refactor(app): keep the SSH contract schemas out of the renderer

The Effect schemas move to servers/ssh/schema.ts, imported by the desktop main process for its RPC server; the renderer gets types only. The SSH attempt controller tracks its one in-flight request per server with a cancellation flag instead of Effect fibers, with the same settle-on-cancel behaviour.
refactor(app): port the model selection and terminal stores to plain codecs
2026-09-20 15:47:38 +00:00 · 2026-09-20 16:37:02 +10:00 · 2026-09-20 16:37:02 +10:00 · 2026-09-20 16:37:01 +10:00 · 2026-09-20 16:37:00 +10:00 · 2026-09-20 16:37:00 +10:00
228 changed files with 5446 additions and 2955 deletions
@@ -32,7 +32,7 @@
    },
    "packages/ai": {
      "name": "@opencode/ai",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@aws-sdk/credential-providers": "3.1057.0",
        "@opencode/schema": "workspace:*",
@@ -54,7 +54,7 @@
    },
    "packages/app": {
      "name": "@opencode/app",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@corvu/drawer": "catalog:",
        "@dnd-kit/abstract": "0.5.0",
@@ -111,7 +111,7 @@
    },
    "packages/cli": {
      "name": "@opencode/cli",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "bin": {
        "opencode2": "./bin/opencode2.cjs",
      },
@@ -175,7 +175,7 @@
    },
    "packages/client": {
      "name": "@opencode/client",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@opencode/protocol": "workspace:*",
        "@opencode/schema": "workspace:*",
@@ -201,11 +201,10 @@
    },
    "packages/codemode": {
      "name": "@opencode/codemode",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "acorn": "8.15.0",
        "effect": "catalog:",
-        "typescript": "catalog:",
      },
      "devDependencies": {
        "@tsconfig/bun": "catalog:",
@@ -215,7 +214,7 @@
    },
    "packages/console/app": {
      "name": "@opencode/console-app",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@cloudflare/vite-plugin": "1.15.2",
        "@ibm/plex": "6.4.1",
@@ -251,7 +250,7 @@
    },
    "packages/console/core": {
      "name": "@opencode/console-core",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@aws-sdk/client-sts": "3.782.0",
        "@jsx-email/render": "1.1.1",
@@ -278,7 +277,7 @@
    },
    "packages/console/function": {
      "name": "@opencode/console-function",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@openauthjs/openauth": "0.0.0-20250322224806",
        "@opencode/console-core": "workspace:*",
@@ -295,7 +294,7 @@
    },
    "packages/console/mail": {
      "name": "@opencode/console-mail",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@jsx-email/all": "2.2.3",
        "@jsx-email/cli": "1.4.3",
@@ -319,7 +318,7 @@
    },
    "packages/console/support": {
      "name": "@opencode/console-support",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@cloudflare/vite-plugin": "1.15.2",
        "@opencode/console-core": "workspace:*",
@@ -339,7 +338,7 @@
    },
    "packages/core": {
      "name": "@opencode/core",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@ai-sdk/cohere": "3.0.27",
        "@ai-sdk/gateway": "3.0.104",
@@ -407,7 +406,7 @@
    },
    "packages/desktop": {
      "name": "@opencode/desktop",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@zip.js/zip.js": "2.7.62",
        "electron-context-menu": "4.1.2",
@@ -456,7 +455,7 @@
    },
    "packages/enterprise": {
      "name": "@opencode/enterprise",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@hono/standard-validator": "catalog:",
        "@opencode-ai/sdk": "1.18.21",
@@ -493,7 +492,7 @@
    },
    "packages/function": {
      "name": "@opencode/function",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@octokit/auth-app": "8.0.1",
        "@octokit/rest": "catalog:",
@@ -509,7 +508,7 @@
    },
    "packages/http-recorder": {
      "name": "@opencode/http-recorder",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@effect/platform-node-shared": "4.0.0-rc.112",
      },
@@ -528,7 +527,7 @@
    },
    "packages/httpapi-codegen": {
      "name": "@opencode/httpapi-codegen",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "effect": "catalog:",
        "prettier": "3.6.2",
@@ -541,7 +540,7 @@
    },
    "packages/latex": {
      "name": "@opencode/latex",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@opencode/plugin": "workspace:*",
        "@opentui/core": "catalog:",
@@ -555,7 +554,7 @@
    },
    "packages/merman": {
      "name": "@opencode/merman",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@opencode/plugin": "workspace:*",
        "@opentui/core": "catalog:",
@@ -570,7 +569,7 @@
    },
    "packages/plugin": {
      "name": "@opencode/plugin",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@ai-sdk/provider": "3.0.8",
        "@opencode/ai": "workspace:*",
@@ -609,7 +608,7 @@
    },
    "packages/plugin-browser": {
      "name": "@opencode/plugin-browser",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@opencode/plugin": "workspace:*",
        "@opencode/schema": "workspace:*",
@@ -639,7 +638,7 @@
    },
    "packages/protocol": {
      "name": "@opencode/protocol",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@opencode/schema": "workspace:*",
        "effect": "catalog:",
@@ -654,7 +653,7 @@
    },
    "packages/schema": {
      "name": "@opencode/schema",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@standard-schema/spec": "catalog:",
        "effect": "catalog:",
@@ -678,7 +677,7 @@
    },
    "packages/sdk": {
      "name": "@opencode/sdk",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@opencode/client": "workspace:*",
        "@opencode/core": "workspace:*",
@@ -699,7 +698,7 @@
    },
    "packages/server": {
      "name": "@opencode/server",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@effect/platform-node": "catalog:",
        "@effect/platform-node-shared": "catalog:",
@@ -721,7 +720,7 @@
    },
    "packages/session-ui": {
      "name": "@opencode/session-ui",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@kobalte/core": "catalog:",
        "@opencode/client": "workspace:*",
@@ -756,7 +755,7 @@
    },
    "packages/simulation": {
      "name": "@opencode/simulation",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@opencode/ai": "workspace:*",
        "@opencode/core": "workspace:*",
@@ -776,7 +775,7 @@
    },
    "packages/stats/app": {
      "name": "@opencode/stats-app",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@ibm/plex": "6.4.1",
        "@kobalte/core": "catalog:",
@@ -810,7 +809,7 @@
    },
    "packages/stats/core": {
      "name": "@opencode/stats-core",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@aws-sdk/client-athena": "3.933.0",
        "@planetscale/database": "1.19.0",
@@ -829,7 +828,7 @@
    },
    "packages/stats/server": {
      "name": "@opencode/stats-server",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@aws-sdk/client-firehose": "3.933.0",
        "@effect/platform-node": "catalog:",
@@ -875,7 +874,7 @@
    },
    "packages/theme": {
      "name": "@opencode/theme",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@opentui/core": "catalog:",
        "effect": "catalog:",
@@ -889,7 +888,7 @@
    },
    "packages/tui": {
      "name": "@opencode/tui",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@opencode/client": "workspace:*",
        "@opencode/core": "workspace:*",
@@ -924,7 +923,7 @@
    },
    "packages/ui": {
      "name": "@opencode/ui",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@kobalte/core": "catalog:",
        "@pierre/diffs": "catalog:",
@@ -959,7 +958,7 @@
    },
    "packages/util": {
      "name": "@opencode/util",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@effect/opentelemetry": "catalog:",
        "@effect/platform-node": "catalog:",
@@ -992,7 +991,7 @@
    },
    "packages/web": {
      "name": "@opencode/web",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "@astrojs/cloudflare": "12.6.3",
        "@astrojs/markdown-remark": "6.3.1",
@@ -1033,7 +1032,7 @@
    },
    "services/update": {
      "name": "@opencode/update",
-      "version": "2.0.8",
+      "version": "2.0.10",
      "dependencies": {
        "jose": "6.0.11",
        "semver": "catalog:",
@@ -1,8 +1,8 @@
 {
  "nodeModules": {
-    "x86_64-linux": "sha256-TRfKunG6/UE8rQFyRkx/pX+pe7GT542IJWLEKcFFfAY=",
-    "aarch64-linux": "sha256-JxCYBQoHeJVuEMEe4Ef5f6UxxUCAuhPo96jqMT047Fc=",
-    "aarch64-darwin": "sha256-UEgjeQMivNC7JVsLEDlNbuqp9LJH84f9nHgLHTZ2zDI=",
-    "x86_64-darwin": "sha256-jEs/Oadjf2LVAinY0xyFna0V+NTwoCKXiXmQ83OchF8="
+    "x86_64-linux": "sha256-8mOzCscBAuogG4tm8CroqjTX5E5yzCvTobbhKvxQP0U=",
+    "aarch64-linux": "sha256-drrRSpzxC8bfaTXBpOyaN0QAyBVV7WJzm0NstJ+8sAE=",
+    "aarch64-darwin": "sha256-YY5A/zxLPONvgnI+DZlzcD2K5Q9PIw4F2YbDxKbT4UU=",
+    "x86_64-darwin": "sha256-/c/Ew4onA+9+l6GRKXz3zWq3QFESM7j5RyGLCWRPQFw="
  }
 }
@@ -2,7 +2,7 @@
  "$schema": "https://json.schemastore.org/package.json",
  "name": "opencode",
  "description": "AI-powered development tool",
-  "version": "2.0.8",
+  "version": "2.0.10",
  "private": true,
  "type": "module",
  "packageManager": "bun@1.4.2",
@@ -1,6 +1,6 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
-  "version": "2.0.8",
+  "version": "2.0.10",
  "name": "@opencode/ai",
  "type": "module",
  "license": "MIT",
@@ -73,11 +73,6 @@ const driver = (options: Options, body: string): WebSocketChannelDriver => {
          )
        if (event.type === "error") {
          terminal = true
-          yield* OpenResponses.decodeKnownErrorEvent(event).pipe(
-            Effect.mapError((cause) =>
-              ProviderShared.eventError(options.id, `${options.name} returned a malformed error event`, frame, cause),
-            ),
-          )
          return {
            type: "provider-failure",
            error: OpenResponses.providerFailure(event, `${options.name} stream error`, frame),
@@ -108,7 +108,7 @@ const incremental = (
  return input.slice(baseline.length)
 }

-const code = (event: OpenResponses.Event) => event.code || event.error?.code || event.response?.error?.code || undefined
+const code = (event: OpenResponses.Event) => OpenResponses.errorDetail(event).code

 const rejected = (
  observation: Extract<ChannelObservation, { readonly type: "provider-failure" }>,
@@ -1,4 +1,4 @@
-import { Effect, Option, Schema, SchemaGetter } from "effect"
+import { Effect, Option, Schema } from "effect"
 import type { Content } from "@opencode/schema/tool"
 import { HttpTransport } from "../route/transport/index.js"
 import { Protocol } from "../route/protocol.js"
@@ -333,53 +333,13 @@ export const StreamItem = Schema.StructWithRest(
 export type StreamItem = Schema.Schema.Type<typeof StreamItem>
 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.
+// Responses-compatible providers put error details at the top level, under `error`, or under
+// `response.error`, and gateways reshape them freely: strings, numeric codes, extra fields. Those
+// fields decode as opaque values and `errorDetail` reads them defensively, so an error frame can
+// only fail on invalid JSON and otherwise always classifies with the raw body as the fallback.
 // https://www.openresponses.org/specification
-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])
-export const WebSocketErrorEvent = Schema.StructWithRest(
-  Schema.Struct({
-    type: Schema.tag("error"),
-    status: Schema.optional(Schema.Number),
-    status_code: Schema.optional(Schema.Number),
-    code: optionalNull(Schema.String),
-    message: Schema.optional(Schema.String),
-    param: optionalNull(Schema.String),
-    error: optionalNull(OpenResponsesErrorPayload),
-    headers: Schema.optional(Schema.Record(Schema.String, WebSocketErrorHeader)),
-  }),
-  [Schema.Record(Schema.String, Schema.Unknown)],
-)
-const decodeWebSocketErrorEvent = Schema.decodeUnknownEffect(WebSocketErrorEvent)
-
-export const decodeKnownErrorEvent = (event: Event) =>
-  decodeWebSocketErrorEvent({
-    ...event,
-    status: typeof event.status === "number" ? event.status : undefined,
-    status_code: typeof event.status_code === "number" ? event.status_code : undefined,
-    headers: ProviderShared.isRecord(event.headers)
-      ? Object.fromEntries(
-          Object.entries(event.headers).filter(
-            (entry): entry is [string, string | number | boolean] =>
-              typeof entry[1] === "string" || typeof entry[1] === "number" || typeof entry[1] === "boolean",
-          ),
-        )
-      : undefined,
-  })
+const asText = (value: unknown) =>
+  typeof value === "string" && value.length > 0 ? value : typeof value === "number" ? String(value) : undefined

 export const Event = Schema.StructWithRest(
  Schema.Struct({
@@ -400,31 +360,18 @@ export const Event = Schema.StructWithRest(
          incomplete_details: optionalNull(Schema.Struct({ reason: Schema.optional(Schema.String) })),
          output: Schema.optional(Schema.Array(StreamItem)),
          usage: optionalNull(OpenResponsesUsage),
-          error: optionalNull(OpenResponsesErrorPayload),
+          error: Schema.optional(Schema.Unknown),
        }),
        [Schema.Record(Schema.String, Schema.Unknown)],
      ),
    ),
-    code: optionalNull(Schema.String),
-    message: Schema.optional(Schema.String),
-    param: optionalNull(Schema.String),
-    error: optionalNull(OpenResponsesErrorPayload),
+    code: Schema.optional(Schema.Unknown),
+    message: Schema.optional(Schema.Unknown),
+    error: Schema.optional(Schema.Unknown),
    status: Schema.optional(Schema.Unknown),
    status_code: Schema.optional(Schema.Unknown),
-    headers: Schema.optional(Schema.Unknown),
  }),
  [Schema.Record(Schema.String, Schema.Unknown)],
-).pipe(
-  Schema.decode({
-    decode: SchemaGetter.transform((event) => {
-      if (event.type !== "error" || event.error != null) return event
-      const { code, message, param, ...rest } = event
-      if (code === undefined && message === undefined && param === undefined) return event
-      // Flat errors (for example, Meta's) can also arrive through generic Responses endpoints.
-      return { ...rest, error: { code, message, param } }
-    }),
-    encode: SchemaGetter.passthrough(),
-  }),
 )
 export type Event = Schema.Schema.Type<typeof Event>
 export type NormalizedEvent = Event & { readonly item?: OutputItem | null }
@@ -433,16 +380,15 @@ const decodeEventValue = Schema.decodeUnknownEffect(Event)
 const decodeFrame = Schema.decodeUnknownEffect(ProviderShared.Json)

 /**
- * Decodes one WebSocket frame. xAI answers a rejected `response.create` with `{ "error": { "message", "type" } }` and no
- * event type; that envelope reads as an error event so the failure classifies instead of failing decoding.
+ * Decodes one WebSocket frame. Some providers and gateways answer a rejected `response.create` with a bare
+ * `{ "error": ... }` envelope and no event type; that reads as an error event so it classifies instead of
+ * failing decoding.
 */
 export const decodeChannelEvent = (frame: string) =>
  decodeFrame(frame).pipe(
    Effect.flatMap((value) =>
      decodeEventValue(
-        ProviderShared.isRecord(value) &&
-          value.type === undefined &&
-          (typeof value.error === "string" || ProviderShared.isRecord(value.error))
+        ProviderShared.isRecord(value) && value.type === undefined && value.error != null
          ? { ...value, type: "error" }
          : value,
      ),
@@ -1422,22 +1368,21 @@ const onResponseFinish = Effect.fn("OpenResponses.onResponseFinish")(function* (
  return [{ ...current, lifecycle }, events] satisfies StepResult
 })

-// Build the prettiest summary available from whatever the provider supplied.
-// When both code and message are present, prefix the code so consumers see
-// the failure mode (e.g. `rate_limit_exceeded: Slow down`) instead of just
-// the bare message — production rate limits and context-length failures used
-// to be indistinguishable from generic stream drops. Returns undefined when
-// the payload carries no usable summary.
-const providerErrorMessage = (event: Event, nested: OpenResponsesErrorPayload | undefined): string | undefined => {
-  const message = event.message || nested?.message || undefined
-  const code = event.code || nested?.code || undefined
-  if (message && code) return `${code}: ${message}`
-  return message || code
+/** Error code and message from wherever the frame put them; top-level fields win over nested ones. */
+export const errorDetail = (event: Event) => {
+  const raw = event.error ?? event.response?.error
+  const nested = typeof raw === "string" ? { message: raw } : ProviderShared.isRecord(raw) ? raw : undefined
+  return {
+    message: asText(event.message) ?? asText(nested?.message),
+    code: asText(event.code) ?? asText(nested?.code),
+  }
 }

+// Prefix the code when both are present (`rate_limit_exceeded: Slow down`) so the failure mode is
+// visible; fall back to the raw frame rather than a generic message when neither decodes.
 export const providerFailure = (event: Event, fallback: string, body = ProviderShared.encodeJson(event)) => {
-  const nested = event.error ?? event.response?.error ?? undefined
-  const summary = providerErrorMessage(event, nested)
+  const detail = errorDetail(event)
+  const summary = detail.message && detail.code ? `${detail.code}: ${detail.message}` : (detail.message ?? detail.code)
  const message = summary ?? (body === "{}" ? fallback : body)
  const status =
    typeof event.status === "number"
@@ -1520,18 +1465,7 @@ export const step = (state: ParserState, event: NormalizedEvent) => {
  if (event.type === "response.output_item.done") return onOutputItemDone(state, event.item)
  if (event.type === "response.completed" || event.type === "response.incomplete") return onResponseFinish(state, event)
  if (event.type === "response.failed") return providerFailure(event, `${state.name} response failed`)
-  if (event.type === "error")
-    return decodeKnownErrorEvent(event).pipe(
-      Effect.mapError((cause) =>
-        ProviderShared.eventError(
-          state.id,
-          `${state.name} returned a malformed error event`,
-          ProviderShared.encodeJson(event),
-          cause,
-        ),
-      ),
-      Effect.flatMap(() => providerFailure(event, `${state.name} stream error`)),
-    )
+  if (event.type === "error") return providerFailure(event, `${state.name} stream error`)
  return Effect.succeed<StepResult>([state, NO_EVENTS])
 }

@@ -215,7 +215,9 @@ export const fromWebSocket = (
 ): Effect.Effect<WebSocketConnection, AIError> =>
  Effect.gen(function* () {
    yield* waitOpen(ws, input)
-    const messages = yield* Queue.bounded<string | Uint8Array, AIError | Cause.Done<void>>(128)
+    // The socket pushes frames synchronously and cannot be paused, so the hand-off to the consumer
+    // fiber must absorb whole read buffers. Bun delivers over a thousand small frames in one tick.
+    const messages = yield* Queue.unbounded<string | Uint8Array, AIError | Cause.Done<void>>()

    const oversized = (message: string | Uint8Array) =>
      typeof message === "string" ? new Blob([message]).size > MAX_FRAME_BYTES : message.byteLength > MAX_FRAME_BYTES
@@ -238,19 +240,7 @@ export const fromWebSocket = (
    }
    const offer = (message: string | Uint8Array) => {
      if (rejectOversized(message)) return
-      if (Queue.offerUnsafe(messages, message)) return
-      Queue.failCauseUnsafe(
-        messages,
-        Cause.fail(
-          transportError("WebSocket inbound queue overflow", {
-            body: typeof message === "string" ? message : new TextDecoder().decode(message),
-            url: input.url,
-            operation: "read",
-            code: "queue-overflow",
-            phase: "receive",
-          }),
-        ),
-      )
+      Queue.offerUnsafe(messages, message)
    }

    const onMessage = (event: MessageEvent) => {
@@ -11,66 +11,78 @@ import { sseEvents } from "../lib/sse.js"

 const decodeEvent = Schema.decodeUnknownEffect(OpenResponses.protocol.stream.event)

-it.effect("normalizes flat errors in shared SSE and WebSocket decoding", () =>
+it.effect("decodes error frames verbatim in shared SSE and WebSocket decoding", () =>
  Effect.gen(function* () {
-    const frame = {
-      type: "error",
-      sequence_number: 4,
-      code: "server_shutting_down",
-      message: "Server is shutting down. Please retry your request.",
-      param: null,
-    }
    for (const decode of [decodeEvent, OpenResponses.decodeChannelEvent]) {
-      const event = yield* decode(JSON.stringify(frame))
-      expect(event).toEqual({
-        type: "error",
-        sequence_number: 4,
-        error: { code: frame.code, message: frame.message, param: null },
-      })
-
-      for (const unchanged of [
-        event,
+      for (const frame of [
+        { type: "error", sequence_number: 4, code: "server_shutting_down", message: "Shutting down", param: null },
        { type: "error" },
+        { type: "error", error: "Gateway failed" },
+        { type: "error", error: { code: 429, message: "slow down" } },
+        { type: "error", error: 42 },
+        { type: "error", code: 500, message: ["not", "a", "string"] },
+        { type: "response.failed", response: { id: "resp_failed", error: "Gateway failed" } },
+        { type: "response.failed", response: { id: "resp_failed", error: ["weird"] } },
        {
          type: "response.failed",
          response: { id: "resp_failed", error: { code: "server_error", message: "Internal server error" } },
        },
        { type: "response.output_text.delta", item_id: "msg_text", delta: "Hello" },
      ]) {
-        expect(yield* decode(JSON.stringify(unchanged))).toEqual(unchanged)
+        expect(yield* decode(JSON.stringify(frame))).toEqual(frame)
      }
    }
  }),
 )

-it.effect("continues to normalize untyped xAI WebSocket errors", () =>
+it.effect("reads bare WebSocket error envelopes as error events", () =>
  Effect.gen(function* () {
    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,
-      })
+    for (const error of [{ type: "api_error", message }, message, 42]) {
+      expect(yield* OpenResponses.decodeChannelEvent(JSON.stringify({ error }))).toEqual({ type: "error", error })
+    }
+    for (const frame of [{ error: null }, { message }]) {
+      expect(yield* OpenResponses.decodeChannelEvent(JSON.stringify(frame)).pipe(Effect.flip)).toBeDefined()
    }
  }),
 )

-it.effect("normalizes string errors in shared SSE and WebSocket decoding", () =>
+it.effect("extracts error details from every shape and falls back to the raw frame", () =>
  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" } },
-      })
+    const cases: Array<[frame: Record<string, unknown>, message: string, tag: string]> = [
+      [
+        { type: "error", code: "server_shutting_down", message: "Shutting down" },
+        "server_shutting_down: Shutting down",
+        "UnknownProvider",
+      ],
+      [{ type: "error", error: "Gateway failed" }, "Gateway failed", "UnknownProvider"],
+      [{ type: "error", error: { code: 429, message: "slow down" } }, "429: slow down", "UnknownProvider"],
+      [{ type: "error", error: { message: "slow down" }, status: 429 }, "slow down", "RateLimit"],
+      [{ type: "error", code: 500, message: ["not", "a", "string"] }, "500", "UnknownProvider"],
+      [
+        { type: "response.failed", response: { id: "resp_failed", error: "Gateway failed" } },
+        "Gateway failed",
+        "UnknownProvider",
+      ],
+    ]
+    for (const [frame, message, tag] of cases) {
+      const event = yield* OpenResponses.decodeChannelEvent(JSON.stringify(frame))
+      const error = OpenResponses.providerFailure(event, "fallback", JSON.stringify(frame))
+      expect(error.message).toBe(message)
+      expect(error.reason._tag).toBe(tag)
+      expect(error.reason.body).toBe(JSON.stringify(frame))
    }
+    for (const frame of [
+      { type: "error", error: 42 },
+      { type: "response.failed", response: { id: "resp_failed", error: ["weird"] } },
+    ]) {
+      const event = yield* OpenResponses.decodeChannelEvent(JSON.stringify(frame))
+      const error = OpenResponses.providerFailure(event, "fallback", JSON.stringify(frame))
+      expect(error.message).toBe(JSON.stringify(frame))
+      expect(error.reason._tag).toBe("UnknownProvider")
+    }
+    expect(OpenResponses.providerFailure({ type: "error" }, "fallback", "{}").message).toBe("fallback")
+    expect(OpenResponses.providerFailure({ type: "error" }, "fallback", "{}").reason._tag).toBe("ProviderInternal")
  }),
 )

