refactor(codemode): check the Headers receiver before calling the host

test(codemode): keep only the Headers WPT cases that exercise the runtime
fix(codemode): let Headers methods report a bad receiver
2026-09-16 22:06:23 +00:00 · 2026-09-16 14:16:08 -05:00 · 2026-09-16 13:19:46 -05:00 · 2026-09-16 13:19:46 -05:00 · 2026-09-16 13:19:46 -05:00 · 2026-09-16 13:19:46 -05:00
103 changed files with 950 additions and 849 deletions
@@ -32,7 +32,7 @@
    },
    "packages/ai": {
      "name": "@opencode/ai",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@aws-sdk/credential-providers": "3.1057.0",
        "@opencode/schema": "workspace:*",
@@ -54,7 +54,7 @@
    },
    "packages/app": {
      "name": "@opencode/app",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@corvu/drawer": "catalog:",
        "@dnd-kit/abstract": "0.5.0",
@@ -113,7 +113,7 @@
    },
    "packages/cli": {
      "name": "@opencode/cli",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "bin": {
        "opencode2": "./bin/opencode2.cjs",
      },
@@ -177,7 +177,7 @@
    },
    "packages/client": {
      "name": "@opencode/client",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/protocol": "workspace:*",
        "@opencode/schema": "workspace:*",
@@ -203,7 +203,7 @@
    },
    "packages/codemode": {
      "name": "@opencode/codemode",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "acorn": "8.15.0",
        "effect": "catalog:",
@@ -217,7 +217,7 @@
    },
    "packages/console/app": {
      "name": "@opencode/console-app",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@cloudflare/vite-plugin": "1.15.2",
        "@ibm/plex": "6.4.1",
@@ -253,7 +253,7 @@
    },
    "packages/console/core": {
      "name": "@opencode/console-core",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@aws-sdk/client-sts": "3.782.0",
        "@jsx-email/render": "1.1.1",
@@ -280,7 +280,7 @@
    },
    "packages/console/function": {
      "name": "@opencode/console-function",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@openauthjs/openauth": "0.0.0-20250322224806",
        "@opencode/console-core": "workspace:*",
@@ -297,7 +297,7 @@
    },
    "packages/console/mail": {
      "name": "@opencode/console-mail",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@jsx-email/all": "2.2.3",
        "@jsx-email/cli": "1.4.3",
@@ -321,7 +321,7 @@
    },
    "packages/console/support": {
      "name": "@opencode/console-support",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@cloudflare/vite-plugin": "1.15.2",
        "@opencode/console-core": "workspace:*",
@@ -341,7 +341,7 @@
    },
    "packages/core": {
      "name": "@opencode/core",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@ai-sdk/cohere": "3.0.27",
        "@ai-sdk/gateway": "3.0.104",
@@ -409,7 +409,7 @@
    },
    "packages/desktop": {
      "name": "@opencode/desktop",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@zip.js/zip.js": "2.7.62",
        "electron-context-menu": "4.1.2",
@@ -461,7 +461,7 @@
    },
    "packages/enterprise": {
      "name": "@opencode/enterprise",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@hono/standard-validator": "catalog:",
        "@opencode-ai/sdk": "1.18.21",
@@ -498,7 +498,7 @@
    },
    "packages/function": {
      "name": "@opencode/function",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@octokit/auth-app": "8.0.1",
        "@octokit/rest": "catalog:",
@@ -514,7 +514,7 @@
    },
    "packages/http-recorder": {
      "name": "@opencode/http-recorder",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@effect/platform-node-shared": "4.0.0-rc.112",
      },
@@ -533,7 +533,7 @@
    },
    "packages/httpapi-codegen": {
      "name": "@opencode/httpapi-codegen",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "effect": "catalog:",
        "prettier": "3.6.2",
@@ -546,7 +546,7 @@
    },
    "packages/latex": {
      "name": "@opencode/latex",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/plugin": "workspace:*",
        "@opentui/core": "catalog:",
@@ -560,7 +560,7 @@
    },
    "packages/merman": {
      "name": "@opencode/merman",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/plugin": "workspace:*",
        "@opentui/core": "catalog:",
@@ -575,7 +575,7 @@
    },
    "packages/plugin": {
      "name": "@opencode/plugin",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@ai-sdk/provider": "3.0.8",
        "@opencode/ai": "workspace:*",
@@ -614,7 +614,7 @@
    },
    "packages/plugin-browser": {
      "name": "@opencode/plugin-browser",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/plugin": "workspace:*",
        "@opencode/schema": "workspace:*",
@@ -644,7 +644,7 @@
    },
    "packages/protocol": {
      "name": "@opencode/protocol",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/schema": "workspace:*",
        "effect": "catalog:",
@@ -659,7 +659,7 @@
    },
    "packages/schema": {
      "name": "@opencode/schema",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@standard-schema/spec": "catalog:",
        "effect": "catalog:",
@@ -683,7 +683,7 @@
    },
    "packages/sdk": {
      "name": "@opencode/sdk",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/client": "workspace:*",
        "@opencode/core": "workspace:*",
@@ -704,7 +704,7 @@
    },
    "packages/server": {
      "name": "@opencode/server",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@effect/platform-node": "catalog:",
        "@effect/platform-node-shared": "catalog:",
@@ -726,7 +726,7 @@
    },
    "packages/session-ui": {
      "name": "@opencode/session-ui",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@kobalte/core": "catalog:",
        "@opencode/client": "workspace:*",
@@ -761,7 +761,7 @@
    },
    "packages/simulation": {
      "name": "@opencode/simulation",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/ai": "workspace:*",
        "@opencode/core": "workspace:*",
@@ -781,7 +781,7 @@
    },
    "packages/stats/app": {
      "name": "@opencode/stats-app",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@ibm/plex": "6.4.1",
        "@kobalte/core": "catalog:",
@@ -815,7 +815,7 @@
    },
    "packages/stats/core": {
      "name": "@opencode/stats-core",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@aws-sdk/client-athena": "3.933.0",
        "@planetscale/database": "1.19.0",
@@ -834,7 +834,7 @@
    },
    "packages/stats/server": {
      "name": "@opencode/stats-server",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@aws-sdk/client-firehose": "3.933.0",
        "@effect/platform-node": "catalog:",
@@ -880,7 +880,7 @@
    },
    "packages/theme": {
      "name": "@opencode/theme",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opentui/core": "catalog:",
        "effect": "catalog:",
@@ -894,7 +894,7 @@
    },
    "packages/tui": {
      "name": "@opencode/tui",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/client": "workspace:*",
        "@opencode/core": "workspace:*",
@@ -929,7 +929,7 @@
    },
    "packages/ui": {
      "name": "@opencode/ui",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@kobalte/core": "catalog:",
        "@pierre/diffs": "catalog:",
@@ -964,7 +964,7 @@
    },
    "packages/util": {
      "name": "@opencode/util",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@effect/opentelemetry": "catalog:",
        "@effect/platform-node": "catalog:",
@@ -997,7 +997,7 @@
    },
    "packages/web": {
      "name": "@opencode/web",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@astrojs/cloudflare": "12.6.3",
        "@astrojs/markdown-remark": "6.3.1",
@@ -1038,7 +1038,7 @@
    },
    "services/update": {
      "name": "@opencode/update",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "jose": "6.0.11",
        "semver": "catalog:",
@@ -2,7 +2,7 @@
  "$schema": "https://json.schemastore.org/package.json",
  "name": "opencode",
  "description": "AI-powered development tool",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "packageManager": "bun@1.4.2",
@@ -1,6 +1,6 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "name": "@opencode/ai",
  "type": "module",
  "license": "MIT",
@@ -336,12 +336,18 @@ export type OutputItem = StreamItem & { readonly id: string }
 // Responses-compatible providers put streaming error details at the top level or
 // under `error`, and response failures under `response.error`. Accept all three shapes.
 // https://www.openresponses.org/specification
-const OpenResponsesErrorPayload = Schema.Struct({
+const OpenResponsesErrorObject = Schema.Struct({
  type: optionalNull(Schema.String),
  code: optionalNull(Schema.String),
  message: optionalNull(Schema.String),
  param: optionalNull(Schema.String),
 })
+const OpenResponsesErrorPayload = Schema.Union([Schema.String, OpenResponsesErrorObject]).pipe(
+  Schema.decodeTo(OpenResponsesErrorObject, {
+    decode: SchemaGetter.transform((error) => (typeof error === "string" ? { message: error } : error)),
+    encode: SchemaGetter.passthrough(),
+  }),
+)
 type OpenResponsesErrorPayload = Schema.Schema.Type<typeof OpenResponsesErrorPayload>

 const WebSocketErrorHeader = Schema.Union([Schema.String, Schema.Number, Schema.Boolean])
@@ -434,7 +440,9 @@ export const decodeChannelEvent = (frame: string) =>
  decodeFrame(frame).pipe(
    Effect.flatMap((value) =>
      decodeEventValue(
-        ProviderShared.isRecord(value) && value.type === undefined && ProviderShared.isRecord(value.error)
+        ProviderShared.isRecord(value) &&
+          value.type === undefined &&
+          (typeof value.error === "string" || ProviderShared.isRecord(value.error))
          ? { ...value, type: "error" }
          : value,
      ),
@@ -1,8 +1,9 @@
 import { expect } from "bun:test"
-import { Effect, Schema } from "effect"
+import { Effect, Schema, Stream } from "effect"
 import { LLM, LLMClient } from "../../src/index.js"
 import { OpenResponses } from "../../src/protocols/open-responses.js"
-import { Meta } from "../../src/providers/index.js"
+import { Azure, Meta, OpenAI, XAI } from "../../src/providers/index.js"
+import { WebSocketTransport } from "../../src/route.js"
 import { configure } from "../../src/providers/openai-compatible-responses.js"
 import { it } from "../lib/effect.js"
 import { fixedResponse } from "../lib/http.js"
@@ -44,11 +45,59 @@ it.effect("normalizes flat errors in shared SSE and WebSocket decoding", () =>

 it.effect("continues to normalize untyped xAI WebSocket errors", () =>
  Effect.gen(function* () {
-    const frame = { error: { type: "api_error", message: "gRPC error: Response with id=resp_missing not found" } }
-    expect(yield* OpenResponses.decodeChannelEvent(JSON.stringify(frame))).toEqual({ ...frame, type: "error" })
+    const message = "gRPC error: Response with id=resp_missing not found"
+    for (const error of [{ type: "api_error", message }, message]) {
+      expect(yield* OpenResponses.decodeChannelEvent(JSON.stringify({ error }))).toEqual({
+        type: "error",
+        error: typeof error === "string" ? { message } : error,
+      })
+    }
  }),
 )

+it.effect("normalizes string errors in shared SSE and WebSocket decoding", () =>
+  Effect.gen(function* () {
+    for (const decode of [decodeEvent, OpenResponses.decodeChannelEvent]) {
+      expect(yield* decode(JSON.stringify({ type: "error", error: "Gateway failed" }))).toEqual({
+        type: "error",
+        error: { message: "Gateway failed" },
+      })
+      expect(
+        yield* decode(
+          JSON.stringify({ type: "response.failed", response: { id: "resp_failed", error: "Gateway failed" } }),
+        ),
+      ).toEqual({
+        type: "response.failed",
+        response: { id: "resp_failed", error: { message: "Gateway failed" } },
+      })
+    }
+  }),
+)
+
+for (const model of [
+  OpenAI.configure({ apiKey: "fixture" }).responses("gpt-5.6-sol"),
+  XAI.configure({ apiKey: "fixture" }).responses("grok-4.6"),
+  Azure.configure({ apiKey: "fixture", resourceName: "fixture" }).responses("deployment"),
+]) {
+  it.effect(`preserves string error messages and raw bodies through ${model.provider} Responses`, () =>
+    Effect.gen(function* () {
+      const raw = '{ "type": "error", "error": "Gateway rejected the request", "trace": "original" }'
+      const webSocket = WebSocketTransport.makeDirect({
+        open: () => Effect.succeed({ sendText: () => Effect.void, messages: Stream.make(raw), close: Effect.void }),
+      })
+      for (const options of [{ webSocket }, {}]) {
+        const error = yield* LLMClient.generate(LLM.request({ model, prompt: "Hello" }), options).pipe(
+          Effect.provide(fixedResponse(sseEvents(raw))),
+          Effect.flip,
+        )
+        expect(error.reason._tag).toBe("UnknownProvider")
+        expect(error.message).toBe("Gateway rejected the request")
+        expect(error.reason.body).toBe(raw)
+      }
+    }),
+  )
+}
+
 it.effect("retains classification and original error bodies through Meta and generic Responses routes", () =>
  Effect.gen(function* () {
    const raw = `{
@@ -405,12 +405,7 @@ test("executes a selected slash command after creating its worktree", async ({ p
        item: { type: "user", payload: { text: expanded }, delivery: "steer" },
      },
    })
-    await route.fulfill({
-      status: 200,
-      headers,
-      contentType: "application/json",
-      body: JSON.stringify({ data: { type: "prompt", inboxID: "msg_workspace_review" } }),
-    })
+    await route.fulfill({ status: 204, headers })
  })
  const editor = page.locator('[data-component="composer-editor"]')
  await editor.fill("/review")
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/app",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "description": "",
  "type": "module",
  "exports": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/cli",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "bin": {
@@ -1,5 +1,4 @@
 import type { AgentSideConnection, PromptResponse, SessionUpdate } from "@agentclientprotocol/sdk"
-import type { Command } from "@opencode/schema/command"
 import type {
  EventSubscribeOutput,
  OpenCodeClient,
@@ -38,9 +37,6 @@ export type TurnStart =
  | { readonly type: "skill"; readonly id: string }
  | { readonly type: "compaction"; readonly id: string }

-/** `prompt` submissions admitted work under the start ID; `immediate` submissions have none to follow. */
-export type Admission = Command.Outcome["type"]
-
 export const ChildSessionUpdatesCapability = "opencode/child-session-updates"
 export const ChildSessionUpdateMethod = "opencode/session/child_update"

@@ -80,7 +76,8 @@ export async function streamTurn(input: {
  readonly cwd: string
  readonly start: TurnStart
  readonly writeTextFile: boolean
-  readonly submit: (signal: AbortSignal) => Promise<Admission>
+  readonly action?: boolean
+  readonly submit: (signal: AbortSignal) => Promise<unknown>
  readonly control: TurnControl
  readonly childSessionUpdate?: (update: ChildSessionUpdate) => Promise<void>
  readonly connectionSignal?: AbortSignal
@@ -117,14 +114,6 @@ export async function streamTurn(input: {
      .catch(() => {})
  }

-  // Command-spawned subagents run while the invoking Session is idle, so cancelling the prompt
-  // must interrupt them directly. Sessions that start after cancellation are interrupted on start.
-  const interruptChildren = async () => {
-    await Promise.all(
-      [...openChildren].map((sessionID) => input.client.session.interrupt({ sessionID }).catch(() => {})),
-    )
-  }
-
  const updateSession = async (value: SessionUpdate, child: ChildSession | undefined, mode: "turn" | "background") => {
    const projected = child ? projectChildUpdate(value, child) : value
    if (mode === "turn" && (!child || !input.childSessionUpdate)) {
@@ -189,10 +178,9 @@ export async function streamTurn(input: {
      if (!started) continue

      if (event.type === "session.execution.started") {
-        if (mode === "turn" && control.cancelled) {
-          await input.client.session.interrupt({ sessionID: event.data.sessionID }).catch(() => {})
+        if (child) {
+          await notifyChild(child, { type: "status", status: "running" })
        }
-        if (child) await notifyChild(child, { type: "status", status: "running" })
        continue
      }

@@ -354,15 +342,11 @@ export async function streamTurn(input: {
    input.sessionSignal?.removeEventListener("abort", connectionAbort)
    await stream.return?.(undefined).catch(() => {})
  }
-  const onCancel = () => void interruptChildren()
-  control.admission.signal.addEventListener("abort", onCancel, { once: true })
  try {
-    const admission = await input.submit(control.admission.signal).catch((error): Admission => {
+    await input.submit(control.admission.signal).catch((error) => {
      if (!control.cancelled) throw error
-      // The request may have been admitted before the abort reached the server; keep observing.
-      return "prompt"
    })
-    if (admission === "immediate") {
+    if (input.action) {
      streamController.abort()
      await completed.catch(() => {})
      return response(undefined, undefined, "succeeded", control.cancelled, undefined)
@@ -400,7 +384,6 @@ export async function streamTurn(input: {
    await completed.catch(() => {})
    throw error
  } finally {
-    control.admission.signal.removeEventListener("abort", onCancel)
    if (!handedOff) await closeStream()
  }
 }
@@ -52,7 +52,6 @@ import {
  ChildSessionUpdatesCapability,
  replayMessages,
  streamTurn,
-  type Admission,
  type ChildSessionUpdate,
  type TurnControl,
  type TurnStart,
@@ -328,6 +327,7 @@ export function make(input: { readonly client: OpenCodeClient; readonly connecti
        cwd: state.cwd,
        start: prepared.start,
        writeTextFile: capabilities.writeTextFile,
+        action: prepared.command !== undefined,
        control,
        connectionSignal: input.connection.signal,
        sessionSignal: state.abort.signal,
@@ -362,12 +362,7 @@ function preparePrompt(catalog: Catalog, prompt: PromptRequest["prompt"], messag
  return { start, text, files, synthetic, slash, command }
 }

