effect } from "effect"
 import { ChildProcess } from "effect/unstable/process"
 import { FileDiff } from "@opencode-ai/schema/file-diff"
-import { BranchList, FileStatus, Info, Mode } from "@opencode-ai/schema/vcs"
+import { Base, BranchList, FileStatus, Info, Mode } from "@opencode-ai/schema/vcs"
 import { AppProcess } from "@opencode-ai/util/process"
 import { Location } from "../../location.js"
 import type { Adapter, BranchOptions, DiffOptions } from "../../vcs.js"
+import { DiffError } from "../../vcs.js"
 import {
   chunksByFile,
   emptyPatch,
@@ -35,9 +36,10 @@ export const Plugin = define({
         id: "git",
         name: "Git",
         info: () => adapter.info(),
+        base: () => adapter.base(),
         branches: (input) => adapter.branches({ search: input.search, limit: input.limit }),
         status: () => adapter.status(),
-        diff: (input) => adapter.diff(input.mode, { context: input.context }),
+        diff: (input) => adapter.diff(input.mode, { context: input.context, base: input.base }),
       })
     })
   }),
@@ -48,7 +50,7 @@ export const Plugin = define({
  * batched through one `git diff` invocation where possible and capped by
  * per-file and total byte budgets, falling back to empty patches when capped.
  */
-function make(proc: AppProcess.Interface, input: { directory: string; worktree: string }): Adapter {
+function make(proc: AppProcess.Interface, input: { directory: string; worktree: string }) {
   // Listing commands scope pathspecs to the requested directory; per-file
   // commands run from the worktree root because git lists root-relative paths.
   const ctx: Ctx = { git: makeGit(proc), directory: input.directory, worktree: input.worktree }
@@ -60,6 +62,7 @@ function make(proc: AppProcess.Interface, input: { directory: string; worktree:
       })
       return { branch: { current, default: root?.name } } satisfies Info
     }),
+    base: () => ctx.git.base(ctx.directory),
     branches: Effect.fn("VcsGit.branches")(function* (options?: BranchOptions) {
       return yield* ctx.git.branches(ctx.directory, options)
     }),
@@ -93,25 +96,23 @@ function make(proc: AppProcess.Interface, input: { directory: string; worktree:
         return yield* track(ctx, (yield* git.hasHead(ctx.directory)) ? "HEAD" : undefined, options)
       }
 
-      const [current, root] = yield* Effect.all([git.branch(ctx.directory), git.defaultBranch(ctx.directory)], {
-        concurrency: 2,
-      })
-      if (!root) return []
-      if (current && current === root.name) return []
-      const ref = yield* git.mergeBase(ctx.directory, root.ref)
-      if (!ref) return []
-      return yield* diffAgainstRef(ctx, ref, options)
+      if (!(yield* git.hasHead(ctx.directory))) {
+        return mode === "committed" ? [] : yield* track(ctx, undefined, options)
+      }
+      const base = options?.base ?? (yield* git.defaultBranch(ctx.directory))?.ref
+      const ref = base ? yield* git.mergeBase(ctx.directory, base) : undefined
+      if (!ref) {
+        return yield* new DiffError({
+          message: base ? `No merge base available for ${base}` : "No review base available",
+        })
+      }
+      return yield* diffAgainstRef(ctx, ref, { ...options, target: mode === "committed" ? "HEAD" : undefined })
     }),
-  }
+  } satisfies Adapter
 }
 
 type Kind = FileStatus["status"]
 
-interface Base {
-  readonly name: string
-  readonly ref: string
-}
-
 interface Item {
   readonly file: string
   readonly code: string
@@ -124,8 +125,11 @@ interface Stat {
   readonly deletions: number
 }
 
-interface PatchOptions {
-  readonly context?: number
+interface GitDiffOptions extends DiffOptions {
+  readonly target?: "HEAD"
+}
+
+interface PatchOptions extends GitDiffOptions {
   readonly maxOutputBytes?: number
 }
 
@@ -196,7 +200,7 @@ function makeGit(proc: AppProcess.Interface) {
     const result = yield* run(["config", "init.defaultBranch"], { cwd })
     const name = result.text().trim()
     if (!name || !list.includes(name)) return
-    return { name, ref: name } satisfies Base
+    return { name, ref: name }
   })
 
   const primary = Effect.fnUntraced(function* (cwd: string) {
@@ -239,15 +243,70 @@ function makeGit(proc: AppProcess.Interface) {
           .trim()
           .replace(/^refs\/remotes\//, "")
         const name = ref.startsWith(`${remote}/`) ? ref.slice(`${remote}/`.length) : ""
-        if (name) return { name, ref } satisfies Base
+        if (name) return { name, ref }
       }
     }
 
     const list = yield* lines(["for-each-ref", "--format=%(refname:short)", "refs/heads"], { cwd })
     const next = yield* configured(cwd, list)
     if (next) return next
-    if (list.includes("main")) return { name: "main", ref: "main" } satisfies Base
-    if (list.includes("master")) return { name: "master", ref: "master" } satisfies Base
+    if (list.includes("main")) return { name: "main", ref: "main" }
+    if (list.includes("master")) return { name: "master", ref: "master" }
+  })
+
+  const resolve = Effect.fnUntraced(function* (cwd: string, ref: string) {
+    const result = yield* run(["rev-parse", "--verify", "--end-of-options", `${ref}^{commit}`], { cwd })
+    if (result.exitCode !== 0) return
+    return result.text().trim() || undefined
+  })
+
+  const ancestor = Effect.fnUntraced(function* (cwd: string, commit: string, ref: string) {
+    if (!/^[a-f0-9]{40,64}$/.test(commit)) return false
+    return (yield* run(["merge-base", "--is-ancestor", commit, ref], { cwd })).exitCode === 0
+  })
+
+  const namedRef = Effect.fnUntraced(function* (cwd: string, input: string) {
+    // Creation hints must identify a branch, not HEAD, an object ID, or a revision expression.
+    if (input === "HEAD" || input.endsWith("/HEAD") || /[~^:@{}\s]/.test(input)) return
+    const ref = (yield* text(["rev-parse", "--symbolic-full-name", "--verify", "--end-of-options", input], {
+      cwd,
+    })).trim()
+    if (!/^refs\/(heads|remotes)\/.+/.test(ref) || ref.endsWith("/HEAD") || !(yield* resolve(cwd, ref))) return
+    return { name: ref.replace(/^refs\/heads\//, "").replace(/^refs\/remotes\/[^/]+\//, ""), ref }
+  })
+
+  const base = Effect.fn("VcsGit.base")(function* (cwd: string) {
+    if (!(yield* hasHead(cwd))) return null
+    const current = yield* branch(cwd)
+    if (!current) return yield* new DiffError({ message: "Choose a review base" })
+    const history = (yield* lines(
+      ["reflog", "show", "--max-count=256", "--format=%H%x00%gs", `refs/heads/${current}`],
+      {
+        cwd,
+      },
+    )).flatMap((line) => {
+      const match = /^([a-f0-9]+)\0(.+)$/.exec(line)
+      return match ? [{ commit: match[1], message: match[2] }] : []
+    })
+    const renamed = history.some((entry) => entry.message.startsWith("Branch: renamed "))
+    const creation = renamed ? undefined : history.find((entry) => entry.message.startsWith("branch: Created from "))
+    const origin = creation?.message.slice("branch: Created from ".length)
+    if (creation && origin) {
+      const candidate = yield* namedRef(cwd, origin)
+      if (
+        candidate &&
+        candidate.name !== current &&
+        (yield* ancestor(cwd, creation.commit, "HEAD")) &&
+        (yield* ancestor(cwd, creation.commit, candidate.ref))
+      ) {
+        return { ...candidate, source: "reflog" } satisfies Base
+      }
+    }
+    const root = yield* defaultBranch(cwd)
+    if (!root || current !== root.name) return yield* new DiffError({ message: "Choose a review base" })
+    const candidate = yield* namedRef(cwd, root.ref)
+    if (!candidate) return yield* new DiffError({ message: "The default review base is unavailable" })
+    return { name: root.name, ref: candidate.ref, source: "default" } satisfies Base
   })
 
   const hasHead = Effect.fn("VcsGit.hasHead")(function* (cwd: string) {
@@ -256,7 +315,9 @@ function makeGit(proc: AppProcess.Interface) {
   })
 
   const mergeBase = Effect.fn("VcsGit.mergeBase")(function* (cwd: string, base: string) {
-    const result = yield* run(["merge-base", base, "HEAD"], { cwd })
+    const ref = yield* resolve(cwd, base)
+    if (!ref) return
+    const result = yield* run(["merge-base", ref, "HEAD"], { cwd })
     if (result.exitCode !== 0) return
     return result.text().trim() || undefined
   })
@@ -272,10 +333,13 @@ function makeGit(proc: AppProcess.Interface) {
     })
   })
 