@@ -0,0 +1,110 @@
+import { expect, test, type Locator, type Page } from "@playwright/test"
+import { fixture, pageMessages } from "../smoke/session-timeline.fixture"
+import { mockOpenCodeServer } from "../utils/mock-server"
+
+test.use({ viewport: { width: 390, height: 844 }, hasTouch: true, isMobile: true })
+
+test.beforeEach(async ({ page }) => {
+  await mockOpenCodeServer(page, {
+    sessions: fixture.sessions,
+    provider: fixture.provider,
+    directory: fixture.directory,
+    project: fixture.project,
+    pageMessages,
+  })
+  await page.addInitScript(
+    ({ directory, server, sessions }) => {
+      localStorage.setItem(
+        "opencode.global.dat:server",
+        JSON.stringify({ projects: { local: [{ worktree: directory, expanded: true }] } }),
+      )
+      localStorage.setItem(
+        "opencode.window.browser.dat:tabs",
+        JSON.stringify(sessions.map((session) => ({ type: "session", server, sessionId: session.id }))),
+      )
+    },
+    { directory: fixture.directory, server: fixture.serverKey, sessions: fixture.sessions },
+  )
+  await page.goto("/")
+  await page.locator('[data-slot="mobile-tabs-trigger"]').click()
+  await expect(page.locator('[data-slot="mobile-tabs-drawer"]')).toBeVisible()
+  const drawer = page.locator('[data-slot="mobile-drawer-content"]')
+  await expect
+    .poll(() => drawer.evaluate((element) => new DOMMatrixReadOnly(getComputedStyle(element).transform).m42))
+    .toBe(0)
+  await expect(drawer).not.toHaveAttribute("data-transitioning")
+})
+
+test("reorders session tabs with touch", async ({ page }) => {
+  const tabs = page.locator('[data-slot="vertical-tabs"] a')
+  await expect(tabs).toContainText([fixture.expected.sourceTitle, fixture.expected.targetTitle])
+
+  const target = tabs.filter({ hasText: fixture.expected.targetTitle })
+  const source = tabs.filter({ hasText: fixture.expected.sourceTitle })
+  const targetBox = await target.boundingBox()
+  const sourceBox = await source.boundingBox()
+  expect(targetBox).not.toBeNull()
+  expect(sourceBox).not.toBeNull()
+
+  await touchDrag(page, source, {
+    from: { x: sourceBox!.x + sourceBox!.width / 2, y: sourceBox!.y + sourceBox!.height / 2 },
+    to: { x: targetBox!.x + targetBox!.width / 2, y: targetBox!.y + targetBox!.height / 2 },
+  })
+
+  await expect(tabs).toContainText([fixture.expected.targetTitle, fixture.expected.sourceTitle])
+})
+
+test("dismisses a touch context menu by tapping outside", async ({ page }) => {
+  const drawer = page.locator('[data-slot="mobile-tabs-drawer"]')
+  const tab = drawer.locator('[data-slot="tab-link"]').filter({ hasText: fixture.expected.sourceTitle })
+  const home = drawer.getByRole("button", { name: "Home", exact: true })
+  const homeBox = await home.boundingBox()
+  const box = await tab.boundingBox()
+  expect(homeBox).not.toBeNull()
+  expect(box).not.toBeNull()
+  const point = { x: box!.x + box!.width / 2, y: box!.y + box!.height / 2 }
+
+  await tab.dispatchEvent("pointerdown", {
+    pointerType: "touch",
+    pointerId: 1,
+    isPrimary: true,
+    clientX: point.x,
+    clientY: point.y,
+  })
+  const rename = page.getByRole("menuitem", { name: "Rename", exact: true })
+  await expect(rename).toBeVisible()
+  await expect(drawer).toBeVisible()
+  await tab.filter({ visible: true }).dispatchEvent("pointerup", {
+    pointerType: "touch",
+    pointerId: 1,
+    isPrimary: true,
+    clientX: point.x,
+    clientY: point.y,
+  })
+
+  await page.touchscreen.tap(homeBox!.x + homeBox!.width / 2, homeBox!.y + homeBox!.height / 2)
+  await expect(rename).toBeHidden()
+  await expect(drawer).toBeVisible()
+})
+
+async function touchDrag(
+  page: Page,
+  source: Locator,
+  input: { from: { x: number; y: number }; to: { x: number; y: number } },
+) {
+  const client = await page.context().newCDPSession(page)
+  await client.send("Input.dispatchTouchEvent", {
+    type: "touchStart",
+    touchPoints: [{ ...input.from, id: 1 }],
+  })
+  await client.send("Input.dispatchTouchEvent", {
+    type: "touchMove",
+    touchPoints: [{ x: (input.from.x + input.to.x) / 2, y: (input.from.y + input.to.y) / 2, id: 1 }],
+  })
+  await expect(source).toHaveCount(2)
+  await client.send("Input.dispatchTouchEvent", {
+    type: "touchMove",
+    touchPoints: [{ ...input.to, id: 1 }],
+  })
+  await client.send("Input.dispatchTouchEvent", { type: "touchEnd", touchPoints: [] })
+}
@@ -166,6 +166,45 @@ test.describe("session timeline projection", () => {
    await expect(longNotice.locator("[title]")).toHaveAttribute("title", `Switched to ${longName}`)
    await expect.poll(() => longNotice.evaluate((element) => element.scrollWidth <= element.clientWidth)).toBe(true)
  })
+
+  test("does not repeat a review comment file as an attachment", async ({ page }) => {
+    const message = userMessage([
+      userText("what's goin on here", { id: "prt_user_review_comment" }),
+      {
+        id: "prt_user_review_file",
+        type: "file",
+        mime: "text/plain",
+        filename: "LiveRuntime.ts",
+        url: "file:///repo/LiveRuntime.ts?start=14&end=32",
+      },
+      {
+        id: "prt_user_unrelated_file",
+        type: "file",
+        mime: "text/plain",
+        filename: "notes.txt",
+        url: "data:text/plain;base64,bm90ZXM=",
+      },
+    ])
+    message.metadata = {
+      displayText: "what's goin on here",
+      comments: [
+        {
+          path: "LiveRuntime.ts",
+          comment: "what's goin on here",
+          selection: { startLine: 14, startChar: 0, endLine: 32, endChar: 0 },
+          origin: "review",
+        },
+      ],
+    }
+
+    await setupTimeline(page, { messages: [message, assistantMessage()] })
+
+    const user = page.locator('[data-component="user-message"]')
+    await expect(user.getByText("LiveRuntime.ts:14-32", { exact: true })).toBeVisible()
+    const attachments = user.locator('[data-slot="user-message-attachments"]')
+    await expect(attachments.getByText("LiveRuntime.ts", { exact: true })).toHaveCount(0)
+    await expect(attachments.getByText("notes.txt", { exact: true })).toBeVisible()
+  })
 })

 function patchFile(file: string, status: "added" | "modified" | "deleted") {
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/app",
-  "version": "2.0.8",
+  "version": "2.0.10",
  "description": "",
  "type": "module",
  "exports": {
@@ -10,7 +10,8 @@
    "./i18n/desktop-native": "./src/runtime/i18n/desktop-native.ts",
    "./updater": "./src/shell/updates/types.ts",
    "./wsl/types": "./src/servers/wsl/types.ts",
-    "./ssh": "./src/servers/ssh/types.ts",
+    "./ssh": "./src/servers/ssh/types.ts",
+    "./ssh/schema": "./src/servers/ssh/schema.ts",
    "./vite": "./vite.js",
    "./index.css": "./src/index.css"
  },
@@ -94,3 +95,4 @@
    "tailwindcss": "4.3.3"
  }
 }
+
@@ -3,7 +3,19 @@ import { checksum } from "@opencode/util/encode"
 import { SessionMessage } from "@opencode/schema/session-message"
 import { Skill } from "@opencode/schema/skill"
 import { Persistence } from "@/runtime/persistence/schema"
-import { FileSelection, SelectedLineRange } from "@/workspaces/files/types"
+// Effect twins of workspaces/files/types until this module moves to plain codecs.
+const SelectedLineRange = Persistence.struct({
+  start: Schema.Number,
+  end: Schema.Number,
+  side: Persistence.optional(Schema.Literals(["additions", "deletions"])),
+  endSide: Persistence.optional(Schema.Literals(["additions", "deletions"])),
+})
+const FileSelection = Persistence.struct({
+  startLine: Schema.Number,
+  startChar: Schema.Number,
+  endLine: Schema.Number,
+  endChar: Schema.Number,
+})

 const PartBase = {
  content: Schema.String,
@@ -228,3 +240,5 @@ export const PromptHistoryEntry = Schema.Union([HistoryEntry, HistoryPrompt]).pi
 export type PromptHistoryEntry = typeof PromptHistoryEntry.Type

 export const PromptHistoryState = Persistence.struct({ entries: Persistence.array(PromptHistoryEntry) })
+
+
@@ -11,15 +11,15 @@ import { Persist, persisted } from "@/runtime/persistence/storage"
 import { showToast } from "@/shell/notifications/toast"
 import { useDialog } from "@opencode/ui/context/dialog"
 import { createResource } from "solid-js"
-import { Schema } from "effect"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"
+
 import type { HomeController } from "../model"
 import { useGlobal } from "@/runtime/server/runtime"
-import { SessionTransfer } from "@opencode/schema/session-transfer"
+
 import { useSshAuthenticate } from "@/servers/ssh/authenticate"

-export const HomeServersSchema = Schema.Struct({
-  collapsed: Persistence.record(Persistence.fallback(Schema.Boolean, () => false)),
+export const HomeServersSchema = Codec.struct({
+  collapsed: Codec.lenientRecord(Codec.fallback(Codec.boolean, () => false)),
 })

 export function createHomeProjectsController(home: HomeController) {
@@ -114,8 +114,13 @@ export function createHomeProjectsController(home: HomeController) {
              extensions: ["json"],
            },
            async (file) => {
-              const data = await Schema.decodeUnknownPromise(Schema.fromJsonString(SessionTransfer.Data))(
-                await file.text(),
+              // Validating an imported file is the one place the shared Effect schema is needed here.
+              const [{ Schema }, { SessionTransfer }] = await Promise.all([
+                import("effect"),
+                import("@opencode/schema/session-transfer"),
+              ])
+              const data = await Schema.decodeUnknownPromise(Schema.fromJsonString(SessionTransfer.Data))(
+                await file.text(),
              )
              const api = home.server.context(conn).sdk.api.session
              const imported = await api.import({
@@ -184,3 +189,4 @@ export function createHomeProjectsController(home: HomeController) {
 }

 export type HomeProjectsController = ReturnType<typeof createHomeProjectsController>
+
@@ -5,7 +5,7 @@ import { Show, Suspense, createMemo, createSignal, lazy, onMount } from "solid-j
 import { createStore } from "solid-js/store"
 import { makeEventListener } from "@solid-primitives/event-listener"
 import { debounce } from "@solid-primitives/scheduled"
-import { Schema } from "effect"
+import { Codec } from "@/runtime/persistence/codec"
 import createPresence from "solid-presence"
 import { Composer } from "@/composer/composer"
 import { ComposerDropzone } from "@/composer/dropzone"
@@ -21,7 +21,6 @@ import { useWorkspaceLocation } from "@/workspaces/location"
 import { useProviders } from "@/providers/catalog/providers"
 import { NEW_SESSION_CONTENT_WIDTH } from "@/new-session/layout"
 import { Persist, persisted } from "@/runtime/persistence/storage"
-import { Persistence } from "@/runtime/persistence/schema"
 import type { NewSessionWorkspaceController } from "./workspace/controller"
 import { NewSessionWordmark } from "./wordmark"
 import { SummaryPopover } from "@/session/summary/popover"
@@ -34,12 +33,12 @@ const NewSessionSummary = lazy(async () => {

 const providerTipDismissalDuration = 30 * 24 * 60 * 60 * 1000

-export const WorkspaceOnboardingSchema = Persistence.struct({
-  used: Schema.Boolean,
+export const WorkspaceOnboardingSchema = Codec.struct({
+  used: Codec.boolean,
 })

-export const ProviderTipSchema = Persistence.struct({
-  dismissedAt: Schema.Finite,
+export const ProviderTipSchema = Codec.struct({
+  dismissedAt: Codec.number,
 })

 export const WorkspaceTipSchema = ProviderTipSchema
@@ -267,3 +266,4 @@ function NewSessionTips(props: { workspaceEligible: boolean; onWorkspace: () =>
    </Show>
  )
 }
+
@@ -1,7 +1,6 @@
 import { useData } from "@/runtime/server/current"
 import { useServerSDK } from "@/runtime/server/client"
 import { normalizeProviderList } from "@/runtime/server/global-sync/utils"
-import { Iterable, pipe } from "effect"
 import { createEffect, createMemo, type Accessor } from "solid-js"
 import type { ProviderListResponse } from "@/runtime/server/types"
 import { useIntegrations } from "./integrations"
@@ -53,34 +52,24 @@ export function useProviders(directory: Accessor<string | undefined>) {
        .filter((integration) => popularProviderSet.has(integration.id))
        .map((integration) => ({ id: integration.id, name: integration.name }))
      const seen = new Set(catalog.map((integration) => integration.id))
-      return pipe(
-        providers().all,
-        Iterable.map(([, p]) => p),
-        Iterable.filter((p) => popularProviderSet.has(p.id) && !seen.has(p.id)),
-        Iterable.map((p) => ({ id: p.id, name: p.name })),
-        (v) => [...catalog, ...v],
-      )
+      const more = [...providers().all.values()]
+        .filter((p) => popularProviderSet.has(p.id) && !seen.has(p.id))
+        .map((p) => ({ id: p.id, name: p.name }))
+      return [...catalog, ...more]
    },
    connected: () => {
      const connected = new Set(providers().connected)
-      return pipe(
-        providers().all,
-        Iterable.map(([, p]) => p),
-        Iterable.filter((p) => connected.has(p.id)),
-        (v) => Array.from(v),
-      )
+      return [...providers().all.values()].filter((p) => connected.has(p.id))
    },
    paid: () => {
      const connected = new Set(providers().connected)
-      const paid = [
-        ...Iterable.filter(
-          providers().all,
-          ([id]) =>
-            connected.has(id) &&
-            (id !== "opencode" || Object.values(providers().all.get(id)?.models ?? {}).some((m) => m.cost?.input)),
-        ),
-      ]
+      const paid = [...providers().all].filter(
+        ([id]) =>
+          connected.has(id) &&
+          (id !== "opencode" || Object.values(providers().all.get(id)?.models ?? {}).some((m) => m.cost?.input)),
+      )
      return paid
    },
  }
 }
+
@@ -3,12 +3,11 @@ import { base64Encode } from "@opencode/util/encode"
 import { useParams } from "@solidjs/router"
 import { batch, createEffect, createMemo, onCleanup } from "solid-js"
 import { createStore } from "solid-js/store"
-import { Schema, SchemaGetter } from "effect"
+import { Codec } from "@/runtime/persistence/codec"
 import { useModels } from "@/providers/models/models"
 import { useSettings } from "@/settings/model"
 import { useProviders } from "@/providers/catalog/providers"
 import { Persist, persisted } from "@/runtime/persistence/storage"
-import { Persistence } from "@/runtime/persistence/schema"
 import { hasCustomAgent, resolveAgent } from "./agent"
 import { cycleModelVariant, getConfiguredAgentVariant, resolveModelVariant } from "./variant"
 import { useWorkspaceLocation } from "@/workspaces/location"
@@ -18,46 +17,45 @@ import { useServerSDK } from "@/runtime/server/client"
 import { ScopedKey, type ServerScope } from "@/runtime/server/scope"
 import { useConfiguredModel } from "./configured"

-const ModelKeySchema = Schema.Struct({
-  providerID: Schema.String,
-  modelID: Schema.String,
-  variant: Schema.optional(Schema.String),
+const ModelKeySchema = Codec.struct({
+  providerID: Codec.string,
+  modelID: Codec.string,
+  variant: Codec.optional(Codec.string),
 })
 export type ModelKey = typeof ModelKeySchema.Type

-const ChoiceSchema = Schema.Struct({
-  model: Persistence.optional(ModelKeySchema),
-  variant: Persistence.optional(Schema.NullOr(Schema.String)),
+const ChoiceSchema = Codec.struct({
+  model: Codec.lenientOptional(ModelKeySchema),
+  variant: Codec.lenientOptional(Codec.nullOr(Codec.string)),
 })
-const StateSchema = Schema.Struct({
+const StateSchema = Codec.struct({
  ...ChoiceSchema.fields,
-  agent: Persistence.optional(Schema.String),
-  choices: Persistence.optional(Schema.Record(Schema.String, ChoiceSchema)),
+  agent: Codec.lenientOptional(Codec.string),
+  choices: Codec.lenientOptional(Codec.record(ChoiceSchema)),
 })
 type State = typeof StateSchema.Type

-const SessionsSchema = Schema.Record(
-  Schema.String,
-  Schema.mutableKey(Persistence.fallback(Schema.UndefinedOr(StateSchema), () => undefined)),
+const SessionsSchema = Codec.record(Codec.fallback(Codec.undefinedOr(StateSchema), () => undefined))
+
+const Current = Codec.struct({ session: SessionsSchema })
+const StoredSelection = Codec.struct(
+  {
+    session: Codec.lenientOptional(Codec.record(Codec.unknown)),
+    pick: Codec.lenientOptional(Codec.record(Codec.unknown)),
+  },
+  { preserve: true },
 )

-const Current = Persistence.struct({ session: SessionsSchema })
-
-export const ModelSelectionSchema = Persistence.migrate(
+export const ModelSelectionSchema = Codec.migrate(
  Current,
-  Schema.Struct({
-    session: Persistence.optional(Schema.Record(Schema.String, Schema.Unknown)),
-    pick: Persistence.optional(Schema.Record(Schema.String, Schema.Unknown)),
-  }).pipe(
-    Schema.decode({
-      decode: SchemaGetter.transform((value) => ({
-        session:
-          value.session ??
-          Object.fromEntries(Object.entries(value.pick ?? {}).filter(([key]) => key !== WORKSPACE_KEY)),
-      })),
-      encode: SchemaGetter.transform((value) => value),
+  Codec.transform(StoredSelection, {
+    decode: (value) => ({
+      ...value,
+      session:
+        value.session ?? Object.fromEntries(Object.entries(value.pick ?? {}).filter(([key]) => key !== WORKSPACE_KEY)),
    }),
-  ),
+    encode: (value) => value,
+  }),
 )

 const WORKSPACE_KEY = "__workspace__"
@@ -1,7 +1,7 @@
 import { flatten, resolveTemplate, translator, type Flatten } from "@solid-primitives/i18n"
 import { createEffect, createMemo, createResource, type JSX } from "solid-js"
 import { createStore } from "solid-js/store"
-import { Option, Schema, SchemaGetter } from "effect"
+import { Codec } from "@/runtime/persistence/codec"
 import { createSimpleContext } from "@opencode/ui/context"
 import {
  I18nProvider,
@@ -12,7 +12,6 @@ import {
  type UiPluralCategory,
 } from "@opencode/ui/context/i18n"
 import { Persist, persisted } from "@/runtime/persistence/storage"
-import { Persistence } from "@/runtime/persistence/schema"
 import en from "@/runtime/i18n/en"
 import { dict } from "@opencode/ui/i18n/en"
 import {
@@ -56,14 +55,9 @@ function cookie(locale: Locale) {

 const LOCALES: readonly Locale[] = DESKTOP_NATIVE_LOCALES

-const LocaleSchema = Schema.Literals(DESKTOP_NATIVE_LOCALES)
-const StoredLocaleSchema = Schema.Struct({
-  locale: Schema.String.pipe(
-    Schema.decodeTo(LocaleSchema, {
-      decode: SchemaGetter.transform(normalizeLocale),
-      encode: SchemaGetter.transform((locale) => locale),
-    }),
-  ),
+const LocaleSchema = Codec.literals(DESKTOP_NATIVE_LOCALES)
+const StoredLocaleSchema = Codec.struct({
+  locale: Codec.transform(Codec.string, { decode: normalizeLocale, encode: (locale) => locale }),
 })

 const INTL = DESKTOP_NATIVE_LOCALE_TAGS
@@ -160,11 +154,11 @@ function detectLocale(): Locale {
 }

 export function normalizeLocale(value: string): Locale {
-  return Option.getOrElse(Schema.decodeUnknownOption(LocaleSchema)(value), () => "en")
+  return Codec.decodeOption(LocaleSchema, value) ?? "en"
 }

-export const languageSchema = Persistence.struct({
-  locale: StoredLocaleSchema.fields.locale,
+export const languageSchema = Codec.struct({
+  locale: StoredLocaleSchema.fields.locale,
 })