-async function submitPrompt(
-  client: OpenCodeClient,
-  session: Attached,
-  prompt: PreparedPrompt,
-  signal: AbortSignal,
-): Promise<Admission> {
+async function submitPrompt(client: OpenCodeClient, session: Attached, prompt: PreparedPrompt, signal: AbortSignal) {
  if (prompt.synthetic.length > 0) {
    await client.session.synthetic({
      sessionID: session.id,
@@ -377,30 +372,23 @@ async function submitPrompt(
      resume: false,
    })
  }
-  if (prompt.start.type === "compaction") {
-    await client.session.compact({ sessionID: session.id, id: prompt.start.id })
-    return "prompt"
-  }
+  if (prompt.start.type === "compaction") return client.session.compact({ sessionID: session.id, id: prompt.start.id })
  if (prompt.command) {
-    // The command admits any resulting input under the turn's start ID so the stream can follow it.
-    const outcome = await client.session.command(
+    return client.session.command(
      {
        sessionID: session.id,
        name: prompt.command.name,
-        id: prompt.start.id,
        text: prompt.slash?.args ?? "",
        files: prompt.files,
        delivery: "steer",
      },
      { signal },
    )
-    return outcome.type
  }
-  await client.session.prompt(
+  return client.session.prompt(
    { sessionID: session.id, id: prompt.start.id, text: prompt.text, files: prompt.files, delivery: "steer" },
    { signal },
  )
-  return "prompt"
 }

 function turnStart(messageID: string, slash: PreparedPrompt["slash"]): TurnStart {
@@ -1,138 +0,0 @@
-import type { PromptResponse, SessionNotification } from "@agentclientprotocol/sdk"
-import { describe, expect, test } from "bun:test"
-import { createAcpFixture, expectOk, initialize, lastUserText, newSession, type ChatRequest } from "./subprocess"
-
-describe("acp slash command subprocess", () => {
-  test("template command stays pending until its model work completes and streams the output", async () => {
-    const script = scriptedModel()
-    await using fixture = await createAcpFixture({
-      respond: script.respond,
-      config: { commands: { audit: { description: "Audit the change", template: "Audit $ARGUMENTS" } } },
-    })
-    const acp = fixture.spawn()
-    await initialize(acp)
-    const session = await newSession(acp, fixture.home)
-
-    const gate = script.hold()
-    const pending = acp
-      .request<PromptResponse>("session/prompt", {
-        sessionId: session.sessionId,
-        prompt: [{ type: "text", text: "/audit now" }],
-      })
-      .then(expectOk)
-    await gate.started
-    expect(lastUserText(fixture.llm.requests.at(-1)!)).toBe("Audit now")
-    // The response is held, so the prompt must still be pending.
-    expect(await Promise.race([pending.then(() => "settled"), Bun.sleep(200).then(() => "pending")])).toBe("pending")
-
-    gate.release("COMMAND_RESPONSE")
-    expect((await pending).stopReason).toBe("end_turn")
-    const chunk = await acp.waitForNotification<SessionNotification>("session/update", (params) =>
-      isAgentText(params, "COMMAND_RESPONSE"),
-    )
-    expect(chunk.params.sessionId).toBe(session.sessionId)
-  }, 60_000)
-
-  test("subagent command follows the child and the parent's follow-up before completing", async () => {
-    const script = scriptedModel()
-    await using fixture = await createAcpFixture({
-      respond: script.respond,
-      config: {
-        commands: { audit: { description: "Audit in a subagent", template: "Audit $ARGUMENTS", subagent: true } },
-      },
-    })
-    const acp = fixture.spawn()
-    await initialize(acp)
-    const session = await newSession(acp, fixture.home)
-
-    const child = script.hold()
-    const parent = script.hold()
-    const pending = acp
-      .request<PromptResponse>("session/prompt", {
-        sessionId: session.sessionId,
-        prompt: [{ type: "text", text: "/audit now" }],
-      })
-      .then(expectOk)
-    await child.started
-    expect(lastUserText(fixture.llm.requests.at(-1)!)).toBe("You are a subagent spawned by another session.\nAudit now")
-    child.release("CHILD_DONE")
-    await parent.started
-    expect(lastUserText(fixture.llm.requests.at(-1)!)).toContain("CHILD_DONE")
-    expect(await Promise.race([pending.then(() => "settled"), Bun.sleep(200).then(() => "pending")])).toBe("pending")
-
-    parent.release("PARENT_DONE")
-    expect((await pending).stopReason).toBe("end_turn")
-    const childChunk = await acp.waitForNotification<SessionNotification>("session/update", (params) =>
-      isAgentText(params, "CHILD_DONE"),
-    )
-    expect(childChunk.params.update._meta?.["opencode/child-session"]).toMatchObject({ parentID: session.sessionId })
-    const parentChunk = await acp.waitForNotification<SessionNotification>("session/update", (params) =>
-      isAgentText(params, "PARENT_DONE"),
-    )
-    expect(parentChunk.params.update._meta?.["opencode/child-session"]).toBeUndefined()
-  }, 60_000)
-
-  test("cancelling during subagent command work interrupts the child and the parent's follow-up", async () => {
-    const script = scriptedModel()
-    await using fixture = await createAcpFixture({
-      respond: script.respond,
-      config: {
-        commands: { audit: { description: "Audit in a subagent", template: "Audit $ARGUMENTS", subagent: true } },
-      },
-    })
-    const acp = fixture.spawn()
-    await initialize(acp)
-    const session = await newSession(acp, fixture.home)
-
-    const child = script.hold()
-    const parent = script.hold()
-    const pending = acp
-      .request<PromptResponse>("session/prompt", {
-        sessionId: session.sessionId,
-        prompt: [{ type: "text", text: "/audit now" }],
-      })
-      .then(expectOk)
-    await child.started
-    await acp.notify("session/cancel", { sessionId: session.sessionId })
-
-    // Both model responses stay held, so the prompt can only settle by interrupting the child and
-    // the parent's follow-up run that the cancelled-subagent notice wakes.
-    expect((await pending).stopReason).toBe("cancelled")
-    child.release("LATE")
-    parent.release("LATE")
-    const followUp = expectOk(
-      await acp.request<PromptResponse>("session/prompt", {
-        sessionId: session.sessionId,
-        prompt: [{ type: "text", text: "hello again" }],
-      }),
-    )
-    expect(followUp.stopReason).toBe("end_turn")
-  }, 60_000)
-})
-
-/** Holds agent-loop model responses in FIFO order; auxiliary requests (no tools) answer immediately. */
-function scriptedModel() {
-  const holds: Array<{ started: () => void; released: Promise<string> }> = []
-  return {
-    respond: (request: ChatRequest) => {
-      const next = request.tools ? holds.shift() : undefined
-      if (!next) return "accepted"
-      next.started()
-      return next.released
-    },
-    hold() {
-      const started = Promise.withResolvers<void>()
-      const released = Promise.withResolvers<string>()
-      holds.push({ started: started.resolve, released: released.promise })
-      return { started: started.promise, release: released.resolve }
-    },
-  }
-}
-
-function isAgentText(params: SessionNotification, text: string) {
-  return (
-    params.update.sessionUpdate === "agent_message_chunk" &&
-    params.update.content.type === "text" &&
-    params.update.content.text === text
-  )
-}
@@ -656,7 +656,6 @@ describe("acp event behavior", () => {
          { signal },
        )
        submitted.resolve()
-        return "prompt"
      },
    })

@@ -695,9 +694,10 @@ describe("acp event behavior", () => {
      writeTextFile: false,
      control,
      submit: (signal) =>
-        fixture.client.session
-          .prompt({ sessionID: "ses_cancel_admission", id: "input_cancel_admission", text: "cancel me" }, { signal })
-          .then(() => "prompt" as const),
+        fixture.client.session.prompt(
+          { sessionID: "ses_cancel_admission", id: "input_cancel_admission", text: "cancel me" },
+          { signal },
+        ),
    })

    try {
@@ -784,9 +784,7 @@ function turn(input: {
    control: { cancelled: false, admission: new AbortController() },
    childSessionUpdate: input.childSessionUpdate,
    submit: (signal) =>
-      input.fixture.client.session
-        .prompt({ sessionID: input.sessionID, id: input.inboxID, text: "hello" }, { signal })
-        .then(() => "prompt" as const),
+      input.fixture.client.session.prompt({ sessionID: input.sessionID, id: input.inboxID, text: "hello" }, { signal }),
  })
 }

@@ -98,7 +98,7 @@ test("acp prompt resolves after ordered turn updates", async () => {
      start: { type: "input", id },
      writeTextFile: false,
      control: { cancelled: false, admission: new AbortController() },
-      submit: () => client.session.prompt({ sessionID: "ses_test", id, text: "hi" }).then(() => "prompt" as const),
+      submit: () => client.session.prompt({ sessionID: "ses_test", id, text: "hi" }),
    })

    expect(updates).toEqual([
@@ -122,7 +122,7 @@ test("acp prompt resolves after ordered turn updates", async () => {
  }
 })

-test("acp immediate admission resolves without prompt lifecycle events", async () => {
+test("acp action resolves without prompt lifecycle events", async () => {
  const encoder = new TextEncoder()
  const server = Bun.serve({
    port: 0,
@@ -150,8 +150,9 @@ test("acp immediate admission resolves without prompt lifecycle events", async (
      cwd: "/workspace",
      start: { type: "input", id: "msg_action" },
      writeTextFile: false,
+      action: true,
      control: { cancelled: false, admission: new AbortController() },
-      submit: async () => "immediate",
+      submit: async () => {},
    })

    expect(response).toMatchObject({ stopReason: "end_turn" })
@@ -547,10 +547,7 @@ function startTurn(fixture: Fixture, connection: Connection, sessionID: string,
    start: { type: "input", id: inboxID },
    writeTextFile: true,
    control: { cancelled: false, admission: new AbortController() },
-    submit: (signal) =>
-      fixture.client.session
-        .prompt({ sessionID, id: inboxID, text: "hello" }, { signal })
-        .then(() => "prompt" as const),
+    submit: (signal) => fixture.client.session.prompt({ sessionID, id: inboxID, text: "hello" }, { signal }),
  })
 }

@@ -12,7 +12,7 @@ describe("acp service prompt routing and usage", () => {
          return Response.json({ data: makeSession("ses_routes") })
        }
        if (request.method === "POST" && request.path === "/api/session/ses_routes/command") {
-          return Response.json({ data: { type: "immediate" } })
+          return new Response(null, { status: 204 })
        }
        if (request.method === "POST" && request.path === "/api/session/ses_routes/compact") {
          const id = requestID(request)
@@ -42,7 +42,6 @@ describe("acp service prompt routing and usage", () => {
    const compact = fixture.requests.find((request) => request.path === "/api/session/ses_routes/compact")
    expect(command?.body).toMatchObject({
      name: "review",
-      id: expect.stringMatching(/^msg_/),
      text: "now",
      files: [],
      delivery: "steer",
@@ -4,7 +4,6 @@ import type {
  SessionConfigOption,
  SessionConfigSelectOption,
 } from "@agentclientprotocol/sdk"
-import { Schema } from "effect"
 import fs from "node:fs/promises"
 import os from "node:os"
 import path from "node:path"
@@ -47,7 +46,6 @@ type Waiter = {

 export type AcpProcess = {
  readonly request: <T>(method: string, params?: unknown) => Promise<JsonRpcResponse<T>>
-  readonly notify: (method: string, params?: unknown) => Promise<void>
  readonly waitForNotification: <T>(
    method: string,
    predicate: (params: T) => boolean,
@@ -66,38 +64,7 @@ description: Verifier compatibility skill.
 # Verifier Skill
 `

-/** The subset of an OpenAI-compatible chat request that tests inspect. */
-const ChatRequest = Schema.Struct({
-  messages: Schema.Array(
-    Schema.Struct({
-      role: Schema.String,
-      content: Schema.Union([
-        Schema.String,
-        Schema.Array(Schema.Struct({ text: Schema.String.pipe(Schema.optional) })),
-      ]).pipe(Schema.optional),
-    }),
-  ),
-  tools: Schema.Array(Schema.Unknown).pipe(Schema.optional),
-})
-export type ChatRequest = typeof ChatRequest.Type
-const decodeChatRequest = Schema.decodeUnknownSync(ChatRequest)
-
-/** Text of the most recent user message. */
-export function lastUserText(request: ChatRequest) {
-  const content = request.messages.findLast((message) => message.role === "user")?.content
-  if (!Array.isArray(content)) return content
-  return content.flatMap((part) => (part.text === undefined ? [] : [part.text])).join("")
-}
-
-export type FixtureOptions = {
-  readonly skill?: string
-  /** Extra opencode.json entries merged over the verifier config. */
-  readonly config?: Record<string, Schema.Json>
-  /** Produce the scripted completion text; awaiting here holds the model response. */
-  readonly respond?: (request: ChatRequest) => string | Promise<string>
-}
-
-export async function createAcpFixture(options: FixtureOptions = {}) {
+export async function createAcpFixture(options: { readonly skill?: string } = {}) {
  const root = await fs.mkdtemp(path.join(os.tmpdir(), "opencode-cli-acp-"))
  const home = path.join(root, "workspace")
  const config = path.join(root, "config")
@@ -109,7 +76,7 @@ export async function createAcpFixture(options: FixtureOptions = {}) {
    await Bun.write(path.join(skills, "verifier-skill", "SKILL.md"), options.skill)
  }

-  const requests: ChatRequest[] = []
+  const requests: unknown[] = []
  const llm = Bun.serve({
    hostname: "127.0.0.1",
    port: 0,
@@ -117,19 +84,15 @@ export async function createAcpFixture(options: FixtureOptions = {}) {
      if (request.method !== "POST" || new URL(request.url).pathname !== "/v1/chat/completions") {
        return new Response("Not found", { status: 404 })
      }
-      const body = decodeChatRequest(await request.json())
-      requests.push(body)
-      return new Response(completion(await (options.respond?.(body) ?? "accepted")), {
+      requests.push(await request.json().catch(() => undefined))
+      return new Response(completion("accepted"), {
        headers: { "content-type": "text/event-stream" },
      })
    },
  })
  await Bun.write(
    path.join(config, "opencode.json"),
-    JSON.stringify({
-      ...verifierConfig(`http://127.0.0.1:${llm.port}/v1`, options.skill ? skills : undefined),
-      ...options.config,
-    }),
+    JSON.stringify(verifierConfig(`http://127.0.0.1:${llm.port}/v1`, options.skill ? skills : undefined)),
  )
  await Bun.write(models, "{}")