-  const diff = Effect.fn("VcsGit.diffNames")(function* (cwd: string, ref: string) {
-    const list = nuls(
-      yield* text(["diff", "--no-ext-diff", "--no-renames", "--name-status", "-z", ref, "--", "."], { cwd }),
+  const diff = Effect.fn("VcsGit.diffNames")(function* (cwd: string, ref: string, target?: string) {
+    const result = yield* run(
+      ["diff", "--no-ext-diff", "--no-renames", "--name-status", "-z", ref, ...(target ? [target] : []), "--", "."],
+      { cwd },
     )
+    if (result.exitCode !== 0) return yield* new DiffError({ message: "Unable to list Git changes" })
+    const list = nuls(result.text())
     return list.flatMap((code, idx) => {
       if (idx % 2 !== 0) return []
       const file = list[idx + 1]
@@ -284,9 +348,12 @@ function makeGit(proc: AppProcess.Interface) {
     })
   })
 
-  const stats = Effect.fn("VcsGit.stats")(function* (cwd: string, ref: string) {
+  const stats = Effect.fn("VcsGit.stats")(function* (cwd: string, ref: string, target?: string) {
     return nuls(
-      yield* text(["diff", "--no-ext-diff", "--no-renames", "--numstat", "-z", ref, "--", "."], { cwd }),
+      yield* text(
+        ["diff", "--no-ext-diff", "--no-renames", "--numstat", "-z", ref, ...(target ? [target] : []), "--", "."],
+        { cwd },
+      ),
     ).flatMap((item) => {
       const a = item.indexOf("\t")
       const b = item.indexOf("\t", a + 1)
@@ -309,7 +376,17 @@ function makeGit(proc: AppProcess.Interface) {
 
   const patch = Effect.fn("VcsGit.patch")(function* (cwd: string, ref: string, file: string, options?: PatchOptions) {
     const result = yield* run(
-      ["diff", "--patch", "--no-ext-diff", "--no-renames", `--unified=${options?.context ?? 3}`, ref, "--", file],
+      [
+        "diff",
+        "--patch",
+        "--no-ext-diff",
+        "--no-renames",
+        `--unified=${options?.context ?? 3}`,
+        ref,
+        ...(options?.target ? [options.target] : []),
+        "--",
+        file,
+      ],
       { cwd, maxOutputBytes: options?.maxOutputBytes },
     )
     return { text: result.truncated ? "" : result.text(), truncated: result.truncated } satisfies Patch
@@ -317,7 +394,17 @@ function makeGit(proc: AppProcess.Interface) {
 
   const patchAll = Effect.fn("VcsGit.patchAll")(function* (cwd: string, ref: string, options?: PatchOptions) {
     const result = yield* run(
-      ["diff", "--patch", "--no-ext-diff", "--no-renames", `--unified=${options?.context ?? 3}`, ref, "--", "."],
+      [
+        "diff",
+        "--patch",
+        "--no-ext-diff",
+        "--no-renames",
+        `--unified=${options?.context ?? 3}`,
+        ref,
+        ...(options?.target ? [options.target] : []),
+        "--",
+        ".",
+      ],
       { cwd, maxOutputBytes: options?.maxOutputBytes },
     )
     return { text: result.text(), truncated: result.truncated } satisfies Patch
@@ -367,6 +454,7 @@ function makeGit(proc: AppProcess.Interface) {
   return {
     branch,
     branches,
+    base,
     defaultBranch,
     hasHead,
     mergeBase,
@@ -393,10 +481,11 @@ const merge = (...lists: Item[][]) => {
 
 const emptyBatch = () => ({ patches: new Map<string, string>(), capped: false })
 
-const batchPatches = Effect.fnUntraced(function* (ctx: Ctx, ref: string, list: Item[], options?: DiffOptions) {
+const batchPatches = Effect.fnUntraced(function* (ctx: Ctx, ref: string, list: Item[], options?: GitDiffOptions) {
   if (list.length === 0) return emptyBatch()
 
   const result = yield* ctx.git.patchAll(ctx.directory, ref, {
+    target: options?.target,
     context: options?.context ?? PATCH_CONTEXT_LINES,
     maxOutputBytes: MAX_TOTAL_PATCH_BYTES,
   })
@@ -407,7 +496,12 @@ const batchPatches = Effect.fnUntraced(function* (ctx: Ctx, ref: string, list: I
   }
 })
 
-const nativePatch = Effect.fnUntraced(function* (ctx: Ctx, ref: string | undefined, item: Item, options?: DiffOptions) {
+const nativePatch = Effect.fnUntraced(function* (
+  ctx: Ctx,
+  ref: string | undefined,
+  item: Item,
+  options?: GitDiffOptions,
+) {
   const result =
     item.code === "??" || !ref
       ? yield* ctx.git.patchUntracked(ctx.worktree, item.file, {
@@ -415,6 +509,7 @@ const nativePatch = Effect.fnUntraced(function* (ctx: Ctx, ref: string | undefin
           maxOutputBytes: MAX_PATCH_BYTES,
         })
       : yield* ctx.git.patch(ctx.worktree, ref, item.file, {
+          target: options?.target,
           context: options?.context ?? PATCH_CONTEXT_LINES,
           maxOutputBytes: MAX_PATCH_BYTES,
         })
@@ -434,7 +529,7 @@ const patchForItem = Effect.fnUntraced(function* (
   item: Item,
   batch: { patches: Map<string, string>; capped: boolean },
   capped: boolean,
-  options?: DiffOptions,
+  options?: GitDiffOptions,
 ) {
   if (capped) return emptyPatch(item.file)
 
@@ -450,7 +545,7 @@ const files = Effect.fnUntraced(function* (
   list: Item[],
   map: Map<string, { additions: number; deletions: number }>,
   batch: { patches: Map<string, string>; capped: boolean },
-  options?: DiffOptions,
+  options?: GitDiffOptions,
 ) {
   const next: FileDiff.Info[] = []
   let total = 0
@@ -459,7 +554,7 @@ const files = Effect.fnUntraced(function* (
   for (const item of list.toSorted((a, b) => a.file.localeCompare(b.file))) {
     const stat =
       map.get(item.file) ??
-      (item.status === "added" ? yield* ctx.git.statUntracked(ctx.worktree, item.file) : undefined)
+      (!options?.target && item.status === "added" ? yield* ctx.git.statUntracked(ctx.worktree, item.file) : undefined)
     const patch = yield* patchForItem(ctx, ref, item, batch, capped, options)
     const result: { patch: string; capped: boolean } = capped
       ? { patch, capped: true }
@@ -481,9 +576,13 @@ const files = Effect.fnUntraced(function* (
   return next
 })
 
-const diffAgainstRef = Effect.fnUntraced(function* (ctx: Ctx, ref: string, options?: DiffOptions) {
+const diffAgainstRef = Effect.fnUntraced(function* (ctx: Ctx, ref: string, options?: GitDiffOptions) {
   const [list, stats, extra] = yield* Effect.all(
-    [ctx.git.diff(ctx.directory, ref), ctx.git.stats(ctx.directory, ref), ctx.git.status(ctx.directory)],
+    [
+      ctx.git.diff(ctx.directory, ref, options?.target),
+      ctx.git.stats(ctx.directory, ref, options?.target),
+      options?.target ? Effect.succeed([]) : ctx.git.status(ctx.directory),
+    ],
     { concurrency: 3 },
   )
   return yield* files(

packages/core/src/plugin/vcs/hg.ts

@@ -10,6 +10,7 @@ import { FSUtil } from "@opencode-ai/util/fs-util"
 import { AppProcess } from "@opencode-ai/util/process"
 import { Location } from "../../location.js"
 import type { Adapter, DiffOptions } from "../../vcs.js"
+import { DiffError } from "../../vcs.js"
 import {
   addPatch,
   chunksByFile,
@@ -42,7 +43,7 @@ export const Plugin = define({
         info: () => adapter.info(),
         branches: (input) => adapter.branches({ search: input.search, limit: input.limit }),
         status: () => adapter.status(),
-        diff: (input) => adapter.diff(input.mode, { context: input.context }),
+        diff: (input) => adapter.diff(input.mode, { context: input.context, base: input.base }),
       })
     })
   }),
@@ -121,6 +122,11 @@ function make(
     }),
     diff: Effect.fn("VcsHg.diff")(function* (mode: Mode, options?: DiffOptions) {
       if (mode === "working") return yield* diffAgainst(undefined, options)
+      if (mode === "committed" || options?.base !== undefined) {
+        return yield* new DiffError({
+          message: "The Mercurial provider does not support committed reviews or explicit bases",
+        })
+      }
 
       const branch = yield* hg.branch()
       if (!branch || branch === "default") return []

packages/core/src/plugin/warming.ts

@@ -1,9 +1,9 @@
 export * as WarmingPlugin from "./warming.js"
 
 import { define } from "@opencode-ai/plugin/effect/plugin"
+import type { Session } from "@opencode-ai/schema/session"
 import { Clock, Duration, Effect, Scope } from "effect"
 import { Config } from "../config.js"
-import { SessionSchema } from "../session/schema.js"
 
 const defaults = {
   prompt: "This is a keep-alive request. Do not perform any work or use tools. Reply with exactly: OK",
@@ -26,8 +26,8 @@ export const Plugin = define({
     })
 
     const scope = yield* Scope.Scope
-    const sessions = new Map<SessionSchema.ID, { last: number; expires: number; settings: typeof defaults }>()
-    const loop: (sessionID: SessionSchema.ID) => Effect.Effect<void> = Effect.fn("WarmingPlugin.loop")(
+    const sessions = new Map<Session.ID, { last: number; expires: number; settings: typeof defaults }>()
+    const loop: (sessionID: Session.ID) => Effect.Effect<void> = Effect.fn("WarmingPlugin.loop")(
       function* (sessionID) {
         const current = sessions.get(sessionID)
         if (!current) return

packages/core/src/pty.ts

@@ -88,233 +88,232 @@ export interface Interface {
 
 export class Service extends Context.Service<Service, Interface>()("@opencode/Pty") {}
 