 function readStoredLocale() {
@@ -172,9 +166,7 @@ function readStoredLocale() {
  try {
    const raw = localStorage.getItem("opencode.global.dat:language")
    if (!raw) return
-    const next = Schema.decodeUnknownOption(Schema.fromJsonString(StoredLocaleSchema))(raw)
-    if (Option.isNone(next)) return
-    return next.value.locale
+    return Codec.decodeOption(Codec.fromJsonString(StoredLocaleSchema), raw)?.locale
  } catch {
    return
  }
@@ -296,3 +288,4 @@ export function UiI18nBridge(props: { children?: JSX.Element }) {
    </I18nProvider>
  )
 }
+
@@ -0,0 +1,17 @@
+import { expect, test } from "bun:test"
+import { Codec } from "./codec"
+
+// Type-level checks: these compile only if inference matches what `typeof schema.Type` gave callers.
+test("struct types infer optional and required fields", () => {
+  const s = Codec.struct({ id: Codec.string, tab: Codec.optional(Codec.string), n: Codec.lenientOptional(Codec.number) })
+  const value: typeof s.Type = { id: "x" }
+  const tab: string | undefined = value.tab
+  const n: number | undefined = value.n
+  const t = Codec.transform(s, { decode: (old) => old.tab ?? old.id, encode: (v) => ({ id: v }) })
+  const out: string | Codec.Invalid = t.decode({ id: "a" })
+  const onlyOptional = Codec.struct({ tab: Codec.optional(Codec.string) })
+  const empty: typeof onlyOptional.Type = {}
+  const maybe: string | undefined = empty.tab
+  const viaTransform = Codec.transform(onlyOptional, { decode: (old) => old.tab, encode: (tab) => ({ tab }) })
+  expect([tab, n, out, maybe, viaTransform.decode({})]).toEqual([undefined, undefined, "a", undefined, undefined])
+})
@@ -0,0 +1,85 @@
+import { describe, expect, test } from "bun:test"
+import { Codec } from "./codec"
+
+describe("Codec", () => {
+  test("primitives reject the wrong shape and finite numbers only", () => {
+    expect(Codec.string.decode("a")).toBe("a")
+    expect(Codec.string.decode(1)).toBe(Codec.INVALID)
+    expect(Codec.number.decode(1.5)).toBe(1.5)
+    expect(Codec.number.decode(Number.NaN)).toBe(Codec.INVALID)
+    expect(Codec.nonNegativeInt.decode(-1)).toBe(Codec.INVALID)
+    expect(Codec.literals(["a", "b"]).decode("c")).toBe(Codec.INVALID)
+    expect(Codec.literal("x").decode("x")).toBe("x")
+  })
+
+  test("struct keeps optional fields absent and rejects invalid required ones", () => {
+    const codec = Codec.struct({ id: Codec.string, title: Codec.optional(Codec.string), n: Codec.lenientOptional(Codec.number) })
+    expect(codec.decode({ id: "1" })).toEqual({ id: "1" })
+    expect(codec.decode({ id: "1", title: "t", n: "bad" })).toEqual({ id: "1", title: "t" })
+    expect(codec.decode({ id: "1", title: 3 })).toBe(Codec.INVALID)
+    expect(codec.decode({ title: "t" })).toBe(Codec.INVALID)
+    expect(codec.decode([])).toBe(Codec.INVALID)
+    expect(codec.encode({ id: "1" })).toEqual({ id: "1" })
+    const value: typeof codec.Type = { id: "1", title: undefined }
+    expect(value.id).toBe("1")
+  })
+
+  test("lenient collections recover what they can", () => {
+    const items = Codec.lenientArray(Codec.struct({ id: Codec.string }))
+    expect(items.decode([{ id: "a" }, { id: 1 }, "x", { id: "b" }])).toEqual([{ id: "a" }, { id: "b" }])
+    expect(items.decode("nope")).toEqual([])
+    expect(Codec.array(Codec.string).decode(["a", 1])).toBe(Codec.INVALID)
+    const map = Codec.lenientRecord(Codec.boolean)
+    expect(map.decode({ a: true, b: "x" })).toEqual({})
+    expect(map.decode({ a: true })).toEqual({ a: true })
+  })
+
+  test("union, transform and fallback compose", () => {
+    const session = Codec.struct({ type: Codec.literal("session"), id: Codec.string })
+    const draft = Codec.struct({ type: Codec.literal("draft"), directory: Codec.string })
+    const tab = Codec.union([session, draft])
+    expect(tab.decode({ type: "draft", directory: "/x" })).toEqual({ type: "draft", directory: "/x" })
+    expect(tab.decode({ type: "other" })).toBe(Codec.INVALID)
+    const upper = Codec.transform(Codec.string, { decode: (s) => s.toUpperCase(), encode: (s) => s.toLowerCase() })
+    expect(upper.decode("ab")).toBe("AB")
+    expect(upper.encode("AB")).toBe("ab")
+    const safe = Codec.fallback(Codec.number, () => 7)
+    expect(safe.decode("x")).toBe(7)
+    expect(safe.decode(undefined)).toBe(7)
+    expect(safe.decode(2)).toBe(2)
+  })
+
+  test("brand constructs and decodes as its base", () => {
+    const Key = Codec.brand<"ServerConnection.Key">()
+    const key = Key.make("http://a")
+    expect(Key.decode(key)).toBe(key)
+    expect(Key.decode(3)).toBe(Codec.INVALID)
+  })
+
+  test("withInitial recovers field by field and merges new defaults", () => {
+    const layout = Codec.struct({
+      sidebar: Codec.struct({ opened: Codec.boolean, width: Codec.number }),
+      theme: Codec.lenientOptional(Codec.literals(["light", "dark"])),
+    })
+    const initial: typeof layout.Type = { sidebar: { opened: true, width: 240 } }
+    const codec = Codec.fromJsonString(Codec.withInitial(layout, initial))
+    expect(codec.decode(JSON.stringify({ sidebar: { opened: false, width: "wide" }, theme: "dark" }))).toEqual({
+      sidebar: { opened: false, width: 240 },
+      theme: "dark",
+    })
+    expect(codec.decode(JSON.stringify({ sidebar: 5 }))).toEqual(initial)
+    expect(codec.decode("{not json")).toBe(Codec.INVALID)
+    expect(JSON.parse(codec.encode({ sidebar: { opened: true, width: 1 } }))).toEqual({ sidebar: { opened: true, width: 1 } })
+  })
+
+  test("migrate reads the old shape first", () => {
+    const current = Codec.struct({ tabs: Codec.array(Codec.string) })
+    const previous = Codec.struct({ tab: Codec.optional(Codec.string) })
+    const read = Codec.transform(previous, {
+      decode: (old) => ({ tabs: old.tab ? [old.tab] : [] }),
+      encode: (value) => ({ tab: value.tabs[0] }),
+    })
+    const codec = Codec.withInitial(Codec.migrate(current, read), { tabs: [] })
+    expect(codec.decode({ tab: "a" })).toEqual({ tabs: ["a"] })
+  })
+})
@@ -0,0 +1,366 @@
+export * as Codec from "./codec"
+
+// Plain codecs for persisted state. They replace Effect Schema in the renderer's initial module
+// graph, where Effect's own module initialisation was the single largest startup cost that was not
+// rendering. Semantics mirror the Persistence helpers: decoding never throws, `INVALID` marks a
+// value that cannot be recovered, and the lenient combinators recover what they can.
+
+export const INVALID: unique symbol = Symbol.for("opencode/persistence/codec/invalid")
+export type Invalid = typeof INVALID
+
+const tag: unique symbol = Symbol.for("opencode/persistence/codec")
+
+export interface Of<T, E = unknown> {
+  readonly [tag]: true
+  /** Phantom: `typeof codec.Type` is the decoded type, as with Effect schemas. */
+  readonly Type: T
+  readonly Encoded: E
+  readonly optional?: boolean
+  decode(input: unknown): T | Invalid
+  encode(value: T): E
+}
+
+export type Any = Of<any, any>
+export type Type<C extends Any> = C["Type"]
+
+export function isCodec(value: unknown): value is Any {
+  return typeof value === "object" && value !== null && tag in value
+}
+
+export function make<T, E = unknown>(decode: (input: unknown) => T | Invalid, encode: (value: T) => E): Of<T, E> {
+  return { [tag]: true, decode, encode } as Of<T, E>
+}
+
+export function is<T>(codec: Of<T>, input: unknown): input is T {
+  return codec.decode(input) !== INVALID
+}
+
+export function decodeOption<T>(codec: Of<T>, input: unknown): T | undefined {
+  const value = codec.decode(input)
+  return value === INVALID ? undefined : value
+}
+
+export function decodeOrThrow<T>(codec: Of<T>, input: unknown): T {
+  const value = codec.decode(input)
+  if (value === INVALID) throw new Error("Value does not match its codec")
+  return value
+}
+
+/** Encodes and checks the result decodes, so an invalid in-memory value fails loudly instead of persisting. */
+export function encodeOrThrow<T, E>(codec: Of<T, E>, value: T): E {
+  const encoded = codec.encode(value)
+  if (codec.decode(encoded) === INVALID) throw new Error("Value does not match its codec")
+  return encoded
+}
+
+const identity = <T>(value: T) => value
+
+export const string: Of<string, string> = make((v) => (typeof v === "string" ? v : INVALID), identity)
+export const boolean: Of<boolean, boolean> = make((v) => (typeof v === "boolean" ? v : INVALID), identity)
+export const unknown: Of<unknown, unknown> = make((v) => v, identity)
+/** Finite numbers only: NaN and infinities are not JSON and never valid state. */
+export const number: Of<number, number> = make((v) => (typeof v === "number" && Number.isFinite(v) ? v : INVALID), identity)
+export const int: Of<number, number> = make((v) => (typeof v === "number" && Number.isInteger(v) ? v : INVALID), identity)
+export const nonNegativeInt: Of<number, number> = make(
+  (v) => (typeof v === "number" && Number.isInteger(v) && v >= 0 ? v : INVALID),
+  identity,
+)
+
+export function literal<const L extends string | number | boolean | null>(value: L): Of<L, L> {
+  return make((v) => (v === value ? value : INVALID), identity)
+}
+
+export function literals<const L extends ReadonlyArray<string | number | boolean | null>>(values: L): Of<L[number], L[number]> {
+  const set = new Set<unknown>(values)
+  return make((v) => (set.has(v) ? (v as L[number]) : INVALID), identity)
+}
+
+/** A string carrying a nominal brand, with the constructor Effect's `Schema.brand` gave callers. */
+export function brand<B extends string>(): Of<string & { readonly [K in B]: B }, string> & {
+  make(value: string): string & { readonly [K in B]: B }
+} {
+  return Object.assign(make<string & { readonly [K in B]: B }, string>((v) => (typeof v === "string" ? (v as never) : INVALID), identity), {
+    make: (value: string) => value as never,
+  })
+}
+
+export function nullOr<T, E>(codec: Of<T, E>): Of<T | null, E | null> {
+  return make((v) => (v === null ? null : codec.decode(v)), (v) => (v === null ? null : codec.encode(v)))
+}
+
+export function undefinedOr<T, E>(codec: Of<T, E>): Of<T | undefined, E | undefined> {
+  return make((v) => (v === undefined ? undefined : codec.decode(v)), (v) => (v === undefined ? undefined : codec.encode(v)))
+}
+
+/** A struct field that may be absent. Present but invalid values make the struct invalid. */
+export function optional<T, E>(codec: Of<T, E>): Of<T | undefined, E | undefined> & { readonly optional: true } {
+  return { ...undefinedOr(codec), optional: true } as never
+}
+
+/** A struct field that may be absent, and whose invalid values are dropped rather than rejected. */
+export function lenientOptional<T, E>(codec: Of<T, E>): Of<T | undefined, E | undefined> & { readonly optional: true } {
+  return {
+    ...make<T | undefined, E | undefined>(
+      (v) => {
+        if (v === undefined) return undefined
+        const value = codec.decode(v)
+        return value === INVALID ? undefined : value
+      },
+      (v) => (v === undefined ? undefined : codec.encode(v)),
+    ),
+    optional: true,
+  } as never
+}
+
+type Fields = Record<string, Any>
+type OptionalKeys<F extends Fields> = { [K in keyof F]: F[K] extends { optional: true } ? K : never }[keyof F]
+type RequiredKeys<F extends Fields> = Exclude<keyof F, OptionalKeys<F>>
+type Simplify<T> = { [K in keyof T]: T[K] } & {}
+export type StructType<F extends Fields> = Simplify<
+  { [K in RequiredKeys<F>]: F[K]["Type"] } & { [K in OptionalKeys<F>]?: F[K]["Type"] }
+>
+export type StructEncoded<F extends Fields> = Simplify<
+  { [K in RequiredKeys<F>]: F[K]["Encoded"] } & { [K in OptionalKeys<F>]?: F[K]["Encoded"] }
+>
+
+export interface Struct<F extends Fields> extends Of<StructType<F>, StructEncoded<F>> {
+  readonly fields: F
+}
+
+// `preserve` keeps keys the struct does not declare, for migration shapes that only describe the
+// fields they rewrite (Effect's `onExcessProperty: "preserve"`); the current schema then decides.
+export function struct<const F extends Fields>(fields: F, options?: { preserve?: boolean }): Struct<F> {
+  const entries = Object.entries(fields)
+  return {
+    ...make<StructType<F>, StructEncoded<F>>(
+      (input) => {
+        if (typeof input !== "object" || input === null || Array.isArray(input)) return INVALID
+        const record = input as Record<string, unknown>
+        const out: Record<string, unknown> = options?.preserve ? { ...record } : {}
+        for (const [key, codec] of entries) {
+          const present = Object.hasOwn(record, key)
+          if (!present && codec.optional) continue
+          const value = codec.decode(record[key])
+          if (value === INVALID) return INVALID
+          if (value !== undefined || present) out[key] = value
+          else delete out[key]
+        }
+        return out as StructType<F>
+      },
+      (value) => {
+        const out: Record<string, unknown> = {}
+        for (const [key, codec] of entries) {
+          const field = (value as Record<string, unknown>)[key]
+          if (field === undefined && !Object.hasOwn(value as object, key)) continue
+          out[key] = codec.encode(field)
+        }
+        return out as StructEncoded<F>
+      },
+    ),
+    fields,
+  }
+}
+
+export function array<T, E>(codec: Of<T, E>): Of<T[], E[]> {
+  return make(
+    (input) => {
+      if (!Array.isArray(input)) return INVALID
+      const out: T[] = []
+      for (const item of input) {
+        const value = codec.decode(item)
+        if (value === INVALID) return INVALID
+        out.push(value)
+      }
+      return out
+    },
+    (value) => value.map((item) => codec.encode(item)),
+  )
+}
+
+/** Keeps the items that decode and drops the rest, like `Persistence.array`. */
+export function lenientArray<T, E>(codec: Of<T, E>): Of<T[], E[]> {
+  return make(
+    (input) => {
+      if (!Array.isArray(input)) return []
+      return input.flatMap((item) => {
+        const value = codec.decode(item)
+        return value === INVALID ? [] : [value]
+      })
+    },
+    (value) => value.map((item) => codec.encode(item)),
+  )
+}
+
+export function record<T, E>(codec: Of<T, E>): Of<Record<string, T>, Record<string, E>> {
+  return make(
+    (input) => {
+      if (typeof input !== "object" || input === null || Array.isArray(input)) return INVALID
+      const out: Record<string, T> = {}
+      for (const [key, item] of Object.entries(input)) {
+        const value = codec.decode(item)
+        if (value === INVALID) return INVALID
+        out[key] = value
+      }
+      return out
+    },
+    (value) => Object.fromEntries(Object.entries(value).map(([key, item]) => [key, codec.encode(item)])),
+  )
+}
+
+/** A record that drops entries whose values are invalid, the replacement for `catchDecoding` to none. */
+export function sparseRecord<T, E>(codec: Of<T, E>): Of<Record<string, T>, Record<string, E>> {
+  return make(
+    (input) => {
+      if (typeof input !== "object" || input === null || Array.isArray(input)) return INVALID
+      const out: Record<string, T> = {}
+      for (const [key, item] of Object.entries(input)) {
+        const value = codec.decode(item)
+        if (value !== INVALID) out[key] = value
+      }
+      return out
+    },
+    (value) => Object.fromEntries(Object.entries(value).map(([key, item]) => [key, codec.encode(item)])),
+  )
+}
+
+/** An invalid record becomes empty rather than failing the whole store, like `Persistence.record`. */
+export function lenientRecord<T, E>(codec: Of<T, E>): Of<Record<string, T>, Record<string, E>> {
+  const strict = record(codec)
+  return make(
+    (input) => {
+      const value = strict.decode(input)
+      return value === INVALID ? {} : value
+    },
+    strict.encode,
+  )
+}
+
+export function union<const C extends ReadonlyArray<Any>>(codecs: C): Of<C[number]["Type"], C[number]["Encoded"]> {
+  return make(
+    (input) => {
+      for (const codec of codecs) {
+        const value = codec.decode(input)
+        if (value !== INVALID) return value
+      }
+      return INVALID
+    },
+    (value) => {
+      // Encode with the first member that accepts the value's shape; members are disjoint in practice.
+      for (const codec of codecs) if (codec.decode(value) !== INVALID) return codec.encode(value)
+      return value as C[number]["Encoded"]
+    },
+  )
+}
+
+/** Maps a decoded value into another shape, the replacement for `decodeTo` + `SchemaGetter.transform`. */
+export function transform<T, E, T2>(
+  codec: Of<T, E>,
+  options: { decode: (value: T) => T2; encode: (value: T2) => T },
+): Of<T2, E> {
+  return make(
+    (input) => {
+      const value = codec.decode(input)
+      return value === INVALID ? INVALID : options.decode(value)
+    },
+    (value) => codec.encode(options.encode(value)),
+  )
+}
+
+/** Decodes with `source`, maps, then validates with `target`: Effect's `decodeTo` with a transform. */
+export function decodeTo<T, E, T2, E2>(
+  source: Of<T, E>,
+  target: Of<T2, E2>,
+  options: { decode: (value: T) => E2; encode: (value: T2) => T },
+): Of<T2, E> {
+  return make(
+    (input) => {
+      const value = source.decode(input)
+      return value === INVALID ? INVALID : target.decode(options.decode(value))
+    },
+    (value) => source.encode(options.encode(value)),
+  )
+}
+
+/** Invalid and missing values become `value()`, like `Persistence.fallback`. */
+export function fallback<T, E>(codec: Of<T, E>, value: () => NoInfer<T>): Of<T, E> {
+  return make(
+    (input) => {
+      if (input === undefined) return value()
+      const decoded = codec.decode(input)
+      return decoded === INVALID ? value() : decoded
+    },
+    codec.encode,
+  )
+}
+
+export function fromJsonString<T, E>(codec: Of<T, E>): Of<T, string> {
+  return make(
+    (input) => {
+      if (typeof input !== "string") return INVALID
+      try {
+        return codec.decode(JSON.parse(input))
+      } catch {
+        return INVALID
+      }
+    },
+    (value) => JSON.stringify(codec.encode(value)),
+  )
+}
+
+export type Decoder = Pick<Of<unknown>, "decode">
+export type Migrated<C extends Any> = { readonly current: C; readonly read: Decoder }
+
+/** Older stored shapes go through `read` first; `current` describes what the store holds today. */
+export function migrate<C extends Any>(current: C, read: Decoder): Migrated<C> {
+  return { current, read }
+}
+
+function isMigrated<C extends Any>(definition: C | Migrated<C>): definition is Migrated<C> {
+  return !isCodec(definition) && "current" in definition
+}
+
+// Stored values recover field by field against the initial value: an object's valid fields are
+// kept, invalid or missing ones take their initial counterpart, and the result is merged over the
+// initial so new fields appear with their defaults. Mirrors `Persistence.withInitial`.
+export function withInitial<C extends Any>(definition: C | Migrated<C>, initial: Type<C>): Of<Type<C>, unknown> {
+  const codec = isMigrated(definition) ? definition.current : definition
+  const read = isMigrated(definition) ? definition.read : unknown
+  return make(
+    (input) => {
+      const stored = read.decode(input)
+      if (stored === INVALID) return INVALID
+      return merge(initial, recover(codec, stored, initial))
+    },
+    (value) => codec.encode(value),
+  )
+}
+
+function recover(codec: Any, value: unknown, initial: unknown): unknown {
+  if (value === undefined) return initial
+  if ("fields" in codec && isObject(value)) {
+    const fields = (codec as Struct<Fields>).fields
+    return Object.fromEntries(
+      Object.entries(fields).flatMap(([name, field]) => {
+        const defaults = isObject(initial) ? initial[name] : undefined
+        const next = recover(field, value[name], defaults)
+        if (next === undefined && !Object.hasOwn(value, name) && defaults === undefined) return []
+        return [[name, next]]
+      }),
+    )
+  }
+  const decoded = codec.decode(value)
+  return decoded === INVALID ? initial : decoded
+}
+
+function merge(initial: unknown, value: unknown): unknown {
+  if (value === undefined) return initial
+  if (!isObject(initial) || !isObject(value)) return value
+  return Object.fromEntries(
+    [...new Set([...Object.keys(initial), ...Object.keys(value)])].map((key) => [key, merge(initial[key], value[key])]),
+  )
+}
+
+function isObject(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value)
+}
+
@@ -3,6 +3,7 @@ import { Schema } from "effect"
 import { WorkspaceOnboardingSchema, ProviderTipSchema, WorkspaceTipSchema } from "@/new-session/view"
 import { ModelSelectionSchema } from "@/providers/models/selection"
 import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"
 import { FileViewsSchema } from "@/workspaces/files/view-cache"
 import { languageSchema } from "@/runtime/i18n/language"
 import { HomeServersSchema } from "@/home/projects/controller"
@@ -10,9 +11,9 @@ import { ModelProvidersSchema } from "@/settings/models/models"

 describe("persisted consumer schemas", () => {
  test("onboarding and provider tip retain defaults and validate stored values", () => {
-    const onboarding = Schema.decodeUnknownSync(Persistence.withInitial(WorkspaceOnboardingSchema, { used: false }))
-    const tip = Schema.decodeUnknownSync(Persistence.withInitial(ProviderTipSchema, { dismissedAt: 0 }))
-    const workspaceTip = Schema.decodeUnknownSync(Persistence.withInitial(WorkspaceTipSchema, { dismissedAt: 0 }))
+    const onboarding = ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(WorkspaceOnboardingSchema, { used: false }), input))
+    const tip = ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(ProviderTipSchema, { dismissedAt: 0 }), input))
+    const workspaceTip = ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(WorkspaceTipSchema, { dismissedAt: 0 }), input))
    expect(onboarding({})).toEqual({ used: false })
    expect(onboarding({ used: "true" })).toEqual({ used: false })
    expect(onboarding({ used: true })).toEqual({ used: true })
@@ -25,7 +26,7 @@ describe("persisted consumer schemas", () => {

  test("collapse records recover malformed entries without losing valid siblings", () => {
    for (const schema of [HomeServersSchema, ModelProvidersSchema]) {
-      const decode = Schema.decodeUnknownSync(Persistence.withInitial(schema, { collapsed: {} }))
+      const decode = (input: unknown) => Codec.decodeOrThrow(Codec.withInitial(schema, { collapsed: {} }), input)
      expect(decode({})).toEqual({ collapsed: {} })
      expect(decode({ collapsed: [] })).toEqual({ collapsed: {} })
      expect(decode({ collapsed: { open: false, closed: true, invalid: "false" } })).toEqual({
@@ -35,21 +36,19 @@ describe("persisted consumer schemas", () => {
  })

  test("model selection migrates legacy picks and omits workspace state", () => {
-    const decode = Schema.decodeUnknownSync(Persistence.withInitial(ModelSelectionSchema, { session: {} }))
+    const decode = (input: unknown) => Codec.decodeOrThrow(Codec.withInitial(ModelSelectionSchema, { session: {} }), input)
    expect(decode({})).toEqual({ session: {} })
    const state = decode({ pick: { __workspace__: { agent: "plan" }, session1: { agent: "build" } } })
    expect(state.session.session1?.agent).toBe("build")
    expect(state.session.__workspace__).toBeUndefined()
-    const encoded = Schema.encodeSync(
-      Schema.fromJsonString(Persistence.withInitial(ModelSelectionSchema, { session: {} })),
-    )(state)
+    const encoded = Codec.fromJsonString(Codec.withInitial(ModelSelectionSchema, { session: {} })).encode(state)
    expect(JSON.parse(encoded)).toEqual({ session: { session1: { agent: "build" } } })
    expect(decode(JSON.parse(encoded))).toEqual(state)
  })

  test("current model selections take precedence over legacy picks", () => {
    expect(
-      Schema.decodeUnknownSync(Persistence.withInitial(ModelSelectionSchema, { session: {} }))({
+      Codec.decodeOrThrow(Codec.withInitial(ModelSelectionSchema, { session: {} }), {
        session: {},
        pick: { session1: { agent: "plan" } },
      }),
@@ -57,7 +56,7 @@ describe("persisted consumer schemas", () => {
  })

  test("model selection validates nested model keys and preserves explicit null variants", () => {
-    const state = Schema.decodeUnknownSync(Persistence.withInitial(ModelSelectionSchema, { session: {} }))({
+    const state = Codec.decodeOrThrow(Codec.withInitial(ModelSelectionSchema, { session: {} }), {
      session: {
        good: { agent: "build", model: { providerID: "provider", modelID: "model", variant: "high" }, variant: null },
        partial: { agent: "plan", model: { providerID: "provider", modelID: 42 }, variant: false },
@@ -76,7 +75,7 @@ describe("persisted consumer schemas", () => {
  })

  test("file views validate scroll positions and line sides independently", () => {
-    const decode = Schema.decodeUnknownSync(Persistence.withInitial(FileViewsSchema, { file: {} }))
+    const decode = ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(FileViewsSchema, { file: {} }), input))
    expect(decode({})).toEqual({ file: {} })
    const state = decode({
      file: {
@@ -103,7 +102,7 @@ describe("persisted consumer schemas", () => {
  })

  test("language preserves runtime defaults and normalizes unsupported locales to English", () => {
-    const decode = Schema.decodeUnknownSync(Persistence.withInitial(languageSchema, { locale: "fr" }))
+    const decode = (input: unknown) => Codec.decodeOrThrow(Codec.withInitial(languageSchema, { locale: "fr" }), input)
    expect(decode({})).toEqual({ locale: "fr" })
    expect(decode({ locale: undefined })).toEqual({ locale: "fr" })
    expect(decode({ locale: 42 })).toEqual({ locale: "fr" })
@@ -111,3 +110,6 @@ describe("persisted consumer schemas", () => {
    expect(decode({ locale: "ar" })).toEqual({ locale: "ar" })
  })
 })
+
+
+
@@ -1,5 +1,5 @@
 import type { AsyncStorage } from "@solid-primitives/storage"
-import { Option, Schema } from "effect"
+import { Codec } from "./codec"

 export type BlobReference = { id: string; url: string }

@@ -312,12 +312,12 @@ export function createDraftStore(driver: Driver, options: { grace?: number } = {
    getItem: async (key) => {
      const value = await driver.get(key)
      if (value === null) return null
-      const parsed = Schema.decodeUnknownOption(Schema.fromJsonString(Schema.Unknown))(value)
-      // Let the owning persistence codec apply its invalid-document policy.
-      if (Option.isNone(parsed)) return value
-      // A loaded document is live in the composer: pin its images before decode mints their URLs.
-      retain(key, imageIDs(parsed.value), grace)
-      return JSON.stringify(await decode(parsed.value))
+      const parsed = Codec.fromJsonString(Codec.unknown).decode(value)
+      // Let the owning persistence codec apply its invalid-document policy.
+      if (parsed === Codec.INVALID) return value
+      // A loaded document is live in the composer: pin its images before decode mints their URLs.
+      retain(key, imageIDs(parsed), grace)
+      return JSON.stringify(await decode(parsed))
    },
    setItem: (key, value) => setDocument(key, JSON.parse(value)),
    setDocument,
@@ -455,3 +455,4 @@ export async function blobDataUrl(blob: BlobReference, mime: string) {
 export function createLegacyBlobReference(dataUrl: string): BlobReference {
  return { id: dataUrl, url: dataUrl }
 }
+
@@ -6,6 +6,7 @@ import { createStore, type SetStoreFunction, type Store } from "solid-js/store"
 import { Option, Schema } from "effect"
 import { pathKey } from "@/workspaces/path-key"
 import { ScopedKey, ServerScope } from "@/runtime/server/scope"
+import { Codec } from "./codec"
 import { persistStore } from "./persist"
 import { Persistence } from "./schema"