@@ -343,12 +306,6 @@ function spawnAcp(input: { readonly env: Record<string, string | undefined> }):
      if (!isResponse<T>(response)) throw new Error(`Invalid ACP response: ${JSON.stringify(response)}`)
      return response
    },
-    async notify(method: string, params?: unknown) {
-      if (inputClosed) throw new Error("ACP stdin is closed")
-      const notification: JsonRpcNotification<unknown> = { jsonrpc: "2.0", method, params }
-      await child.stdin.write(encoder.encode(`${JSON.stringify(notification)}\n`))
-      await child.stdin.flush()
-    },
    async waitForNotification<T>(method: string, predicate: (params: T) => boolean, timeoutMs = 20_000) {
      const notification = await take(
        (message) => isNotification<T>(message) && message.method === method && predicate(message.params),
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/client",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -15,7 +15,6 @@ import type { SessionMessage } from "@opencode/schema/session-message"
 import type { SessionInbox } from "@opencode/schema/session-inbox"
 import type { PromptInput } from "@opencode/schema/prompt-input"
 import type { AgentAttachment } from "@opencode/schema/prompt"
-import type { Command } from "@opencode/schema/command"
 import type { Skill } from "@opencode/schema/skill"
 import type { FileDiff } from "@opencode/schema/file-diff"
 import type { InstructionEntry } from "@opencode/schema/instruction-entry"
@@ -30,6 +29,7 @@ import type { Mcp } from "@opencode/schema/mcp"
 import type { Credential } from "@opencode/schema/credential"
 import type { PermissionSaved } from "@opencode/schema/permission-saved"
 import type { FileSystem } from "@opencode/schema/filesystem"
+import type { Command } from "@opencode/schema/command"
 import type { OpenCodeEvent } from "@opencode/protocol/groups/event"
 import type { Pty } from "@opencode/schema/pty"
 import type { PtyTicket } from "@opencode/schema/pty-ticket"
@@ -266,14 +266,13 @@ export type SessionPromptOperation<E = never> = (input: SessionPromptInput) => E
 export type SessionCommandInput = {
  readonly sessionID: Session.ID
  readonly name: string
-  readonly id?: SessionMessage.ID | undefined
  readonly text: string
  readonly files?: ReadonlyArray<PromptInput.FileAttachment> | undefined
  readonly agents?: ReadonlyArray<AgentAttachment> | undefined
  readonly skills?: ReadonlyArray<PromptInput.SkillAttachment> | undefined
  readonly delivery?: SessionInbox.Delivery | undefined
 }
-export type SessionCommandOutput = Command.Outcome
+export type SessionCommandOutput = void
 export type SessionCommandOperation<E = never> = (input: SessionCommandInput) => Effect.Effect<SessionCommandOutput, E>

 export type SessionSkillInput = {
@@ -484,17 +484,13 @@ const EndpointSessionCommand = (raw: RawClient["server.session"]) => (input: Ses
      params: { sessionID: input["sessionID"] },
      payload: {
        name: input["name"],
-        id: input["id"],
        text: input["text"],
        files: input["files"],
        agents: input["agents"],
        skills: input["skills"],
        delivery: input["delivery"],
      },
-    }).pipe(
-      Effect.mapError(mapClientError),
-      Effect.map((value) => value.data),
-    ),
+    }).pipe(Effect.mapError(mapClientError)),
  )

 const EndpointSessionSkill = (raw: RawClient["server.session"]) => (input: SessionSkillInput) =>
@@ -682,25 +682,24 @@ export function make(options: ClientOptions) {
          requestOptions,
        ).then((value) => value.data),
      command: (input: SessionCommandInput, requestOptions?: RequestOptions) =>
-        request<{ readonly data: SessionCommandOutput }>(
+        request<SessionCommandOutput>(
          {
            method: "POST",
            path: `/api/session/${encodeURIComponent(input.sessionID)}/command`,
            body: {
              name: input["name"],
-              id: input["id"],
              text: input["text"],
              files: input["files"],
              agents: input["agents"],
              skills: input["skills"],
              delivery: input["delivery"],
            },
-            successStatus: 200,
+            successStatus: 204,
            declaredStatuses: [400, 401, 404, 500],
-            empty: false,
+            empty: true,
          },
          requestOptions,
-        ).then((value) => value.data),
+        ),
      skill: (input: SessionSkillInput, requestOptions?: RequestOptions) =>
        request<SessionSkillOutput>(
          {
@@ -161,8 +161,6 @@ export type SessionActive = { type: "running" }

 export type SessionInboxDelivery = "steer" | "queue"

-export type CommandOutcome = { type: "immediate" } | { type: "prompt"; inboxID: string }
-
 export type SessionInboxSyntheticPayload = { text: string; description?: string; metadata?: { [x: string]: JsonValue } }

 export type SessionInboxCompactionPayload = {}
@@ -4109,7 +4107,6 @@ export type SessionCommandInput = {
  readonly sessionID: { readonly sessionID: string }["sessionID"]
  readonly name: {
    readonly name: string
-    readonly id?: string | null
    readonly text: string
    readonly files?: ReadonlyArray<{
      readonly uri: string
@@ -4127,29 +4124,8 @@ export type SessionCommandInput = {
    }>
    readonly delivery?: ("steer" | "queue") | null
  }["name"]
-  readonly id?: {
-    readonly name: string
-    readonly id?: string | null
-    readonly text: string
-    readonly files?: ReadonlyArray<{
-      readonly uri: string
-      readonly name?: string
-      readonly description?: string
-      readonly mention?: { readonly start: number; readonly end: number; readonly text: string }
-    }>
-    readonly agents?: ReadonlyArray<{
-      readonly name: string
-      readonly mention?: { readonly start: number; readonly end: number; readonly text: string }
-    }>
-    readonly skills?: ReadonlyArray<{
-      readonly id: string
-      readonly mention?: { readonly start: number; readonly end: number; readonly text: string }
-    }>
-    readonly delivery?: ("steer" | "queue") | null
-  }["id"]
  readonly text: {
    readonly name: string
-    readonly id?: string | null
    readonly text: string
    readonly files?: ReadonlyArray<{
      readonly uri: string
@@ -4169,7 +4145,6 @@ export type SessionCommandInput = {
  }["text"]
  readonly files?: {
    readonly name: string
-    readonly id?: string | null
    readonly text: string
    readonly files?: ReadonlyArray<{
      readonly uri: string
@@ -4189,7 +4164,6 @@ export type SessionCommandInput = {
  }["files"]
  readonly agents?: {
    readonly name: string
-    readonly id?: string | null
    readonly text: string
    readonly files?: ReadonlyArray<{
      readonly uri: string
@@ -4209,7 +4183,6 @@ export type SessionCommandInput = {
  }["agents"]
  readonly skills?: {
    readonly name: string
-    readonly id?: string | null
    readonly text: string
    readonly files?: ReadonlyArray<{
      readonly uri: string
@@ -4229,7 +4202,6 @@ export type SessionCommandInput = {
  }["skills"]
  readonly delivery?: {
    readonly name: string
-    readonly id?: string | null
    readonly text: string
    readonly files?: ReadonlyArray<{
      readonly uri: string
@@ -4249,7 +4221,7 @@ export type SessionCommandInput = {
  }["delivery"]
 }

-export type SessionCommandOutput = { data: CommandOutcome }["data"]
+export type SessionCommandOutput = void

 export type SessionSkillInput = {
  readonly sessionID: { readonly sessionID: string }["sessionID"]
@@ -13,8 +13,8 @@ The idea of code mode was originally introduced by Cloudflare. See

 ## How it differs from JavaScript

- **Only supported APIs are available.** Programs can use the provided tools and supported JavaScript built-ins. APIs
-  such as `fetch`, timers, `process`, filesystem access, imports, and modules are unavailable.
+- **Only supported APIs are available.** Programs can use the provided tools, supported JavaScript built-ins, and the
+  globals the host adds through extensions. Timers, `process`, filesystem access, imports, and modules are unavailable.
 - **Unfinished work is interrupted.** Tool calls and async functions start when called. When the program finishes,
  anything still running is interrupted. Unhandled rejections from un-awaited promises are returned as warnings.
 - **REPL-style results.** Without an explicit `return`, the final top-level expression becomes the result. `undefined`
@@ -94,11 +94,19 @@ receive `{ extension, name, args }`. An `after` hook also receives how the call
 `failure` with its error, or `interrupted`). A failing `before` hook denies the call, and the program catches the
 failure as a thrown error.

-### `Values`
+### `Extension.make`

-`Values` exports the runtime's non-JSON value classes: `Values.URL`, `Values.URLSearchParams`, `Values.Date`,
-`Values.RegExp`, `Values.Map`, `Values.Set`, and `Values.Promise`. The interpreter recognizes these by class; a
-program's `new URL(...)` is a `Values.URL` wrapping the host `URL`. `Values.isValue` narrows to the data-like kinds.
+Extensions are host functions a program calls directly as globals, such as `fetch`. Unlike tools they are not in the
+catalog, not counted against `maxToolCalls`, and not described to the model; the host decides what they mean.
+
+```ts
+const web = Extension.make({ name: "web", globals: { fetch: (url: string) => globalThis.fetch(url) } })
+const runtime = CodeMode.make({ tools, extensions: [web] })
+```
+
+Every value crossing in either direction is converted, never shared: arguments come in as copies, results go out as
+copies, and a function inside a result is callable the same way. A global that shadows a built-in or another
+extension throws at `CodeMode.make`.

 ### OpenAPI tools

@@ -29,7 +29,7 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
      Uint8Array is rejected with a hint to encode as text, and own `__proto__` keys are dropped so merging tool
      inputs or results cannot replace a prototype. In-program `JSON.stringify` keeps JS behavior except for the
      Error form and a promise, which is a `TypeError` with an await hint rather than a silent `{}`.
- [x] Live Date, RegExp, Map, Set, URL, URLSearchParams, and Uint8Array values inside CodeMode.
+- [x] Live Date, RegExp, Map, Set, URL, URLSearchParams, Headers, and Uint8Array values inside CodeMode.
 - [x] Tool calls through the host-provided `tools` tree only.
 - [x] The global `search(...)` built-in: synchronous tool discovery that counts as an admitted tool call and is
      shadowable by program declarations like other globals.
@@ -47,8 +47,8 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 ## Values and literals

 - [x] `null`, `undefined`, booleans, finite and non-finite numbers, and strings.
- [x] Array literals, including holes and spread from arrays, strings, Maps, Sets, URLSearchParams, custom synchronous
-      iterators, and synchronous generators.
+- [x] Array literals, including holes and spread from arrays, strings, Maps, Sets, URLSearchParams, Headers, custom
+      synchronous iterators, and synchronous generators.
 - [x] Object literals with shorthand, computed string/number keys, and spread following ToObject: data objects and
      arrays copy own enumerable keys, strings copy index keys, and other values contribute nothing.
 - [x] Template literals with interpolation.
@@ -95,8 +95,8 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] `if`/`else` and conditional expressions.
 - [x] `switch`, including default clauses and fallthrough.
 - [x] `for`, `while`, and `do...while`.
- [x] `for...of` over arrays, strings, Maps, Sets, URLSearchParams, custom synchronous iterators, and confined
-      synchronous generators. Abrupt completion invokes the iterator's optional `return()`.
+- [x] `for...of` over arrays, strings, Maps, Sets, URLSearchParams, Headers, custom synchronous iterators, and
+      confined synchronous generators. Abrupt completion invokes the iterator's optional `return()`.
 - [x] `for...in` over own keys of plain objects, arrays, strings, and tool references; other values iterate nothing.
 - [x] Unlabeled `break` and `continue`.
 - [x] `try`, `catch`, optional catch bindings, and `finally`.
@@ -127,7 +127,7 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
      string). A detached method loses its receiver, as in JS: `values.filter("abc".includes)` is a `TypeError`
      because `includes` is called without a string `this`.
 - [x] Constructors work as callbacks with JS call semantics: `Error` types construct (`messages.map(Error)`),
-      and new-requiring constructors (`Map`, `Set`, `URL`, `URLSearchParams`, `Promise`) throw a `TypeError`,
+      and new-requiring constructors (`Map`, `Set`, `URL`, `URLSearchParams`, `Headers`, `Promise`) throw a `TypeError`,
      like JS.
 - [x] Tool references and detached `Promise` statics are rejected as callbacks with a hint to wrap them in an
      arrow function.
@@ -179,10 +179,10 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] Sequence expressions (the comma operator).
 - [x] `await` for CodeMode promises and callable thenables; a plain value passes through unchanged, though every
      `await` still defers its continuation one reaction turn.
- [x] `new` for Array, Object, Error types, Date, RegExp, Map, Set, URL, URLSearchParams, and Promise. `new` on any
-      other value throws a catchable `TypeError` naming the callee: other built-in functions such as `Number` say
-      `new` is unsupported and point at the plain call, user-defined functions report the constructor gap below, and
-      non-callable values are not constructors.
+- [x] `new` for Array, Object, Error types, Date, RegExp, Map, Set, URL, URLSearchParams, Headers, and Promise. `new`
+      on any other value throws a catchable `TypeError` naming the callee: other built-in functions such as `Number`
+      say `new` is unsupported and point at the plain call, user-defined functions report the constructor gap below,
+      and non-callable values are not constructors.
 - [x] Arithmetic operators: `+`, `-`, `*`, `/`, `%`, and `**`.
 - [x] Equality and ordering: `==`, `!=`, `===`, `!==`, `<`, `<=`, `>`, and `>=`.
 - [x] Bitwise operators: `&`, `|`, `^`, `~`, `<<`, `>>`, and `>>>`.
@@ -450,7 +450,13 @@ with a hint to encode as text first (`TextDecoder`, `toBase64`, `toHex`).
 - [x] `crypto.randomUUID()` and `crypto.getRandomValues(uint8Array)`.
 - [x] `TextEncoder` and `TextDecoder` for UTF-8 only: any other label is a `RangeError`. `TextDecoder` accepts the
      `fatal` and `ignoreBOM` options; `decode` takes a Uint8Array or nothing.
- [ ] `crypto.subtle`, `Blob`, and `TextDecoder` streaming or non-UTF-8 encodings.
+- [x] `new Headers()` from records, synchronous iterables of pairs, and Headers, wrapping the host's `Headers`: names
+      fold to lowercase, values are normalized and combined, and invalid names or values throw a `TypeError`.
+- [x] Headers `append`, `delete`, `get`, `getSetCookie`, `has`, `set`, `forEach`, `keys`, `values`, and `entries`;
+      iteration is live and sorted by name, with `set-cookie` values kept apart.
+- [x] Headers serialize to a `{ name: value }` object in JSON, in results, and in tool arguments.
+- [ ] `Request`, `Response`, and `Blob`.
+- [ ] `crypto.subtle` and `TextDecoder` streaming or non-UTF-8 encodings.

 ## Extensions

@@ -460,8 +466,8 @@ Nothing is exposed unless a host provides it; extension calls are not tool calls
 - [x] Each global is a function, callable but not constructible, run with `this` undefined. A global that shadows
      a built-in or another extension throws at `make`.
 - [x] Every value crossing in either direction is converted, never shared: plain objects and arrays are copied,
-      `Date`, `RegExp`, `URL`, `URLSearchParams`, `Map`, `Set`, and `Uint8Array` become fresh copies with their
-      contents converted (a host `ArrayBuffer` comes in as a `Uint8Array`; other typed arrays cannot come out),
+      `Date`, `RegExp`, `URL`, `URLSearchParams`, `Headers`, `Map`, `Set`, and `Uint8Array` become fresh copies with
+      their contents converted (a host `ArrayBuffer` comes in as a `Uint8Array`; other typed arrays cannot come out),
      errors cross as errors with their name and message, and a `__proto__` key is dropped. Functions, generators,
      un-awaited promises, and symbols cannot be passed in; a class instance, a symbol, or a BigInt cannot come out.
 - [x] A host function inside a result becomes a program function whose calls cross the same way, so a result can
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/codemode",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "description": "Effect-native confined code execution over schema-described tools",
  "type": "module",
  "license": "MIT",
@@ -17,6 +17,7 @@ import {
  record,
  SetObj,
  URLSearchParamsObj,
+  HeadersObj,
 } from "./interpreter/objects.js"
 import { typeofValue } from "./interpreter/references.js"

@@ -69,6 +70,7 @@ const walk = <R>(
        )
      }
      if (boundary && value instanceof URLSearchParamsObj) return value.params.toString()
+      if (value instanceof HeadersObj) return Object.fromEntries(value.headers)
      const target = boundary && value instanceof SetObj ? new Arr(ctx.builtins.Array, [...value.set]) : value
      if (stack.has(target)) throw typeError("Converting circular structure to JSON.")
      stack.add(target)
@@ -24,6 +24,7 @@ import {
  SetObj,
  URLObj,
  URLSearchParamsObj,
+  HeadersObj,
 } from "./objects.js"
 import { describeValue } from "./references.js"