-const layer = () =>
-  Layer.effect(
-    Service,
-    Effect.gen(function* () {
-      const bus = yield* Bus.Service
-      const location = yield* Location.Service
-      const shell = yield* ShellSelect.Service
-      const context = yield* Effect.context()
-      const runFork = Effect.runForkWith(context)
-      const sessions = new Map<PtyID, Active>()
-      const exitOrder: PtyID[] = []
+const layer = Layer.effect(
+  Service,
+  Effect.gen(function* () {
+    const bus = yield* Bus.Service
+    const location = yield* Location.Service
+    const shell = yield* ShellSelect.Service
+    const context = yield* Effect.context()
+    const runFork = Effect.runForkWith(context)
+    const sessions = new Map<PtyID, Active>()
+    const exitOrder: PtyID[] = []
 
-      function notifyEnd(session: Active, event: { exitCode?: number }) {
-        for (const subscriber of session.subscribers.values()) {
-          if (!subscriber.active) {
-            subscriber.end = event
-            continue
-          }
-          try {
-            subscriber.onEnd(event)
-          } catch {}
+    function notifyEnd(session: Active, event: { exitCode?: number }) {
+      for (const subscriber of session.subscribers.values()) {
+        if (!subscriber.active) {
+          subscriber.end = event
+          continue
         }
-        session.subscribers.clear()
+        try {
+          subscriber.onEnd(event)
+        } catch {}
       }
+      session.subscribers.clear()
+    }
 
-      function teardown(session: Active) {
-        for (const listener of session.listeners) listener.dispose()
-        session.listeners.length = 0
-        if (session.info.status === "running") {
-          try {
-            session.process.kill()
-          } catch {}
-        }
-        notifyEnd(session, {})
+    function teardown(session: Active) {
+      for (const listener of session.listeners) listener.dispose()
+      session.listeners.length = 0
+      if (session.info.status === "running") {
+        try {
+          session.process.kill()
+        } catch {}
       }
+      notifyEnd(session, {})
+    }
 
-      yield* Effect.addFinalizer(() =>
-        Effect.sync(() => {
-          for (const session of sessions.values()) teardown(session)
-          sessions.clear()
-          exitOrder.length = 0
-        }),
-      )
+    yield* Effect.addFinalizer(() =>
+      Effect.sync(() => {
+        for (const session of sessions.values()) teardown(session)
+        sessions.clear()
+        exitOrder.length = 0
+      }),
+    )
 
-      const requireSession = Effect.fn("Pty.requireSession")(function* (id: PtyID) {
-        const session = sessions.get(id)
-        if (!session) return yield* new NotFoundError({ ptyID: id })
-        return session
-      })
+    const requireSession = Effect.fn("Pty.requireSession")(function* (id: PtyID) {
+      const session = sessions.get(id)
+      if (!session) return yield* new NotFoundError({ ptyID: id })
+      return session
+    })
 
-      const removeSession = Effect.fnUntraced(function* (id: PtyID) {
-        const session = sessions.get(id)
-        if (!session) return
-        sessions.delete(id)
-        const index = exitOrder.indexOf(id)
-        if (index !== -1) exitOrder.splice(index, 1)
-        yield* Effect.logInfo("removing session", { id })
-        teardown(session)
-        yield* bus.publish(Pty.Event.Deleted, { id: session.info.id })
-      })
+    const removeSession = Effect.fnUntraced(function* (id: PtyID) {
+      const session = sessions.get(id)
+      if (!session) return
+      sessions.delete(id)
+      const index = exitOrder.indexOf(id)
+      if (index !== -1) exitOrder.splice(index, 1)
+      yield* Effect.logInfo("removing session", { id })
+      teardown(session)
+      yield* bus.publish(Pty.Event.Deleted, { id: session.info.id })
+    })
 
-      const remove = Effect.fn("Pty.remove")(function* (id: PtyID) {
-        yield* requireSession(id)
-        yield* removeSession(id)
-      })
+    const remove = Effect.fn("Pty.remove")(function* (id: PtyID) {
+      yield* requireSession(id)
+      yield* removeSession(id)
+    })
 
-      const list = Effect.fn("Pty.list")(function* () {
-        return Array.from(sessions.values()).map((session) => session.info)
-      })
+    const list = Effect.fn("Pty.list")(function* () {
+      return Array.from(sessions.values()).map((session) => session.info)
+    })
 
-      const get = Effect.fn("Pty.get")(function* (id: PtyID) {
-        return (yield* requireSession(id)).info
-      })
+    const get = Effect.fn("Pty.get")(function* (id: PtyID) {
+      return (yield* requireSession(id)).info
+    })
 