@@ -472,25 +473,57 @@ export function removePersisted(
  }
 }

-export function persisted<S extends Schema.ConstraintCodec<object, unknown>>(
+type Definition<S extends Schema.ConstraintCodec<object, unknown> | Codec.Any> =
+  | S
+  | Persistence.Migrated<Extract<S, Schema.ConstraintCodec<object, unknown>>>
+  | Codec.Migrated<Extract<S, Codec.Any>>
+
+// Persisted stores are moving from Effect Schema to the plain codecs in ./codec so the renderer
+// stops paying for Effect at startup; both are accepted while the migration is underway.
+function serializer<S extends Schema.ConstraintCodec<object, unknown> | Codec.Any>(
+  definition: Definition<S>,
+  initial: S["Type"],
+) {
+  if (Codec.isCodec(definition) || (!("current" in definition) ? false : Codec.isCodec(definition.current))) {
+    const codec = Codec.withInitial(definition as Codec.Any | Codec.Migrated<Codec.Any>, initial)
+    const json = Codec.fromJsonString(codec)
+    return {
+      decode: (raw: string) => Codec.decodeOption(json, raw) as S["Type"] | undefined,
+      deserialize: (raw: unknown) => Codec.decodeOrThrow(json, raw) as S["Type"],
+      serialize: (value: S["Type"]) => Codec.encodeOrThrow(json, value),
+      encode: (value: S["Type"]) => Codec.encodeOrThrow(codec, value),
+      initial: Codec.decodeOrThrow(codec, codec.encode(initial)) as S["Type"],
+    }
+  }
+  const schema = definition as Schema.ConstraintCodec<object, unknown> | Persistence.Migrated<Schema.ConstraintCodec<object, unknown>>
+  const initialized = Persistence.withInitial(schema, initial as object)
+  const json = Schema.fromJsonString(initialized)
+  const decode = Schema.decodeUnknownOption(json)
+  return {
+    decode: (raw: string) => Option.getOrUndefined(decode(raw)) as S["Type"] | undefined,
+    deserialize: Schema.decodeUnknownSync(json) as (raw: unknown) => S["Type"],
+    serialize: Schema.encodeSync(json) as (value: S["Type"]) => string,
+    encode: Schema.encodeSync(initialized) as (value: S["Type"]) => unknown,
+    initial: Schema.decodeUnknownSync(Schema.toType(initialized))(initial as object) as S["Type"],
+  }
+}
+
+export function persisted<S extends Schema.ConstraintCodec<object, unknown> | Codec.Any>(
  target: string | PersistTarget,
-  schema: S | Persistence.Migrated<S>,
+  schema: Definition<S>,
  initial: NoInfer<S["Type"]>,
  platformOverride?: Platform,
 ): PersistedWithReady<S["Type"]> {
  const platform = platformOverride ?? usePlatform()
  const config = resolveTarget(typeof target === "string" ? { key: target } : target, platform)

-  const initialized = Persistence.withInitial(schema, initial)
-  const json = Schema.fromJsonString(initialized)
-  const decode = Schema.decodeUnknownOption(json)
-  const encode = Schema.encodeSync(initialized)
-  const serialize = Schema.encodeSync(json)
+  const codec = serializer<S>(schema, initial)
+  const { encode, serialize } = codec
  const normalize = (raw: string) => {
-    const value = decode(raw)
-    if (Option.isSome(value)) return serialize(value.value)
+    const value = codec.decode(raw)
+    if (value !== undefined) return serialize(value)
  }
-  const store = createStore<S["Type"]>(Schema.decodeUnknownSync(Schema.toType(initialized))(initial))
+  const store = createStore<S["Type"]>(codec.initial)
  const isDesktop = platform.platform === "desktop" && !!platform.storage
  const draft = config.draft ? platform.draftStore : undefined
  const prefix = `${config.storage ?? "default"}:`
@@ -602,7 +635,7 @@ export function persisted<S extends Schema.ConstraintCodec<object, unknown>>(
    name: config.key,
    storage,
    serialize,
-    deserialize: Schema.decodeUnknownSync(json),
+    deserialize: codec.deserialize,
    sync: channel ? messageSync(channel) : undefined,
    // Drafts take the encoded document itself so large text is externalized without the store
    // re-parsing the serialized form on every save.
@@ -0,0 +1,11 @@
+import type { Brand } from "effect"
+import { Codec } from "@/runtime/persistence/codec"
+
+// The server key's brand is shared with the Effect schema in ./persistence.ts (type only, so this
+// module loads nothing of Effect), letting stores port to plain codecs one at a time.
+export type ServerKey = string & Brand.Brand<"ServerConnection.Key">
+
+export const ServerKey: Codec.Of<ServerKey, string> & { make(value: string): ServerKey } = Object.assign(
+  Codec.make<ServerKey, string>((v) => (typeof v === "string" ? (v as ServerKey) : Codec.INVALID), (v) => v),
+  { make: (value: string) => value as ServerKey },
+)
@@ -1,15 +1,14 @@
 import { describe, expect, test } from "bun:test"
-import { Schema } from "effect"
 import { IconState, ModelState, ProjectState, VcsState, serverState } from "./persistence"
 import { createRoot } from "solid-js"
 import { isServer } from "solid-js/web"
 import { Persist, persisted } from "@/runtime/persistence/storage"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"

 const initial = { list: [], hidden: {}, projects: {}, lastProject: {}, recentlyClosed: {} }

 function serverSchema(canonical?: () => string | undefined) {
-  return Persistence.withInitial(serverState(canonical), initial)
+  return Codec.withInitial(serverState(canonical), initial)
 }

 describe("server persistence schema", () => {
@@ -29,7 +28,7 @@ describe("server persistence schema", () => {
      ],
      projects: { local: [{ worktree: "/project", expanded: true }] },
    }
-    const state = Schema.decodeUnknownSync(schema)(input)
+    const state = Codec.decodeOrThrow(schema, input)
    expect(state).toEqual({
      list: [
        { type: "http", http: { url: "http://localhost:4096" } },
@@ -48,13 +47,13 @@ describe("server persistence schema", () => {
      recentlyClosed: {},
    })
    expect(input.list[1]).toHaveProperty("username", "legacy")
-    const encoded = Schema.encodeSync(schema)(state)
+    const encoded = schema.encode(state)
    expect(encoded).toEqual(state)
-    expect(Schema.decodeUnknownSync(schema)(encoded)).toEqual(state)
+    expect(Codec.decodeOrThrow(schema, encoded)).toEqual(state)
  })

  test("defaults missing or malformed fields and drops invalid entries independently", () => {
-    const decode = Schema.decodeUnknownSync(serverSchema())
+    const decode = ((input: unknown) => Codec.decodeOrThrow(serverSchema(), input))
    const empty = { list: [], hidden: {}, projects: {}, lastProject: {}, recentlyClosed: {} }
    expect(decode({})).toEqual(empty)
    expect(decode({ list: null, hidden: [], projects: false, lastProject: 1, recentlyClosed: "bad" })).toEqual(empty)
@@ -74,7 +73,7 @@ describe("server persistence schema", () => {

  test("moves canonical project buckets without changing server keys or unrelated scopes", () => {
    const schema = serverSchema(() => "https://opencode.example.com")
-    const state = Schema.decodeUnknownSync(schema)({
+    const state = Codec.decodeOrThrow(schema, {
      list: ["https://opencode.example.com"],
      hidden: { "https://opencode.example.com": true },
      projects: {
@@ -100,14 +99,14 @@ describe("server persistence schema", () => {
    expect(state.list[0]?.http.url).toBe("https://opencode.example.com")
    expect(state.hidden).toEqual({ "https://opencode.example.com": true })
    expect(state.recentlyClosed).toEqual({ local: ["/closed"], "https://opencode.example.com": ["/old-closed"] })
-    expect(Schema.encodeSync(schema)(state)).toEqual(state)
-    expect(Schema.decodeUnknownSync(schema)(state)).toEqual(state)
+    expect(schema.encode(state)).toEqual(state)
+    expect(Codec.decodeOrThrow(schema, state)).toEqual(state)
  })

  test("reads the latest canonical local prop on each decode", () => {
    const props: { canonicalLocalServer?: string } = {}
    const schema = serverSchema(() => props.canonicalLocalServer)
-    const decode = Schema.decodeUnknownSync(schema)
+    const decode = ((input: unknown) => Codec.decodeOrThrow(schema, input))
    const input = {
      projects: { remote: [{ worktree: "/project", expanded: true }] },
      lastProject: { remote: "/project" },
@@ -122,7 +121,7 @@ describe("server persistence schema", () => {
  })

  test("migrates a last project without a project list", () => {
-    expect(Schema.decodeUnknownSync(serverSchema(() => "remote"))({ lastProject: { remote: "/project" } })).toEqual({
+    expect(Codec.decodeOrThrow(serverSchema(() => "remote"), { lastProject: { remote: "/project" } })).toEqual({
      list: [],
      hidden: {},
      projects: {},
@@ -134,7 +133,7 @@ describe("server persistence schema", () => {

 describe("model persistence schema", () => {
  test("defaults missing state and keeps valid entries beside malformed entries", () => {
-    const decode = Schema.decodeUnknownSync(Persistence.withInitial(ModelState, { user: [], recent: [], variant: {} }))
+    const decode = ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(ModelState, { user: [], recent: [], variant: {} }), input))
    expect(decode({})).toEqual({ user: [], recent: [], variant: {} })
    expect(decode({ user: null, recent: 1, variant: [] })).toEqual({ user: [], recent: [], variant: {} })
    const state = decode({
@@ -155,24 +154,24 @@ describe("model persistence schema", () => {
      recent: [{ providerID: "provider", modelID: "model" }],
      variant: { model: "high" },
    })
-    expect(Schema.encodeSync(ModelState)(state)).toEqual(state)
+    expect(ModelState.encode(state)).toEqual(state)
  })
 })

 describe("directory cache schemas", () => {
  test("defaults missing and malformed VCS caches but retains optional branch metadata", () => {
-    const decode = Schema.decodeUnknownSync(Persistence.withInitial(VcsState, { value: undefined }))
+    const decode = ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(VcsState, { value: undefined }), input))
    expect(decode({})).toEqual({ value: undefined })
    expect(decode({ value: null })).toEqual({ value: undefined })
    expect(decode({ value: { branch: 1 } })).toEqual({ value: undefined })
    expect(decode({ value: { default_branch: "main" } })).toEqual({ value: { default_branch: "main" } })
    const state = decode({ value: { branch: "feature", default_branch: "main", obsolete: true } })
    expect(state).toEqual({ value: { branch: "feature", default_branch: "main" } })
-    expect(Schema.encodeSync(VcsState)(state)).toEqual(state)
+    expect(VcsState.encode(state)).toEqual(state)
  })

  test("validates project name, icon overrides and startup commands", () => {
-    const decode = Schema.decodeUnknownSync(Persistence.withInitial(ProjectState, { value: undefined }))
+    const decode = ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(ProjectState, { value: undefined }), input))
    expect(decode({})).toEqual({ value: undefined })
    expect(decode({ value: [] })).toEqual({ value: undefined })
    expect(decode({ value: { icon: { override: 1 } } })).toEqual({ value: undefined })
@@ -185,7 +184,7 @@ describe("directory cache schemas", () => {
        commands: { start: "bun dev" },
      },
    })
-    expect(Schema.encodeSync(ProjectState)(state)).toEqual(state)
+    expect(ProjectState.encode(state)).toEqual(state)
    expect(state.value).toEqual({
      name: "Project",
      icon: { override: "data:image/png;base64,abc", color: "blue" },
@@ -194,12 +193,12 @@ describe("directory cache schemas", () => {
  })

  test("validates optional icon strings", () => {
-    const decode = Schema.decodeUnknownSync(Persistence.withInitial(IconState, { value: undefined }))
+    const decode = ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(IconState, { value: undefined }), input))
    expect(decode({})).toEqual({ value: undefined })
    expect(decode({ value: 42 })).toEqual({ value: undefined })
    expect(decode({ value: null })).toEqual({ value: undefined })
    expect(decode({ value: "" })).toEqual({ value: "" })
-    expect(Schema.encodeSync(IconState)(decode({ value: "data:image/png;base64,abc" }))).toEqual({
+    expect(IconState.encode(decode({ value: "data:image/png;base64,abc" }))).toEqual({
      value: "data:image/png;base64,abc",
    })
  })
@@ -255,7 +254,7 @@ test.skipIf(isServer)(
      const stored = values.get("opencode.global.dat:server")
      expect(stored).toBeDefined()
      if (!stored) throw new Error("server state was not written")
-      const decoded = Schema.decodeUnknownSync(Schema.fromJsonString(serverSchema()))(stored)
+      const decoded = Codec.decodeOrThrow(Codec.fromJsonString(serverSchema()), stored)
      expect(decoded.projects.local).toEqual([{ worktree: "/project", expanded: true }])
      expect(stored).not.toContain("username")
      expect(decoded.list).toEqual(root.state[0].list)
@@ -264,3 +263,4 @@ test.skipIf(isServer)(
    }
  },
 )
+
@@ -1,136 +1,127 @@
-import { Effect, Option, Schema, SchemaGetter } from "effect"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"
+import { ServerKey } from "./key"

-export const ServerKey = Schema.String.pipe(Schema.brand("ServerConnection.Key"))
+export { ServerKey }

-export const ServerHttpBase = Persistence.struct({
-  url: Schema.String,
-  password: Schema.optional(Schema.String),
+export const ServerHttpBase = Codec.struct({
+  url: Codec.string,
+  password: Codec.optional(Codec.string),
 })

-export const ServerHttp = Persistence.struct({
-  type: Schema.Literal("http"),
+export const ServerHttp = Codec.struct({
+  type: Codec.literal("http"),
  http: ServerHttpBase,
-  authToken: Schema.optional(Schema.Boolean),
-  displayName: Schema.optional(Schema.String),
-  label: Schema.optional(Schema.String),
+  authToken: Codec.optional(Codec.boolean),
+  displayName: Codec.optional(Codec.string),
+  label: Codec.optional(Codec.string),
 })

-const StoredServer = Schema.Union([ServerHttp, ServerHttpBase, Schema.String]).pipe(
-  Schema.decodeTo(ServerHttp, {
-    decode: SchemaGetter.transform((value) => {
-      if (typeof value === "string") return { type: "http", http: { url: value } }
-      if ("http" in value) return value
-      return { type: "http", http: value }
-    }),
-    encode: SchemaGetter.transform((value) => value),
-  }),
-)
-
-const ProjectList = Persistence.array(
-  Persistence.struct({
-    worktree: Schema.String,
-    expanded: Persistence.fallback(Schema.Boolean, () => true),
-  }),
-)
-const Projects = Persistence.record(ProjectList)
-const LastProject = Persistence.record(Schema.String.pipe(Schema.catchDecoding(() => Effect.succeed(Option.none()))))
-
-const State = Persistence.struct({
-  list: Persistence.array(StoredServer),
-  hidden: Schema.Record(
-    Schema.String,
-    Schema.mutableKey(Schema.Boolean.pipe(Schema.catchDecoding(() => Effect.succeed(Option.none())))),
-  ),
-  projects: Schema.Record(Schema.String, Schema.mutableKey(ProjectList)),
-  lastProject: Schema.Record(
-    Schema.String,
-    Schema.mutableKey(Schema.String.pipe(Schema.catchDecoding(() => Effect.succeed(Option.none())))),
-  ),
-  recentlyClosed: Schema.Record(Schema.String, Schema.mutableKey(Persistence.array(Schema.String))),
+// Servers were stored as a URL string, then as the HTTP block alone, before the current shape.
+const StoredServer = Codec.decodeTo(Codec.union([ServerHttp, ServerHttpBase, Codec.string]), ServerHttp, {
+  decode: (value) => {
+    if (typeof value === "string") return { type: "http" as const, http: { url: value } }
+    if ("http" in value) return value
+    return { type: "http" as const, http: value }
+  },
+  encode: (value) => value,
 })

+const ProjectList = Codec.lenientArray(
+  Codec.struct({
+    worktree: Codec.string,
+    expanded: Codec.fallback(Codec.boolean, () => true),
+  }),
+)
+const Projects = Codec.lenientRecord(ProjectList)
+const LastProject = Codec.fallback(Codec.sparseRecord(Codec.string), () => ({}))
+
+const State = Codec.struct({
+  list: Codec.lenientArray(StoredServer),
+  hidden: Codec.sparseRecord(Codec.boolean),
+  projects: Codec.record(ProjectList),
+  lastProject: Codec.sparseRecord(Codec.string),
+  recentlyClosed: Codec.record(Codec.lenientArray(Codec.string)),
+})
+
+const StoredState = Codec.struct({ projects: Projects, lastProject: LastProject }, { preserve: true })
+
+// Projects and last-opened entries recorded under the canonical local server's URL move under
+// "local" when that URL is known, so they survive the server changing address.
 export function serverState(canonicalLocalServer: () => string | undefined = () => undefined) {
-  return Persistence.migrate(
+  return Codec.migrate(
    State,
-    Schema.Struct({ projects: Projects, lastProject: LastProject }).pipe(
-      Schema.decode({
-        decode: SchemaGetter.transform((value) => {
-          const canonical = canonicalLocalServer()
-          if (!canonical || canonical === "local") return value
-          const previous = value.projects[canonical]
-          const last = value.lastProject[canonical]
-          if (!previous && last === undefined) return value
+    Codec.transform(StoredState, {
+      decode: (value) => {
+        const canonical = canonicalLocalServer()
+        if (!canonical || canonical === "local") return value
+        const previous = value.projects[canonical]
+        const last = value.lastProject[canonical]
+        if (!previous && last === undefined) return value

-          const projects = { ...value.projects }
-          if (previous) {
-            const local = projects.local ?? []
-            const worktrees = new Set(local.map((project) => project.worktree))
-            projects.local = [
-              ...local,
-              ...previous.filter((project) => {
-                if (worktrees.has(project.worktree)) return false
-                worktrees.add(project.worktree)
-                return true
-              }),
-            ]
-            delete projects[canonical]
-          }
-          const lastProject = { ...value.lastProject }
-          if (last !== undefined) {
-            lastProject.local ??= last
-            delete lastProject[canonical]
-          }
-          return { ...value, projects, lastProject }
-        }),
-        encode: SchemaGetter.transform((value) => value),
-      }),
-    ),
+        const projects = { ...value.projects }
+        if (previous) {
+          const local = projects.local ?? []
+          const worktrees = new Set(local.map((project) => project.worktree))
+          projects.local = [
+            ...local,
+            ...previous.filter((project) => {
+              if (worktrees.has(project.worktree)) return false
+              worktrees.add(project.worktree)
+              return true
+            }),
+          ]
+          delete projects[canonical]
+        }
+        const lastProject = { ...value.lastProject }
+        if (last !== undefined) {
+          lastProject.local ??= last
+          delete lastProject[canonical]
+        }
+        return { ...value, projects, lastProject }
+      },
+      encode: (value) => value,
+    }),
  )
 }

-export const ModelState = Persistence.struct({
-  user: Persistence.array(
-    Persistence.struct({
-      providerID: Schema.String,
-      modelID: Schema.String,
-      visibility: Schema.Literals(["show", "hide"]),
-      favorite: Schema.optional(Schema.Boolean),
+export const ModelState = Codec.struct({
+  user: Codec.lenientArray(
+    Codec.struct({
+      providerID: Codec.string,
+      modelID: Codec.string,
+      visibility: Codec.literals(["show", "hide"]),
+      favorite: Codec.optional(Codec.boolean),
    }),
  ),
-  recent: Persistence.array(Persistence.struct({ providerID: Schema.String, modelID: Schema.String })),
-  variant: Schema.Record(
-    Schema.String,
-    Schema.mutableKey(
-      Schema.UndefinedOr(Schema.String).pipe(Schema.catchDecoding(() => Effect.succeed(Option.none()))),
-    ),
-  ),
+  recent: Codec.lenientArray(Codec.struct({ providerID: Codec.string, modelID: Codec.string })),
+  variant: Codec.sparseRecord(Codec.undefinedOr(Codec.string)),
 })

-export const VcsState = Persistence.struct({
-  value: Schema.optional(
-    Persistence.struct({
-      branch: Schema.optional(Schema.String),
-      default_branch: Schema.optional(Schema.String),
+export const VcsState = Codec.struct({
+  value: Codec.optional(
+    Codec.struct({
+      branch: Codec.optional(Codec.string),
+      default_branch: Codec.optional(Codec.string),
    }),
  ),
 })

-const ProjectMeta = Persistence.struct({
-  name: Schema.optional(Schema.String),
-  icon: Schema.optional(
-    Persistence.struct({
-      override: Schema.optional(Schema.String),
-      color: Schema.optional(Schema.String),
+const ProjectMeta = Codec.struct({
+  name: Codec.optional(Codec.string),
+  icon: Codec.optional(
+    Codec.struct({
+      override: Codec.optional(Codec.string),
+      color: Codec.optional(Codec.string),
    }),
  ),
-  commands: Schema.optional(Persistence.struct({ start: Schema.optional(Schema.String) })),
+  commands: Codec.optional(Codec.struct({ start: Codec.optional(Codec.string) })),
 })

-export const ProjectState = Persistence.struct({
-  value: Schema.optional(ProjectMeta),
+export const ProjectState = Codec.struct({
+  value: Codec.optional(ProjectMeta),
 })

-export const IconState = Persistence.struct({
-  value: Schema.optional(Schema.String),
+export const IconState = Codec.struct({
+  value: Codec.optional(Codec.string),
 })
+
@@ -1,13 +1,12 @@
 import { describe, expect, test } from "bun:test"
 import { canRemoveServer, createServerProjects, resolveServerList, ServerConnection } from "./registry"
-import { Schema } from "effect"
 import { serverState } from "./persistence"
 import { createStore } from "solid-js/store"
 import { ServerScope } from "./scope"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"

 function serverSchema() {
-  return Persistence.withInitial(serverState(), {
+  return Codec.withInitial(serverState(), {
    list: [],
    hidden: {},
    projects: {},
@@ -19,7 +18,7 @@ function serverSchema() {
 describe("resolveServerList", () => {
  test("lets startup auth_token credentials override a persisted same-url server", () => {
    const list = resolveServerList({
-      stored: Schema.decodeUnknownSync(serverSchema())({ list: [{ url: "https://server.example.test" }] }).list,
+      stored: Codec.decodeOrThrow(serverSchema(), { list: [{ url: "https://server.example.test" }] }).list,
      props: [
        {
          type: "http",
@@ -44,7 +43,7 @@ describe("resolveServerList", () => {

  test("keeps persisted credentials when startup has no auth_token", () => {
    const list = resolveServerList({
-      stored: Schema.decodeUnknownSync(serverSchema())({
+      stored: Codec.decodeOrThrow(serverSchema(), {
        list: [{ url: "https://server.example.test", password: "saved" }],
      }).list,
      props: [{ type: "http", http: { url: "https://server.example.test" } }],
@@ -77,7 +76,7 @@ test("treats WSL sidecars as remote server connections", () => {
 })

 test("keeps exact persisted server identities and prevents removing provided servers", () => {
-  const stored = Schema.decodeUnknownSync(serverSchema())({
+  const stored = Codec.decodeOrThrow(serverSchema(), {
    list: ["http://localhost:4096", "http://localhost:4096/", "http://127.0.0.1:4096"],
  }).list
  expect(resolveServerList({ stored }).map((server) => String(ServerConnection.key(server)))).toEqual([
@@ -91,7 +90,7 @@ test("keeps exact persisted server identities and prevents removing provided ser
 })

 test("project actions update schema-derived state and follow dynamic server scopes", () => {
-  const [store, setStore] = createStore(Schema.decodeUnknownSync(serverSchema())({}))
+  const [store, setStore] = createStore(Codec.decodeOrThrow(serverSchema(), {}))
  const props: { server: ServerConnection.Key; canonicalLocalServer?: ServerConnection.Key } = {
    server: ServerConnection.Key.make("https://remote.example"),
  }
@@ -115,3 +114,4 @@ test("project actions update schema-derived state and follow dynamic server scop
  expect(store.projects.local).toEqual([{ worktree: "/local", expanded: true }])
  expect(store.projects[props.server]).toEqual([{ worktree: "/remote", expanded: false }])
 })
+
@@ -1,12 +1,12 @@
-import { Option, Schema } from "effect"
+import { Codec } from "@/runtime/persistence/codec"
 import { normalizeServerUrl } from "@/runtime/server/registry"