@@ -49,6 +50,7 @@ export const extensionGlobals = <R>(
    if (value instanceof RegExpObj) return new RegExp(value.regex.source, value.regex.flags)
    if (value instanceof URLObj) return new URL(value.url.href)
    if (value instanceof URLSearchParamsObj) return new URLSearchParams(value.params)
+    if (value instanceof HeadersObj) return new Headers(value.headers)
    const next = (item: unknown) => toHost(item, label, depth + 1, seen)
    if (value instanceof MapObj) return new Map([...value.map].map(([key, item]) => [next(key), next(item)]))
    if (value instanceof SetObj) return new Set([...value.set].map(next))
@@ -96,6 +98,7 @@ export const extensionGlobals = <R>(
      if (value instanceof URLSearchParams) {
        return new URLSearchParamsObj(builtins.URLSearchParams, new URLSearchParams(value))
      }
+      if (value instanceof Headers) return new HeadersObj(builtins.Headers, new Headers(value))
      const next = (item: unknown, path: string) => fromHost(item, path, depth + 1, seen)
      if (value instanceof Map) {
        const wrapped = new MapObj(builtins.Map)
@@ -11,6 +11,7 @@ import { objectGlobal } from "../stdlib/object.js"
 import { regexpGlobal } from "../stdlib/regexp.js"
 import { stringGlobal } from "../stdlib/string.js"
 import { uriGlobal, urlGlobal, urlSearchParamsGlobal } from "../stdlib/url.js"
+import { headersGlobal } from "../stdlib/headers.js"
 import { coercion } from "../stdlib/value.js"
 import { base64Global, cryptoGlobal } from "../stdlib/web.js"
 import { ToolReference } from "../tool-runtime.js"
@@ -80,6 +81,7 @@ const table: Record<string, Factory> = {
  Set: (ctx) => setGlobal(ctx),
  URL: (ctx) => urlGlobal(ctx),
  URLSearchParams: (ctx) => urlSearchParamsGlobal(ctx),
+  Headers: (ctx) => headersGlobal(ctx),
  Uint8Array: (ctx) => uint8ArrayGlobal(ctx),
  TextEncoder: (ctx) => textEncoderGlobal(ctx),
  TextDecoder: (ctx) => textDecoderGlobal(ctx),
@@ -84,6 +84,7 @@ import {
  PromiseObj,
  SetObj,
  URLSearchParamsObj,
+  HeadersObj,
  record,
  remove,
  set,
@@ -653,7 +654,7 @@ class Frame<R> {
      const cursor = iterator === undefined ? yield* self.iterate(right, node) : undefined
      if (iterator === undefined && cursor === undefined) {
        throw invalidData(
-          `${awaiting ? "for await...of" : "for...of"} requires an array, string, Map, Set, or URLSearchParams, or custom iterator value.`,
+          `${awaiting ? "for await...of" : "for...of"} requires an array, string, Map, Set, URLSearchParams, or Headers, or custom iterator value.`,
          node,
        )
      }
@@ -756,9 +757,11 @@ class Frame<R> {
              ? value.set.values()
              : value instanceof URLSearchParamsObj
                ? value.params.entries()
-                : value instanceof Bytes
-                  ? value.bytes.values()
-                  : undefined
+                : value instanceof HeadersObj
+                  ? value.headers.entries()
+                  : value instanceof Bytes
+                    ? value.bytes.values()
+                    : undefined
    if (iterator !== undefined) {
      const proto = this.ctx.builtins.Array
      return Effect.succeed({
@@ -1848,6 +1851,7 @@ class Frame<R> {
        value instanceof MapObj ||
        value instanceof SetObj ||
        value instanceof URLSearchParamsObj ||
+        value instanceof HeadersObj ||
        value instanceof Bytes
      ) {
        const cursor = yield* self.iterate(value, node)
@@ -29,6 +29,7 @@ const builtins = [
  "Set",
  "URL",
  "URLSearchParams",
+  "Headers",
  "Uint8Array",
  "TextEncoder",
  "TextDecoder",
@@ -80,6 +81,7 @@ export const createBuiltins = (): Builtins => {
    Set: plain(),
    URL: plain(),
    URLSearchParams: plain(),
+    Headers: plain(),
    Uint8Array: plain(),
    TextEncoder: plain(),
    TextDecoder: plain(),
@@ -156,6 +156,15 @@ export class URLSearchParamsObj extends Obj {
  }
 }

+export class HeadersObj extends Obj {
+  constructor(
+    proto: Obj,
+    readonly headers: Headers,
+  ) {
+    super(proto)
+  }
+}
+
 export class URLObj extends Obj {
  readonly searchParams: URLSearchParamsObj
  constructor(
@@ -181,13 +190,14 @@ export class Bytes extends Obj {
 /** Built-in objects that wrap a host value; data-like, but never plain data. */
 export const isWrapper = (
  value: unknown,
-): value is DateObj | RegExpObj | MapObj | SetObj | URLObj | URLSearchParamsObj | Bytes =>
+): value is DateObj | RegExpObj | MapObj | SetObj | URLObj | URLSearchParamsObj | HeadersObj | Bytes =>
  value instanceof DateObj ||
  value instanceof RegExpObj ||
  value instanceof MapObj ||
  value instanceof SetObj ||
  value instanceof URLObj ||
  value instanceof URLSearchParamsObj ||
+  value instanceof HeadersObj ||
  value instanceof Bytes

 const MAX_ARRAY_INDEX = 4_294_967_295
@@ -16,6 +16,7 @@ import {
  SetObj,
  URLObj,
  URLSearchParamsObj,
+  HeadersObj,
 } from "./objects.js"

 /** Values that cannot cross the data boundary. */
@@ -85,6 +86,7 @@ export const describeValue = (value: unknown): string => {
  if (value instanceof SetObj) return "a Set"
  if (value instanceof URLObj) return "a URL"
  if (value instanceof URLSearchParamsObj) return "a URLSearchParams"
+  if (value instanceof HeadersObj) return "a Headers"
  if (value instanceof Bytes) return "a Uint8Array"
  if (value instanceof GeneratorObj) return "a generator"
  if (isRuntimeReference(value)) return "a function"
@@ -12,6 +12,7 @@ import {
  SetObj,
  URLObj,
  URLSearchParamsObj,
+  HeadersObj,
 } from "../interpreter/objects.js"
 import { containsOpaqueReference, isRuntimeReference } from "../interpreter/references.js"
 import type { Interpreter } from "../interpreter/interpreter.js"
@@ -66,6 +67,7 @@ const formatConsoleValue = (value: unknown, seen: Set<object>, depth: number): s
  if (value instanceof RegExpObj) return coerceToString(value)
  if (value instanceof URLObj) return coerceToString(value)
  if (value instanceof URLSearchParamsObj) return coerceToString(value)
+  if (value instanceof HeadersObj) return `Headers ${JSON.stringify(Object.fromEntries(value.headers))}`
  if (value instanceof Bytes) return `Uint8Array(${value.bytes.length}) [${value.bytes.join(",")}]`
  if (depth > MAX_CONSOLE_DEPTH) return "..."
  if (seen.has(value)) return "[Circular]"
@@ -0,0 +1,119 @@
+import { Effect } from "effect"
+import { constructor, methods, prototypeFrom, receiver, requiresNew } from "../interpreter/native.js"
+import { typeError } from "../interpreter/model.js"
+import { entries, Arr, HeadersObj, Obj } from "../interpreter/objects.js"
+import { applyCollectionCallback } from "../interpreter/callback.js"
+import { isRuntimeReference } from "../interpreter/references.js"
+import type { Interpreter } from "../interpreter/interpreter.js"
+import { coerceToString } from "./value.js"
+import { readPairs } from "./url.js"
+
+// The host validates header names and values and throws its own TypeError; the program gets one of its own.
+const attempt = <T>(run: () => T): T => {
+  try {
+    return run()
+  } catch (error) {
+    throw typeError(error instanceof Error ? error.message : String(error))
+  }
+}
+
+const constructHeaders = <R>(ctx: Interpreter<R>, init: unknown, proto: Obj): Effect.Effect<HeadersObj, unknown, R> => {
+  const wrap = (headers: Headers) => new HeadersObj(proto, headers)
+  if (init === undefined) return Effect.succeed(wrap(new Headers()))
+  return Effect.gen(function* () {
+    const pairs = init instanceof Obj ? yield* readPairs(ctx, init, "new Headers(...)") : undefined
+    if (pairs !== undefined) return wrap(attempt(() => new Headers(pairs)))
+    if (!(init instanceof Obj) || isRuntimeReference(init)) {
+      throw typeError("new Headers(...) expects a record of names to values, iterable [name, value] pairs, or Headers.")
+    }
+    return wrap(
+      attempt(() => new Headers(Object.fromEntries(entries(init).map(([key, value]) => [key, coerceToString(value)])))),
+    )
+  })
+}
+
+export const headersGlobal = <R>(ctx: Interpreter<R>) => {
+  const builtins = ctx.builtins
+  const proto = builtins.Headers
+  const headers = constructor<R>(builtins, proto, {
+    name: "Headers",
+    call: requiresNew("Headers"),
+    construct: (args, newTarget) => constructHeaders(ctx, args[0], prototypeFrom(newTarget, proto)),
+  })
+  const self = (thisValue: unknown, name: string) => receiver(HeadersObj, thisValue, `Headers.prototype.${name}`)
+  const wrap = (items: Array<unknown>) => new Arr(builtins.Array, items)
+  const arg = (args: Array<unknown>, index: number): string => coerceToString(args[index])
+  const requireArgs = (name: string, args: Array<unknown>, count: number): void => {
+    if (args.length < count) throw typeError(`Headers.${name} requires ${count} argument${count === 1 ? "" : "s"}.`)
+  }
+  methods(builtins, proto, [
+    [
+      "append",
+      2,
+      (thisValue, args) => {
+        requireArgs("append", args, 2)
+        const target = self(thisValue, "append").headers
+        return attempt(() => target.append(arg(args, 0), arg(args, 1)))
+      },
+    ],
+    [
+      "delete",
+      1,
+      (thisValue, args) => {
+        requireArgs("delete", args, 1)
+        const target = self(thisValue, "delete").headers
+        return attempt(() => target.delete(arg(args, 0)))
+      },
+    ],
+    [
+      "get",
+      1,
+      (thisValue, args) => {
+        requireArgs("get", args, 1)
+        const target = self(thisValue, "get").headers
+        return attempt(() => target.get(arg(args, 0)))
+      },
+    ],
+    ["getSetCookie", 0, (thisValue) => wrap(self(thisValue, "getSetCookie").headers.getSetCookie())],
+    [
+      "has",
+      1,
+      (thisValue, args) => {
+        requireArgs("has", args, 1)
+        const target = self(thisValue, "has").headers
+        return attempt(() => target.has(arg(args, 0)))
+      },
+    ],
+    [
+      "set",
+      2,
+      (thisValue, args) => {
+        requireArgs("set", args, 2)
+        const target = self(thisValue, "set").headers
+        return attempt(() => target.set(arg(args, 0), arg(args, 1)))
+      },
+    ],
+    ["keys", 0, (thisValue) => wrap(Array.from(self(thisValue, "keys").headers.keys()))],
+    ["values", 0, (thisValue) => wrap(Array.from(self(thisValue, "values").headers.values()))],
+    [
+      "entries",
+      0,
+      (thisValue) =>
+        wrap(Array.from(self(thisValue, "entries").headers.entries(), ([key, value]) => wrap([key, value]))),
+    ],
+    [
+      "forEach",
+      1,
+      (thisValue, args) => {
+        requireArgs("forEach", args, 1)
+        const target = self(thisValue, "forEach")
+        const apply = applyCollectionCallback(ctx, args[0], "Headers.forEach")
+        return Effect.gen(function* () {
+          for (const [key, value] of Array.from(target.headers.entries())) yield* apply([value, key, target])
+          return undefined
+        })
+      },
+    ],
+  ])
+  return headers
+}
@@ -107,12 +107,10 @@ export const urlGlobal = <R>(ctx: Interpreter<R>) => {
  return url
 }

-const readPair = <R>(ctx: Interpreter<R>, value: unknown): Effect.Effect<Array<string>, unknown, R> =>
+const readPair = <R>(ctx: Interpreter<R>, value: unknown, label: string): Effect.Effect<Array<string>, unknown, R> =>
  Effect.gen(function* () {
    const cursor = yield* ctx.iterate(value)
-    if (cursor === undefined) {
-      throw typeError("new URLSearchParams(...) expects iterable [name, value] pairs.")
-    }
+    if (cursor === undefined) throw typeError(`${label} expects iterable [name, value] pairs.`)
    const items: Array<string> = []
    while (true) {
      const step = yield* cursor.next
@@ -126,6 +124,29 @@ const readPair = <R>(ctx: Interpreter<R>, value: unknown): Effect.Effect<Array<s
    }
  })

+/**
+ * Reads a synchronous iterable of `[name, value]` pairs as strings; `undefined` when `init` is not iterable. As in
+ * WebIDL, the whole sequence is converted before any pair's length is checked.
+ */
+export const readPairs = <R>(
+  ctx: Interpreter<R>,
+  init: unknown,
+  label: string,
+): Effect.Effect<Array<[string, string]> | undefined, unknown, R> =>
+  Effect.gen(function* () {
+    const cursor = yield* ctx.iterate(init)
+    if (cursor === undefined) return undefined
+    const pairs: Array<Array<string>> = []
+    while (true) {
+      const step = yield* cursor.next
+      if (step.done) {
+        if (pairs.some((entry) => entry.length !== 2)) throw typeError(`${label} expects iterable [name, value] pairs.`)
+        return pairs as Array<[string, string]>
+      }
+      pairs.push(yield* preserveConsumerError(cursor, readPair(ctx, step.value, label)))
+    }
+  })
+
 const constructURLSearchParams = <R>(
  ctx: Interpreter<R>,
  init: unknown,
@@ -139,20 +160,8 @@ const constructURLSearchParams = <R>(
    return Effect.succeed(wrap(new URLSearchParams(coerceToString(init))))
  }
  return Effect.gen(function* () {
-    const cursor = yield* ctx.iterate(init)
-    if (cursor !== undefined) {
-      const pairs: Array<Array<string>> = []
-      while (true) {
-        const step = yield* cursor.next
-        if (step.done) {
-          if (pairs.some((entry) => entry.length !== 2)) {
-            throw typeError("new URLSearchParams(...) expects iterable [name, value] pairs.")
-          }
-          return wrap(new URLSearchParams(pairs.map((entry): [string, string] => [entry[0] ?? "", entry[1] ?? ""])))
-        }
-        pairs.push(yield* preserveConsumerError(cursor, readPair(ctx, step.value)))
-      }
-    }
+    const pairs = yield* readPairs(ctx, init, "new URLSearchParams(...)")
+    if (pairs !== undefined) return wrap(new URLSearchParams(pairs))
    if (isRuntimeReference(init)) {
      throw typeError("new URLSearchParams(...) expects a query string, data object, or synchronous iterable pairs.")
    }
@@ -13,6 +13,7 @@ import {
  SetObj,
  URLObj,
  URLSearchParamsObj,
+  HeadersObj,
 } from "../interpreter/objects.js"
 import type { Interpreter } from "../interpreter/interpreter.js"

@@ -28,6 +29,7 @@ export const coerceToString = (value: unknown): string => {
  if (value instanceof SetObj) return "[object Set]"
  if (value instanceof URLObj) return value.url.href
  if (value instanceof URLSearchParamsObj) return value.params.toString()
+  if (value instanceof HeadersObj) return "[object Headers]"
  if (value instanceof Bytes) return value.bytes.join(",")
  if (value instanceof ErrorObj) {
    // Match Error.prototype.toString: "name: message", or just one when the other is empty.
@@ -128,6 +128,34 @@ describe("values are converted at the boundary, never shared", () => {
    expect([...(held[0] as Set<{ z: number }>)][0]).toEqual({ z: 1 })
  })

+  test("Headers cross as copies in both directions", async () => {
+    const stored = new Headers({ "X-A": "1" })
+    const target = CodeMode.make({
+      extensions: [
+        Extension.make({
+          name: "http",
+          globals: {
+            headers: () => stored,
+            keep: (value: Headers) => {
+              held.push(value)
+              return value
+            },
+          },
+        }),
+      ],
+    })
+    held.length = 0
+    expect(
+      await value(
+        `const h = headers(); h.set("x-a", "2"); const back = keep(h); back.set("x-a", "3"); return [h instanceof Headers, h.get("x-a"), back === h, back.get("x-a"), [...back]]`,
+        target,
+      ),
+    ).toEqual([true, "2", false, "3", [["x-a", "3"]]])
+    expect(stored.get("x-a")).toBe("1")
+    expect(held[0]).toBeInstanceOf(Headers)
+    expect((held[0] as Headers).get("x-a")).toBe("2")
+  })
+
  test("bytes cross as copies in both directions; ArrayBuffer comes in as Uint8Array", async () => {
    const stored = new Uint8Array([1, 2, 3])
    const target = CodeMode.make({
@@ -635,6 +635,154 @@ describe("URL and URI helpers", () => {
  })
 })