-      const create = Effect.fn("Pty.create")(function* (input: CreateInput) {
-        const id = PtyID.ascending()
-        const command = input.command || (yield* shell.resolve({ priority: "config" }))
-        const args = ShellSelect.login(command) ? [...(input.args ?? []), "-l"] : [...(input.args ?? [])]
-        const cwd = input.cwd || location.directory
-        const env = {
-          ...process.env,
-          ...input.env,
-          TERM: "xterm-256color",
-          OPENCODE_TERMINAL: "1",
-        } as Record<string, string>
-        if (process.platform === "win32") {
-          env.LC_ALL = "C.UTF-8"
-          env.LC_CTYPE = "C.UTF-8"
-          env.LANG = "C.UTF-8"
-        }
-        yield* Effect.logInfo("creating session", { id, cmd: command, args, cwd })
-        const { spawn } = yield* Effect.promise(() => pty())
-        const proc = yield* Effect.sync(() => spawn(command, args, { name: "xterm-256color", cwd, env }))
-        const info: Info = {
-          id,
-          title: input.title || `Terminal ${id.slice(-4)}`,
-          command,
-          args,
-          cwd,
-          status: "running",
-          pid: proc.pid,
-        }
-        const session: Active = {
-          info,
-          process: proc,
-          buffer: "",
-          bufferCursor: 0,
-          cursor: 0,
-          subscribers: new Map(),
-          listeners: [],
-        }
-        sessions.set(id, session)
-        session.listeners.push(
-          proc.onData((chunk) => {
-            session.cursor += chunk.length
-            for (const [token, subscriber] of session.subscribers.entries()) {
-              if (!subscriber.active) {
-                subscriber.pending.push(chunk)
-                continue
-              }
-              try {
-                subscriber.onData(chunk)
-              } catch {
-                session.subscribers.delete(token)
-              }
+    const create = Effect.fn("Pty.create")(function* (input: CreateInput) {
+      const id = PtyID.ascending()
+      const command = input.command || (yield* shell.resolve({ priority: "config" }))
+      const args = ShellSelect.login(command) ? [...(input.args ?? []), "-l"] : [...(input.args ?? [])]
+      const cwd = input.cwd || location.directory
+      const env = {
+        ...process.env,
+        ...input.env,
+        TERM: "xterm-256color",
+        OPENCODE_TERMINAL: "1",
+      } as Record<string, string>
+      if (process.platform === "win32") {
+        env.LC_ALL = "C.UTF-8"
+        env.LC_CTYPE = "C.UTF-8"
+        env.LANG = "C.UTF-8"
+      }
+      yield* Effect.logInfo("creating session", { id, cmd: command, args, cwd })
+      const { spawn } = yield* Effect.promise(() => pty())
+      const proc = yield* Effect.sync(() => spawn(command, args, { name: "xterm-256color", cwd, env }))
+      const info: Info = {
+        id,
+        title: input.title || `Terminal ${id.slice(-4)}`,
+        command,
+        args,
+        cwd,
+        status: "running",
+        pid: proc.pid,
+      }
+      const session: Active = {
+        info,
+        process: proc,
+        buffer: "",
+        bufferCursor: 0,
+        cursor: 0,
+        subscribers: new Map(),
+        listeners: [],
+      }
+      sessions.set(id, session)
+      session.listeners.push(
+        proc.onData((chunk) => {
+          session.cursor += chunk.length
+          for (const [token, subscriber] of session.subscribers.entries()) {
+            if (!subscriber.active) {
+              subscriber.pending.push(chunk)
+              continue
             }
-            session.buffer += chunk
-            if (session.buffer.length <= BUFFER_LIMIT) return
-            const excess = session.buffer.length - BUFFER_LIMIT
-            session.buffer = session.buffer.slice(excess)
-            session.bufferCursor += excess
-          }),
-          proc.onExit(({ exitCode }) => {
-            if (session.info.status === "exited") return
-            session.info.status = "exited"
-            session.info.exitCode = exitCode
-            notifyEnd(session, { exitCode })
-            exitOrder.push(id)
-            runFork(
-              Effect.gen(function* () {
-                yield* Effect.logInfo("session exited", { id, exitCode })
-                yield* bus.publish(Pty.Event.Exited, { id, exitCode })
-                while (exitOrder.length > EXITED_LIMIT) {
-                  const oldest = exitOrder[0]
-                  if (!oldest) break
-                  yield* removeSession(oldest)
-                }
-              }),
-            )
-          }),
-        )
-        yield* bus.publish(Pty.Event.Created, { info })
-        return info
-      })
-
-      const update = Effect.fn("Pty.update")(function* (id: PtyID, input: UpdateInput) {
-        const session = yield* requireSession(id)
-        if (input.title) session.info.title = input.title
-        if (input.size && session.info.status === "running") session.process.resize(input.size.cols, input.size.rows)
-        yield* bus.publish(Pty.Event.Updated, { info: session.info })
-        return session.info
-      })
-
-      const write = Effect.fn("Pty.write")(function* (id: PtyID, data: string) {
-        const session = yield* requireSession(id)
-        if (session.info.status === "running") session.process.write(data)
-      })
-
-      const attach = Effect.fn("Pty.attach")(function* (id: PtyID, input: AttachInput) {
-        const session = yield* requireSession(id)
-        if (session.info.status !== "running") return yield* new ExitedError({ ptyID: id })
-        yield* Effect.logInfo("client attached to session", { id, directory: location.directory })
-        const token = {}
-        const subscriber: Subscriber = {
-          onData: input.onData,
-          onEnd: input.onEnd,
-          active: false,
-          detached: false,
-          pending: [],
-        }
-        session.subscribers.set(token, subscriber)
-        const start = session.bufferCursor
-        const end = session.cursor
-        const from =
-          input.cursor === -1
-            ? end
-            : typeof input.cursor === "number" && Number.isSafeInteger(input.cursor)
-              ? Math.max(0, input.cursor)
-              : 0
-        const replay = (() => {
-          if (!session.buffer || from >= end) return ""
-          const offset = Math.max(0, from - start)
-          if (offset >= session.buffer.length) return ""
-          return session.buffer.slice(offset)
-        })()
-        return {
-          replay,
-          cursor: end,
-          write: (data: string) => {
-            if (session.info.status === "running") session.process.write(data)
-          },
-          activate: () => {
-            if (subscriber.active || subscriber.detached) return
-            subscriber.active = true
             try {
-              for (const chunk of subscriber.pending) subscriber.onData(chunk)
-              subscriber.pending.length = 0
-              if (subscriber.end) subscriber.onEnd(subscriber.end)
+              subscriber.onData(chunk)
             } catch {
               session.subscribers.delete(token)
             }
-          },
-          detach: () => {
-            subscriber.detached = true
-            subscriber.pending.length = 0
-            subscriber.end = undefined
-            session.subscribers.delete(token)
-          },
-        }
-      })
+          }
+          session.buffer += chunk
+          if (session.buffer.length <= BUFFER_LIMIT) return
+          const excess = session.buffer.length - BUFFER_LIMIT
+          session.buffer = session.buffer.slice(excess)
+          session.bufferCursor += excess
+        }),
+        proc.onExit(({ exitCode }) => {
+          if (session.info.status === "exited") return
+          session.info.status = "exited"
+          session.info.exitCode = exitCode
+          notifyEnd(session, { exitCode })
+          exitOrder.push(id)
+          runFork(
+            Effect.gen(function* () {
+              yield* Effect.logInfo("session exited", { id, exitCode })
+              yield* bus.publish(Pty.Event.Exited, { id, exitCode })
+              while (exitOrder.length > EXITED_LIMIT) {
+                const oldest = exitOrder[0]
+                if (!oldest) break
+                yield* removeSession(oldest)
+              }
+            }),
+          )
+        }),
+      )
+      yield* bus.publish(Pty.Event.Created, { info })
+      return info
+    })
 
-      return Service.of({ list, get, create, update, remove, write, attach })
-    }),
-  )
+    const update = Effect.fn("Pty.update")(function* (id: PtyID, input: UpdateInput) {
+      const session = yield* requireSession(id)
+      if (input.title) session.info.title = input.title
+      if (input.size && session.info.status === "running") session.process.resize(input.size.cols, input.size.rows)
+      yield* bus.publish(Pty.Event.Updated, { info: session.info })
+      return session.info
+    })
+
+    const write = Effect.fn("Pty.write")(function* (id: PtyID, data: string) {
+      const session = yield* requireSession(id)
+      if (session.info.status === "running") session.process.write(data)
+    })
+
+    const attach = Effect.fn("Pty.attach")(function* (id: PtyID, input: AttachInput) {
+      const session = yield* requireSession(id)
+      if (session.info.status !== "running") return yield* new ExitedError({ ptyID: id })
+      yield* Effect.logInfo("client attached to session", { id, directory: location.directory })
+      const token = {}
+      const subscriber: Subscriber = {
+        onData: input.onData,
+        onEnd: input.onEnd,
+        active: false,
+        detached: false,
+        pending: [],
+      }
+      session.subscribers.set(token, subscriber)
+      const start = session.bufferCursor
+      const end = session.cursor
+      const from =
+        input.cursor === -1
+          ? end
+          : typeof input.cursor === "number" && Number.isSafeInteger(input.cursor)
+            ? Math.max(0, input.cursor)
+            : 0
+      const replay = (() => {
+        if (!session.buffer || from >= end) return ""
+        const offset = Math.max(0, from - start)
+        if (offset >= session.buffer.length) return ""
+        return session.buffer.slice(offset)
+      })()
+      return {
+        replay,
+        cursor: end,
+        write: (data: string) => {
+          if (session.info.status === "running") session.process.write(data)
+        },
+        activate: () => {
+          if (subscriber.active || subscriber.detached) return
+          subscriber.active = true
+          try {
+            for (const chunk of subscriber.pending) subscriber.onData(chunk)
+            subscriber.pending.length = 0
+            if (subscriber.end) subscriber.onEnd(subscriber.end)
+          } catch {
+            session.subscribers.delete(token)
+          }
+        },
+        detach: () => {
+          subscriber.detached = true
+          subscriber.pending.length = 0
+          subscriber.end = undefined
+          session.subscribers.delete(token)
+        },
+      }
+    })
+
+    return Service.of({ list, get, create, update, remove, write, attach })
+  }),
+)
 
 export const node = makeLocationNode({
   service: Service,
-  layer: layer(),
+  layer,
   deps: [Bus.node, Location.node, ShellSelect.node],
 })

packages/core/src/pty/ticket.ts

@@ -1,6 +1,6 @@
 export * as PtyTicket from "./ticket.js"
 