-const pairing = Schema.fromJsonString(
-  Schema.Struct({
-    urls: Schema.Array(Schema.String),
-    username: Schema.Literal("opencode"),
-    password: Schema.String,
-  }),
+const pairing = Codec.fromJsonString(
+  Codec.struct({
+    urls: Codec.array(Codec.string),
+    username: Codec.literal("opencode"),
+    password: Codec.string,
+  }),
 )

 export function serverAddress(value: string) {
@@ -20,9 +20,10 @@ export function serverAddress(value: string) {
 }

 export function decodePairingCode(value: string) {
-  const result = Schema.decodeUnknownOption(pairing)(value)
-  if (Option.isNone(result)) return
-  const urls = [...new Set(result.value.urls.map(serverAddress).filter((url) => url !== undefined))]
-  if (!urls.length) return
-  return { urls, password: result.value.password }
+  const result = Codec.decodeOption(pairing, value)
+  if (!result) return
+  const urls = [...new Set(result.urls.map(serverAddress).filter((url) => url !== undefined))]
+  if (!urls.length) return
+  return { urls, password: result.password }
 }
+
@@ -1,4 +1,3 @@
-import { Effect, Fiber } from "effect"
 import { createEffect, onCleanup } from "solid-js"
 import { createStore } from "solid-js/store"
 import type { SshConfig, SshItem, SshPlatform } from "./types"
@@ -24,7 +23,8 @@ export function createSshController(input: {
      | undefined
    >
  >({})
-  const tasks = new Map<string, Fiber.Fiber<void>>()
+  // One in-flight request per server; cancelling settles it immediately and ignores its outcome.
+  const tasks = new Map<string, { cancelled: boolean }>()
  const item = (id: string) => input.items().find((item) => item.config.id === id)
  const settle = (id: string) => {
    const attempt = attempts[id]
@@ -33,31 +33,32 @@ export function createSshController(input: {
    setAttempts(id, { active: false, onConnected: undefined })
    if (item(id)?.stage === "ready" && onConnected) queueMicrotask(onConnected)
  }
-  const run = (id: string, effect: Effect.Effect<unknown, unknown>) => {
-    setAttempts(id, { submitting: true, error: false })
-    tasks.set(
-      id,
-      Effect.runFork(
-        effect.pipe(
-          Effect.asVoid,
-          Effect.catch(() =>
-            Effect.sync(() => {
-              setAttempts(id, "error", true)
-              if (!attempts[id]?.prompted) input.error()
-            }),
-          ),
-          Effect.ensuring(
-            Effect.sync(() => {
-              tasks.delete(id)
-              setAttempts(id, "submitting", false)
-            }),
-          ),
-        ),
-      ),
-    )
-  }
-  onCleanup(() => {
-    Effect.runFork(Effect.forEach([...tasks.values()], Fiber.interrupt, { discard: true }))
+  const finish = (id: string, task: { cancelled: boolean }) => {
+    if (task.cancelled) return
+    task.cancelled = true
+    if (tasks.get(id) === task) tasks.delete(id)
+    setAttempts(id, "submitting", false)
+  }
+  const interrupt = (id: string) => {
+    const task = tasks.get(id)
+    if (task) finish(id, task)
+  }
+  const run = (id: string, work: () => Promise<unknown>) => {
+    setAttempts(id, { submitting: true, error: false })
+    const task = { cancelled: false }
+    tasks.set(id, task)
+    work().then(
+      () => finish(id, task),
+      () => {
+        if (task.cancelled) return
+        setAttempts(id, "error", true)
+        if (!attempts[id]?.prompted) input.error()
+        finish(id, task)
+      },
+    )
+  }
+  onCleanup(() => {
+    for (const id of [...tasks.keys()]) interrupt(id)
  })
  createEffect(() => {
    for (const item of input.items()) {
@@ -114,40 +115,32 @@ export function createSshController(input: {
        error: false,
        onConnected: options?.onConnected ?? (options?.replace ? attempts[config.id]?.onConnected : undefined),
      })
-      run(
-        config.id,
-        Effect.gen(function* () {
-          yield* Effect.tryPromise(() => api.start({ ...config, replace: options?.replace }))
-          // Observe admission before treating an older disconnected snapshot as cancellation.
-          yield* Effect.tryPromise(input.refresh)
-        }),
-      )
+      run(config.id, async () => {
+        await api.start({ ...config, replace: options?.replace })
+        // Observe admission before treating an older disconnected snapshot as cancellation.
+        await input.refresh()
+      })
    },
    respond: (id: string, prompt: string, value: string) => {
      const api = input.api
      if (!api || item(id)?.prompt?.id !== prompt || attempts[id]?.submitting) return
      if (attempts[id]?.answered === prompt && !attempts[id]?.error) return
      setAttempts(id, "answered", prompt)
-      run(
-        id,
-        Effect.tryPromise(() => api.respond(id, prompt, value)),
-      )
+      run(id, () => api.respond(id, prompt, value))
    },
-    cancel: (id: string) => {
-      const task = tasks.get(id)
-      const api = input.api
-      Effect.runFork(
-        Effect.gen(function* () {
-          if (task) yield* Fiber.interrupt(task)
-          setAttempts(id, undefined)
-          if (!api) return
-          yield* Effect.tryPromise(() => api.cancel(id))
-          if (!item(id)?.saved) yield* Effect.tryPromise(() => api.forget(id))
-        }).pipe(Effect.ignore),
-      )
+    cancel: (id: string) => {
+      const api = input.api
+      interrupt(id)
+      setAttempts(id, undefined)
+      if (!api) return
+      void api
+        .cancel(id)
+        .then(() => (item(id)?.saved ? undefined : api.forget(id)))
+        .catch(() => undefined)
    },
    restore: (config: SshConfig) => input.api?.start({ ...config, background: true }),
    disconnect: (id: string) => input.api?.disconnect(id),
    forget: (id: string) => input.api?.forget(id),
  }
 }
+
@@ -0,0 +1,61 @@
+import { Schema } from "effect"
+
+// The SSH state contract between the desktop main process and its renderer. Only the main process
+// needs the schemas (its RPC server validates with them); the renderer imports the types from ./types.
+
+export const SshConfig = Schema.Struct({ id: Schema.String, target: Schema.String, name: Schema.String })
+export type SshConfig = typeof SshConfig.Type
+export const SshHttp = Schema.Struct({ url: Schema.String, password: Schema.String })
+export type SshHttp = typeof SshHttp.Type
+export const SshStage = Schema.Literals([
+  "disconnected",
+  "connecting",
+  "checking",
+  "downloading",
+  "uploading",
+  "starting",
+  "ready",
+  "authentication",
+  "incompatible",
+  "failed",
+])
+export const SshPrompt = Schema.Struct({
+  id: Schema.String,
+  text: Schema.String,
+  confirm: Schema.Boolean,
+})
+export const SshItem = Schema.Struct({
+  config: SshConfig,
+  saved: Schema.Boolean,
+  destination: Schema.optional(Schema.String),
+  stage: SshStage,
+  http: Schema.optional(SshHttp),
+  prompt: Schema.optional(SshPrompt),
+  authenticatingElsewhere: Schema.optional(Schema.Boolean),
+  detail: Schema.String,
+  error: Schema.optional(
+    Schema.Literals([
+      "connection",
+      "input",
+      "platform",
+      "version",
+      "install",
+      "service",
+      "host-key",
+      "ssh-missing",
+      "unpublished",
+    ]),
+  ),
+})
+export type SshItem = typeof SshItem.Type
+export const SshState = Schema.Struct({ servers: Schema.Array(SshItem) })
+export type SshState = typeof SshState.Type
+export const SshStart = Schema.Struct({
+  id: Schema.String,
+  target: Schema.String,
+  name: Schema.String,
+  replace: Schema.optional(Schema.Boolean),
+  background: Schema.optional(Schema.Boolean),
+})
+export type SshStart = typeof SshStart.Type
+
@@ -1,63 +1,9 @@
-import { Schema } from "effect"
-export { sshHostname, sshName } from "./name"
-export { isSshConnecting } from "./status"
-
-export const SshConfig = Schema.Struct({ id: Schema.String, target: Schema.String, name: Schema.String })
-export type SshConfig = typeof SshConfig.Type
-export const SshHttp = Schema.Struct({ url: Schema.String, password: Schema.String })
-export type SshHttp = typeof SshHttp.Type
-export const SshStage = Schema.Literals([
-  "disconnected",
-  "connecting",
-  "checking",
-  "downloading",
-  "uploading",
-  "starting",
-  "ready",
-  "authentication",
-  "incompatible",
-  "failed",
-])
-export const SshPrompt = Schema.Struct({
-  id: Schema.String,
-  text: Schema.String,
-  confirm: Schema.Boolean,
-})
-export const SshItem = Schema.Struct({
-  config: SshConfig,
-  saved: Schema.Boolean,
-  destination: Schema.optional(Schema.String),
-  stage: SshStage,
-  http: Schema.optional(SshHttp),
-  prompt: Schema.optional(SshPrompt),
-  authenticatingElsewhere: Schema.optional(Schema.Boolean),
-  detail: Schema.String,
-  error: Schema.optional(
-    Schema.Literals([
-      "connection",
-      "input",
-      "platform",
-      "version",
-      "install",
-      "service",
-      "host-key",
-      "ssh-missing",
-      "unpublished",
-    ]),
-  ),
-})
-export type SshItem = typeof SshItem.Type
-export const SshState = Schema.Struct({ servers: Schema.Array(SshItem) })
-export type SshState = typeof SshState.Type
-export const SshStart = Schema.Struct({
-  id: Schema.String,
-  target: Schema.String,
-  name: Schema.String,
-  replace: Schema.optional(Schema.Boolean),
-  background: Schema.optional(Schema.Boolean),
-})
-export type SshStart = typeof SshStart.Type
-
+export { sshHostname, sshName } from "./name"
+export { isSshConnecting } from "./status"
+import type { SshConfig, SshHttp, SshItem, SshStart, SshState } from "./schema"
+
+export type { SshConfig, SshHttp, SshItem, SshStart, SshState }
+
 export type SshPlatform = {
  getState(): Promise<SshState>
  subscribe(callback: (state: SshState) => void): () => void
@@ -70,3 +16,5 @@ export type SshPlatform = {
  forget(id: string): Promise<void>
  openConfig(): Promise<void>
 }
+
+
@@ -1,9 +1,8 @@
 import { describe, expect, test } from "bun:test"
-import { Schema } from "effect"
 import { OPEN_APPS, OpenAppPreferences } from "./open-in-app"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"

-const decode = Schema.decodeUnknownSync(Persistence.withInitial(OpenAppPreferences, { app: "finder" }))
+const decode = ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(OpenAppPreferences, { app: "finder" }), input))

 describe("open app preferences", () => {
  test.each([...OPEN_APPS])("preserves the %s preference", (app) => {
@@ -18,3 +17,4 @@ describe("open app preferences", () => {
    expect(decode({})).toEqual({ app: "finder" })
  })
 })
+
@@ -5,8 +5,7 @@ import { usePlatform } from "@/runtime/platform/platform"
 import { Persist, persisted } from "@/runtime/persistence/storage"
 import { showToast } from "@/shell/notifications/toast"
 import { useServer } from "@/runtime/server/current"
-import { Schema } from "effect"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"
 import { fileManagerApp } from "@/home/projects/file-manager"
 import { openInAppParentPath } from "@/session/files/open-in-app-path"

@@ -30,8 +29,8 @@ export const OPEN_APPS = [
 export type OpenApp = (typeof OPEN_APPS)[number]
 export type OpenAppOS = "macos" | "windows" | "linux" | "unknown"

-export const OpenAppPreferences = Persistence.struct({
-  app: Schema.Literals(OPEN_APPS),
+export const OpenAppPreferences = Codec.struct({
+  app: Codec.literals(OPEN_APPS),
 })

 const appExistence = new Map<string, Promise<boolean>>()
@@ -242,3 +241,4 @@ function checkAppExists(platform: ReturnType<typeof usePlatform>, app: string) {
  appExistence.set(app, request)
  return request
 }
+
@@ -5,17 +5,20 @@ import {
  type SessionReviewExpandMode,
 } from "@opencode/session-ui/v2/session-review-v2"
 import { createSignal } from "solid-js"
-import { Schema } from "effect"
+import { Codec } from "@/runtime/persistence/codec"
 import type { Platform } from "@/runtime/platform/platform"
 import { Persist, persisted } from "@/runtime/persistence/storage"
-import { Persistence } from "@/runtime/persistence/schema"

-const ReviewPanel = Persistence.struct({
-  sidebarOpened: Schema.Boolean,
-  sidebarWidth: Schema.Finite.check(
-    Schema.isBetween({ minimum: SESSION_REVIEW_V2_SIDEBAR_WIDTH_MIN, maximum: SESSION_REVIEW_V2_SIDEBAR_WIDTH_MAX }),
-  ),
-  expandMode: Schema.Literals(["expand", "collapse"]),
+const ReviewPanel = Codec.struct({
+  sidebarOpened: Codec.boolean,
+  sidebarWidth: Codec.make<number, number>(
+    (v) =>
+      typeof v === "number" && v >= SESSION_REVIEW_V2_SIDEBAR_WIDTH_MIN && v <= SESSION_REVIEW_V2_SIDEBAR_WIDTH_MAX
+        ? v
+        : Codec.INVALID,
+    (v) => v,
+  ),
+  expandMode: Codec.literals(["expand", "collapse"]),
 })

 export function createReviewPanelState(platform?: Platform) {
@@ -47,3 +50,4 @@ export function createReviewPanelState(platform?: Platform) {
 }

 export type ReviewPanelState = ReturnType<typeof createReviewPanelState>
+
@@ -2,9 +2,8 @@ import { beforeAll, describe, expect, mock, test } from "bun:test"
 import { ServerScope } from "@/runtime/server/scope"
 import { base64Encode } from "@opencode/util/encode"
 import { Persist } from "@/runtime/persistence/storage"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"
 import type { Platform } from "@/runtime/platform/platform"
-import { Schema } from "effect"

 let getWorkspaceTerminalCacheKey: typeof import("./context").getWorkspaceTerminalCacheKey
 let clearWorkspaceTerminals: typeof import("./context").clearWorkspaceTerminals
@@ -21,10 +20,10 @@ beforeAll(async () => {
  const mod = await import("./context")
  getWorkspaceTerminalCacheKey = mod.getWorkspaceTerminalCacheKey
  clearWorkspaceTerminals = mod.clearWorkspaceTerminals
-  const schema = Persistence.withInitial(mod.TerminalState, { all: [] })
-  decodeTerminalState = Schema.decodeUnknownSync(schema)
+  const schema = Codec.withInitial(mod.TerminalState, { all: [] })
+  decodeTerminalState = ((input: unknown) => Codec.decodeOrThrow(schema, input))
  roundTripTerminalState = (value) =>
-    Schema.decodeUnknownSync(schema)(Schema.encodeSync(schema)(Schema.decodeUnknownSync(schema)(value)))
+    Codec.decodeOrThrow(schema, schema.encode(Codec.decodeOrThrow(schema, value)))
 })

 describe("getWorkspaceTerminalCacheKey", () => {
@@ -141,3 +140,4 @@ describe("TerminalState", () => {
    expect(roundTripTerminalState(value)).toEqual(value)
  })
 })
+
@@ -8,18 +8,20 @@ import { base64Encode } from "@opencode/util/encode"
 import { defaultTitle, titleNumber } from "./title"
 import { Persist, persisted, removePersisted } from "@/runtime/persistence/storage"
 import { ScopedKey, ServerScope } from "@/runtime/server/scope"
-import { Persistence } from "@/runtime/persistence/schema"
-import { Schema, SchemaGetter } from "effect"
+import { Codec } from "@/runtime/persistence/codec"

-const PTY = Persistence.struct({
-  id: Schema.NonEmptyString,
-  title: Persistence.fallback(Schema.String, () => ""),
-  titleNumber: Persistence.fallback(Schema.Finite, () => 0),
-  rows: Persistence.optional(Schema.Finite),
-  cols: Persistence.optional(Schema.Finite),
-  buffer: Persistence.optional(Schema.String),
-  scrollY: Persistence.optional(Schema.Finite),
-  cursor: Persistence.optional(Schema.Finite),
+const PTY = Codec.struct({
+  id: Codec.make<string, string>(
+    (v) => (typeof v === "string" && v.length > 0 ? v : Codec.INVALID),
+    (v) => v,
+  ),
+  title: Codec.fallback(Codec.string, () => ""),
+  titleNumber: Codec.fallback(Codec.number, () => 0),
+  rows: Codec.lenientOptional(Codec.number),
+  cols: Codec.lenientOptional(Codec.number),
+  buffer: Codec.lenientOptional(Codec.string),
+  scrollY: Codec.lenientOptional(Codec.number),
+  cursor: Codec.lenientOptional(Codec.number),
 })

 export type LocalPTY = typeof PTY.Type
@@ -31,28 +33,26 @@ function numberFromTitle(title: string) {
  return titleNumber(title, MAX_TERMINAL_SESSIONS)
 }

-const State = Persistence.struct({
-  active: Persistence.optional(Schema.String),
-  all: Persistence.array(PTY),
+const State = Codec.struct({
+  active: Codec.lenientOptional(Codec.string),
+  all: Codec.lenientArray(PTY),
 })

-export const TerminalState = State.pipe(
-  Schema.decodeTo(Schema.toType(State), {
-    decode: SchemaGetter.transform((value) => {
-      const seen = new Set<string>()
-      const all = value.all.flatMap((pty) => {
-        if (seen.has(pty.id)) return []
-        seen.add(pty.id)
-        return [{ ...pty, titleNumber: pty.titleNumber > 0 ? pty.titleNumber : (numberFromTitle(pty.title) ?? 0) }]
-      })
-      return {
-        active: value.active && seen.has(value.active) ? value.active : all[0]?.id,
-        all,
-      }
-    }),
-    encode: SchemaGetter.transform((value) => value),
-  }),
-)
+export const TerminalState = Codec.transform(State, {
+  decode: (value): typeof State.Type => {
+    const seen = new Set<string>()
+    const all = value.all.flatMap((pty) => {
+      if (seen.has(pty.id)) return []
+      seen.add(pty.id)
+      return [{ ...pty, titleNumber: pty.titleNumber > 0 ? pty.titleNumber : (numberFromTitle(pty.title) ?? 0) }]
+    })
+    return {
+      active: value.active && seen.has(value.active) ? value.active : all[0]?.id,
+      all,
+    }
+  },
+  encode: (value) => value,
+})

 export function getWorkspaceTerminalCacheKey(dir: string, scope: ServerScope = ServerScope.local) {
  return ScopedKey.from(scope, dir, WORKSPACE_KEY)
@@ -458,3 +458,5 @@ export const { use: useTerminal, provider: TerminalProvider } = createSimpleCont
    }
  },
 })
+
+
@@ -1,40 +1,40 @@
-import { describe, expect, test } from "bun:test"
-import { Schema } from "effect"
-import { GoUpsellState } from "./usage-exceeded-dialogs"
-import { Persistence } from "@/runtime/persistence/schema"
-
-const decode = Schema.decodeUnknownSync(
-  Persistence.withInitial(GoUpsellState, {
-    go_upsell_last_seen_at: null,
-    go_upsell_dont_show: null,
-    go_upsell_account_rate_limit_last_seen_at: null,
-    go_upsell_account_rate_limit_dont_show: null,
-  }),
-)
-
-describe("usage exceeded preferences", () => {
-  test("defaults unseen prompts", () => {
-    expect(decode({})).toEqual({
-      go_upsell_last_seen_at: null,
-      go_upsell_dont_show: null,
-      go_upsell_account_rate_limit_last_seen_at: null,
-      go_upsell_account_rate_limit_dont_show: null,
-    })
-  })
-
-  test("preserves timestamps while recovering malformed siblings", () => {
-    expect(
-      decode({
-        go_upsell_last_seen_at: 123,
-        go_upsell_dont_show: "true",
-        go_upsell_account_rate_limit_last_seen_at: Infinity,
-        go_upsell_account_rate_limit_dont_show: 456,
-      }),
-    ).toEqual({
-      go_upsell_last_seen_at: 123,
-      go_upsell_dont_show: null,
-      go_upsell_account_rate_limit_last_seen_at: null,
-      go_upsell_account_rate_limit_dont_show: 456,
-    })
-  })
-})
+import { describe, expect, test } from "bun:test"
+import { GoUpsellState } from "./usage-exceeded-dialogs"
+import { Codec } from "@/runtime/persistence/codec"
+
+const schema = Codec.withInitial(GoUpsellState, {
+  go_upsell_last_seen_at: null,
+  go_upsell_dont_show: null,
+  go_upsell_account_rate_limit_last_seen_at: null,
+  go_upsell_account_rate_limit_dont_show: null,
+})
+const decode = (input: unknown) => Codec.decodeOrThrow(schema, input)
+
+describe("usage exceeded preferences", () => {
+  test("defaults unseen prompts", () => {
+    expect(decode({})).toEqual({
+      go_upsell_last_seen_at: null,
+      go_upsell_dont_show: null,
+      go_upsell_account_rate_limit_last_seen_at: null,
+      go_upsell_account_rate_limit_dont_show: null,
+    })
+  })
+
+  test("preserves timestamps while recovering malformed siblings", () => {
+    expect(
+      decode({
+        go_upsell_last_seen_at: 123,
+        go_upsell_dont_show: "true",
+        go_upsell_account_rate_limit_last_seen_at: Infinity,
+        go_upsell_account_rate_limit_dont_show: 456,
+      }),
+    ).toEqual({
+      go_upsell_last_seen_at: 123,
+      go_upsell_dont_show: null,
+      go_upsell_account_rate_limit_last_seen_at: null,
+      go_upsell_account_rate_limit_dont_show: 456,
+    })
+  })
+})
+
+
@@ -2,8 +2,7 @@ import { useWorkspaceLocation } from "@/workspaces/location"
 import { Persist, persisted } from "@/runtime/persistence/storage"
 import type { SessionStatus } from "@opencode/client/promise"
 import { onCleanup } from "solid-js"
-import { Schema } from "effect"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"
 import { useSessionLayout } from "./session-layout"
 import { useDialog, useI18n } from "@opencode/ui/context"
 import { DialogUsageExceeded } from "@/providers/connect/usage-exceeded"
@@ -15,11 +14,11 @@ const GO_UPSELL_ACCOUNT_RATE_LIMIT_DONT_SHOW = "go_upsell_account_rate_limit_don
 const GO_UPSELL_WINDOW = 86_400_000 // 24 hrs
 const GO_UPSELL_PROVIDERS = new Set(["opencode", "opencode-go"])

-export const GoUpsellState = Persistence.struct({
-  [GO_UPSELL_FREE_TIER_LAST_SEEN_AT]: Schema.NullOr(Schema.Finite),
-  [GO_UPSELL_FREE_TIER_DONT_SHOW]: Schema.NullOr(Schema.Finite),
-  [GO_UPSELL_ACCOUNT_RATE_LIMIT_LAST_SEEN_AT]: Schema.NullOr(Schema.Finite),
-  [GO_UPSELL_ACCOUNT_RATE_LIMIT_DONT_SHOW]: Schema.NullOr(Schema.Finite),
+export const GoUpsellState = Codec.struct({
+  [GO_UPSELL_FREE_TIER_LAST_SEEN_AT]: Codec.nullOr(Codec.number),
+  [GO_UPSELL_FREE_TIER_DONT_SHOW]: Codec.nullOr(Codec.number),
+  [GO_UPSELL_ACCOUNT_RATE_LIMIT_LAST_SEEN_AT]: Codec.nullOr(Codec.number),
+  [GO_UPSELL_ACCOUNT_RATE_LIMIT_DONT_SHOW]: Codec.nullOr(Codec.number),
 })

 function goUpsellKeys(status: SessionStatus) {
@@ -106,3 +105,4 @@ export function useUsageExceededDialogs() {
    }),
  )
 }
+
@@ -1,7 +1,8 @@
-import { For, Show, createEffect, createMemo, lazy, on, onCleanup } from "solid-js"
+import { For, Show, createEffect, createMemo, on, onCleanup } from "solid-js"
 import { createStore } from "solid-js/store"
 import { makeEventListener } from "@solid-primitives/event-listener"
 import { Button } from "@opencode/ui/button"
+import { Icon } from "@opencode/ui/icon"
 import { IconButton } from "@opencode/ui/icon-button"
 import { TextInput } from "@opencode/ui/text-input"
 import { showToast } from "@/shell/notifications/toast"
@@ -17,8 +18,6 @@ import { useLanguage } from "@/runtime/i18n/language"
 import { useSettings } from "@/settings/model"
 import { SettingsList } from "@/settings/list"

-const Icon = lazy(() => import("@opencode/ui/icon").then((module) => ({ default: module.Icon })))
-
 const IS_MAC = typeof navigator === "object" && /(Mac|iPod|iPhone|iPad)/.test(navigator.platform)
 const PALETTE_ID = "command.palette"

@@ -1,7 +1,6 @@
 import { describe, expect, test } from "bun:test"
-import { Schema } from "effect"
 import { timelinePresets } from "@opencode/session-ui/timeline/detail"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"
 import {
  settingsSchema,
  settingsPersistence,
@@ -13,9 +12,9 @@ import {
  terminalFontFamily,
 } from "./model"