+describe("Headers", () => {
+  test("constructs from records, pairs, Maps, and Headers; names fold to lowercase and values combine", async () => {
+    expect(
+      await value(`
+        const headers = new Headers({ "Content-Type": "text/plain", "X-Count": 1, "X-Null": null })
+        headers.append("Accept", "text/html")
+        headers.append("accept", "application/json")
+        headers.set("x-count", "2")
+        headers.delete("x-null")
+        const copy = new Headers(headers)
+        copy.set("content-type", "text/html")
+        return {
+          get: headers.get("content-type"),
+          missing: headers.get("x-missing"),
+          combined: headers.get("ACCEPT"),
+          has: [headers.has("Accept"), headers.has("x-null")],
+          count: headers.get("x-count"),
+          copied: [headers.get("content-type"), copy.get("content-type")],
+          pairs: [...new Headers([["b", "2"], ["A", "1"]])],
+          map: [...new Headers(new Map([["k", "v"]]))],
+          keys: headers.keys(),
+          values: headers.values(),
+          entries: headers.entries(),
+        }
+      `),
+    ).toEqual({
+      get: "text/plain",
+      missing: null,
+      combined: "text/html, application/json",
+      has: [true, false],
+      count: "2",
+      copied: ["text/plain", "text/html"],
+      pairs: [
+        ["a", "1"],
+        ["b", "2"],
+      ],
+      map: [["k", "v"]],
+      keys: ["accept", "content-type", "x-count"],
+      values: ["text/html, application/json", "text/plain", "2"],
+      entries: [
+        ["accept", "text/html, application/json"],
+        ["content-type", "text/plain"],
+        ["x-count", "2"],
+      ],
+    })
+  })
+
+  test("iterates in sorted order everywhere iteration is allowed, and getSetCookie keeps cookies apart", async () => {
+    expect(
+      await value(`
+        const headers = new Headers({ b: "2", a: "1" })
+        headers.append("Set-Cookie", "x=1")
+        headers.append("set-cookie", "y=2")
+        const seen = []
+        headers.forEach((value, name, self) => seen.push(name + "=" + value + ":" + (self === headers)))
+        const [first] = headers
+        function* pairs() { yield* headers }
+        return {
+          seen,
+          first,
+          spread: [...headers],
+          from: Array.from(headers).length,
+          generator: [...pairs()].length,
+          object: Object.fromEntries(headers),
+          cookies: headers.getSetCookie(),
+        }
+      `),
+    ).toEqual({
+      seen: ["a=1:true", "b=2:true", "set-cookie=x=1:true", "set-cookie=y=2:true"],
+      first: ["a", "1"],
+      spread: [
+        ["a", "1"],
+        ["b", "2"],
+        ["set-cookie", "x=1"],
+        ["set-cookie", "y=2"],
+      ],
+      from: 4,
+      generator: 4,
+      object: { a: "1", b: "2", "set-cookie": "y=2" },
+      cookies: ["x=1", "y=2"],
+    })
+  })
+
+  test("serializes as a name-to-value object at the boundary and in JSON; prints for console", async () => {
+    const result = await run(`
+      const headers = new Headers({ "X-A": "1", b: "2" })
+      console.log(headers)
+      return { headers, json: JSON.stringify({ headers }), text: String(headers), type: typeof headers, is: headers instanceof Headers }
+    `)
+    expect(result.ok && result.value).toEqual({
+      headers: { b: "2", "x-a": "1" },
+      json: '{"headers":{"b":"2","x-a":"1"}}',
+      text: "[object Headers]",
+      type: "object",
+      is: true,
+    })
+    expect(result.ok && result.logs?.[0]).toBe('Headers {"b":"2","x-a":"1"}')
+  })
+
+  test("rejects what it cannot build from, and invalid names and values, with TypeErrors the program can catch", async () => {
+    expect(
+      await value(`
+        function message(run) {
+          try { run(); return null } catch (error) { return error instanceof TypeError ? error.message : error }
+        }
+        const headers = new Headers()
+        return [
+          message(() => Headers()),
+          message(() => new Headers(null)),
+          message(() => new Headers(1)),
+          message(() => new Headers("a=1")),
+          message(() => new Headers(new Date())),
+          message(() => new Headers(() => 1)),
+          message(() => new Headers([["name"]])),
+          message(() => new Headers([["a", "b", "c"]])),
+          message(() => new Headers({ "bad name": "x" })),
+          message(() => new Headers({ name: "bad\u0000value" })),
+          message(() => headers.get("invalid\u0100")),
+          message(() => headers.has({})),
+          message(() => headers.set("a", "invalid\u0100")),
+          message(() => headers.append("a")),
+          message(() => headers.forEach()),
+          message(() => headers.forEach(1)),
+          message(() => { const get = headers.get; return get("a") }),
+        ]
+      `),
+    ).toEqual([
+      "Constructor Headers requires 'new'.",
+      "new Headers(...) expects a record of names to values, iterable [name, value] pairs, or Headers.",
+      "new Headers(...) expects a record of names to values, iterable [name, value] pairs, or Headers.",
+      "new Headers(...) expects a record of names to values, iterable [name, value] pairs, or Headers.",
+      "new Headers(...) expects a record of names to values, iterable [name, value] pairs, or Headers.",
+      "new Headers(...) expects a record of names to values, iterable [name, value] pairs, or Headers.",
+      "new Headers(...) expects iterable [name, value] pairs.",
+      "new Headers(...) expects iterable [name, value] pairs.",
+      expect.stringContaining("bad name"),
+      expect.stringContaining("invalid value"),
+      expect.stringContaining("Invalid header name"),
+      expect.stringContaining("[object Object]"),
+      expect.stringContaining("invalid value"),
+      "Headers.append requires 2 arguments.",
+      "Headers.forEach requires 1 argument.",
+      "Headers.forEach expects a function callback.",
+      "Headers.prototype.get called on incompatible receiver undefined.",
+    ])
+  })
+})
+
 describe("Map", () => {
  test("get/set/has/size with chaining", async () => {
    expect(
@@ -3,10 +3,13 @@
 * - html/webappapis/atob/base64.any.js (btoa reference encoder, input list, and atob WebIDL cases)
 * - fetch/data-urls/resources/base64.json (copied to fixtures/wpt-base64.json)
 * - WebCryptoAPI/randomUUID.https.any.js
+ * - fetch/api/headers/{headers-basic,headers-errors}.any.js
 *
 * Copyright © web-platform-tests contributors. Governed by the 3-Clause BSD license in LICENSE.wpt.
 *
 * `assert_throws_dom("InvalidCharacterError", …)` becomes a check for a TypeError: CodeMode has no DOMException.
+ * Headers cases that need `Symbol.iterator`, iterator objects from `keys()`/`values()`/`entries()` (CodeMode returns
+ * arrays), or a custom iterator on a Headers instance are left out.
 */
 import { describe, expect, test } from "bun:test"
 import { Effect } from "effect"
@@ -166,3 +169,225 @@ describe("crypto.randomUUID WPT parity (WebCryptoAPI/randomUUID.https.any.js)",
    ).toEqual([true, true, true, 768])
  })
 })
+
+// Enough of testharness.js to run the Headers files close to verbatim; each `test` records its failure, if any.
+const testharness = `
+  const failures = []
+  function test(run, name) { try { run() } catch (error) { failures.push(name + ": " + (error && error.message ? error.message : error)) } }
+  function assert_equals(actual, expected, message) { if (actual !== expected) throw new Error((message || "") + " expected " + JSON.stringify(expected) + " got " + JSON.stringify(actual)) }
+  function assert_true(actual, message) { assert_equals(actual, true, message) }
+  function assert_false(actual, message) { assert_equals(actual, false, message) }
+  function assert_array_equals(actual, expected, message) { assert_equals(JSON.stringify(actual), JSON.stringify(expected), message) }
+  function assert_throws_js(type, run) { try { run() } catch (error) { if (error instanceof type) return; throw new Error("threw " + error.name) } throw new Error("did not throw") }
+  function assert_unreached() { throw new Error("unreachable") }
+`
+
+describe("Headers WPT parity (fetch/api/headers)", () => {
+  test("headers-basic.any.js", async () => {
+    expect(
+      await value(`
+        ${testharness}
+        test(function() { new Headers() }, "Create headers from no parameter")
+        test(function() { new Headers(undefined) }, "Create headers from undefined parameter")
+        test(function() { new Headers({}) }, "Create headers from empty object")
+        var parameters = [null, 1]
+        parameters.forEach(function(parameter) {
+          test(function() { assert_throws_js(TypeError, function() { new Headers(parameter) }) }, "Create headers with " + parameter + " should throw")
+        })
+        var headerDict = {"name1": "value1", "name2": "value2", "name3": "value3", "name4": null, "name5": undefined, "name6": 1, "Content-Type": "value4"}
+        var headerSeq = []
+        for (var name in headerDict) headerSeq.push([name, headerDict[name]])
+        test(function() {
+          var headers = new Headers(headerSeq)
+          for (name in headerDict) assert_equals(headers.get(name), String(headerDict[name]), "name: " + name + " has value: " + headerDict[name])
+          assert_equals(headers.get("length"), null, "init should be treated as a sequence, not as a dictionary")
+        }, "Create headers with sequence")
+        test(function() {
+          var headers = new Headers(headerDict)
+          for (name in headerDict) assert_equals(headers.get(name), String(headerDict[name]), "name: " + name + " has value: " + headerDict[name])
+        }, "Create headers with record")
+        test(function() {
+          var headers = new Headers(headerDict)
+          var headers2 = new Headers(headers)
+          for (name in headerDict) assert_equals(headers2.get(name), String(headerDict[name]), "name: " + name + " has value: " + headerDict[name])
+        }, "Create headers with existing headers")
+        test(function() {
+          var headers = new Headers()
+          for (name in headerDict) {
+            headers.append(name, headerDict[name])
+            assert_equals(headers.get(name), String(headerDict[name]), "name: " + name + " has value: " + headerDict[name])
+          }
+        }, "Check append method")
+        test(function() {
+          var headers = new Headers()
+          for (name in headerDict) {
+            headers.set(name, headerDict[name])
+            assert_equals(headers.get(name), String(headerDict[name]), "name: " + name + " has value: " + headerDict[name])
+          }
+        }, "Check set method")
+        test(function() {
+          var headers = new Headers(headerDict)
+          for (name in headerDict) assert_true(headers.has(name), "headers has name " + name)
+          assert_false(headers.has("nameNotInHeaders"), "headers do not have header: nameNotInHeaders")
+        }, "Check has method")
+        test(function() {
+          var headers = new Headers(headerDict)
+          for (name in headerDict) {
+            assert_true(headers.has(name), "headers have a header: " + name)
+            headers.delete(name)
+            assert_true(!headers.has(name), "headers do not have anymore a header: " + name)
+          }
+        }, "Check delete method")
+        test(function() {
+          var headers = new Headers(headerDict)
+          for (name in headerDict) assert_equals(headers.get(name), String(headerDict[name]), "name: " + name + " has value: " + headerDict[name])
+          assert_equals(headers.get("nameNotInHeaders"), null, "header: nameNotInHeaders has no value")
+        }, "Check get method")
+        var headerEntriesDict = {"name1": "value1", "Name2": "value2", "name": "value3", "content-Type": "value4", "Content-Typ": "value5", "Content-Types": "value6"}
+        var sortedHeaderDict = {}
+        var headerValues = []
+        var sortedHeaderKeys = Object.keys(headerEntriesDict).map(function(value) {
+          sortedHeaderDict[value.toLowerCase()] = headerEntriesDict[value]
+          headerValues.push(headerEntriesDict[value])
+          return value.toLowerCase()
+        }).sort()
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          assert_array_equals(headers.keys(), sortedHeaderKeys)
+          for (const key of headers.keys()) assert_true(sortedHeaderKeys.indexOf(key) != -1)
+        }, "Check keys method")
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          assert_array_equals(headers.values(), sortedHeaderKeys.map((key) => sortedHeaderDict[key]))
+          for (const value of headers.values()) assert_true(headerValues.indexOf(value) != -1)
+        }, "Check values method")
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          assert_array_equals(headers.entries(), sortedHeaderKeys.map((key) => [key, sortedHeaderDict[key]]))
+          for (const entry of headers.entries()) assert_equals(entry[1], sortedHeaderDict[entry[0]])
+        }, "Check entries method")
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          assert_array_equals([...headers], sortedHeaderKeys.map((key) => [key, sortedHeaderDict[key]]))
+        }, "Check Symbol.iterator method")
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          var index = 0
+          headers.forEach(function(value, key, container) {
+            assert_equals(headers, container)
+            assert_equals(key, sortedHeaderKeys[index])
+            assert_equals(value, sortedHeaderDict[sortedHeaderKeys[index]])
+            index++
+          })
+          assert_equals(index, sortedHeaderKeys.length)
+        }, "Check forEach method")
+        test(() => {
+          const headers = new Headers({"foo": "2", "baz": "1", "BAR": "0"})
+          const actualKeys = []
+          const actualValues = []
+          for (const [header, value] of headers) {
+            actualKeys.push(header)
+            actualValues.push(value)
+            headers.delete("foo")
+          }
+          assert_array_equals(actualKeys, ["bar", "baz"])
+          assert_array_equals(actualValues, ["0", "1"])
+        }, "Iteration skips elements removed while iterating")
+        test(() => {
+          const headers = new Headers({"foo": "2", "baz": "1", "BAR": "0", "quux": "3"})
+          const actualKeys = []
+          const actualValues = []
+          for (const [header, value] of headers) {
+            actualKeys.push(header)
+            actualValues.push(value)
+            if (header === "baz") headers.delete("bar")
+          }
+          assert_array_equals(actualKeys, ["bar", "baz", "quux"])
+          assert_array_equals(actualValues, ["0", "1", "3"])
+        }, "Removing elements already iterated over causes an element to be skipped during iteration")
+        test(() => {
+          const headers = new Headers({"foo": "2", "baz": "1", "BAR": "0", "quux": "3"})
+          const actualKeys = []
+          const actualValues = []
+          for (const [header, value] of headers) {
+            actualKeys.push(header)
+            actualValues.push(value)
+            if (header === "baz") headers.append("X-yZ", "4")
+          }
+          assert_array_equals(actualKeys, ["bar", "baz", "foo", "quux", "x-yz"])
+          assert_array_equals(actualValues, ["0", "1", "2", "3", "4"])
+        }, "Appending a value pair during iteration causes it to be reached during iteration")
+        test(() => {
+          const headers = new Headers({"foo": "2", "baz": "1", "BAR": "0", "quux": "3"})
+          const actualKeys = []
+          const actualValues = []
+          for (const [header, value] of headers) {
+            actualKeys.push(header)
+            actualValues.push(value)
+            if (header === "baz") headers.append("abc", "-1")
+          }
+          assert_array_equals(actualKeys, ["bar", "baz", "baz", "foo", "quux"])
+          assert_array_equals(actualValues, ["0", "1", "1", "2", "3"])
+        }, "Prepending a value pair before the current element position causes it to be skipped during iteration and adds the current element a second time")
+        return failures
+      `),
+    ).toEqual([])
+  })
+
+  test("headers-errors.any.js", async () => {
+    expect(
+      await value(`
+        ${testharness}
+        test(function() { assert_throws_js(TypeError, function() { new Headers([["name"]]) }) }, "Create headers giving an array having one string as init argument")
+        test(function() { assert_throws_js(TypeError, function() { new Headers([["invalid", "invalidValue1", "invalidValue2"]]) }) }, "Create headers giving an array having three strings as init argument")
+        test(function() { assert_throws_js(TypeError, function() { new Headers([["invalid\u0100", "Value1"]]) }) }, "Create headers giving bad header name as init argument")
+        test(function() { assert_throws_js(TypeError, function() { new Headers([["name", "invalidValue\u0100"]]) }) }, "Create headers giving bad header value as init argument")
+        var badNames = ["invalid\u0100", {}]
+        var badValues = ["invalid\u0100"]
+        badNames.forEach(function(name) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.get(name) }) }, "Check headers get with an invalid name " + name)
+        })
+        badNames.forEach(function(name) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.delete(name) }) }, "Check headers delete with an invalid name " + name)
+        })
+        badNames.forEach(function(name) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.has(name) }) }, "Check headers has with an invalid name " + name)
+        })
+        badNames.forEach(function(name) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.set(name, "Value1") }) }, "Check headers set with an invalid name " + name)
+        })
+        badValues.forEach(function(value) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.set("name", value) }) }, "Check headers set with an invalid value " + value)
+        })
+        badNames.forEach(function(name) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.append("invalid\u0100", "Value1") }) }, "Check headers append with an invalid name " + name)
+        })
+        badValues.forEach(function(value) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.append("name", value) }) }, "Check headers append with an invalid value " + value)
+        })
+        test(function() {
+          var headers = new Headers([["name", "value"]])
+          assert_throws_js(TypeError, function() { headers.forEach() })
+          assert_throws_js(TypeError, function() { headers.forEach(undefined) })
+          assert_throws_js(TypeError, function() { headers.forEach(1) })
+        }, "Headers forEach throws if argument is not callable")
+        test(function() {
+          var headers = new Headers([["name1", "value1"], ["name2", "value2"], ["name3", "value3"]])
+          var counter = 0
+          try {
+            headers.forEach(function(value, name) {
+              counter++
+              if (name == "name2") throw "error"
+            })
+          } catch (e) {
+            assert_equals(counter, 2)
+            assert_equals(e, "error")
+            return
+          }
+          assert_unreached()
+        }, "Headers forEach loop should stop if callback is throwing exception")
+        return failures
+      `),
+    ).toEqual([])
+  })
+})
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/console-app",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "scripts": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/console-core",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/console-function",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "$schema": "https://json.schemastore.org/package.json",
  "private": true,
  "type": "module",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/console-mail",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "dependencies": {
    "@jsx-email/all": "2.2.3",
    "@jsx-email/cli": "1.4.3",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/console-support",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "scripts": {
@@ -1,6 +1,6 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "name": "@opencode/core",
  "type": "module",
  "license": "MIT",
@@ -4,7 +4,6 @@ import { Command } from "@opencode/schema/command"
 import type { PromptInput } from "@opencode/schema/prompt-input"
 import type { Session } from "@opencode/schema/session"
 import type { SessionInbox } from "@opencode/schema/session-inbox"
-import type { SessionMessage } from "@opencode/schema/session-message"
 import { makeLocationNode } from "@opencode/util/effect/app-node"
 import { Context, Effect, Layer, Schema } from "effect"
 import { Bus } from "./bus.js"
@@ -12,23 +11,10 @@ import { State } from "./state.js"

 export const Info = Command.Info
 export type Info = Command.Info
-export const Outcome = Command.Outcome
-export type Outcome = Command.Outcome
 export { Event } from "@opencode/schema/command"