-import { Workspace } from "../workspace.js"
+import type { Workspace } from "@opencode-ai/schema/workspace"
 import { PtyTicket } from "@opencode-ai/schema/pty-ticket"
 import { PtyID } from "./schema.js"
 import { Cache, Context, Duration, Effect, Layer } from "effect"

packages/core/src/ripgrep.ts

@@ -134,10 +134,9 @@ const layer = Layer.effect(
             }),
             Stream.take(input.limit + 1),
             Stream.runCollect,
-            Effect.map((chunk) => [...chunk]),
           )
           const truncated = rows.length > input.limit
-          if (truncated) return { items: rows.slice(0, input.limit), truncated, partial: false }
+          if (truncated) return rows.slice(0, input.limit)
 
           const code = yield* handle.exitCode
           const stderr = yield* Fiber.join(stderrFiber)
@@ -147,7 +146,7 @@ const layer = Layer.effect(
           if (code !== 0 && code !== 1 && code !== 2) {
             return yield* failure(stderr.trim() || `ripgrep failed with code ${code}`)
           }
-          return { items: code === 1 ? [] : rows, truncated: false, partial: code === 2 }
+          return code === 1 ? [] : rows
         }),
       )
       const abortable = input.signal ? program.pipe(Effect.raceFirst(waitForAbort(input.signal))) : program
@@ -178,7 +177,7 @@ const layer = Layer.effect(
           parse: (line) => Effect.succeed(normalizePath(line)),
         }).pipe(
           Effect.map((result) =>
-            result.items.map((relative) =>
+            result.map((relative) =>
               Entry.make({
                 path: RelativePath.make(relative),
                 type: "file",
@@ -212,10 +211,7 @@ const layer = Layer.effect(
             )
           },
           onItem: input.onEntry,
-        }).pipe(
-          Effect.map((result) => result.items),
-          Effect.catchTag("Ripgrep.InvalidPatternError", (cause) => Effect.fail(failure(cause.message, cause))),
-        ),
+        }).pipe(Effect.catchTag("Ripgrep.InvalidPatternError", (cause) => Effect.fail(failure(cause.message, cause)))),
       grep: (input) =>
         run<RawMatchData>({
           ...input,
@@ -248,7 +244,7 @@ const layer = Layer.effect(
             ),
         }).pipe(
           Effect.map((result) =>
-            result.items.map((match) =>
+            result.map((match) =>
               Match.make({
                 entry: Entry.make({
                   path: RelativePath.make(match.path.text),

packages/core/src/session.ts

@@ -1,7 +1,7 @@
 export * as Session from "./session.js"
 export * from "./session/schema.js"
 
-import { Cause, Effect, Layer, Schema, Context, RcMap, Stream, Scope } from "effect"
+import { Cause, Effect, Fiber, Layer, Schema, Context, RcMap, Stream, Scope } from "effect"
 import { ListAnchor } from "@opencode-ai/schema/session"
 import { and, asc, desc, eq, gt, isNull, like, lt, or, type SQL } from "drizzle-orm"
 import { Project } from "./project.js"
@@ -50,8 +50,7 @@ import { Job } from "./job.js"
 import { Command } from "./command.js"
 import { Shell } from "./shell.js"
 import { Global } from "@opencode-ai/util/global"
-import { Shell as ShellSchema } from "@opencode-ai/schema/shell"
-import { KeyedMutex } from "./effect/keyed-mutex.js"
+import { ShellResult } from "./shell/result.js"
 import { fileURLToPath } from "url"
 import { SessionEnvironment } from "./session/environment.js"
 import { SessionHistory } from "./session/history.js"
@@ -347,8 +346,6 @@ const layer = Layer.effect(
     const jobs = yield* Job.Service
     const environments = yield* SessionEnvironment.Service
     const scope = yield* Scope.Scope
-    const activeShells = new Set<SessionSchema.ID>()
-    const shellLocks = KeyedMutex.makeUnsafe<SessionSchema.ID>()
     const closeTransport = Effect.fn("Session.closeTransport")(function* (session: SessionSchema.Info) {
       const location = Location.Ref.make({
         directory: session.location.directory,
@@ -680,10 +677,7 @@ const layer = Layer.effect(
             // retried payload, metadata, and delivery mode.
             if (admitted.type !== "user" || admitted.sessionID !== input.sessionID)
               return yield* new PromptConflictError({ sessionID: input.sessionID, messageID })
-            if (input.resume !== false) {
-              if (activeShells.has(admitted.sessionID)) return admitted
-              yield* execution.wake(admitted.sessionID)
-            }
+            if (input.resume !== false) yield* execution.wake(admitted.sessionID)
             return admitted
           }),
         ),
@@ -717,60 +711,62 @@ const layer = Layer.effect(
       }),
       shell: Effect.fn("Session.shell")(function* (input) {
         const session = yield* result.get(input.sessionID)
-        yield* shellLocks.withLock(input.sessionID)(
-          Effect.gen(function* () {
-            activeShells.add(input.sessionID)
-            yield* execution.awaitIdle(input.sessionID)
-            const started = yield* Effect.gen(function* () {
-              const plugins = yield* PluginSupervisor.Service
-              yield* plugins.flush
-              const shell = yield* Shell.Service
-              return yield* shell
-                .create({
-                  command: input.command,
-                  cwd: session.location.directory,
-                  timeout: 0,
-                  metadata: { sessionID: input.sessionID },
-                })
-                .pipe(Effect.orDie)
-            }).pipe(Effect.provide(locations.get(session.location)))
-            yield* bus.publish(
-              SessionEvent.Shell.Started,
-              {
-                sessionID: input.sessionID,
-                shell: started,
-              },
-              { id: input.id },
-            )
-            const completed = yield* Effect.gen(function* () {
-              const shell = yield* Shell.Service
-              const terminal = yield* shell.wait(started.id).pipe(
-                Effect.map((info) => ({ info, retained: true as const })),
-                Effect.catchTag("Shell.NotFoundError", () =>
-                  Effect.succeed({ info: synthesizeTerminalShellInfo(started), retained: false as const }),
-                ),
-              )
-              const output = terminal.retained
-                ? yield* shell
-                    .output(started.id, { limit: SHELL_MAX_CAPTURE_BYTES })
-                    .pipe(Effect.catchTag("Shell.NotFoundError", () => Effect.succeed(missingShellOutput())))
-                : missingShellOutput()
-              return { shell: terminal.info, output }
-            }).pipe(Effect.provide(locations.get(session.location)))
-            yield* bus.publish(SessionEvent.Shell.Ended, {
-              sessionID: input.sessionID,
-              shell: completed.shell,
-              output: completed.output,
+        // The server owns completion recording even if the submitting client disconnects.
+        const running = yield* Effect.gen(function* () {
+          // Resolve shell services here without pinning Session events to this Location after a move.
+          const shell = yield* Effect.gen(function* () {
+            const plugins = yield* PluginSupervisor.Service
+            yield* plugins.flush
+            return yield* Shell.Service
+          }).pipe(Effect.provide(locations.get(session.location)))
+          const started = yield* shell
+            .create({
+              command: input.command,
+              cwd: session.location.directory,
+              timeout: 0,
+              metadata: { sessionID: input.sessionID, background: true },
             })
-          }).pipe(
-            Effect.ensuring(
-              Effect.gen(function* () {
-                activeShells.delete(input.sessionID)
-                yield* execution.wake(input.sessionID)
-              }),
-            ),
-          ),
-        )
+            .pipe(
+              Effect.tapError((error) =>
+                result.synthetic({
+                  sessionID: input.sessionID,
+                  text: `User shell command failed to start:\n${input.command}\n\n${error.message}`,
+                  description: input.command,
+                  metadata: { source: "shell", state: "error" },
+                  resume: false,
+                }),
+              ),
+              Effect.orDie,
+            )
+          yield* bus.publish(
+            SessionEvent.Shell.Started,
+            {
+              sessionID: input.sessionID,
+              shell: started,
+            },
+            { id: input.id },
+          )
+          const terminal = yield* shell.result(started)
+          const preview = yield* shell
+            .output(started.id, { limit: SHELL_MAX_CAPTURE_BYTES })
+            .pipe(Effect.catchTag("Shell.NotFoundError", () => Effect.succeed(ShellResult.unavailable)))
+          yield* bus.publish(SessionEvent.Shell.Ended, {
+            sessionID: input.sessionID,
+            shell: terminal.info,
+            output: preview,
+          })
+          yield* result
+            .synthetic({
+              ...ShellResult.userNotification(terminal),
+              sessionID: input.sessionID,
+              resume: false,
+            })
+            .pipe(
+              Effect.catchTag("Session.NotFoundError", () => Effect.void),
+              Effect.orDie,
+            )
+        }).pipe(Effect.forkIn(scope, { startImmediately: true }))
+        yield* Fiber.join(running)
       }),
       skill: Effect.fn("Session.skill")(function* (input) {
         const session = yield* result.get(input.sessionID)
@@ -994,26 +990,6 @@ const layer = Layer.effect(
   }),
 )
 