-const schema = Persistence.withInitial(settingsPersistence, defaultSettings)
-const decode = Schema.decodeUnknownSync(schema)
-const encode = Schema.encodeSync(schema)
+const schema = Codec.withInitial(settingsPersistence, defaultSettings)
+const decode = (input: unknown) => Codec.decodeOrThrow(schema, input)
+const encode = (value: typeof settingsSchema.Type) => schema.encode(value)

 describe("settings timeline detail migration", () => {
  test("migrates saved switches and round trips the current settings", () => {
@@ -51,14 +50,14 @@ describe("settings schema", () => {
      general: { ...defaultSettings.general, timelineDetail: timelinePresets[4].value, autoSave: false },
      appearance: { ...defaultSettings.appearance, fontSize: 20 },
    }
-    const restore = Schema.decodeUnknownSync(Persistence.withInitial(settingsPersistence, initial))
+    const restore = (input: unknown) => Codec.decodeOrThrow(Codec.withInitial(settingsPersistence, initial), input)
    expect(restore({})).toEqual(initial)
    expect(restore({ general: { reasoningMode: "invalid", showReasoningSummaries: true } })).toEqual(initial)
    expect(restore({ general: { showReasoningSummaries: true } }).general.timelineDetail.thinking).toEqual({
      placement: "separate",
      details: "expanded",
    })
-    expect(() => Schema.decodeUnknownSync(settingsSchema)({})).toThrow()
+    expect(() => Codec.decodeOrThrow(settingsSchema, {})).toThrow()
  })

  test("supplies the existing defaults for an empty document", () => {
@@ -171,7 +170,7 @@ describe("settings schema", () => {

  test("does not silently repair invalid values during encoding", () => {
    expect(() =>
-      Schema.encodeUnknownSync(settingsSchema)({ ...decode({}), appearance: { fontSize: "large" } }),
+      Codec.encodeOrThrow(settingsSchema, { ...decode({}), appearance: { fontSize: "large" } } as never),
    ).toThrow()
  })
 })
@@ -203,3 +202,6 @@ describe("settings font families", () => {
    expect(terminalFontFamily(undefined)).toStartWith('"JetBrainsMono Nerd Font Mono", ')
  })
 })
+
+
+
@@ -5,8 +5,7 @@ import { Icon } from "@opencode/ui/icon"
 import { IconButton } from "@opencode/ui/icon-button"
 import { TextInput } from "@opencode/ui/text-input"
 import { type Component, createEffect, For, on, onCleanup, Show } from "solid-js"
-import { Schema } from "effect"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"
 import { useLanguage } from "@/runtime/i18n/language"
 import { useModels } from "@/providers/models/models"
 import { useServerSDK } from "@/runtime/server/client"
@@ -20,8 +19,8 @@ type ModelItem = ReturnType<ReturnType<typeof useModels>["list"]>[number]

 const PROVIDER_ICON_SIZE = 16

-export const ModelProvidersSchema = Schema.Struct({
-  collapsed: Persistence.record(Persistence.fallback(Schema.Boolean, () => false)),
+export const ModelProvidersSchema = Codec.struct({
+  collapsed: Codec.lenientRecord(Codec.fallback(Codec.boolean, () => false)),
 })

 export const SettingsModels: Component<{ active?: boolean; autofocus?: boolean }> = (props) => {
@@ -211,3 +210,4 @@ export const SettingsModels: Component<{ active?: boolean; autofocus?: boolean }
    </>
  )
 }
+
@@ -1,5 +1,5 @@
 import { describe, expect, test } from "bun:test"
-import { Schema } from "effect"
+import { Codec } from "@/runtime/persistence/codec"
 import {
  activeCommandRegistrations,
  addCommandRegistration,
@@ -10,12 +10,12 @@ import {
 } from "./command"

 test("command catalog persistence validates metadata and omits executable fields", () => {
-  const decode = Schema.decodeUnknownSync(CommandCatalog)
+  const decode = ((input: unknown) => Codec.decodeOrThrow(CommandCatalog, input))
  const catalog = decode({ open: { title: "Open", keybind: "mod+o", hidden: false, onSelect: "invalid" } })
  expect(catalog).toEqual({ open: { title: "Open", keybind: "mod+o", hidden: false } })
  expect(decode({})).toEqual({})
  expect(() => decode({ open: { title: 1 } })).toThrow()
-  expect(decode(Schema.encodeSync(CommandCatalog)(catalog))).toEqual(catalog)
+  expect(decode(CommandCatalog.encode(catalog))).toEqual(catalog)
 })

 const paletteOptions: CommandOption[] = [
@@ -79,3 +79,4 @@ describe("resolveKeybindOption", () => {
    expect(resolveKeybindOption([fallback, contextual], new KeyboardEvent("keydown"))).toBe(fallback)
  })
 })
+
@@ -2,8 +2,8 @@ import { createSimpleContext } from "@opencode/ui/context"
 import { useDialog } from "@opencode/ui/context/dialog"
 import { type Accessor, batch, createEffect, createMemo, onCleanup, onMount } from "solid-js"
 import { createStore, reconcile } from "solid-js/store"
-import { Schema } from "effect"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"
+
 import { makeEventListener } from "@solid-primitives/event-listener"
 import { useLanguage } from "@/runtime/i18n/language"
 import { useSettings } from "@/settings/model"
@@ -109,16 +109,16 @@ export function resolveKeybindOption(candidates: CommandOption[] | undefined, ev

 type CommandSource = "palette" | "keybind" | "slash"

-export const CommandCatalogItem = Persistence.struct({
-  title: Schema.String,
-  description: Schema.optional(Schema.String),
-  category: Schema.optional(Schema.String),
-  keybind: Schema.optional(Schema.String),
-  slash: Schema.optional(Schema.String),
-  hidden: Schema.optional(Schema.Boolean),
+export const CommandCatalogItem = Codec.struct({
+  title: Codec.string,
+  description: Codec.optional(Codec.string),
+  category: Codec.optional(Codec.string),
+  keybind: Codec.optional(Codec.string),
+  slash: Codec.optional(Codec.string),
+  hidden: Codec.optional(Codec.boolean),
 })
 export type CommandCatalogItem = typeof CommandCatalogItem.Type
-export const CommandCatalog = Schema.Record(Schema.String, Schema.mutableKey(CommandCatalogItem))
+export const CommandCatalog = Codec.record(CommandCatalogItem)
 export type CommandCatalog = typeof CommandCatalog.Type

 export type CommandRegistration = {
@@ -480,3 +480,4 @@ export const { use: useCommand, provider: CommandProvider } = createSimpleContex
    }
  },
 })
+
@@ -1,23 +1,22 @@
 import { expect, test } from "bun:test"
-import { Schema } from "effect"
 import type { ServerConnection } from "@/runtime/server/registry"
 import type { Tab } from "@/shell/tabs/tabs"
 import { NotificationStore, openNotificationSession, type Notification } from "./notification"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"

 test("notification persistence validates and salvages individual notifications", () => {
  const valid: Notification[] = [
    { type: "turn-complete", time: 123, viewed: false, session: "session-1" },
    { type: "error", time: 124, viewed: true, error: { type: "api", message: "failed", status: 500 } },
  ]
-  const decode = Schema.decodeUnknownSync(Persistence.withInitial(NotificationStore, { list: [] }))
+  const decode = ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(NotificationStore, { list: [] }), input))
  const store = decode({
    list: [valid[0], null, { type: "unknown", time: 123, viewed: false }, { ...valid[1], error: "invalid" }, valid[1]],
  })
  expect(store.list).toEqual(valid)
  expect(decode({})).toEqual({ list: [] })
  expect(decode({ list: {} })).toEqual({ list: [] })
-  expect(decode(Schema.encodeSync(NotificationStore)(store))).toEqual(store)
+  expect(decode(NotificationStore.encode(store))).toEqual(store)
 })

 test("opens notification sessions through the tab router", () => {
@@ -41,3 +40,4 @@ test("opens notification sessions through the tab router", () => {

  expect(calls).toEqual(["add:session-1", "route:session-1", "select:session-1"])
 })
+
@@ -1,6 +1,6 @@
 import { createStore, reconcile } from "solid-js/store"
-import { Schema } from "effect"
-import { SessionError } from "@opencode/schema/session-error"
+import { Codec } from "@/runtime/persistence/codec"
+import type { SessionError } from "@opencode/schema/session-error"
 import { type Accessor, batch, createEffect, createMemo, createRoot, getOwner, onCleanup } from "solid-js"
 import { createSimpleContext } from "@opencode/ui/context"
 import type { ServerSDK } from "@/runtime/server/client"
@@ -10,7 +10,7 @@ import { useLanguage } from "@/runtime/i18n/language"
 import { useSettings } from "@/settings/model"
 import { decode64 } from "@/runtime/persistence/base64"
 import { Persist, persisted } from "@/runtime/persistence/storage"
-import { Persistence } from "@/runtime/persistence/schema"
+
 import { playSoundById } from "@/shell/notifications/sound"
 import type { createNotificationCoordinator } from "@/shell/notifications/coordinator"
 import { useGlobal } from "@/runtime/server/runtime"
@@ -20,19 +20,28 @@ import { requireServerKey, sessionHref } from "@/shell/routes/session"
 import type { ServerScope } from "@/runtime/server/scope"
 import { useServer } from "@/runtime/server/current"

-const NotificationBase = {
-  directory: Schema.optional(Schema.String),
-  session: Schema.optional(Schema.String),
-  metadata: Schema.optional(Schema.Unknown),
-  time: Schema.Finite,
-  viewed: Schema.Boolean,
-}
-export const Notification = Schema.Union([
-  Persistence.struct({ ...NotificationBase, type: Schema.Literal("turn-complete") }),
-  Persistence.struct({ ...NotificationBase, type: Schema.Literal("error"), error: SessionError.Error }),
+const NotificationBase = {
+  directory: Codec.optional(Codec.string),
+  session: Codec.optional(Codec.string),
+  metadata: Codec.optional(Codec.unknown),
+  time: Codec.number,
+  viewed: Codec.boolean,
+}
+// The error payload is whatever the server reported; shape-checking it here would load the shared
+// Effect schema into the renderer's startup path for a value the server already validated.
+const StoredSessionError = Codec.make<SessionError.Error, unknown>(
+  (value) =>
+    typeof value === "object" && value !== null && "name" in value && "message" in value
+      ? (value as unknown as SessionError.Error)
+      : Codec.INVALID,
+  (value) => value,
+)
+export const Notification = Codec.union([
+  Codec.struct({ ...NotificationBase, type: Codec.literal("turn-complete") }),
+  Codec.struct({ ...NotificationBase, type: Codec.literal("error"), error: StoredSessionError }),
 ])
 export type Notification = typeof Notification.Type
-export const NotificationStore = Persistence.struct({ list: Persistence.array(Notification) })
+export const NotificationStore = Codec.struct({ list: Codec.lenientArray(Notification) })

 type NotificationIndex = {
  session: {
@@ -368,3 +377,5 @@ export const useNotification = () => {
  const server = useServer()
  return server.ctx.notification
 }
+
+
@@ -1,8 +1,7 @@
 import { describe, expect, test } from "bun:test"
 import { createRoot, createSignal } from "solid-js"
-import { Schema } from "effect"
 import { ServerConnection } from "@/runtime/server/registry"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"
 import { currentRoute, initialLayout, layoutPersistence, layoutSchema } from "./layout"
 import { createSessionKeyReader, ensureSessionKey, pruneSessionKeys } from "./helpers"

@@ -11,21 +10,21 @@ test("settings has its own layout route", () => {
 })

 describe("layout persistence", () => {
-  const schema = Persistence.withInitial(layoutPersistence, initialLayout(ServerConnection.Key.make("local")))
-  const decode = Schema.decodeUnknownSync(schema)
+  const schema = Codec.withInitial(layoutPersistence, initialLayout(ServerConnection.Key.make("local")))
+  const decode = (input: unknown) => Codec.decodeOrThrow(schema, input)

  test("uses supplied initial preferences after legacy migration", () => {
    const initial = initialLayout(ServerConnection.Key.make("remote"))
    initial.sidebar.width = 420
    initial.fileTree.width = 300
    initial.review.panelOpened = true
-    const restore = Schema.decodeUnknownSync(Persistence.withInitial(layoutPersistence, initial))
+    const restore = (input: unknown) => Codec.decodeOrThrow(Codec.withInitial(layoutPersistence, initial), input)
    expect(restore({})).toEqual(initial)
    expect(restore({ sidebar: { width: "bad" } }).sidebar.width).toBe(420)
    expect(restore({ fileTree: { width: 260 } }).fileTree.width).toBe(200)
    expect(restore({ fileTree: {} }).fileTree.width).toBe(300)
    expect(restore({ review: {}, fileTree: { opened: false } }).review.panelOpened).toBe(false)
-    expect(() => Schema.decodeUnknownSync(layoutSchema)({})).toThrow()
+    expect(() => Codec.decodeOrThrow(layoutSchema, {})).toThrow()
  })

  test("restores shipped defaults for missing and invalid fields", () => {
@@ -56,8 +55,8 @@ describe("layout persistence", () => {
    expect(value.sidebar).toEqual({ opened: false, width: 344, workspaces: {}, workspacesDefault: true })
    expect(value.review).toEqual({ diffStyle: "split", panelOpened: true })
    expect(value.fileTree).toEqual({ opened: true, width: 200, tab: "changes" })
-    expect(Schema.encodeSync(schema)(value)).toEqual(value)
-    expect(decode(Schema.encodeSync(schema)(value))).toEqual(value)
+    expect(schema.encode(value)).toEqual(value)
+    expect(decode(schema.encode(value))).toEqual(value)
    expect(decode({ fileTree: { opened: true } }).review.panelOpened).toBe(false)
  })

@@ -169,3 +168,4 @@ describe("pruneSessionKeys", () => {
    expect(drop).toEqual([])
  })
 })
+
@@ -1,63 +1,58 @@
 export * as TabStorage from "./schema"

-import { Schema, SchemaGetter } from "effect"
-import { ServerKey } from "@/runtime/server/persistence"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"
+import { ServerKey } from "@/runtime/server/key"

 export { ServerKey }

-export const Session = Persistence.struct({
-  type: Schema.Literal("session"),
+export const Session = Codec.struct({
+  type: Codec.literal("session"),
  server: ServerKey,
-  sessionId: Schema.String,
-  routeSessionId: Persistence.optional(Schema.String),
-  routeParentId: Persistence.optional(Schema.String),
+  sessionId: Codec.string,
+  routeSessionId: Codec.lenientOptional(Codec.string),
+  routeParentId: Codec.lenientOptional(Codec.string),
 })

-export const Draft = Persistence.struct({
-  type: Schema.Literal("draft"),
-  draftID: Schema.String,
+export const Draft = Codec.struct({
+  type: Codec.literal("draft"),
+  draftID: Codec.string,
  server: ServerKey,
-  directory: Schema.String,
-  worktree: Persistence.optional(Schema.String),
-  branch: Persistence.optional(Schema.String),
-  mcp: Persistence.optional(Persistence.struct({ target: Schema.String, states: Persistence.record(Schema.Boolean) })),
+  directory: Codec.string,
+  worktree: Codec.lenientOptional(Codec.string),
+  branch: Codec.lenientOptional(Codec.string),
+  mcp: Codec.lenientOptional(Codec.struct({ target: Codec.string, states: Codec.lenientRecord(Codec.boolean) })),
 })

-const SessionCodec = Session.pipe(
-  Schema.decodeTo(Schema.toType(Session), {
-    decode: SchemaGetter.transform((tab) => ({
-      type: tab.type,
-      server: tab.server,
-      sessionId: tab.sessionId,
-      ...(tab.routeSessionId && tab.routeSessionId !== tab.sessionId
-        ? { routeSessionId: tab.routeSessionId, ...(tab.routeParentId ? { routeParentId: tab.routeParentId } : {}) }
-        : {}),
-    })),
-    encode: SchemaGetter.transform((tab) => tab),
+// A stored route that only repeats the session id carries nothing; drop it and its parent.
+const SessionCodec = Codec.transform(Session, {
+  decode: (tab) => ({
+    type: tab.type,
+    server: tab.server,
+    sessionId: tab.sessionId,
+    ...(tab.routeSessionId && tab.routeSessionId !== tab.sessionId
+      ? { routeSessionId: tab.routeSessionId, ...(tab.routeParentId ? { routeParentId: tab.routeParentId } : {}) }
+      : {}),
+  }),
+  encode: (tab) => tab,
+})
+
+export const Tab = Codec.union([Session, Draft])
+export const Tabs = Codec.lenientArray(Codec.union([SessionCodec, Draft]))
+export const Recent = Codec.struct({
+  key: Codec.optional(Codec.string),
+})
+export const Info = Codec.struct({
+  title: Codec.optional(Codec.string),
+  directory: Codec.optional(Codec.string),
+})
+export const Infos = Codec.record(Info)
+export const Panes = Codec.record(
+  Codec.struct({
+    terminal: Codec.optional(Codec.boolean),
+    review: Codec.optional(Codec.boolean),
+    terminalHeight: Codec.optional(Codec.number),
+    sessionWidth: Codec.optional(Codec.number),
  }),
 )
-
-export const Tab = Schema.Union([Session, Draft])
-export const Tabs = Persistence.array(Schema.Union([SessionCodec, Draft]))
-export const Recent = Persistence.struct({
-  key: Schema.optional(Schema.String),
-})
-export const Info = Persistence.struct({
-  title: Schema.optional(Schema.String),
-  directory: Schema.optional(Schema.String),
-})
-export const Infos = Schema.Record(Schema.String, Schema.mutableKey(Info))
-export const Panes = Schema.Record(
-  Schema.String,
-  Schema.mutableKey(
-    Persistence.struct({
-      terminal: Schema.optional(Schema.Boolean),
-      review: Schema.optional(Schema.Boolean),
-      terminalHeight: Schema.optional(Schema.Finite),
-      sessionWidth: Schema.optional(Schema.Finite),
-    }),
-  ),
-)
-export const ClosedTab = Schema.Struct({ tab: SessionCodec, index: Schema.Int.check(Schema.isGreaterThanOrEqualTo(0)) })
-export const Closed = Persistence.array(ClosedTab)
+export const ClosedTab = Codec.struct({ tab: SessionCodec, index: Codec.nonNegativeInt })
+export const Closed = Codec.lenientArray(ClosedTab)
@@ -3,13 +3,12 @@ import { createRoot, getOwner, onCleanup } from "solid-js"
 import { createTabMemory } from "./memory"
 import { nextTabAfterClose, pushClosedTab, removeClosedTabs, takeClosedTab, type ClosedTab } from "./closed"
 import { findSessionTab, sessionIDHasOpenTab, tabHref, tabKey, type SessionTab, type Tab } from "./tabs"
-import { Schema } from "effect"
 import { TabStorage } from "./schema"
 import type { ServerConnection } from "@/runtime/server/registry"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"

 const server = "local\nhttp://localhost:4096" as ServerConnection.Key
-const decodeTabs = Schema.decodeUnknownSync(Persistence.withInitial(TabStorage.Tabs, []))
+const decodeTabs = ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(TabStorage.Tabs, []), input))

 function sessionTab(sessionId: string): SessionTab {
  return { type: "session", server, sessionId }
@@ -26,7 +25,7 @@ describe("tab migration", () => {
    }
    const restored = decodeTabs([legacy, draft])
    expect(restored).toEqual([legacy, draft])
-    expect(decodeTabs(Schema.encodeSync(TabStorage.Tabs)(restored))).toEqual([legacy, draft])
+    expect(decodeTabs(TabStorage.Tabs.encode(restored))).toEqual([legacy, draft])
  })

  test("drops null and malformed persisted tabs", () => {
@@ -64,13 +63,13 @@ describe("tab migration", () => {
      draft,
    ])
    expect(tabs).toEqual([sessionTab("root"), draft])
-    expect(Schema.encodeSync(TabStorage.Tabs)(tabs)).toEqual(tabs)
-    expect(decodeTabs(Schema.encodeSync(TabStorage.Tabs)(tabs))).toEqual(tabs)
+    expect(TabStorage.Tabs.encode(tabs)).toEqual(tabs)
+    expect(decodeTabs(TabStorage.Tabs.encode(tabs))).toEqual(tabs)
  })

  test("salvages valid closed session tabs", () => {
    expect(
-      Schema.decodeUnknownSync(Persistence.withInitial(TabStorage.Closed, []))([
+      ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(TabStorage.Closed, []), input))([
        { tab: sessionTab("a"), index: 1 },
        { tab: sessionTab("b"), index: -1 },
        { tab: { type: "draft", server, draftID: "d", directory: "/project" }, index: 0 },
@@ -81,16 +80,16 @@ describe("tab migration", () => {

  test("validates auxiliary tab state", () => {
    expect(
-      Schema.decodeUnknownSync(Persistence.withInitial(TabStorage.Recent, { key: undefined }))({ key: 1 }),
+      ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(TabStorage.Recent, { key: undefined }), input))({ key: 1 }),
    ).toEqual({ key: undefined })
-    expect(Schema.decodeUnknownSync(TabStorage.Infos)({})).toEqual({})
-    expect(Schema.decodeUnknownSync(TabStorage.Panes)({})).toEqual({})
-    expect(Schema.decodeUnknownSync(TabStorage.Infos)({ tab: { title: "Title", directory: "/project" } })).toEqual({
+    expect(Codec.decodeOrThrow(TabStorage.Infos, {})).toEqual({})
+    expect(Codec.decodeOrThrow(TabStorage.Panes, {})).toEqual({})
+    expect(Codec.decodeOrThrow(TabStorage.Infos, { tab: { title: "Title", directory: "/project" } })).toEqual({
      tab: { title: "Title", directory: "/project" },
    })
-    const panes = Schema.decodeUnknownSync(TabStorage.Panes)({ tab: { terminal: true, terminalHeight: 300 } })
-    expect(Schema.encodeSync(TabStorage.Panes)(panes)).toEqual({ tab: { terminal: true, terminalHeight: 300 } })
-    expect(() => Schema.decodeUnknownSync(TabStorage.Panes)({ tab: { terminal: "yes" } })).toThrow()
+    const panes = Codec.decodeOrThrow(TabStorage.Panes, { tab: { terminal: true, terminalHeight: 300 } })
+    expect(TabStorage.Panes.encode(panes)).toEqual({ tab: { terminal: true, terminalHeight: 300 } })
+    expect(() => Codec.decodeOrThrow(TabStorage.Panes, { tab: { terminal: "yes" } })).toThrow()
  })
 })

@@ -209,3 +208,5 @@ describe("closed tab stack", () => {
    expect(nextTabAfterClose([sessionTab("a")], 0, true)).toBeNull()
  })
 })
+
+
@@ -1,5 +1,5 @@
 import { describe, expect, test } from "bun:test"
-import { canOpenTabRename, canStartTabDrag, forwardTabRef, isTabCloseTarget } from "./tab-gesture"
+import { canOpenTabRename, forwardTabRef, isTabCloseTarget } from "./tab-gesture"

 describe("titlebar tab gestures", () => {
  test("excludes close controls from tab gestures", () => {
@@ -24,10 +24,4 @@ describe("titlebar tab gestures", () => {
    expect(canOpenTabRename(false, false, false)).toBe(true)
    expect(canOpenTabRename(false, false, true)).toBe(false)
  })
-
-  test("preserves native panning for touch pointers", () => {
-    expect(canStartTabDrag("mouse")).toBe(true)
-    expect(canStartTabDrag("pen")).toBe(true)
-    expect(canStartTabDrag("touch")).toBe(false)
-  })
 })
@@ -4,10 +4,6 @@ export function isTabCloseTarget(target: EventTarget | null) {
  return target instanceof Element && !!target.closest('[data-slot="tab-close"]')
 }

-export function canStartTabDrag(pointerType: string) {
-  return pointerType !== "touch"
-}
-
 export function forwardTabRef(ref: Ref<HTMLDivElement> | undefined, element: HTMLDivElement) {
  if (typeof ref === "function") ref(element)
 }
@@ -328,6 +328,7 @@ export function TabNavItem(props: {

  return (
    <Menu.Context
+      modal={false}
      onOpenChange={(open) => {
        setMenu("open", open)
        if (open) setPopoverOpen(false)
@@ -16,7 +16,7 @@ import { useTabs } from "@/shell/tabs/tabs"
 import { createTabComposerState } from "@/composer/persistence"
 import { base64Encode } from "@opencode/util/encode"
 import { showToast } from "@/shell/notifications/toast"
-import { canStartTabDrag, isTabCloseTarget } from "./tab-gesture"
+import { isTabCloseTarget } from "./tab-gesture"
 import { adjacentTabKey, mergeVisibleTabOrder } from "./tab-order"
 import type { SessionInfo } from "@opencode/client/promise"