-export const immediate: Outcome = { type: "immediate" }
-
-export function prompted(admitted: { readonly id: SessionMessage.ID }): Outcome {
-  return { type: "prompt", inboxID: admitted.id }
-}
-
 export interface Invocation {
  readonly sessionID: Session.ID
-  /**
-   * Identity for the input this command admits. Commands that prompt a Session must admit
-   * with this ID and report it in their outcome so clients can follow the resulting work.
-   */
-  readonly messageID: SessionMessage.ID
  readonly prompt: PromptInput.Prompt
  readonly delivery: SessionInbox.Delivery
 }
@@ -36,8 +22,7 @@ export interface Invocation {
 export interface Definition {
  readonly name: string
  readonly description?: string
-  /** Resolve with an Outcome to report admitted work; `void` means the command finished immediately. */
-  readonly execute: (input: Invocation) => Effect.Effect<Outcome | void, unknown>
+  readonly execute: (input: Invocation) => Effect.Effect<void, unknown>
 }

 export type Editor = {
@@ -60,7 +45,7 @@ export interface Interface extends State.Transformable<Editor> {
  readonly execute: (input: {
    readonly name: string
    readonly invocation: Invocation
-  }) => Effect.Effect<Outcome, NotFoundError | ExecutionError>
+  }) => Effect.Effect<void, NotFoundError | ExecutionError>
 }

 export class Service extends Context.Service<Service, Interface>()("@opencode/Command") {}
@@ -97,22 +82,10 @@ export const layer = Layer.effect(
        const definition = state.get().get(input.name)
        if (!definition)
          return yield* new NotFoundError({ command: input.name, message: `Command not found: ${input.name}` })
-        const outcome = yield* definition.execute(input.invocation).pipe(
+        return yield* definition.execute(input.invocation).pipe(
          Effect.tapError((error) => Effect.logError("command execution failed", { command: input.name, error })),
          Effect.mapError((error) => new ExecutionError({ command: input.name, message: errorMessage(error) })),
        )
-        if (outcome === undefined) return immediate
-        // Plugin callbacks cross a JavaScript boundary; only a well-formed outcome is reportable.
-        if (!isOutcome(outcome))
-          return yield* new ExecutionError({ command: input.name, message: "Command returned an invalid outcome" })
-        // Clients follow the invocation ID, so a command that admitted under another ID (typically by
-        // omitting `id: messageID` from its prompt) would leave them waiting forever. Fail loudly instead.
-        if (outcome.type === "prompt" && outcome.inboxID !== input.invocation.messageID)
-          return yield* new ExecutionError({
-            command: input.name,
-            message: `Command admitted ${outcome.inboxID} instead of the invocation message ID ${input.invocation.messageID}`,
-          })
-        return outcome
      }),
    })
  }),
@@ -124,8 +97,6 @@ export const node = makeLocationNode({
  deps: [Bus.node],
 })

-const isOutcome = Schema.is(Outcome)
-
 function errorMessage(error: unknown) {
  if (error instanceof Error) return error.message
  if (typeof error === "string") return error
@@ -11,7 +11,6 @@ import { Effect, Option, PubSub, Schema, Stream } from "effect"
 import { ChildProcess } from "effect/unstable/process"
 import { Agent } from "../../agent.js"
 import { Config } from "../../config.js"
-import { Command } from "../../command.js"
 import { Location } from "../../location.js"
 import { Session } from "../../session.js"
 import { SubagentJob } from "../../session/subagent-job.js"
@@ -105,10 +104,9 @@ export const Plugin = define({
                    agent: selected.id,
                    model: model ?? selected.info?.model ?? parent.model,
                  })
-                  const admitted = yield* sessions.prompt({
+                  yield* sessions.prompt({
                    ...input.prompt,
                    sessionID: child.id,
-                    id: input.messageID,
                    text: ["You are a subagent spawned by another session.", text].join("\n"),
                    resume: false,
                  })
@@ -121,22 +119,20 @@ export const Plugin = define({
                  }
                  yield* subagents.start(recovery)
                  yield* subagents.background(recovery)
-                  return Command.prompted(admitted)
+                  return
                }
                if (agent !== undefined) {
                  const session = yield* ctx.session.get({ sessionID: input.sessionID })
                  if (session.agent !== agent) yield* ctx.session.switchAgent({ sessionID: input.sessionID, agent })
                }
                if (model !== undefined) yield* ctx.session.switchModel({ sessionID: input.sessionID, model })
-                const admitted = yield* ctx.session.prompt({
+                yield* ctx.session.prompt({
                  ...input.prompt,
                  sessionID: input.sessionID,
-                  id: input.messageID,
                  text,
                  delivery: input.delivery,
                })
-                return Command.prompted(admitted)
-              }),
+              }).pipe(Effect.asVoid),
          })
        }
      }
@@ -3,7 +3,6 @@ export * as CommandPlugin from "./command.js"
 import { define } from "@opencode/plugin/effect/plugin"
 import { Effect, Stream } from "effect"
 import { Bus } from "../bus.js"
-import { Command } from "../command.js"
 import { Location } from "../location.js"
 import { Mcp } from "../mcp/index.js"
 import PROMPT_INITIALIZE from "./command/initialize.txt"
@@ -35,11 +34,10 @@ export const Plugin = define({
            .prompt({
              ...input.prompt,
              sessionID: input.sessionID,
-              id: input.messageID,
              text: append(PROMPT_INITIALIZE.replace("${path}", location.project.directory), input.prompt.text),
              delivery: input.delivery,
            })
-            .pipe(Effect.map(Command.prompted)),
+            .pipe(Effect.asVoid),
      })
      editor.add({
        name: "review",
@@ -49,11 +47,10 @@ export const Plugin = define({
            .prompt({
              ...input.prompt,
              sessionID: input.sessionID,
-              id: input.messageID,
              text: append(PROMPT_REVIEW.replace("${path}", location.project.directory), input.prompt.text),
              delivery: input.delivery,
            })
-            .pipe(Effect.map(Command.prompted)),
+            .pipe(Effect.asVoid),
      })
      for (const prompt of loaded.prompts) {
        editor.add({
@@ -70,18 +67,16 @@ export const Plugin = define({
                ),
              })
              if (!result) return yield* Effect.fail(new Error(`MCP prompt not found: ${prompt.server}:${prompt.name}`))
-              const admitted = yield* ctx.session.prompt({
+              yield* ctx.session.prompt({
                ...input.prompt,
                sessionID: input.sessionID,
-                id: input.messageID,
                text: result.messages
                  .map((message) => promptMessageText(message.content))
                  .join("\n")
                  .trim(),
                delivery: input.delivery,
              })
-              return Command.prompted(admitted)
-            }),
+            }).pipe(Effect.asVoid),
        })
      }
    })
@@ -167,7 +167,8 @@ export const AzurePlugin = define({
                draft.settings.baseURL,
                resolveResourceName(draft.settings, resourceName) ?? resourceName,
              )
-            if (responsesWebSocketCapable(item.provider, draft)) draft.transport = "websocket"
+            if (responsesWebSocketCapable(item.provider, draft))
+              draft.transport = item.provider.transport ?? "websocket"
          })
        }
      }
@@ -270,7 +270,7 @@ export const OpenAIPlugin = define({
        // ChatGPT-plan tokens only authorize codex-eligible models, and the
        // subscription covers usage, so hide the rest and zero the cost.
        models.update(model.providerID, model.id, (draft) => {
-          draft.transport = "websocket"
+          draft.transport = models.provider.get(model.providerID)?.provider.transport ?? "websocket"
          if (!chatgpt) return
          if (Schema.is(Schema.Struct({ mode: Schema.Literal("pro") }))(draft.body?.reasoning)) {
            draft.enabled = false
@@ -98,7 +98,7 @@ export const XAIPlugin = define({
    yield* ctx.model.transform((models) => {
      for (const model of models.list(providerID)) {
        models.update(providerID, model.id, (draft) => {
-          draft.transport = "websocket"
+          draft.transport = models.provider.get(providerID)?.provider.transport ?? "websocket"
        })
      }
    })
@@ -186,13 +186,12 @@ export interface Interface {
  readonly command: (input: {
    sessionID: SessionSchema.ID
    command: string
-    id?: SessionMessage.ID
    text: string
    files?: PromptInput.Prompt["files"]
    agents?: PromptInput.Prompt["agents"]
    skills?: PromptInput.Prompt["skills"]
    delivery?: SessionInbox.Delivery
-  }) => Effect.Effect<Command.Outcome, NotFoundError | Command.NotFoundError | Command.ExecutionError>
+  }) => Effect.Effect<void, NotFoundError | Command.NotFoundError | Command.ExecutionError>
  readonly shell: (
    input: Parameters<Session.Handle["shell"]>[0] & { sessionID: SessionSchema.ID },
  ) => ReturnType<Session.Handle["shell"]>
@@ -3,7 +3,6 @@ export * as SessionCommand from "./command.js"
 import type { PromptInput } from "@opencode/schema/prompt-input"
 import type { Session } from "@opencode/schema/session"
 import type { SessionInbox } from "@opencode/schema/session-inbox"
-import { SessionMessage } from "@opencode/schema/session-message"
 import { Effect } from "effect"
 import { Command } from "../command.js"
 import { Instance } from "../instance/service.js"
@@ -12,7 +11,6 @@ import { Plugin } from "../plugin/service.js"
 export const execute = Effect.fn("SessionCommand.execute")(function* (input: {
  session: Session.Info
  command: string
-  id?: SessionMessage.ID
  text: string
  files?: PromptInput.Prompt["files"]
  agents?: PromptInput.Prompt["agents"]
@@ -21,11 +19,10 @@ export const execute = Effect.fn("SessionCommand.execute")(function* (input: {
 }) {
  const instances = yield* Instance.Service
  const commands = yield* Plugin.awaitActivation.pipe(Effect.andThen(Command.Service), instances.provide(input.session))
-  return yield* commands.execute({
+  yield* commands.execute({
    name: input.command,
    invocation: {
      sessionID: input.session.id,
-      messageID: input.id ?? SessionMessage.ID.create(),
      prompt: {
        text: input.text,
        files: input.files,
@@ -2,7 +2,6 @@ import { describe, expect } from "bun:test"
 import { Command } from "@opencode/core/command"
 import { AppNodeBuilder } from "@opencode/core/effect/app-node-builder"
 import { Session } from "@opencode/schema/session"
-import { SessionMessage } from "@opencode/schema/session-message"
 import { Effect } from "effect"
 import { testEffect } from "./lib/effect"

@@ -17,10 +16,7 @@ describe("Command", () => {
        editor.add({
          name: "goal",
          description: "Manage the session goal",
-          execute: (input) =>
-            Effect.sync(() => {
-              calls.push(input)
-            }),
+          execute: (input) => Effect.sync(() => calls.push(input)),
        })
      })

@@ -29,41 +25,14 @@ describe("Command", () => {
      )
      const invocation = {
        sessionID: Session.ID.make("ses_test"),
-        messageID: SessionMessage.ID.make("msg_goal"),
        prompt: { text: "ship it", files: [{ uri: "file:///tmp/plan.md" }] },
        delivery: "steer" as const,
      }
-      expect(yield* command.execute({ name: "goal", invocation })).toEqual(Command.immediate)
+      yield* command.execute({ name: "goal", invocation })
      expect(calls).toEqual([invocation])
    }),
  )

-  it.effect("returns prompt outcomes and rejects ones admitted under another message ID", () =>
-    Effect.gen(function* () {
-      const command = yield* Command.Service
-      yield* command.transform((editor) => {
-        editor.add({ name: "ask", execute: (input) => Effect.succeed(Command.prompted({ id: input.messageID })) })
-        editor.add({
-          name: "stray",
-          execute: () => Effect.succeed(Command.prompted({ id: SessionMessage.ID.make("msg_other") })),
-        })
-      })
-      const invocation = {
-        sessionID: Session.ID.make("ses_test"),
-        messageID: SessionMessage.ID.make("msg_ask"),
-        prompt: { text: "" },
-        delivery: "steer" as const,
-      }
-
-      expect(yield* command.execute({ name: "ask", invocation })).toEqual(
-        Command.prompted({ id: invocation.messageID }),
-      )
-      const error = yield* command.execute({ name: "stray", invocation }).pipe(Effect.flip)
-      expect(error).toBeInstanceOf(Command.ExecutionError)
-      expect(error.message).toBe("Command admitted msg_other instead of the invocation message ID msg_ask")
-    }),
-  )
-
  it.effect("replaces commands with later definitions", () =>
    Effect.gen(function* () {
      const command = yield* Command.Service
@@ -91,7 +60,6 @@ describe("Command", () => {
          name: "fail",
          invocation: {
            sessionID: Session.ID.make("ses_test"),
-            messageID: SessionMessage.ID.make("msg_fail"),
            prompt: { text: "" },
            delivery: "steer",
          },
@@ -13,7 +13,6 @@ import { Model } from "@opencode/core/model"
 import { Provider } from "@opencode/core/provider"
 import { AbsolutePath } from "@opencode/core/schema"
 import { Session } from "@opencode/core/session"
-import { SessionMessage } from "@opencode/schema/session-message"
 import { SessionRunnerModel } from "@opencode/core/session/runner/model"
 import { LayerNode } from "@opencode/util/effect/layer-node"
 import { Global } from "@opencode/util/global"
@@ -84,18 +83,12 @@ describe("command subagents", () => {
        const gate = yield* llm.gate()

        // This must return while the child's model is still blocked.
-        const outcome = yield* sessions.command({
-          sessionID: parent.id,
-          command: "review",
-          id: SessionMessage.ID.make("msg_review"),
-          text: "changes",
-        })
+        yield* sessions.command({ sessionID: parent.id, command: "review", text: "changes" })
        yield* gate.started
        const children = (yield* sessions.list({ parentID: parent.id })).data
        expect(children).toHaveLength(1)
        const child = children[0]
        if (!child) return yield* Effect.die("Expected a child session")
-        expect(outcome).toEqual({ type: "prompt", inboxID: SessionMessage.ID.make("msg_review") })
        expect(child).toMatchObject({ agent: fixture.agent, model: { id: fixture.model }, title: "Review code" })
        expect(yield* sessions.get(parent.id)).toMatchObject({ agent: "build", model: parentModel })
        expect(yield* sessions.context(parent.id)).toEqual([])
@@ -105,7 +105,7 @@ describe("ConfigCommandPlugin.Plugin", () => {
                Effect.sync(() => {
                  prompts.push({ text: input.text, delivery: input.delivery })
                  return SessionInbox.User.make({
-                    id: input.id ?? SessionMessage.ID.make("msg_test"),
+                    id: SessionMessage.ID.make("msg_test"),
                    sessionID: input.sessionID,
                    time: { created: DateTime.makeUnsafe(0) },
                    type: "user",
@@ -129,7 +129,6 @@ describe("ConfigCommandPlugin.Plugin", () => {
          name: "explain",
          invocation: {
            sessionID: Session.ID.make("ses_test"),
-            messageID: SessionMessage.ID.make("msg_explain"),
            prompt: { text: item.input },
            delivery: "queue",
          },
@@ -177,7 +176,7 @@ Review files`,
                  Effect.sync(() => {
                    prompts.push({ text: input.text, files: input.files, delivery: input.delivery })
                    return SessionInbox.User.make({
-                      id: input.id ?? SessionMessage.ID.make("msg_test"),
+                      id: SessionMessage.ID.make("msg_test"),
                      sessionID: input.sessionID,
                      time: { created: DateTime.makeUnsafe(0) },
                      type: "user",
@@ -211,7 +210,6 @@ Review files`,
            name: "nested/docs",
            invocation: {
              sessionID: Session.ID.make("ses_test"),
-              messageID: SessionMessage.ID.make("msg_docs"),
              prompt: { text: "details", files: [{ uri: "file:///tmp/context.md" }] },
              delivery: "queue",
            },
@@ -238,7 +236,6 @@ Review files`,
            name: "review",
            invocation: {
              sessionID: Session.ID.make("ses_test"),
-              messageID: SessionMessage.ID.make("msg_latest"),
              prompt: { text: "latest" },
              delivery: "steer",
            },
@@ -10,6 +10,9 @@ import { Model } from "@opencode/core/model"
 import { ModelResolver } from "@opencode/core/model-resolver"
 import { Plugin } from "@opencode/core/plugin"
 import { PluginHost } from "@opencode/core/plugin/host"
+import { AzurePlugin } from "@opencode/core/plugin/provider/azure"
+import { OpenAIPlugin } from "@opencode/core/plugin/provider/openai"
+import { XAIPlugin } from "@opencode/core/plugin/provider/xai"
 import { Provider } from "@opencode/core/provider"
 import { withEnv } from "../fixture/env"
 import { testEffect } from "../lib/effect"
@@ -106,6 +109,50 @@ describe("ConfigProviderPlugin.Plugin", () => {
    }),
  )