-function missingShellOutput() {
-  const output = "Shell command output is no longer available."
-  return {
-    output,
-    cursor: Buffer.byteLength(output),
-    size: Buffer.byteLength(output),
-    truncated: false,
-  }
-}
-
-function synthesizeTerminalShellInfo(started: ShellSchema.Info): ShellSchema.Info {
-  return {
-    ...started,
-    // The Shell record was removed before waiters could observe it; publish a terminal
-    // boundary instead of leaving the Session shell message permanently running.
-    status: "killed",
-    time: { ...started.time, completed: Date.now() },
-  }
-}
-
 const preparePrompt = Effect.fn("Session.preparePrompt")(function* (
   request: Parameters<Interface["prompt"]>[0],
   messageID: SessionMessage.ID,

packages/core/src/session/compaction.ts

@@ -1,6 +1,7 @@
 export * as SessionCompaction from "./compaction.js"
 
 import { LLMClient, LLMEvent, Message } from "@opencode-ai/ai"
+import { Agent } from "@opencode-ai/schema/agent"
 import { SessionError } from "@opencode-ai/schema/session-error"
 import { Context, Effect, Layer, Stream } from "effect"
 import { Bus } from "../bus.js"
@@ -15,7 +16,6 @@ import { SessionSchema } from "./schema.js"
 import { toSessionError } from "./to-session-error.js"
 import { Token } from "../util/token.js"
 import { SessionUsage } from "./usage.js"
-import { Agent } from "../agent.js"
 import { State } from "../state.js"
 
 const DEFAULT_BUFFER = 20_000
@@ -164,7 +164,9 @@ const serialize = (message: SessionMessage.Info) => {
   if (message.type === "synthetic") return `[Synthetic context]: ${message.text}`
   if (message.type === "skill") return `[Skill activated: ${message.name}]\n${message.text}`
   if (message.type === "shell")
-    return `[Shell]: ${message.command}\n${truncateToolOutput(message.output?.output ?? "")}`
+    return message.metadata?.background === true
+      ? ""
+      : `[Shell]: ${message.command}\n${truncateToolOutput(message.output?.output ?? "")}`
   return ""
 }
 
@@ -393,26 +395,27 @@ export const layer = Layer.effect(
           error: { type: "compaction.unavailable", message: "Nothing to compact yet" },
           inputID: input.inputID,
         })
-      const resolved = yield* input.resolveModel(input.session).pipe(
-        Effect.catch((cause) =>
-          failed({
-            sessionID: input.session.id,
-            reason: "manual",
-            error: toSessionError(cause),
-            inputID: input.inputID,
-          }),
-        ),
+      return yield* input.resolveModel(input.session).pipe(
+        Effect.matchEffect({
+          onFailure: (cause) =>
+            failed({
+              sessionID: input.session.id,
+              reason: "manual",
+              error: toSessionError(cause),
+              inputID: input.inputID,
+            }),
+          onSuccess: (resolved) =>
+            execute({
+              session: input.session,
+              resolved,
+              prepare: input.prepare,
+              reason: "manual",
+              inputID: input.inputID,
+              started: input.started,
+              ...content,
+            }),
+        }),
       )
-      if ("status" in resolved) return resolved
-      return yield* execute({
-        session: input.session,
-        resolved,
-        prepare: input.prepare,
-        reason: "manual",
-        inputID: input.inputID,
-        started: input.started,
-        ...content,
-      })
     })
     return Service.of({
       transform: state.transform,

packages/core/src/session/context.ts

@@ -1,5 +1,6 @@
 export * as SessionContext from "./context.js"
 
+import { Model } from "@opencode-ai/schema/model"
 import { Context, Effect, Layer } from "effect"
 import { Agent } from "../agent.js"
 import { Catalog } from "../catalog.js"
@@ -12,7 +13,6 @@ import { InstructionBuiltIns } from "../instructions/builtins.js"
 import { Location } from "../location.js"
 import { McpInstructions } from "../mcp/instructions.js"
 import { McpTool } from "../tool/mcp.js"
-import { Model } from "../model.js"
 import { PluginSupervisor } from "../plugin/supervisor.js"
 import { ReferenceInstructions } from "../reference/instructions.js"
 import { SkillInstructions } from "../skill/instructions.js"

packages/core/src/session/execution/restart.ts

@@ -9,6 +9,8 @@ import { SessionEvent } from "../event.js"
 import { SessionExecution } from "../execution.js"
 import { SessionSchema } from "../schema.js"
 import { SessionStore } from "../store.js"
+import { ShellResult } from "../../shell/result.js"
+import { SubagentCompletion } from "../subagent-completion.js"
 
 const CONTINUE_AFTER_SERVER_RESTART =
   "The server restarted while you were working. Continue from where you left off without repeating completed work."
@@ -115,13 +117,13 @@ export const layer = (options?: Options) =>
             id: background.notificationID,
             sessionID: recovery.sessionID,
             description: recovery.command,
-            text: `<shell id="${background.id}" state="${state}" command="${recovery.command}">\n${text}\n</shell>`,
-            metadata: {
-              source: "shell",
+            ...ShellResult.notification({
               jobID: background.id,
               shellID: recovery.shellID,
+              command: recovery.command,
               state,
-            },
+              text,
+            }),
             ...(suspended.has(recovery.sessionID) ? { resume: false } : {}),
           })
           .pipe(
@@ -143,29 +145,12 @@ export const layer = (options?: Options) =>
         }
 
         const notify = Effect.fnUntraced(function* (result: Pick<Job.Background, "status" | "output" | "error">) {
-          if (result.status === "running") return
-          const text =
-            result.status === "completed"
-              ? (result.output ?? "Subagent completed without a text response.")
-              : result.status === "error"
-                ? (result.error ?? "Subagent failed")
-                : "Subagent cancelled"
-          yield* sessions
-            .synthetic({
-              id: background.notificationID,
-              sessionID: recovery.parentSessionID,
-              ...(suspended.has(recovery.parentSessionID) ? { resume: false } : {}),
-              description: recovery.description,
-              text: `<subagent sessionID="${recovery.childSessionID}" state="${result.status}" description="${recovery.description}">\n${text}\n</subagent>`,
-              metadata: {
-                source: "subagent",
-                childID: recovery.childSessionID,
-                agent: recovery.agent,
-                state: result.status,
-              },
-            })
-            .pipe(Effect.orDie)
-          yield* jobs.completeBackground(background.notificationID)
+          yield* SubagentCompletion.deliver(sessions, jobs, {
+            ...result,
+            recovery,
+            notificationID: background.notificationID,
+            resume: suspended.has(recovery.parentSessionID) ? false : undefined,
+          }).pipe(Effect.orDie)
         })
 
         if (background.status !== "running") {

packages/core/src/session/instruction-entry.ts

@@ -131,11 +131,7 @@ const layer = Layer.effect(
       return (yield* rows(sessionID, false)).map((row) => ({ key: row.key, value: row.value }))
     })
 
-    const put = Effect.fn("InstructionEntry.put")(function* (input: {
-      readonly sessionID: SessionSchema.ID
-      readonly key: Key
-      readonly value: Schema.Json
-    }) {
+    const put = Effect.fn("InstructionEntry.put")(function* (input: Parameters<Interface["put"]>[0]) {
       const actualBytes = Buffer.byteLength(JSON.stringify(input.value), "utf8")
       if (actualBytes > MaxValueBytes)
         yield* new ValueTooLargeError({
@@ -159,10 +155,7 @@ const layer = Layer.effect(
         .pipe(Effect.orDie)
     })
 
-    const remove = Effect.fn("InstructionEntry.remove")(function* (input: {
-      readonly sessionID: SessionSchema.ID
-      readonly key: Key
-    }) {
+    const remove = Effect.fn("InstructionEntry.remove")(function* (input: Parameters<Interface["remove"]>[0]) {
       yield* db
         .update(InstructionEntryTable)
         .set({ value: null, removed: true, time_updated: Date.now() })

packages/core/src/session/instructions.ts

@@ -1,7 +1,7 @@
 export * as SessionInstructions from "./instructions.js"
 
 import { relative } from "path"
-import { Context, DateTime, Effect, Layer, Option, Ref, Schema } from "effect"
+import { Context, Effect, Layer, Option, Ref, Schema } from "effect"
 import { makeLocationNode } from "@opencode-ai/util/effect/app-node"
 import { Bus } from "../bus.js"
 import { FSUtil } from "@opencode-ai/util/fs-util"
@@ -43,10 +43,7 @@ const layer = Layer.effect(
     // are re-discovered and re-injected instead of staying silently lost.
     const inFlight = yield* Ref.make<Map<SessionSchema.ID, Set<string>>>(new Map())
 