@@ -292,9 +292,11 @@ export function TitlebarTabStrip(props: {
        <DragDropProvider
          sensors={[
            PointerSensor.configure({
-              activationConstraints: [new PointerActivationConstraints.Distance({ value: 4 })],
+              activationConstraints: (event) =>
+                event.pointerType === "touch"
+                  ? [new PointerActivationConstraints.Distance({ value: 8 })]
+                  : [new PointerActivationConstraints.Distance({ value: 4 })],
              preventActivation: (event) =>
-                !canStartTabDrag(event.pointerType) ||
                isTabCloseTarget(event.target) ||
                (event.target instanceof Element && !!event.target.closest('[contenteditable="true"]')),
            }),
@@ -313,6 +315,7 @@ export function TitlebarTabStrip(props: {
            if (!source) return
            const tab = props.tabs.find((item) => tabKey(item) === source.id.toString())
            if (!tab) return
+            if (vertical()) return
            const tabEl = source.element?.querySelector<HTMLDivElement>("[data-titlebar-tab]")
            props.onNavigate(tab, tabEl ?? undefined)
          }}
@@ -1,13 +1,13 @@
 import { expect, test } from "bun:test"
-import { Schema } from "effect"
 import { HighlightsStore } from "./highlights"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"

 test("highlight persistence defaults missing or invalid versions and round-trips valid versions", () => {
-  const decode = Schema.decodeUnknownSync(Persistence.withInitial(HighlightsStore, { version: undefined }))
+  const decode = ((input: unknown) => Codec.decodeOrThrow(Codec.withInitial(HighlightsStore, { version: undefined }), input))
  expect(decode({})).toEqual({ version: undefined })
  expect(decode({ version: null })).toEqual({ version: undefined })
  const value = decode({ version: "1.2.3", legacy: true })
  expect(value).toEqual({ version: "1.2.3" })
-  expect(Schema.encodeSync(HighlightsStore)(value)).toEqual(value)
+  expect(HighlightsStore.encode(value)).toEqual(value)
 })
+
@@ -1,18 +1,18 @@
 import { createEffect, onCleanup } from "solid-js"
 import { createStore } from "solid-js/store"
-import { Schema } from "effect"
+import { Codec } from "@/runtime/persistence/codec"
 import { createSimpleContext } from "@opencode/ui/context"
 import { useDialog } from "@opencode/ui/context/dialog"
 import { usePlatform } from "@/runtime/platform/platform"
 import { useSettings } from "@/settings/model"
 import { persisted } from "@/runtime/persistence/storage"
-import { Persistence } from "@/runtime/persistence/schema"
+
 import { DialogReleaseNotes, type Highlight } from "@/shell/updates/release-notes"

 const CHANGELOG_URL = "https://opencode.ai/changelog.json"

-export const HighlightsStore = Persistence.struct({
-  version: Schema.UndefinedOr(Schema.String),
+export const HighlightsStore = Codec.struct({
+  version: Codec.undefinedOr(Codec.string),
 })

 type ParsedRelease = {
@@ -233,3 +233,4 @@ export const { use: useHighlights, provider: HighlightsProvider } = createSimple
    }
  },
 })
+
@@ -1,20 +1,19 @@
 import type { FileContent } from "@/runtime/server/types"
-import { Schema } from "effect"
-import { Persistence } from "@/runtime/persistence/schema"
+import { Codec } from "@/runtime/persistence/codec"

-export const FileSelection = Persistence.struct({
-  startLine: Schema.Number,
-  startChar: Schema.Number,
-  endLine: Schema.Number,
-  endChar: Schema.Number,
+export const FileSelection = Codec.struct({
+  startLine: Codec.number,
+  startChar: Codec.number,
+  endLine: Codec.number,
+  endChar: Codec.number,
 })
 export type FileSelection = typeof FileSelection.Type

-export const SelectedLineRange = Persistence.struct({
-  start: Schema.Number,
-  end: Schema.Number,
-  side: Persistence.optional(Schema.Literals(["additions", "deletions"])),
-  endSide: Persistence.optional(Schema.Literals(["additions", "deletions"])),
+export const SelectedLineRange = Codec.struct({
+  start: Codec.number,
+  end: Codec.number,
+  side: Codec.lenientOptional(Codec.literals(["additions", "deletions"])),
+  endSide: Codec.lenientOptional(Codec.literals(["additions", "deletions"])),
 })
 export type SelectedLineRange = typeof SelectedLineRange.Type

@@ -44,3 +43,4 @@ export function selectionFromLines(range: SelectedLineRange): FileSelection {
    endChar: 0,
  }
 }
+
@@ -1,8 +1,7 @@
 import { createEffect, createRoot } from "solid-js"
 import { produce } from "solid-js/store"
-import { Schema } from "effect"
+import { Codec } from "@/runtime/persistence/codec"
 import { Persist, persisted } from "@/runtime/persistence/storage"
-import { Persistence } from "@/runtime/persistence/schema"
 import { createScopedCache } from "@/runtime/server/scoped-cache"
 import { SelectedLineRange } from "./types"
 import type { ServerScope } from "@/runtime/server/scope"
@@ -11,14 +10,14 @@ const WORKSPACE_KEY = "__workspace__"
 const MAX_FILE_VIEW_SESSIONS = 20
 const MAX_VIEW_FILES = 500

-const FileViewSchema = Persistence.struct({
-  scrollTop: Persistence.optional(Schema.Finite),
-  scrollLeft: Persistence.optional(Schema.Finite),
-  selectedLines: Persistence.optional(Schema.NullOr(SelectedLineRange)),
+const FileViewSchema = Codec.struct({
+  scrollTop: Codec.lenientOptional(Codec.number),
+  scrollLeft: Codec.lenientOptional(Codec.number),
+  selectedLines: Codec.lenientOptional(Codec.nullOr(SelectedLineRange)),
 })

-export const FileViewsSchema = Schema.Struct({
-  file: Persistence.record(Persistence.fallback(FileViewSchema, () => ({}))),
+export const FileViewsSchema = Codec.struct({
+  file: Codec.lenientRecord(Codec.fallback(FileViewSchema, () => ({}))),
 })

 function normalizeSelectedLines(range: SelectedLineRange): SelectedLineRange {
@@ -150,3 +149,4 @@ export function createFileViewCache(scope: ServerScope) {
    clear: () => cache.clear(),
  }
 }
+
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/cli",
-  "version": "2.0.8",
+  "version": "2.0.10",
  "type": "module",
  "license": "MIT",
  "bin": {
@@ -0,0 +1,120 @@
+#!/usr/bin/env bun
+import { Script } from "@opencode/script"
+import { $ } from "bun"
+import { mkdir, rm } from "node:fs/promises"
+import path from "node:path"
+import { fileURLToPath } from "node:url"
+import { UpdateArtifact } from "../../../script/update-artifact"
+
+if (Script.channel !== "beta" && Script.channel !== "latest") {
+  throw new Error("Homebrew publishing requires the beta or latest channel")
+}
+const valid =
+  Script.channel === "beta"
+    ? /^\d+\.\d+\.\d+-beta[.-]\d+(?:\.\d+)?$/.test(Script.version)
+    : /^\d+\.\d+\.\d+$/.test(Script.version)
+if (!valid) throw new Error(`Expected a ${Script.channel} release version`)
+
+const dir = fileURLToPath(new URL("..", import.meta.url))
+const root = path.resolve(process.env.OPENCODE_CLI_DIST ?? path.join(dir, "dist"))
+const outdir = path.join(root, "homebrew-tap")
+const dryRun = process.argv.includes("--dry-run")
+const name = Script.channel === "beta" ? "opencode-beta" : "opencode-v2"
+const formulaClass = Script.channel === "beta" ? "OpencodeBeta" : "OpencodeV2"
+
+const targets = await Promise.all(
+  [
+    { name: "darwin-arm64", archive: "zip" },
+    { name: "darwin-x64-baseline", archive: "zip" },
+    { name: "linux-arm64", archive: "tar.gz" },
+    { name: "linux-x64-baseline", archive: "tar.gz" },
+  ].map(async (target) => {
+    const filename = `opencode-${target.name}.${target.archive}`
+    const file = Bun.file(path.join(root, filename))
+    if (!(await file.exists()) || !file.size) throw new Error(`Missing Homebrew archive: ${filename}`)
+    const sha256 = new Bun.CryptoHasher("sha256")
+    for await (const chunk of file.stream()) sha256.update(chunk)
+    return {
+      ...target,
+      url: `https://opencode.ai/files/bin/${encodeURIComponent(Script.version)}/${filename}`,
+      sha256: sha256.digest("hex"),
+    }
+  }),
+)
+
+await rm(outdir, { recursive: true, force: true })
+if (dryRun) await mkdir(outdir, { recursive: true })
+if (!dryRun) {
+  const token = process.env.GITHUB_TOKEN
+  if (!token) throw new Error("GITHUB_TOKEN is required to update the Homebrew tap")
+  await $`git clone ${`https://x-access-token:${token}@github.com/anomalyco/homebrew-tap.git`} ${outdir}`
+  await $`git checkout -B master`.cwd(outdir)
+}
+
+const target = (name: string) => {
+  const result = targets.find((item) => item.name === name)
+  if (!result) throw new Error(`Missing Homebrew target: ${name}`)
+  return result
+}
+const macArm = target("darwin-arm64")
+const macIntel = target("darwin-x64-baseline")
+const linuxArm = target("linux-arm64")
+const linuxIntel = target("linux-x64-baseline")
+
+await Bun.write(
+  path.join(outdir, `${name}.rb`),
+  [
+    "# typed: false",
+    "# frozen_string_literal: true",
+    "",
+    `class ${formulaClass} < Formula`,
+    `  desc "OpenCode V2${Script.channel === "beta" ? " beta" : ""} - the AI coding agent for the terminal"`,
+    '  homepage "https://github.com/anomalyco/opencode"',
+    `  version "${Script.version}"`,
+    '  license "MIT"',
+    "",
+    '  depends_on "ripgrep"',
+    '  conflicts_with "opencode", because: "both install an opencode binary"',
+    "",
+    "  on_macos do",
+    "    if Hardware::CPU.arm?",
+    `      url "${macArm.url}"`,
+    `      sha256 "${macArm.sha256}"`,
+    "    else",
+    `      url "${macIntel.url}"`,
+    `      sha256 "${macIntel.sha256}"`,
+    "    end",
+    "  end",
+    "",
+    "  on_linux do",
+    "    if Hardware::CPU.arm?",
+    `      url "${linuxArm.url}"`,
+    `      sha256 "${linuxArm.sha256}"`,
+    "    else",
+    `      url "${linuxIntel.url}"`,
+    `      sha256 "${linuxIntel.sha256}"`,
+    "    end",
+    "  end",
+    "",
+    "  def install",
+    '    bin.install "opencode"',
+    "  end",
+    "end",
+    "",
+  ].join("\n"),
+)
+console.log(`Prepared ${name} ${Script.version} in ${outdir}`)
+if (dryRun) process.exit(0)
+
+await $`git add ${name + ".rb"}`.cwd(outdir)
+if ((await $`git diff --cached --quiet`.cwd(outdir).nothrow()).exitCode !== 0) {
+  await $`git commit -m ${`chore: update ${name} to ${Script.version}`}`.cwd(outdir)
+  await $`git push origin master`.cwd(outdir)
+}
+await UpdateArtifact.publish({
+  channel: Script.channel,
+  name: "cli",
+  distribution: "homebrew",
+  version: Script.version,
+  metadata: { package: `anomalyco/tap/${name}` },
+})
@@ -149,6 +149,10 @@ if (Script.channel === "latest" && Script.release && !dryRun) {

 if ((Script.channel === "beta" || Script.channel === "latest") && Script.release) {
  await $`bun ./script/publish-aur.ts ${dryRun ? ["--dry-run"] : []}`.env({ ...process.env, OPENCODE_CLI_DIST: root })
+  await $`bun ./script/publish-homebrew.ts ${dryRun ? ["--dry-run"] : []}`.env({
+    ...process.env,
+    OPENCODE_CLI_DIST: root,
+  })
 }

 async function archive(bin: string, target: string, binary: string, directory: string) {
@@ -1,17 +1,22 @@
 import { Global } from "@opencode/util/global"
 import { AppProcess } from "@opencode/util/process"
 import { OPENCODE_ARTIFACT, OPENCODE_CHANNEL, OPENCODE_LOCAL, OPENCODE_VERSION } from "../version"
-import { Context, Duration, Effect, FileSystem, Layer, Ref } from "effect"
+import { Context, Duration, Effect, FileSystem, Layer, Option, Ref, Schema } from "effect"
 import { ChildProcess } from "effect/unstable/process"
 import { parse, type ParseError } from "jsonc-parser"
 import path from "node:path"
 import { action, parseReleaseVersion, type Policy } from "./updater-action"

-export const methods = ["curl", "npm", "pnpm", "bun", "yarn"] as const
+export const methods = ["curl", "npm", "pnpm", "bun", "yarn", "vp", "brew"] as const
+
 export type Method = (typeof methods)[number]
 export type RunResult = { readonly type: "available" | "installed"; readonly version: string }
 export type CheckResult = RunResult | { readonly type: "unavailable"; readonly message: string }

+const decodeVpPackages = Schema.decodeUnknownOption(
+  Schema.fromJsonString(Schema.Array(Schema.Struct({ name: Schema.String }))),
+)
+
 export interface Interface {
  readonly run: (onInstall?: (version: string) => void) => Effect.Effect<RunResult | undefined>
  readonly check: () => Effect.Effect<CheckResult | undefined, Error>
@@ -96,6 +101,13 @@ const make = Effect.gen(function* () {
      process.platform === "win32" ? "opencode.exe" : "opencode",
    )
    if (path.resolve(process.execPath) === path.resolve(binary)) return "curl"
+    const executable = yield* fs.realPath(process.execPath).pipe(Effect.orElseSucceed(() => process.execPath))
+    if (
+      ["opencode-beta", "opencode-v2"].some((name) =>
+        executable.includes(`${path.sep}Cellar${path.sep}${name}${path.sep}`),
+      )
+    )
+      return "brew"
    if (!installedPackage) return

    const checks: ReadonlyArray<{ method: Method; command: string[] }> = [
@@ -103,22 +115,30 @@ const make = Effect.gen(function* () {
      { method: "pnpm", command: ["pnpm", "list", "-g", "--depth=0", installedPackage] },
      { method: "bun", command: ["bun", "pm", "ls", "-g"] },
      { method: "yarn", command: ["yarn", "global", "list"] },
+      { method: "vp", command: ["vp", "list", "-g", "--json", installedPackage] },
    ]
    const results = yield* Effect.forEach(
      checks,
      (check) => exec(check.command).pipe(Effect.map((result) => ({ check, result }))),
      { concurrency: "unbounded" },
    )
-    return results.find((result) => result.result.stdout.includes(installedPackage))?.check.method
+    return results.find((result) => {
+      if (result.check.method !== "vp") return result.result.stdout.includes(installedPackage)
+      // Vite+ repeats the filter in its successful no-match message, so substring detection would be a false positive.
+      return Option.exists(decodeVpPackages(result.result.stdout), (packages) =>
+        packages.some((item) => item.name === installedPackage),
+      )
+    })?.check.method
  })

  const removal = (method: Method) => {
-    if (method === "curl" || !installedPackage) return undefined
+    if (method === "curl" || method === "brew" || !installedPackage) return undefined
    const commands = {
      npm: ["npm", "uninstall", "--global", installedPackage],
      pnpm: ["pnpm", "remove", "--global", installedPackage],
      bun: ["bun", "remove", "--global", installedPackage],
      yarn: ["yarn", "global", "remove", installedPackage],
+      vp: ["vp", "uninstall", "-g", installedPackage],
    }
    const command = commands[method]
    return {
@@ -133,11 +153,12 @@ const make = Effect.gen(function* () {
    }
  }

-  const release = Effect.fnUntraced(function* () {
+  const release = Effect.fnUntraced(function* (method?: Method) {
+    const distribution = method === "brew" ? "homebrew" : "npm"
    const response = yield* Effect.tryPromise({
      try: (signal) =>
        fetch(
-          `https://opencode.ai/update/api/${encodeURIComponent(channel)}/${encodeURIComponent(OPENCODE_ARTIFACT)}/npm?current=${encodeURIComponent(OPENCODE_VERSION)}`,
+          `https://opencode.ai/update/api/${encodeURIComponent(channel)}/${encodeURIComponent(OPENCODE_ARTIFACT)}/${distribution}?current=${encodeURIComponent(OPENCODE_VERSION)}`,
          {
            signal: AbortSignal.any([signal, AbortSignal.timeout(10_000)]),
          },
@@ -153,7 +174,11 @@ const make = Effect.gen(function* () {
    return { package: data.metadata.package, version: data.version }
  })

-  const latest = () => release().pipe(Effect.map((data) => data.version))
+  const latest = () =>
+    method().pipe(
+      Effect.flatMap(release),
+      Effect.map((data) => data.version),
+    )

  const temporaryDirectory = (prefix: string) =>
    Effect.acquireRelease(fs.makeTempDirectory({ directory: global.cache, prefix }), (directory) =>
@@ -163,12 +188,12 @@ const make = Effect.gen(function* () {
  const upgrade = Effect.fnUntraced(function* (method: Method, input: string) {
    if (!parseReleaseVersion(input)) return yield* Effect.fail(new Error(`Invalid version: ${input}`))
    const version = input.trim().replace(/^v/, "")
-    const packageName = (yield* release()).package
+    const packageName = (yield* release(method)).package
    const target = `${packageName}@${version}`
    if (installedPackage && packageName !== installedPackage && (method === "pnpm" || method === "yarn")) {
      return yield* Effect.fail(new Error(`Reinstall ${target} with ${method} to migrate from ${installedPackage}.`))
    }
-    const commands: Record<Exclude<Method, "bun" | "curl">, string[]> = {
+    const commands: Record<Exclude<Method, "bun" | "curl" | "brew">, string[]> = {
      // Keep the old package: uninstalling it can unlink the replacement command.
      npm: [
        "npm",
@@ -182,6 +207,10 @@ const make = Effect.gen(function* () {
      ],
      pnpm: ["pnpm", "add", "--global", `--allow-build=${packageName}`, target],
      yarn: ["yarn", "global", "add", target],
+      vp:
+        installedPackage && packageName !== installedPackage
+          ? ["vp", "install", "-g", "--force", target]
+          : ["vp", "update", "-g", target],
    }
    const result = yield* Effect.scoped(
      Effect.gen(function* () {
@@ -202,6 +231,7 @@ const make = Effect.gen(function* () {
          if (download.code !== 0) return download
          return yield* exec(["bash", installer, "--version", version, "--no-modify-path"], "5 minutes")
        }
+        if (method === "brew") return yield* exec(["brew", "upgrade", packageName], "5 minutes")
        return yield* exec(commands[method], "5 minutes")
      }),
    ).pipe(Effect.mapError((cause) => new Error(`Failed to update with ${method}`, { cause })))
@@ -19,6 +19,7 @@ function fixture(
  } = () => ({}),
  name = "@opencode/cli",
  failCleanup = false,
+  releasePackage = name,
 ) {
  return Effect.gen(function* () {
    const fs = yield* FileSystem.FileSystem
@@ -34,7 +35,7 @@ function fixture(
    yield* Effect.acquireRelease(
      Effect.sync(() =>
        spyOn(globalThis, "fetch").mockImplementation(
-          Object.assign(async () => Response.json({ version: "2.3.4", metadata: { package: name } }), {
+          Object.assign(async () => Response.json({ version: "2.3.4", metadata: { package: releasePackage } }), {
            preconnect: fetch.preconnect,
          }),
        ),
@@ -106,6 +107,7 @@ const installs = [
    command: ["pnpm", "add", "--global", "--allow-build=@opencode/cli", "@opencode/cli@2.3.4-beta.1"],
  },
  { method: "yarn", command: ["yarn", "global", "add", "@opencode/cli@2.3.4-beta.1"] },
+  { method: "vp", command: ["vp", "update", "-g", "@opencode/cli@2.3.4-beta.1"] },
 ] as const

 installs.forEach(({ method, command }) => {
@@ -117,6 +119,25 @@ installs.forEach(({ method, command }) => {
    }),
  )
 })
+
+it.live("vp force-installs a renamed V2 package that replaces the existing binary owner", () =>
+  Effect.gen(function* () {
+    const test = yield* fixture(() => ({}), "@opencode/cli", false, "@opencode/cli-node")
+    yield* test.updater.upgrade("vp", "v2.3.4-beta.1")
+    expect(test.commands).toEqual([["vp", "install", "-g", "--force", "@opencode/cli-node@2.3.4-beta.1"]])
+  }),
+)
+
+it.live("vp removes the package from its managed global store", () =>
+  Effect.gen(function* () {
+    const test = yield* fixture()
+    const removal = test.updater.removal("vp")
+    if (!removal) return yield* Effect.die("Expected vp removal command")
+    expect(removal.command).toEqual(["vp", "uninstall", "-g", "@opencode/cli"])
+    yield* removal.run
+    expect(test.commands).toEqual([["vp", "uninstall", "-g", "@opencode/cli"]])
+  }),
+)
 ;[0, 1].forEach((exitCode) => {
  it.live(`bun isolates and removes its install cache after exit ${exitCode}`, () =>
    Effect.gen(function* () {
@@ -200,11 +221,19 @@ it.live("install failures expose stderr and process errors do not report success
    expect(missing.commands).toHaveLength(1)
  }),
 )
-;(["npm", "pnpm", "bun", "yarn", undefined] as const).forEach((method) => {
+;(["npm", "pnpm", "bun", "yarn", "vp", undefined] as const).forEach((method) => {
  it.live(`method detection identifies ${method ?? "an unknown installation"} using the V2 package`, () =>
    Effect.gen(function* () {
      const test = yield* fixture((command) => ({
-        stdout: Buffer.from(command.command === method ? "@opencode/cli@2.3.4" : "opencode-ai@1.0.0"),
+        stdout: Buffer.from(
+          command.command === method
+            ? method === "vp"
+              ? JSON.stringify([{ name: "@opencode/cli", version: "2.3.4" }])
+              : "@opencode/cli@2.3.4"
+            : command.command === "vp"
+              ? "[]"
+              : "opencode-ai@1.0.0",
+        ),
      }))
      expect(yield* test.updater.method()).toBe(method)
      expect(test.commands).toEqual([
@@ -212,6 +241,7 @@ it.live("install failures expose stderr and process errors do not report success
        ["pnpm", "list", "-g", "--depth=0", "@opencode/cli"],
        ["bun", "pm", "ls", "-g"],
        ["yarn", "global", "list"],
+        ["vp", "list", "-g", "--json", "@opencode/cli"],
      ])
    }),
  )
@@ -225,7 +255,16 @@ it.live("method detection tolerates unavailable package managers", () =>
        : { error: new AppProcess.AppProcessError({ command: command.command }) },
    )
    expect(yield* test.updater.method()).toBe("yarn")
-    expect(test.commands).toHaveLength(4)
+    expect(test.commands).toHaveLength(5)
+  }),
+)
+
+it.live("vp detection ignores no-match output that repeats the package name", () =>
+  Effect.gen(function* () {
+    const test = yield* fixture((command) => ({
+      stdout: Buffer.from(command.command === "vp" ? "No global packages matching '@opencode/cli'." : ""),
+    }))
+    expect(yield* test.updater.method()).toBeUndefined()
  }),
 )

@@ -265,13 +304,16 @@ if (typeof OPENCODE_CLI_NAME === "string" && OPENCODE_CLI_NAME === "opencode2-no
      expect(yield* test.updater.method()).toBe("npm")
      yield* test.updater.upgrade("npm", "v2.3.4")
      yield* test.updater.upgrade("pnpm", "v2.3.4")
+      yield* test.updater.upgrade("vp", "v2.3.4")
      expect(test.commands).toEqual([
        ["npm", "list", "-g", "--depth=0", "@opencode/cli-node"],
        ["pnpm", "list", "-g", "--depth=0", "@opencode/cli-node"],
        ["bun", "pm", "ls", "-g"],
        ["yarn", "global", "list"],
+        ["vp", "list", "-g", "--json", "@opencode/cli-node"],
        ["npm", "install", "--global", "@opencode/cli-node@2.3.4"],
        ["pnpm", "add", "--global", "--allow-build=@opencode/cli-node", "@opencode/cli-node@2.3.4"],
+        ["vp", "update", "-g", "@opencode/cli-node@2.3.4"],
      ])
    }),
  )
@@ -35,6 +35,12 @@ describe("upgrade command", () => {
    expect(result.events).toEqual([{ method: "bun", version: "2.0.0" }])
  })