+  for (const builtin of [
+    { id: "openai", model: "gpt-5.6-sol", package: "@opencode/ai/providers/openai/responses", plugin: OpenAIPlugin },
+    { id: "xai", model: "grok-4.6", package: "@opencode/ai/providers/xai", plugin: XAIPlugin },
+    { id: "azure", model: "gpt-5.6-sol", package: "@opencode/ai/providers/azure/responses", plugin: AzurePlugin },
+    { id: "custom-azure", model: "deployment", package: "@opencode/ai/providers/azure/responses", plugin: AzurePlugin },
+  ]) {
+    it.live(`provider transport overrides ${builtin.id} defaults while model overrides still win`, () =>
+      Effect.gen(function* () {
+        const providers = yield* Provider.Service
+        const models = yield* Model.Service
+        const plugin = yield* Plugin.Service
+        const host = yield* PluginHost.make(plugin)
+        const providerID = Provider.ID.make(builtin.id)
+        const modelID = Model.ID.make(builtin.model)
+        yield* providers.transform((editor) => {
+          editor.update(providerID, (provider) => {
+            provider.activation = "enabled"
+            provider.package = builtin.package
+          })
+          editor.models.update(providerID, modelID, () => {})
+        })
+        yield* builtin.plugin.effect(host)
+        expect((yield* models.get(providerID, modelID))?.transport).toBe("websocket")
+
+        yield* addPlugin([
+          new Document({
+            type: "document",
+            info: decode({
+              providers: {
+                [builtin.id]: {
+                  transport: "http",
+                  models: { override: { modelID: builtin.model, transport: "websocket" } },
+                },
+              },
+            }),
+          }),
+        ])
+
+        expect((yield* models.get(providerID, modelID))?.transport).toBe("http")
+        expect((yield* models.get(providerID, Model.ID.make("override")))?.transport).toBe("websocket")
+      }),
+    )
+  }
+
  it.effect("adds key auth for custom providers without env credentials", () =>
    Effect.gen(function* () {
      const integrations = yield* Integration.Service
@@ -11,7 +11,6 @@ import { PluginModule } from "@opencode/core/plugin/module"
 import { Watcher } from "@opencode/core/filesystem/watcher"
 import { fromPromise } from "@opencode/plugin/promise/adapter"
 import { Session } from "@opencode/schema/session"
-import { SessionMessage } from "@opencode/schema/session-message"
 import { testEffect } from "./lib/effect"
 import { PluginTestLayer } from "./plugin/fixture"

@@ -498,12 +497,7 @@ it.effect("reloading a plugin replaces its command implementation", () =>
      ])
    const request = {
      name: "greet",
-      invocation: {
-        sessionID: Session.ID.make("ses_plugin"),
-        messageID: SessionMessage.ID.make("msg_greet"),
-        prompt: { text: "" },
-        delivery: "steer" as const,
-      },
+      invocation: { sessionID: Session.ID.make("ses_plugin"), prompt: { text: "" }, delivery: "steer" as const },
    }

    yield* load("1", "before")
@@ -37,7 +37,6 @@ describe("CommandPlugin.Plugin", () => {
    Effect.gen(function* () {
      const command = yield* Command.Service
      const prompts: {
-        id?: string
        text: string
        files?: readonly { readonly uri: string }[]
        delivery?: "steer" | "queue"
@@ -52,9 +51,9 @@ describe("CommandPlugin.Plugin", () => {
          session: {
            prompt: (input) =>
              Effect.sync(() => {
-                prompts.push({ id: input.id, text: input.text, files: input.files, delivery: input.delivery })
+                prompts.push({ text: input.text, files: input.files, delivery: input.delivery })
                return SessionInbox.User.make({
-                  id: input.id ?? SessionMessage.ID.make("msg_test"),
+                  id: SessionMessage.ID.make("msg_test"),
                  sessionID: input.sessionID,
                  time: { created: DateTime.makeUnsafe(0) },
                  type: "user",
@@ -79,11 +78,10 @@ describe("CommandPlugin.Plugin", () => {
        name: "review",
        description: "review changes [commit|branch|pr], defaults to uncommitted",
      })
-      const outcome = yield* command.execute({
+      yield* command.execute({
        name: "init",
        invocation: {
          sessionID: Session.ID.make("ses_test"),
-          messageID: SessionMessage.ID.make("msg_init"),
          prompt: { text: "extra context", files: [{ uri: "file:///tmp/context.md" }] },
          delivery: "queue",
        },
@@ -92,7 +90,6 @@ describe("CommandPlugin.Plugin", () => {
        name: "review",
        invocation: {
          sessionID: Session.ID.make("ses_test"),
-          messageID: SessionMessage.ID.make("msg_review"),
          prompt: { text: "  branch $& $$ $` $'  " },
          delivery: "steer",
        },
@@ -101,7 +98,6 @@ describe("CommandPlugin.Plugin", () => {
        name: "init",
        invocation: {
          sessionID: Session.ID.make("ses_test"),
-          messageID: SessionMessage.ID.make("msg_init_empty"),
          prompt: { text: "" },
          delivery: "steer",
        },
@@ -110,33 +106,27 @@ describe("CommandPlugin.Plugin", () => {
        name: "review",
        invocation: {
          sessionID: Session.ID.make("ses_test"),
-          messageID: SessionMessage.ID.make("msg_review_empty"),
          prompt: { text: "   " },
          delivery: "steer",
        },
      })
-      expect(outcome).toEqual({ type: "prompt", inboxID: SessionMessage.ID.make("msg_init") })
      expect(prompts).toEqual([
        {
-          id: "msg_init",
          text: PROMPT_INITIALIZE.replace("${path}", project).replaceAll("$ARGUMENTS", "extra context"),
          files: [{ uri: "file:///tmp/context.md" }],
          delivery: "queue",
        },
        {
-          id: "msg_review",
          text: PROMPT_REVIEW.replace("${path}", project).replaceAll("$ARGUMENTS", () => "branch $& $$ $` $'"),
          files: undefined,
          delivery: "steer",
        },
        {
-          id: "msg_init_empty",
          text: PROMPT_INITIALIZE.replace("${path}", project).replaceAll("$ARGUMENTS", ""),
          files: undefined,
          delivery: "steer",
        },
        {
-          id: "msg_review_empty",
          text: PROMPT_REVIEW.replace("${path}", project).replaceAll("$ARGUMENTS", ""),
          files: undefined,
          delivery: "steer",
@@ -586,26 +586,26 @@ describe("OpencodePlugin", () => {
          expect(yield* websearch.default()).toBeUndefined()

          state.advertised = true
-          yield* TestClock.adjust("9 minutes")
+          yield* TestClock.adjust("50 seconds")
          yield* drain
          expect(state.requests).toBe(1)
          expect(rebuilds).toEqual(initial)
          expect(yield* websearch.default()).toBeUndefined()

-          yield* TestClock.adjust("1 minute")
+          yield* TestClock.adjust("10 seconds")
          yield* drain
          expect(state.requests).toBe(2)
          expect(rebuilds).toEqual({ provider: initial.provider + 1, websearch: initial.websearch + 1 })
          expect(yield* websearch.default()).toEqual({ id: WebSearch.ID.make("opencode"), name: "OpenCode Web Search" })

-          yield* TestClock.adjust("10 minutes")
+          yield* TestClock.adjust("1 minute")
          yield* drain
          expect(state.requests).toBe(3)
          expect(rebuilds).toEqual({ provider: initial.provider + 1, websearch: initial.websearch + 1 })
          expect(yield* websearch.default()).toEqual({ id: WebSearch.ID.make("opencode"), name: "OpenCode Web Search" })

          state.advertised = false
-          yield* TestClock.adjust("10 minutes")
+          yield* TestClock.adjust("1 minute")
          yield* drain
          expect(state.requests).toBe(4)
          expect(rebuilds).toEqual({ provider: initial.provider + 2, websearch: initial.websearch + 2 })
@@ -1,7 +1,7 @@
 {
  "name": "@opencode/desktop",
  "private": true,
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "homepage": "https://opencode.ai",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/enterprise",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/function",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "$schema": "https://json.schemastore.org/package.json",
  "private": true,
  "type": "module",
@@ -1,6 +1,6 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "name": "@opencode/http-recorder",
  "description": "Record and replay Effect HTTP and WebSocket traffic with deterministic cassettes",
  "type": "module",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/httpapi-codegen",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "exports": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/latex",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "exports": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/merman",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "exports": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/plugin-browser",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "description": "OpenCode's desktop browser plugin",
  "type": "module",
  "license": "MIT",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/plugin",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "scripts": {
@@ -1,30 +1,20 @@
 import type { CommandApi } from "@opencode/client/effect/api"
-import type { Command } from "@opencode/schema/command"
 import type { PromptInput } from "@opencode/schema/prompt-input"
 import type { Session } from "@opencode/schema/session"
 import type { SessionInbox } from "@opencode/schema/session-inbox"
-import type { SessionMessage } from "@opencode/schema/session-message"
 import type { Effect } from "effect"
 import type { Transform } from "./registration.js"

 export interface CommandInvocation {
  readonly sessionID: Session.ID
-  /**
-   * Identity for the input this command admits. Pass it as the prompt `id` and report it in a
-   * `prompt` outcome so clients can follow the resulting work.
-   */
-  readonly messageID: SessionMessage.ID
  readonly prompt: PromptInput.Prompt
  readonly delivery: SessionInbox.Delivery
 }

-/** Resolve with `prompt` when the command admitted session input; `void` or `immediate` finish the command now. */
-export type CommandOutcome = Command.Outcome
-
 export interface CommandDefinition {
  readonly name: string
  readonly description?: string
-  readonly execute: (input: CommandInvocation) => Effect.Effect<CommandOutcome | void, unknown>
+  readonly execute: (input: CommandInvocation) => Effect.Effect<void, unknown>
 }

 export interface CommandEditor {
@@ -1,29 +1,19 @@
 import type { CommandApi } from "@opencode/client/promise/api"
-import type { Command } from "@opencode/schema/command"
 import type { PromptInput } from "@opencode/schema/prompt-input"
 import type { Session } from "@opencode/schema/session"
 import type { SessionInbox } from "@opencode/schema/session-inbox"
-import type { SessionMessage } from "@opencode/schema/session-message"
 import type { Transform } from "./registration.js"

 export interface CommandInvocation {
  readonly sessionID: Session.ID
-  /**
-   * Identity for the input this command admits. Pass it as the prompt `id` and report it in a
-   * `prompt` outcome so clients can follow the resulting work.
-   */
-  readonly messageID: SessionMessage.ID
  readonly prompt: PromptInput.Prompt
  readonly delivery: SessionInbox.Delivery
 }

-/** Resolve with `prompt` when the command admitted session input; `void` or `immediate` finish the command now. */
-export type CommandOutcome = Command.Outcome
-
 export interface CommandDefinition {
  readonly name: string
  readonly description?: string
-  readonly execute: (input: CommandInvocation) => Promise<CommandOutcome | void>
+  readonly execute: (input: CommandInvocation) => Promise<void>
 }

 export interface CommandEditor {
@@ -2066,22 +2066,8 @@
        ],
        "security": [],
        "responses": {
-          "200": {
-            "description": "Success",
-            "content": {
-              "application/json": {
-                "schema": {
-                  "type": "object",
-                  "properties": {
-                    "data": {
-                      "$ref": "#/components/schemas/Command.Outcome"
-                    }
-                  },
-                  "required": ["data"],
-                  "additionalProperties": false
-                }
-              }
-            }
+          "204": {
+            "description": "<No Content>"
          },
          "400": {
            "description": "InvalidRequestError",
@@ -2134,7 +2120,7 @@
            }
          }
        },
-        "description": "Execute a slash command callback. Returns whether the command finished immediately or admitted session input whose execution continues after this request.",
+        "description": "Execute a slash command callback immediately.",
        "summary": "Run command",
        "requestBody": {
          "content": {
@@ -2145,18 +2131,6 @@
                  "name": {
                    "type": "string"
                  },
-                  "id": {
-                    "anyOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^msg_"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Message ID for input the command admits, so its resulting work can be correlated."
-                  },
                  "text": {
                    "type": "string"
                  },
@@ -12493,37 +12467,6 @@
        "required": ["name"],
        "additionalProperties": false
      },
-      "Command.Outcome": {
-        "anyOf": [
-          {
-            "type": "object",
-            "properties": {
-              "type": {
-                "type": "string",
-                "enum": ["immediate"]
-              }
-            },
-            "required": ["type"],
-            "additionalProperties": false
-          },
-          {
-            "type": "object",
-            "properties": {
-              "type": {
-                "type": "string",
-                "enum": ["prompt"]
-              },
-              "inboxID": {
-                "type": "string",
-                "pattern": "^msg_",
-                "description": "Admitted inbox item ID. Must equal the invocation message ID."
-              }
-            },
-            "required": ["type", "inboxID"],
-            "additionalProperties": false
-          }
-        ]
-      },
      "CommandExecutionErrorEncoded": {
        "type": "object",
        "properties": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/protocol",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -33,7 +33,6 @@ import {
  UnknownError,
 } from "../errors.js"
 import { Agent } from "@opencode/schema/agent"
-import { Command } from "@opencode/schema/command"
 import { Skill } from "@opencode/schema/skill"
 import { Model } from "@opencode/schema/model"
 import { Permission } from "@opencode/schema/permission"
@@ -415,13 +414,10 @@ export const makeSessionGroup = <
        params: { sessionID: Session.ID },
        payload: Schema.Struct({
          name: Schema.String,
-          id: SessionMessage.ID.pipe(Schema.optional).annotate({
-            description: "Message ID for input the command admits, so its resulting work can be correlated.",
-          }),
          ...PromptInput.Prompt.fields,
          delivery: SessionInbox.Delivery.pipe(Schema.optional),
        }),
-        success: Schema.Struct({ data: Command.Outcome }),
+        success: HttpApiSchema.NoContent,
        error: [SessionNotFoundError, CommandNotFoundError, CommandExecutionError],
      })
        .middleware(sessionLocationMiddleware)
@@ -429,8 +425,7 @@ export const makeSessionGroup = <
          OpenApi.annotations({
            identifier: "session.command",
            summary: "Run command",
-            description:
-              "Execute a slash command callback. Returns whether the command finished immediately or admitted session input whose execution continues after this request.",
+            description: "Execute a slash command callback immediately.",
          }),
        ),
    )
@@ -563,7 +558,9 @@ export const makeSessionGroup = <
        error: [SessionNotFoundError, SessionBusyError],
      })
        .middleware(sessionLocationMiddleware)
-        .annotateMerge(OpenApi.annotations({ identifier: "session.revert.commit", summary: "Commit staged revert" })),
+        .annotateMerge(
+          OpenApi.annotations({ identifier: "session.revert.commit", summary: "Commit staged revert" }),
+        ),
    )
    .add(
      HttpApiEndpoint.get("session.context", "/api/session/:sessionID/context", {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/schema",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -3,7 +3,6 @@ export * as Command from "./command.js"
 import { Schema } from "effect"
 import { ephemeral, inventory } from "./event.js"
 import { optional } from "./schema.js"
-import { SessionMessage } from "./session-message.js"

 const Updated = ephemeral({ type: "command.updated", schema: {} })

@@ -13,22 +12,6 @@ export const Info = Schema.Struct({
  description: Schema.String.pipe(optional),
 }).annotate({ identifier: "Command.Info" })

-/**
- * What a command did when invoked. `immediate` commands finish inside the request;
- * `prompt` commands durably admitted session input whose resulting work clients
- * follow through the invocation message ID.
- */
-export const Outcome = Schema.Union([
-  Schema.Struct({ type: Schema.tag("immediate") }),
-  Schema.Struct({
-    type: Schema.tag("prompt"),
-    inboxID: SessionMessage.ID.annotate({
-      description: "Admitted inbox item ID. Must equal the invocation message ID.",
-    }),
-  }),
-]).pipe(Schema.toTaggedUnion("type"), Schema.annotate({ identifier: "Command.Outcome" }))
-export type Outcome = typeof Outcome.Type
-
 export const Event = {
  Updated,
  Definitions: inventory(Updated),
@@ -1,6 +1,6 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "name": "@opencode/sdk",
  "type": "module",
  "license": "MIT",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/server",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -336,11 +336,10 @@ export const SessionHandler = HttpApiBuilder.group(Api, "server.session", (handl
      .handle(
        "session.command",
        Effect.fn(function* (ctx) {
-          const outcome = yield* session
+          yield* session
            .command({
              sessionID: ctx.params.sessionID,
              command: ctx.payload.name,
-              id: ctx.payload.id,
              text: ctx.payload.text,
              files: ctx.payload.files,
              agents: ctx.payload.agents,
@@ -366,7 +365,7 @@ export const SessionHandler = HttpApiBuilder.group(Api, "server.session", (handl
                ),
              ),
            )
-          return { data: outcome }
+          return HttpApiSchema.NoContent.make()
        }),
      )
      .handle(
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/session-ui",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/simulation",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/stats-app",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/stats-core",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -1,5 +1,5 @@
 import { describe, expect, test } from "bun:test"
-import { toGeoAggregate, toModelAggregate, toProviderAggregate } from "./inference"
+import { buildStatsQuery, toGeoAggregate, toModelAggregate, toProviderAggregate } from "./inference"
 import { modelAuthor, normalizeInferenceModel, statModel, statProvider } from "./model-normalization"

 describe("inference stat normalization", () => {
@@ -38,6 +38,22 @@ describe("inference stat normalization", () => {
    expect(statProvider("unknown", "", "custom-provider")).toBe("custom-provider")
  })