-    const load = Effect.fn("SessionInstructions.load")(function* (input: {
-      readonly sessionID: SessionSchema.ID
-      readonly paths: ReadonlyArray<string>
-    }) {
+    const load = Effect.fn("SessionInstructions.load")(function* (input: Parameters<Interface["load"]>[0]) {
       const claimed = yield* Ref.modify(inFlight, (map) => {
         const existing = map.get(input.sessionID) ?? new Set<string>()
         const newlyClaimed = input.paths.filter((path) => !existing.has(path))

packages/core/src/session/message-updater.ts

@@ -169,7 +169,8 @@ export function update(adapter: Adapter, event: SessionEvent.DurableEvent) {
           SessionMessage.Shell.make({
             id: SessionMessage.ID.fromEvent(event.id),
             type: "shell",
-            metadata: event.metadata,
+            metadata:
+              event.data.shell.metadata.background === true ? { ...event.metadata, background: true } : event.metadata,
             shellID: event.data.shell.id,
             command: event.data.shell.command,
             status: event.data.shell.status,

packages/core/src/session/model-request.ts

@@ -2,12 +2,13 @@ export * as SessionModelRequest from "./model-request.js"
 
 import { HttpOptions, LanguageModel, LLM, LLMRequest, Message, SystemPart } from "@opencode-ai/ai"
 import type { StreamOptions } from "@opencode-ai/ai/route"
+import type { Agent } from "@opencode-ai/schema/agent"
+import type { Model } from "@opencode-ai/schema/model"
 import type { Content } from "@opencode-ai/schema/tool"
 import { Cause, Config, Context, Effect, Layer, Result, Stream } from "effect"
 import { HttpClientRequest, HttpClientResponse } from "effect/unstable/http"
 import { makeLocationNode } from "@opencode-ai/util/effect/app-node"
 import { App } from "../app.js"
-import { Model } from "../model.js"
 import { Permission } from "../permission.js"
 import { PluginHooks } from "../plugin/hooks.js"
 import { QuestionTool } from "../tool/plugin/question.js"
@@ -18,7 +19,6 @@ import { SessionSchema } from "./schema.js"
 import { SessionSystemPrompt } from "./system-prompt.js"
 import { toLLMMessages } from "./runner/to-llm-message.js"
 import type { SessionMessage } from "./message.js"
-import type { Agent } from "../agent.js"
 
 const IMAGE_BYTES_TRIGGER = 25 * 1024 * 1024 // 25 MiB
 const IMAGE_BYTES_TARGET = 15 * 1024 * 1024 // 15 MiB
@@ -48,6 +48,7 @@ const declineDefect = (cause: Cause.Cause<Tool.Error>) => {
 export interface Prepared {
   readonly request: LLMRequest
   readonly options: StreamOptions
+  readonly retry: (event: PluginHooks.Domains["session"]["retry"]) => Effect.Effect<void>
   /**
    * One request-scoped execution operation. Unknown and hook-removed calls
    * fail individually through the same seam.
@@ -364,9 +365,11 @@ export const layer = Layer.effect(
         tools
           .execute({ ...input, definitions: hooked })
           .pipe(Effect.catchCauseFilter(declineDefect, (decline) => Effect.fail(decline)))
+      const retry: Prepared["retry"] = (event) => hooks.trigger("session", "retry", event).pipe(Effect.asVoid)
       return {
         request,
         options,
+        retry,
         executeTool,
       }
     })

packages/core/src/session/runner/llm.ts

@@ -1,7 +1,7 @@
 export * as SessionRunnerLLM from "./llm.js"
 
 import { Message } from "@opencode-ai/ai"
-import { Cause, Effect, Exit, FiberMap, Layer, Pull, Schedule } from "effect"
+import { Cause, Effect, Exit, FiberMap, Layer } from "effect"
 import { Database } from "../../database/database.js"
 import { Bus } from "../../bus.js"
 import { InstructionState } from "../instruction-state.js"
@@ -15,7 +15,7 @@ import { SessionMessage } from "../message.js"
 import { SessionSchema } from "../schema.js"
 import { SessionStore } from "../store.js"
 import { SessionTitle } from "../title.js"
-import { DrainResult, Service, type Continuation } from "./index.js"
+import { DrainResult, Service, type Interface } from "./index.js"
 import { Snapshot } from "../../snapshot.js"
 import { makeLocationNode } from "@opencode-ai/util/effect/app-node"
 import { llmClient } from "../../effect/app-node-platform.js"
@@ -44,12 +44,7 @@ const layer = Layer.effect(
     // Title generation starts once input is visible and must not delay model execution.
     const titles = yield* FiberMap.make<SessionSchema.ID, void, never>()
 
-    const drain = Effect.fn("SessionRunner.drain")(function* (input: {
-      readonly sessionID: SessionSchema.ID
-      readonly force: boolean
-      readonly continuation?: Continuation
-      readonly promotable?: SessionInbox.Promotable
-    }) {
+    const drain = Effect.fn("SessionRunner.drain")(function* (input: Parameters<Interface["drain"]>[0]) {
       const sessionID = input.sessionID
       let force = input.force
       let continuing = input.continuation !== undefined
@@ -176,7 +171,7 @@ const layer = Layer.effect(
     const runStep = Effect.fn("SessionRunner.runStep")(function* (first: SessionContext.Loaded, step: number) {
       const sessionID = first.session.id
       let assistantMessageID = SessionMessage.ID.create()
-      const retry = yield* Schedule.toStepWithSleep(SessionRunnerRetry.schedule(bus, sessionID))
+      const retry = yield* SessionRunnerRetry.make(bus, sessionID)
       let initial: SessionContext.Loaded | undefined = first
       let recoverOverflow = true
       let recoverContinuation = true
@@ -222,6 +217,15 @@ const layer = Layer.effect(
           agent: loaded.agent.id,
           model: loaded.model,
           prepared,
+          retry: (cause, error, proposed) =>
+            retry.decide({
+              cause,
+              error,
+              agent: loaded.agent.id,
+              model: loaded.model.ref,
+              hook: prepared.retry,
+              retry: proposed,
+            }),
           recoverContinuation,
           recoverOverflow: Effect.suspend(() =>
             recoverOverflow && compaction.enabled()
@@ -232,18 +236,17 @@ const layer = Layer.effect(
         const completed = yield* SessionStep.Outcome.$match(outcome, {
           Completed: (outcome) => Effect.succeed(outcome.needsContinuation),
           Retry: (outcome) =>
-            retry({ cause: outcome.cause, error: outcome.error, assistantMessageID }).pipe(
-              Pull.catchDone(() =>
-                bus
-                  .publish(SessionEvent.Step.Failed, { sessionID, assistantMessageID, error: outcome.error })
-                  .pipe(Effect.andThen(outcome.cause)),
-              ),
-              Effect.asVoid,
-            ),
+            retry.wait({
+              decision: outcome.decision,
+              error: outcome.error,
+              assistantMessageID,
+            }),
           Continue: Effect.fnUntraced(function* (outcome) {
-            yield* retry({ cause: outcome.cause, error: outcome.error, assistantMessageID }).pipe(
-              Pull.catchDone(() => outcome.cause),
-            )
+            yield* retry.wait({
+              decision: outcome.decision,
+              error: outcome.error,
+              assistantMessageID,
+            })
             yield* bus.publish(SessionEvent.Synthetic, { sessionID, text: CONTINUE_AFTER_INCOMPLETE_STREAM })
             assistantMessageID = SessionMessage.ID.create()
           }),

packages/core/src/session/runner/model.ts

@@ -2,10 +2,10 @@ export * as SessionRunnerModel from "./model.js"
 
 import { makeLocationNode } from "@opencode-ai/util/effect/app-node"
 import { LanguageModel } from "@opencode-ai/ai"
+import { Model } from "@opencode-ai/schema/model"
+import { Provider } from "@opencode-ai/schema/provider"
 import { Context, Effect, Layer, Schema } from "effect"
 import { ModelResolver } from "../../model-resolver.js"
-import { Capabilities, ID, Info, Ref, VariantID } from "../../model.js"
-import { Provider } from "../../provider.js"
 import { SessionSchema } from "../schema.js"
 
 export class ModelNotSelectedError extends Schema.TaggedError<ModelNotSelectedError>()(
@@ -19,7 +19,7 @@ export class ModelNotSelectedError extends Schema.TaggedError<ModelNotSelectedEr
 
 export class ModelUnavailableError extends Schema.TaggedError<ModelUnavailableError>()(
   "SessionRunnerModel.ModelUnavailableError",
-  { providerID: Provider.ID, modelID: ID },
+  { providerID: Provider.ID, modelID: Model.ID },
 ) {
   override get message() {
     if (this.providerID === "azure-cognitive-services")
@@ -43,7 +43,7 @@ export interface Interface {
   /** Availability is sampled lazily for each explicitly selected model resolution. */
   readonly resolve: (
     session: SessionSchema.Info,
-    available: () => Effect.Effect<ReadonlyArray<Info>>,
+    available: () => Effect.Effect<ReadonlyArray<Model.Info>>,
   ) => Effect.Effect<Resolved, Error>
 }
 
@@ -53,15 +53,15 @@ export class Service extends Context.Service<Service, Interface>()("@opencode/Se
 export const resolved = (
   model: LanguageModel,
   options: {
-    readonly capabilities: Capabilities
-    readonly variant?: VariantID
-    readonly cost: Info["cost"]
-    readonly limit: Info["limit"]
+    readonly capabilities: Model.Capabilities
+    readonly variant?: Model.VariantID
+    readonly cost: Model.Info["cost"]
+    readonly limit: Model.Info["limit"]
   },
 ): Resolved => ({
   model,
-  ref: Ref.make({
-    id: ID.make(model.id),
+  ref: Model.Ref.make({
+    id: Model.ID.make(model.id),
     providerID: Provider.ID.make(model.provider),
     ...(options.variant === undefined ? {} : { variant: options.variant }),
   }),

packages/core/src/session/runner/publish-llm-event.ts

@@ -1,15 +1,16 @@
 import { type LLMEvent, type ProviderMetadata, type ToolResultValue } from "@opencode-ai/ai"
+import type { Agent } from "@opencode-ai/schema/agent"
+import type { Model } from "@opencode-ai/schema/model"
+import type { RelativePath } from "@opencode-ai/schema/schema"
+import type { Snapshot } from "@opencode-ai/schema/snapshot"
 import { Clock, Effect, Iterable } from "effect"
+import { isArrayNonEmpty, isReadonlyArrayNonEmpty } from "effect/Array"
 import { Bus } from "../../bus.js"
-import { Model } from "../../model.js"
 import { SessionEvent } from "../event.js"
 import { SessionMessage } from "../message.js"
 import { SessionSchema } from "../schema.js"
 import { SessionError } from "@opencode-ai/schema/session-error"
 import { Money } from "@opencode-ai/schema/money"
-import { Agent } from "../../agent.js"
-import { Snapshot } from "../../snapshot.js"
-import { RelativePath } from "../../schema.js"
 import { SessionUsage } from "../usage.js"
 import { Tool } from "@opencode-ai/schema/tool"
 
@@ -45,9 +46,6 @@ export interface StepRecord {
 /** Derives canonical model content from a provider-hosted tool result. */
 type NonEmptyContent = readonly [Tool.Content, ...Tool.Content[]]
 
-const nonEmpty = (content: ReadonlyArray<Tool.Content>): NonEmptyContent | undefined =>
-  content.length > 0 ? (content as NonEmptyContent) : undefined
-
 const stringify = (value: unknown) => {
   if (typeof value === "string") return value
   try {
@@ -58,10 +56,7 @@ const stringify = (value: unknown) => {
 }
 
 const hostedContent = (result: ToolResultValue): NonEmptyContent => {
-  if (result.type === "content") {
-    const content = nonEmpty(result.value)
-    if (content !== undefined) return content
-  }
+  if (result.type === "content" && isReadonlyArrayNonEmpty(result.value)) return result.value
   return [{ type: "text", text: stringify(result.value) }]
 }
 
@@ -72,7 +67,9 @@ const hostedContent = (result: ToolResultValue): NonEmptyContent => {
  * concurrently without a lock. Two rules keep that safe, and every method must preserve
  * them. (1) Commit state marks synchronously before the first await: never a yield
  * between a check (`tool.settled`, `stepStarted`, ...) and its mark, so check-and-mark
- * stays atomic under cooperative scheduling. (2) Never require a cross-source event
+ * stays atomic under cooperative scheduling. Provider-event publication remains
+ * uninterruptible through its writes so cancellation cannot strand a mark without
+ * its durable event. (2) Never require a cross-source event
  * order: each publishing fiber is sequential, so per-source order holds by construction,
  * and consumers fold by id/ordinal rather than global position.
  */
@@ -533,7 +530,7 @@ export const createLLMEventPublisher = (bus: Pick<Bus.Interface, "publish">, inp
         yield* failAssistant({ type: "provider.unknown", message: event.message })
         return
     }
-  })
+  }, Effect.uninterruptible)
 
   const publishTraced = Effect.fn("SessionRunner.publishLLMEvent")(publish)
 
@@ -563,12 +560,12 @@ export const createLLMEventPublisher = (bus: Pick<Bus.Interface, "publish">, inp
         : result.content === undefined
           ? []
           : [...result.content]
-    if (content.length === 0) return yield* Effect.die(new Error(`Tool execution has no content: ${id}`))
+    if (!isArrayNonEmpty(content)) return yield* Effect.die(new Error(`Tool execution has no content: ${id}`))
     yield* bus.publish(SessionEvent.Tool.Success, {
       sessionID: input.sessionID,
       assistantMessageID,
       id,
-      content: [content[0], ...content.slice(1)],
+      content,
       ...(result.metadata === undefined ? {} : { metadata: result.metadata }),
       executed: tool.providerExecuted,
     })

packages/core/src/session/runner/retry.ts

@@ -1,17 +1,29 @@
 export * as SessionRunnerRetry from "./retry.js"
 
 import { AIError } from "@opencode-ai/ai"
+import { Agent } from "@opencode-ai/schema/agent"
+import { Model } from "@opencode-ai/schema/model"
 import { SessionError } from "@opencode-ai/schema/session-error"
-import { Duration, Effect, Schedule } from "effect"
+import { Clock, Duration, Effect, Pull, Schedule } from "effect"
 import { Bus } from "../../bus.js"
+import type { PluginHooks } from "../../plugin/hooks.js"
 import { SessionEvent } from "../event.js"
 import { SessionMessage } from "../message.js"
 import { SessionSchema } from "../schema.js"
 
-export interface Input {
+interface Input {
   readonly cause: AIError
   readonly error: SessionError.Error
-  readonly assistantMessageID: SessionMessage.ID
+  readonly agent: Agent.ID
+  readonly model: Model.Ref
+  readonly hook: (event: PluginHooks.Domains["session"]["retry"]) => Effect.Effect<void>
+  readonly retry: boolean
+}
+
+export interface Decision {
+  readonly retry: true
+  readonly attempt: number
+  readonly delay: number
 }
 
 export function isRetryable(error: AIError) {
@@ -55,22 +67,58 @@ const retryAfter = (input: Input) => {
   return undefined
 }
 
-export const schedule = (bus: Bus.Interface, sessionID: SessionSchema.ID) =>
-  Schedule.max([Schedule.exponential("2 seconds"), Schedule.recurs(4)]).pipe(
-    Schedule.jittered,
-    Schedule.setInputType<Input>(),
-    Schedule.modifyDelay(({ input, duration: delay }) => {
-      const minimum = retryAfter(input)
-      const duration = minimum === undefined ? delay : Duration.max(delay, Duration.millis(minimum))
-      return Effect.succeed(Duration.millis(Math.ceil(Duration.toMillis(duration))))
-    }),
-    Schedule.tap((metadata) =>
-      bus.publish(SessionEvent.RetryScheduled, {
-        sessionID,
-        assistantMessageID: metadata.input.assistantMessageID,
-        attempt: metadata.attempt + 1,
-        at: metadata.now + Duration.toMillis(metadata.duration),
-        error: metadata.input.error,
-      }),
-    ),
-  )
+const schedule = Schedule.max([Schedule.exponential("2 seconds"), Schedule.recurs(4)]).pipe(
+  Schedule.jittered,
+  Schedule.setInputType<Input>(),
+  Schedule.modifyDelay(({ input, duration: delay }) => {
+    const minimum = retryAfter(input)
+    const duration = minimum === undefined ? delay : Duration.max(delay, Duration.millis(minimum))
+    return Effect.succeed(Duration.millis(Math.ceil(Duration.toMillis(duration))))
+  }),
+)
+
+export const make = (bus: Bus.Interface, sessionID: SessionSchema.ID) =>
+  Effect.gen(function* () {
+    const step = yield* Schedule.toStep(schedule)
+    let attempt = 1
+    const decide = (input: Input) =>
+      Effect.gen(function* () {
+        const now = yield* Clock.currentTimeMillis
+        const next = yield* step(now, input).pipe(Pull.catchDone(() => Effect.succeed(undefined)))
+        if (!next) return { retry: false as const }
+        const [, duration] = next
+        attempt++
+        const delay = Math.ceil(Duration.toMillis(duration))
+        const event: PluginHooks.Domains["session"]["retry"] = {
+          sessionID,
+          agent: input.agent,
+          model: input.model,
+          error: input.error,
+          attempt,
+          decision: input.retry ? { retry: true, delay } : { retry: false },
+        }
+        yield* input.hook(event)
+        if (!event.decision.retry) return event.decision
+        const normalized =
+          Number.isFinite(event.decision.delay) && event.decision.delay >= 0 ? Math.ceil(event.decision.delay) : delay
+        return { retry: true as const, attempt, delay: normalized }
+      })
+    const wait = (input: {
+      readonly decision: Decision
+      readonly assistantMessageID: SessionMessage.ID
+      readonly error: SessionError.Error
+    }) =>
+      Effect.gen(function* () {
+        const scheduled = yield* Clock.currentTimeMillis
+        yield* bus.publish(SessionEvent.RetryScheduled, {
+          sessionID,
+          assistantMessageID: input.assistantMessageID,
+          attempt: input.decision.attempt,
+          at: scheduled + input.decision.delay,
+          error: input.error,
+        })
+        const remaining = Math.max(0, scheduled + input.decision.delay - (yield* Clock.currentTimeMillis))
+        yield* Effect.sleep(Duration.millis(remaining))
+      })
+    return { decide, wait }
+  })