+  test("merges union alpha routes without exposing the provider", () => {
+    ;["opencode-go/union-alpha", "opencode/union-alpha"].forEach((model) => {
+      expect(statModel(model, "")).toBe("union-alpha")
+      expect(statProvider(model, "gpt-test-model", "test-provider")).toBe("unknown")
+      expect(
+        toModelAggregate({ ...aggregate(model, "test-provider"), provider_model: "gpt-test-model" }),
+      ).toMatchObject([{ model: "union-alpha", provider: "unknown", requests: 1 }])
+      expect(toProviderAggregate(aggregate(model, "test-provider"))).toMatchObject([
+        { provider: "unknown", requests: 1 },
+      ])
+      expect(toGeoAggregate({ ...aggregate(model, "test-provider"), country: "US" })).toMatchObject([
+        { model: "union-alpha", provider: "unknown", country: "US", requests: 1 },
+      ])
+    })
+  })
+
  test("merges renamed models under their current name", () => {
    expect(statModel("deepseek-flash", "")).toBe("deepseek-v4.1-flash")
    expect(statModel("x-preview-f", "")).toBe("ox-alpha")
@@ -94,6 +110,20 @@ describe("inference stat normalization", () => {
      }),
    ).toMatchObject([{ period_key: "2026-W20" }])
  })
+
+  test("normalizes union alpha routes in stat queries", () => {
+    process.env.SST_RESOURCE_InferenceEvent = JSON.stringify({
+      catalog: "inference",
+      database: "events",
+      table: "generation",
+    })
+    process.env.SST_RESOURCE_StatsSyncConfig = JSON.stringify({ dataset: "zen" })
+    const query = buildStatsQuery(new Date("2026-05-20T00:00:00.000Z"), new Date("2026-05-21T00:00:00.000Z"))
+
+    expect(query).toContain("WHEN lower(model) = 'opencode-go/union-alpha' THEN 'union-alpha'")
+    expect(query).toContain("WHEN lower(model) = 'opencode/union-alpha' THEN 'union-alpha'")
+    expect(query).toContain("WHEN lower(model) IN ('omen-alpha', 'union-alpha') THEN 'unknown'")
+  })
 })

 function aggregate(model: string, provider: string) {
@@ -7,6 +7,7 @@ import {
  MODEL_AUTHOR_RULES,
  MODEL_NAME_ALIASES,
  RETIRED_STAT_PROVIDERS,
+  STEALTH_MODELS,
  statModel,
  statProvider,
 } from "./model-normalization"
@@ -263,6 +264,7 @@ ${Object.entries(MODEL_NAME_ALIASES)

 function statProviderSql(model: string, providerModel: string, provider: string) {
  return `CASE
+      WHEN lower(${model}) IN (${[...STEALTH_MODELS].map(sqlString).join(", ")}) THEN 'unknown'
 ${MODEL_AUTHOR_RULES.map((item) => `      WHEN strpos(lower(${providerModel}), ${sqlString(item.match)}) > 0 THEN ${sqlString(item.author)}`).join("\n")}
 ${MODEL_AUTHOR_RULES.map((item) => `      WHEN strpos(lower(${model}), ${sqlString(item.match)}) > 0 THEN ${sqlString(item.author)}`).join("\n")}
      WHEN ${provider} <> '' AND lower(${provider}) NOT IN (${RETIRED_STAT_PROVIDERS.map(sqlString).join(", ")}) THEN ${provider}
@@ -13,8 +13,11 @@ export const MODEL_AUTHOR_RULES = [
  { match: "qwen", author: "qwen" },
 ] as const
 export const EXCLUDED_MODELS = new Set(["alpha-gpt-next"])
+export const STEALTH_MODELS = new Set(["omen-alpha", "union-alpha"])
 export const MODEL_NAME_ALIASES: Record<string, string> = {
  "deepseek-flash": "deepseek-v4.1-flash",
+  "opencode-go/union-alpha": "union-alpha",
+  "opencode/union-alpha": "union-alpha",
  "x-preview-f": "ox-alpha",
  "xiaomi/mimo-v2.5": "mimo-v2.5",
 }
@@ -45,7 +48,10 @@ export function statProvider(
  providerModel: string | undefined,
  provider: string | undefined,
 ) {
-  const modelAuthorValue = modelAuthor(statModel(model, providerModel))
+  const normalized = statModel(model, providerModel)
+  if (STEALTH_MODELS.has(normalized.toLowerCase())) return "unknown"
+
+  const modelAuthorValue = modelAuthor(normalized)
  if (!modelAuthorValue) return undefined

  const providerModelAuthor = modelAuthor(providerModel)
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/stats-server",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/theme",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/tui",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -128,7 +128,7 @@ export function createTuiAttention(input: {
  return {
    async notify(request) {
      try {
-        if (!input.config.attention.enabled) return skipped("attention_disabled")
+        if (!input.config.attention.notifications && !input.config.attention.sound) return skipped("attention_disabled")
        if (disposed || input.renderer.isDestroyed) return skipped("renderer_destroyed")

        const message = normalizeText(request.message, "", MESSAGE_LIMIT)
@@ -253,20 +253,11 @@ export const settings: Setting[] = [
    format: (value) => `${value} ms`,
    keywords: ["leader key", "shortcut timeout"],
  },
-  {
-    title: "Attention",
-    category: "Alerts",
-    path: ["attention", "enabled"],
-    default: false,
-    values: [false, true],
-    labels: ["off", "on"],
-    keywords: ["alerts"],
-  },
  {
    title: "Notifications",
    category: "Alerts",
    path: ["attention", "notifications"],
-    default: true,
+    default: false,
    values: [false, true],
    labels: ["off", "on"],
    keywords: ["system notifications", "desktop notifications", "alerts"],
@@ -275,10 +266,10 @@ export const settings: Setting[] = [
    title: "Sounds",
    category: "Alerts",
    path: ["attention", "sound"],
-    default: true,
+    default: false,
    values: [false, true],
    labels: ["off", "on"],
-    keywords: ["audio", "sound effects"],
+    keywords: ["audio", "sound effects", "alerts"],
  },
  {
    title: "Volume",
@@ -95,7 +95,6 @@ export const Info = Schema.Struct({
  ).annotate({ description: "Scrolling behavior" }),
  attention: Schema.optional(
    Schema.Struct({
-      enabled: Schema.optional(Schema.Boolean).annotate({ description: "Enable attention alerts" }),
      notifications: Schema.optional(Schema.Boolean).annotate({ description: "Show system notifications" }),
      sound: Schema.optional(Schema.Boolean).annotate({ description: "Play attention sounds" }),
      volume: Schema.optional(
@@ -242,7 +241,6 @@ export type Info = Schema.Schema.Type<typeof Info>

 export type Resolved = Omit<Info, "attention" | "cursor" | "keybinds" | "leader" | "mouse" | "session" | "tabs"> & {
  attention: {
-    enabled: boolean
    notifications: boolean
    sound: boolean
    volume: number
@@ -285,9 +283,8 @@ export function resolve(input: Info, options: { terminalSuspend: boolean }): Res
  return {
    ...input,
    attention: {
-      enabled: input.attention?.enabled ?? false,
-      notifications: input.attention?.notifications ?? true,
-      sound: input.attention?.sound ?? true,
+      notifications: input.attention?.notifications ?? false,
+      sound: input.attention?.sound ?? false,
      volume: input.attention?.volume ?? 0.4,
      sound_pack: input.attention?.sound_pack ?? "opencode.default",
      sounds: input.attention?.sounds ?? {},
@@ -1751,8 +1751,7 @@ export async function createSessionTransport(input: StreamInput): Promise<Sessio
    }

    input.trace?.write("send.command", { sessionID: input.sessionID, messageID, command: command.name, delivery })
-    // Command outcomes are not inbox items; the event stream observes any admitted work.
-    await client.session.command(
+    return client.session.command(
      {
        sessionID: input.sessionID,
        name: command.name,
@@ -712,9 +712,9 @@ describe("V2 mini transport", () => {
    })

    while (!ui.commits.some((commit) => commit.text === "Done.")) await Bun.sleep(0)
-    expect(
-      ui.commits.filter((commit) => commit.kind === "assistant" || commit.kind === "tool").map((commit) => commit.text),
-    ).toEqual(["Done."])
+    expect(ui.commits.filter((commit) => commit.kind === "assistant" || commit.kind === "tool").map((commit) => commit.text)).toEqual([
+      "Done.",
+    ])
    await transport.close()
  })

@@ -742,11 +742,7 @@ describe("V2 mini transport", () => {
              model: { providerID: "test", id: "model" },
              content: [
                { type: "text", text: "I'll check." },
-                canonicalToolPart("read", {
-                  status: "completed",
-                  input: {},
-                  content: [{ type: "text", text: "file" }],
-                }),
+                canonicalToolPart("read", { status: "completed", input: {}, content: [{ type: "text", text: "file" }] }),
              ],
              time: { created: 2, completed: 3 },
            },
@@ -763,9 +759,7 @@ describe("V2 mini transport", () => {

    while (!ui.commits.some((commit) => commit.text === "Done.")) await Bun.sleep(0)
    expect(
-      ui.commits
-        .filter((commit) => commit.kind === "user" || commit.kind === "assistant" || commit.kind === "tool")
-        .map((commit) => commit.text),
+      ui.commits.filter((commit) => commit.kind === "user" || commit.kind === "assistant" || commit.kind === "tool").map((commit) => commit.text),
    ).toEqual(["what happened", "Done."])
    await transport.close()
  })
@@ -2935,7 +2929,10 @@ describe("V2 mini transport", () => {
      { sessionID: "ses_1", model: { providerID: "openai", id: "gpt-5", variant: "high" } },
      { signal: undefined },
    )
-    expect(defaultModel).toHaveBeenCalledWith({ location: { directory: "/project" } }, { signal: undefined })
+    expect(defaultModel).toHaveBeenCalledWith(
+      { location: { directory: "/project" } },
+      { signal: undefined },
+    )
    await transport.close()
  })

@@ -3409,7 +3406,7 @@ describe("V2 mini transport", () => {
          data: { sessionID: "ses_1" },
        })
      })
-      return ok({ type: "prompt" as const, inboxID: "msg_cmd" })
+      return ok(undefined)
    })

    await transport.runPromptTurn({
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/ui",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/util",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -2,7 +2,7 @@
  "name": "@opencode/web",
  "type": "module",
  "license": "MIT",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "scripts": {
    "dev": "astro dev",
    "dev:remote": "VITE_API_URL=https://api.opencode.ai astro dev",
@@ -2,7 +2,7 @@
  "name": "opencode",
  "displayName": "opencode",
  "description": "opencode for VS Code",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "publisher": "sst-dev",
  "repository": {
    "type": "git",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/update",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "scripts": {
@@ -2066,22 +2066,8 @@
        ],
        "security": [],
        "responses": {
-          "200": {
-            "description": "Success",
-            "content": {
-              "application/json": {
-                "schema": {
-                  "type": "object",
-                  "properties": {
-                    "data": {
-                      "$ref": "#/components/schemas/Command.Outcome"
-                    }
-                  },
-                  "required": ["data"],
-                  "additionalProperties": false
-                }
-              }
-            }
+          "204": {
+            "description": "<No Content>"
          },
          "400": {
            "description": "InvalidRequestError",
@@ -2134,7 +2120,7 @@
            }
          }
        },
-        "description": "Execute a slash command callback. Returns whether the command finished immediately or admitted session input whose execution continues after this request.",
+        "description": "Execute a slash command callback immediately.",
        "summary": "Run command",
        "requestBody": {
          "content": {
@@ -2145,18 +2131,6 @@
                  "name": {
                    "type": "string"
                  },
-                  "id": {
-                    "anyOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^msg_"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Message ID for input the command admits, so its resulting work can be correlated."
-                  },
                  "text": {
                    "type": "string"
                  },
@@ -12493,37 +12467,6 @@
        "required": ["name"],
        "additionalProperties": false
      },
-      "Command.Outcome": {
-        "anyOf": [
-          {
-            "type": "object",
-            "properties": {
-              "type": {
-                "type": "string",
-                "enum": ["immediate"]
-              }
-            },
-            "required": ["type"],
-            "additionalProperties": false
-          },
-          {
-            "type": "object",
-            "properties": {
-              "type": {
-                "type": "string",
-                "enum": ["prompt"]
-              },
-              "inboxID": {
-                "type": "string",
-                "pattern": "^msg_",
-                "description": "Admitted inbox item ID. Must equal the invocation message ID."
-              }
-            },
-            "required": ["type", "inboxID"],
-            "additionalProperties": false
-          }
-        ]
-      },
      "CommandExecutionErrorEncoded": {
        "type": "object",
        "properties": {
@@ -2066,22 +2066,8 @@
        ],
        "security": [],
        "responses": {
-          "200": {
-            "description": "Success",
-            "content": {
-              "application/json": {
-                "schema": {
-                  "type": "object",
-                  "properties": {
-                    "data": {
-                      "$ref": "#/components/schemas/Command.Outcome"
-                    }
-                  },
-                  "required": ["data"],
-                  "additionalProperties": false
-                }
-              }
-            }
+          "204": {
+            "description": "<No Content>"
          },
          "400": {
            "description": "InvalidRequestError",
@@ -2134,7 +2120,7 @@
            }
          }
        },
-        "description": "Execute a slash command callback. Returns whether the command finished immediately or admitted session input whose execution continues after this request.",
+        "description": "Execute a slash command callback immediately.",
        "summary": "Run command",
        "requestBody": {
          "content": {
@@ -2145,18 +2131,6 @@
                  "name": {
                    "type": "string"
                  },
-                  "id": {
-                    "anyOf": [
-                      {
-                        "type": "string",
-                        "pattern": "^msg_"
-                      },
-                      {
-                        "type": "null"
-                      }
-                    ],
-                    "description": "Message ID for input the command admits, so its resulting work can be correlated."
-                  },
                  "text": {
                    "type": "string"
                  },
@@ -12493,37 +12467,6 @@
        "required": ["name"],
        "additionalProperties": false
      },
-      "Command.Outcome": {
-        "anyOf": [
-          {
-            "type": "object",
-            "properties": {
-              "type": {
-                "type": "string",
-                "enum": ["immediate"]
-              }
-            },
-            "required": ["type"],
-            "additionalProperties": false
-          },
-          {
-            "type": "object",
-            "properties": {
-              "type": {
-                "type": "string",
-                "enum": ["prompt"]
-              },
-              "inboxID": {
-                "type": "string",
-                "pattern": "^msg_",
-                "description": "Admitted inbox item ID. Must equal the invocation message ID."
-              }
-            },
-            "required": ["type", "inboxID"],
-            "additionalProperties": false
-          }
-        ]
-      },
      "CommandExecutionErrorEncoded": {
        "type": "object",
        "properties": {
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Aiden Cline	c635a03165	refactor(codemode): check the Headers receiver before calling the host	2026-09-16 14:16:08 -05:00
Aiden Cline	99084d8a9b	test(codemode): keep only the Headers WPT cases that exercise the runtime	2026-09-16 13:19:46 -05:00
Aiden Cline	c3d278a906	fix(codemode): let Headers methods report a bad receiver	2026-09-16 13:19:46 -05:00
Aiden Cline	e919bcc308	docs(codemode): replace the stale Values section with Extension.make	2026-09-16 13:19:46 -05:00
Aiden Cline	0880378abb	feat(codemode): add the Headers built-in	2026-09-16 13:19:46 -05:00
Shoubhit Dash	2cdd938152	fix: honor provider transport overrides and preserve errors (#49350 )	2026-09-16 22:42:23 +05:30
opencode	4d73b40e59	sync release versions for v2.0.5	2026-09-16 16:35:05 +00:00
opencode-agent[bot]andadamdotdevin	276f2eef3e	fix(stats): hide Union Alpha provider (#49355 ) Co-authored-by: adamdotdevin <2363879+adamdotdevin@users.noreply.github.com>	2026-09-16 10:58:41 -05:00
Dax Raad	8806d34ed4	feat(tui): make notification and sound alerts independent toggles Remove the attention.enabled master switch. Notifications and sounds are now enabled independently and both default to off. Existing enabled keys are ignored; there is no migration.	2026-09-16 11:39:09 -04:00
Shoubhit Dash	cda2bc5100	test(core): match the one minute Console config refresh interval (#49327 )	2026-09-16 17:37:14 +05:30