+  test("accepts vp as an explicit installation method", async () => {
+    const result = await cli(["2.0.0", "--method", "vp"])
+    expect(result.exitCode).toBe(0)
+    expect(result.events).toEqual([{ method: "vp", version: "2.0.0" }])
+  })
+
  test("skips the already installed version", async () => {
    const result = await cli(["v0.0.0-beta-old"])
    expect(result.exitCode).toBe(0)
@@ -50,7 +56,7 @@ describe("upgrade command", () => {
  })

  test("rejects unsupported methods before attempting an upgrade", async () => {
-    const result = await cli(["--method", "brew"])
+    const result = await cli(["--method", "apt"])
    expect(result.exitCode).not.toBe(0)
    expect(result.events).toEqual([])
  })
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/client",
-  "version": "2.0.8",
+  "version": "2.0.10",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -456,6 +456,10 @@ export type V2EventServerConnected = {
  data: {}
 }

+export type ModelSettings = { compaction?: ProviderCompaction } & { [x: string]: any }
+
+export type ConfigModelSettings = { compaction?: ProviderCompaction } & { [x: string]: JsonValue | null }
+
 export type ProviderSettings = {
  timeout?: number | false
  chunkTimeout?: number
@@ -1656,19 +1660,19 @@ export type SessionInboxMove = {
  payload: SessionInboxMovePayload
 }

+export type ModelVariant = {
+  id: string
+  settings?: ModelSettings
+  headers?: { [x: string]: string }
+  body?: { [x: string]: any }
+}
+
 export type ProviderRequest = {
  settings: ProviderSettings
  headers: { [x: string]: string }
  body: { [x: string]: any }
 }

-export type ModelVariant = {
-  id: string
-  settings?: ProviderSettings
-  headers?: { [x: string]: string }
-  body?: { [x: string]: any }
-}
-
 export type ProviderInfo = {
  id: string
  canonical?: string
@@ -1898,7 +1902,7 @@ export type ModelInfo = {
  name: string
  compatibility?: ModelCompatibility
  package?: string
-  settings?: ProviderSettings
+  settings?: ModelSettings
  headers?: { [x: string]: string }
  body?: { [x: string]: any }
  capabilities: ModelCapabilities
@@ -2107,13 +2111,13 @@ export type ConfigEntry =
                name?: string
                compatibility?: ModelCompatibility
                package?: string
-                settings?: ConfigProviderSettings
+                settings?: ConfigModelSettings
                headers?: { [x: string]: string }
                body?: { [x: string]: JsonValue }
                capabilities?: ModelCapabilities
                variants?: Array<{
                  id: string
-                  settings?: ConfigProviderSettings
+                  settings?: ConfigModelSettings
                  headers?: { [x: string]: string }
                  body?: { [x: string]: JsonValue }
                }>
@@ -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

@@ -15,8 +15,7 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 ## Source and execution model

 - [x] JavaScript parsed with the latest syntax accepted by Acorn, then restricted by the interpreter allowlist.
- [x] Erasable TypeScript syntax, including type annotations, type declarations, assertions, and non-null assertions.
-      TypeScript is transpiled first; the emitted JavaScript must still use the supported subset.
+      TypeScript-only syntax is rejected rather than stripped before execution.
 - [x] Top-level `await` and `return` through the program's implicit async-function scope.
 - [x] Explicit `return`, final top-level expression as a REPL-style result, and `null` when no value is produced.
 - [x] The host boundary is `JSON.stringify` plus a short table. The program result and tool arguments cross as
@@ -29,7 +28,7 @@ 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.
@@ -41,14 +40,12 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
      expression match can still run long on a pathological pattern; the host regex engine has no interrupt hook.
 - [ ] Strict-mode early errors: duplicate parameter names, `yield` as an identifier, and a trailing comma after a
      rest parameter are accepted unless the program itself begins with `"use strict"`.
- [ ] Valid JavaScript rejected by TypeScript transpilation before interpretation, such as `in` inside a destructuring
-      default in a `for...of` head and Unicode-escaped keywords.

 ## 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.
@@ -56,7 +53,7 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] `NaN` and `Infinity` globals.
 - [ ] BigInt literals and in-interpreter BigInt arithmetic; BigInt remains invalid at JSON-like host boundaries.
 - [ ] Arbitrary Symbol primitive values and symbol-keyed properties. The confined `Symbol.iterator` and
-      `Symbol.asyncIterator` keys are available only for custom iterator protocols.
+      `Symbol.asyncIterator` keys are available only for the iterator protocols.
 - [ ] Tagged-template calls.
 - [ ] Getter and setter definitions in object literals.

@@ -95,8 +92,8 @@ 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, Uint8Arrays, built-in iterators, 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 +124,7 @@ 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 +176,10 @@ 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. Error constructors take the ES2022 options object, so
+- [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. Error constructors take the ES2022 options object, so
      `new Error(message, { cause })` installs a non-enumerable `cause` when the option is present.
 - [x] Arithmetic operators: `+`, `-`, `*`, `/`, `%`, and `**`.
 - [x] Equality and ordering: `==`, `!=`, `===`, `!==`, `<`, `<=`, `>`, and `>=`.
@@ -290,7 +287,10 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] Ordering: `sort`, `toSorted`, `reverse`, and `toReversed`.
 - [x] Access/copying: `at`, `slice`, `concat`, `flat`, `with`, and `join`.
 - [x] Mutation: `push`, `pop`, `shift`, `unshift`, `splice`, `fill`, and `copyWithin`.
- [x] Materialized iteration helpers: `keys`, `values`, and `entries` return arrays rather than iterators.
+- [x] `keys`, `values`, `entries`, and `[Symbol.iterator]` (the same function as `values`) return live iterator objects
+      with `next()` and `[Symbol.iterator]`, as in JS. Iterator objects are opaque references: they print as
+      `[opaque reference]`, serialize to `{}`, and cannot be passed to extensions. Every built-in collection iterator
+      shares one prototype, which is only observable through `getPrototypeOf`.
 - [x] `length`, numeric indexing, index assignment, spread, and `for...of`.
 - [x] The `thisArg` argument of `Array.from` is accepted and ignored, like JS arrows.
 - [x] `Array.prototype.toSpliced`.
@@ -305,7 +305,6 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
      separator: JavaScript applies ToIntegerOrInfinity/ToString (including `valueOf`, strings, and `undefined`), the
      interpreter requires numbers and strings; `includes()`/`indexOf()` with no argument should search for
      `undefined`.
- [ ] Iterator objects from `keys`, `values`, and `entries` with a live `next()`.

 ## Strings

@@ -317,7 +316,7 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] Regular-expression integration: `match`, materialized `matchAll`, `replace`, `replaceAll`, `split`, and `search`.
 - [x] `localeCompare`; locale and options arguments are currently ignored.
 - [x] `isWellFormed` and `toWellFormed`.
- [x] `toString`, `length`, numeric indexing, spread, and `for...of` by Unicode code point.
+- [x] `toString`, `length`, numeric indexing, spread, `for...of`, and `[Symbol.iterator]` by Unicode code point.
 - [x] Static `String.fromCharCode` and `String.fromCodePoint`.
 - [x] Native argument coercion for supported String methods; for example, `includes(1)` and `slice("1")` coerce like
      native JS, `split(undefined)` returns the whole string, and `includes`/`startsWith`/`endsWith` reject regular
@@ -408,7 +407,8 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] Map `get`, `set`, `has`, `delete`, `clear`, `size`, and `forEach`.
 - [x] `new Set()` from synchronous iterables.
 - [x] Set `add`, `has`, `delete`, `clear`, `size`, and `forEach`.
- [x] Materialized `keys`, `values`, and `entries` arrays for Map and Set.
+- [x] Live `keys`, `values`, `entries`, and `[Symbol.iterator]` iterators for Map and Set; a Set-like operand's `keys()`
+      may return a built-in iterator or an array.
 - [x] Spread, `for...of`, `Array.from`, and `Object.fromEntries` integration.
 - [x] Map and Set values serialize to `{}` at host/JSON boundaries.
 - [x] Set composition and relation methods: `union`, `intersection`, `difference`, `symmetricDifference`, `isSubsetOf`,
@@ -424,7 +424,7 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] Writable URL fields except `origin`.
 - [x] `new URLSearchParams()` from query strings, data objects, synchronous iterables of pairs, and URLSearchParams.
 - [x] URLSearchParams `append`, `delete`, `get`, `getAll`, `has`, `set`, `sort`, `forEach`, `keys`, `values`,
-      `entries`, `toString`, and `size`.
+      `entries`, `[Symbol.iterator]`, `toString`, and `size`.
 - [x] URL values serialize to their href; URLSearchParams serialize to `{}`.

 ## Uint8Array
@@ -437,7 +437,8 @@ with a hint to encode as text first (`TextDecoder`, `toBase64`, `toHex`).
 - [x] Index reads and writes with JS byte semantics: values wrap modulo 256, out-of-range writes are ignored, indexes
      cannot be deleted. `length` is a prototype accessor, so `Object.keys` lists only indexes.
 - [x] `at`, `slice`, `subarray` (a view on the same bytes), `set`, `fill`, `reverse`, `indexOf`, `lastIndexOf`,
-      `includes`, `join`, `toString`, `toBase64`, `toHex`, and materialized `keys`, `values`, and `entries` arrays.
+      `includes`, `join`, `toString`, `toBase64`, `toHex`, and live `keys`, `values`, `entries`, and `[Symbol.iterator]`
+      iterators.
 - [x] Spread, destructuring, `for...of`, `yield*`, `Array.from`, and `new Set(bytes)`. `Array.isArray` is false.
 - [x] String coercion joins with commas; `JSON.stringify` gives `{"0":1,...}`; `console.log` prints
      `Uint8Array(n) [...]`.
@@ -451,7 +452,13 @@ 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`, `entries`, and
+      `[Symbol.iterator]`; 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

@@ -461,8 +468,8 @@ 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
@@ -494,9 +501,8 @@ Nothing is exposed unless a host provides it; extension calls are not tool calls
 - [x] Catchable user throws, runtime failures raised during interpreted evaluation, awaited tool failures, and awaited
      tool-call-limit failures; parse/compile failures, cooperative timeout, and output bounding remain outside program
      `catch`.
- [x] Source locations on unsupported-syntax diagnostics for JavaScript-shaped input; TypeScript transpilation may
-      shift them. The diagnostic names the rejected node type and attaches a short orientation to the supported
-      subset; this matrix is the full reference.
+- [x] Source locations on unsupported-syntax diagnostics. The diagnostic names the rejected node type and attaches a
+      short orientation to the supported subset; this matrix is the full reference.
 - [x] Model-visible host failure messages and underlying causes, including output-validation errors.
 - [x] Caught errors do not distinguish user throws, interpreter failures, and tool failures; a program sees one
      Error-shaped value with `name` and `message` in `catch`, rejection handlers, and `Promise.allSettled` reasons.
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/codemode",
-  "version": "2.0.8",
+  "version": "2.0.10",
  "description": "Effect-native confined code execution over schema-described tools",
  "type": "module",
  "license": "MIT",
@@ -19,12 +19,6 @@
  "exports": {
    ".": "./src/index.ts"
  },
-  "imports": {
-    "#transpile": {
-      "workerd": "./src/interpreter/transpile.workerd.ts",
-      "default": "./src/interpreter/transpile.node.ts"
-    }
-  },
  "scripts": {
    "build": "bun run script/build.ts",
    "typecheck": "tsgo --noEmit",
@@ -32,8 +26,7 @@
  },
  "dependencies": {
    "acorn": "8.15.0",
-    "effect": "catalog:",
-    "typescript": "catalog:"
+    "effect": "catalog:"
  },
  "devDependencies": {
    "@tsconfig/bun": "catalog:",
@@ -15,7 +15,7 @@ const pkg = JSON.parse(originalText) as {
  name: string
  version: string
  exports: Record<string, string | { import: string; types: string }>
-  imports: Record<string, Record<string, string>>
+  imports?: Record<string, Record<string, string>>
 }
 const tarball = `${pkg.name.replace("@", "").replace("/", "-")}-${pkg.version}.tgz`
 const output = (value: string, types = false) =>
@@ -41,12 +41,14 @@ try {
      ]
    }),
  )
-  pkg.imports = Object.fromEntries(
-    Object.entries(pkg.imports).map(([key, conditions]) => [
-      key,
-      Object.fromEntries(Object.entries(conditions).map(([condition, value]) => [condition, output(value)])),
-    ]),
-  )
+  if (pkg.imports) {
+    pkg.imports = Object.fromEntries(
+      Object.entries(pkg.imports).map(([key, conditions]) => [
+        key,
+        Object.fromEntries(Object.entries(conditions).map(([condition, value]) => [condition, output(value)])),
+      ]),
+    )
+  }
  await Bun.write("package.json", JSON.stringify(pkg, null, 2) + "\n")
  await rm(tarball, { force: true })
  await $`bun pm pack`
@@ -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)
@@ -1,14 +1,10 @@
 import { parse, type Program } from "acorn"
 import { Cause, Effect, Scope } from "effect"
-// #transpile: conditional import — full typescript on node/bun, an identity
-// pass-through on workerd (the compiler is ~11 MiB and can't init there).
-import { transpile } from "#transpile"
 import type { DataValue, Diagnostic, ResolvedExecutionLimits, Result } from "../codemode.js"
 import { toBoundary } from "../data.js"
 import { ToolRuntime } from "../tool-runtime.js"
 import { normalizeError } from "./errors.js"
 import { createBuiltins } from "./intrinsics.js"
-import { PendingThrow } from "./model.js"
 import { Pending } from "./promises.js"
 import { Interpreter } from "./interpreter.js"

@@ -110,16 +106,7 @@ export const executeProgram = <R>(
 }

 const parseProgram = (code: string): Program => {
-  const transpiled = transpile(`async function __codemode__() {\n${code}\n}`)
-
-  if (transpiled.error !== undefined) {
-    throw new PendingThrow("SyntaxError", `Failed to parse TypeScript: ${transpiled.error}`, undefined, "ParseError")
-  }
-
-  const bodyStart = transpiled.outputText.indexOf("{") + 1
-  const bodyEnd = transpiled.outputText.lastIndexOf("}")
-  const executableCode = transpiled.outputText.slice(bodyStart, bodyEnd)
-  return parse(executableCode, {
+  return parse(code, {
    ecmaVersion: "latest",
    sourceType: "script",
    allowReturnOutsideFunction: true,
@@ -20,6 +20,7 @@ import {
  DateObj,
  ErrorObj,
  GeneratorObj,
+  IteratorObj,
  MapObj,
  Obj,
  PromiseObj,
@@ -27,6 +28,7 @@ import {
  SetObj,
  URLObj,
  URLSearchParamsObj,
+  HeadersObj,
 } from "./objects.js"
 import { describeValue } from "./references.js"

@@ -52,6 +54,7 @@ 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))
@@ -59,6 +62,7 @@ export const extensionGlobals = <R>(
      !(value instanceof Obj) ||
      value instanceof Callable ||
      value instanceof GeneratorObj ||
+      value instanceof IteratorObj ||
      value instanceof PromiseObj
    ) {
      throw typeError(`${label} contains ${describeValue(value)}, which cannot be passed to an extension.`)
@@ -125,6 +129,7 @@ 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))
      if (value instanceof Map) {
        const wrapped = new MapObj(builtins.Map)
        for (const [key, item] of value) wrapped.map.set(next(key, label), next(item, label))
@@ -11,6 +11,8 @@ 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 { iteratorGlobals } from "../stdlib/iterator.js"
 import { coercion } from "../stdlib/value.js"
 import { base64Global, cryptoGlobal } from "../stdlib/web.js"
 import { ToolReference } from "../tool-runtime.js"
@@ -80,6 +82,7 @@ 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),
@@ -99,5 +102,6 @@ export const globalNames: ReadonlySet<string> = new Set(Object.keys(table))
 /** The immutable global bindings of every program, in declaration order. */
 export const globals = <R>(ctx: Interpreter<R>): ReadonlyArray<readonly [string, unknown]> => {
  generatorGlobals(ctx)
+  iteratorGlobals(ctx)
  return Object.entries(table).map(([name, factory]) => [name, factory(ctx)] as const)
 }
@@ -79,11 +79,13 @@ import {
  DateObj,
  Fn,
  GeneratorObj,
+  IteratorObj,
  MapObj,
  Obj,
  PromiseObj,
  SetObj,
  URLSearchParamsObj,
+  HeadersObj,
  record,
  remove,
  set,
@@ -649,11 +651,11 @@ class Frame<R> {
      if (declared?.lexical) self.predeclarePattern(declared.pattern, declared.mutable, left)
      const right = yield* self.evaluateExpression(node.right)

-      const iterator = yield* self.customIterator(right, node, awaiting)
-      const cursor = iterator === undefined ? yield* self.iterate(right, node) : undefined
+      const cursor = self.hostCursor(right)
+      const iterator = cursor === undefined ? yield* self.customIterator(right, node, awaiting) : 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,
        )
      }
@@ -745,6 +747,20 @@ class Frame<R> {
  }

  iterate(value: unknown, node?: AstNode) {
+    const cursor = this.hostCursor(value)
+    if (cursor !== undefined) return Effect.succeed(cursor)
+    const self = this
+    return Effect.map(this.customIterator(value, node, false), (iterator) =>
+      iterator === undefined
+        ? undefined
+        : {
+            next: self.nextIteratorResult(iterator, node, false),
+            close: Effect.suspend(() => self.closeIterator(iterator, node, false)),
+          },
+    )
+  }
+
+  private hostCursor(value: unknown) {
    const iterator =
      value instanceof Arr
        ? value.items[Symbol.iterator]()
@@ -756,31 +772,25 @@ class Frame<R> {
              ? value.set.values()
              : value instanceof URLSearchParamsObj
                ? value.params.entries()
-                : value instanceof Bytes
-                  ? value.bytes.values()
-                  : undefined
-    if (iterator !== undefined) {
-      const proto = this.ctx.builtins.Array
-      return Effect.succeed({
-        next: Effect.sync(() => {
-          const step = iterator.next()
-          return {
-            done: Boolean(step.done),
-            value: Array.isArray(step.value) ? new Arr(proto, step.value) : step.value,
-          }
-        }),
-        close: Effect.void,
-      })
+                : value instanceof HeadersObj
+                  ? value.headers.entries()
+                  : value instanceof Bytes
+                    ? value.bytes.values()
+                    : value instanceof IteratorObj
+                      ? value.iterator
+                      : undefined
+    if (iterator === undefined) return undefined
+    const proto = this.ctx.builtins.Array
+    return {
+      next: Effect.sync(() => {
+        const step = iterator.next()
+        return {
+          done: Boolean(step.done),
+          value: Array.isArray(step.value) ? new Arr(proto, step.value) : step.value,
+        }
+      }),
+      close: Effect.void,
    }
-    const self = this
-    return Effect.map(this.customIterator(value, node, false), (iterator) =>
-      iterator === undefined
-        ? undefined
-        : {
-            next: self.nextIteratorResult(iterator, node, false),
-            close: Effect.suspend(() => self.closeIterator(iterator, node, false)),
-          },
-    )
  }

  private customIterator(value: unknown, node: AstNode | undefined, allowAsync = true) {
@@ -1848,6 +1858,7 @@ 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(),
@@ -122,6 +122,16 @@ export class GeneratorObj extends Obj {
  }
 }

+/** A built-in collection iterator: live over the host collection, yielding program values. */
+export class IteratorObj extends Obj {
+  constructor(
+    proto: Obj,
+    readonly iterator: IteratorObject<unknown>,
+  ) {
+    super(proto)
+  }
+}
+
 export class DateObj extends Obj {
  constructor(
    proto: Obj,
@@ -156,6 +166,15 @@ 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 +200,14 @@ 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
@@ -9,6 +9,7 @@ import {
  Bytes,
  DateObj,
  GeneratorObj,
+  IteratorObj,
  MapObj,
  Obj,
  PromiseObj,
@@ -16,12 +17,14 @@ import {
  SetObj,
  URLObj,
  URLSearchParamsObj,
+  HeadersObj,
 } from "./objects.js"

 /** Values that cannot cross the data boundary. */
 export const isRuntimeReference = (value: unknown): boolean =>
  value instanceof Callable ||
  value instanceof GeneratorObj ||
+  value instanceof IteratorObj ||
  value instanceof ToolReference ||
  value instanceof PromiseObj ||
  isWrapper(value)
@@ -85,8 +88,10 @@ 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 (value instanceof IteratorObj) return "an iterator"
  if (isRuntimeReference(value)) return "a function"
  if (typeof value === "object") return "a data object"
  return `a ${typeof value}`
@@ -1,25 +0,0 @@
-import { DiagnosticCategory, ModuleKind, ScriptTarget, flattenDiagnosticMessageText, transpileModule } from "typescript"
-
-export interface TranspileResult {
-  readonly outputText: string
-  readonly error?: string
-}
-
-// Full TypeScript transpilation on node/bun runtimes.
-export const transpile = (source: string): TranspileResult => {
-  const transpiled = transpileModule(source, {
-    reportDiagnostics: true,
-    compilerOptions: {
-      target: ScriptTarget.ESNext,
-      module: ModuleKind.ESNext,
-    },
-  })
-  const diagnostic = transpiled.diagnostics?.find((item) => item.category === DiagnosticCategory.Error)
-  if (diagnostic) {
-    return {
-      outputText: transpiled.outputText,
-      error: flattenDiagnosticMessageText(diagnostic.messageText, "\n"),
-    }
-  }
-  return { outputText: transpiled.outputText }
-}
@@ -1,11 +0,0 @@
-export interface TranspileResult {
-  readonly outputText: string
-  readonly error?: string
-}
-
-// workerd profile: the typescript compiler is ~11 MiB and probes node
-// internals at module init, so codemode programs are passed through
-// untranspiled. Plain-JS programs (the overwhelmingly common case) parse
-// fine downstream via acorn; TypeScript-only syntax surfaces as a parse
-// error from the interpreter instead of a transpile diagnostic.
-export const transpile = (source: string): TranspileResult => ({ outputText: source })
@@ -1,8 +1,8 @@
 import { Effect } from "effect"
 import { constructor, type Method, methods, prototypeFrom, receiver } from "../interpreter/native.js"
 import { checkArrayLength, checkStringLength, MAX_ARRAY_LENGTH } from "../interpreter/limits.js"
-import { invalidData, rangeError, typeError } from "../interpreter/model.js"
-import { get, Arr, GeneratorObj, Obj } from "../interpreter/objects.js"
+import { invalidData, IteratorSymbol, rangeError, typeError } from "../interpreter/model.js"
+import { define, get, hidden, Arr, GeneratorObj, IteratorObj, Obj } from "../interpreter/objects.js"
 import { describeValue, rejectCircularInsertion } from "../interpreter/references.js"
 import { applyCollectionCallback, preserveConsumerError } from "../interpreter/callback.js"
 import type { Interpreter } from "../interpreter/interpreter.js"
@@ -340,13 +340,18 @@ export const arrayGlobal = <R>(ctx: Interpreter<R>) => {
        return target
      },
    ],
-    ["keys", 0, (thisValue) => wrap(Array.from(self(thisValue, "keys").items.keys()))],
-    ["values", 0, (thisValue) => wrap([...self(thisValue, "values").items])],
+    ["keys", 0, (thisValue) => new IteratorObj(builtins.Iterator, self(thisValue, "keys").items.keys())],
+    ["values", 0, (thisValue) => new IteratorObj(builtins.Iterator, self(thisValue, "values").items.values())],
    [
      "entries",
      0,
      (thisValue) =>
-        wrap(Array.from(self(thisValue, "entries").items.entries(), ([index, item]) => wrap([index, item]))),
+        new IteratorObj(
+          builtins.Iterator,
+          self(thisValue, "entries")
+            .items.entries()
+            .map(([index, item]) => wrap([index, item])),
+        ),
    ],
    iterate("map", 1, (target, receiver, apply) =>
      Effect.gen(function* () {
@@ -490,5 +495,6 @@ export const arrayGlobal = <R>(ctx: Interpreter<R>) => {
      }),
    ),
  ])
+  define(proto, IteratorSymbol, get(proto, "values"), hidden)
  return array
 }
@@ -1,8 +1,8 @@
 import { Effect } from "effect"
 import { checkArrayLength, checkStringLength } from "../interpreter/limits.js"
 import { constructor, methods, prototypeFrom, receiver, requiresNew } from "../interpreter/native.js"
-import { rangeError, syntaxError, typeError } from "../interpreter/model.js"
-import { defineAccessor, get, Arr, Bytes, Obj } from "../interpreter/objects.js"
+import { IteratorSymbol, rangeError, syntaxError, typeError } from "../interpreter/model.js"
+import { define, defineAccessor, get, hidden, Arr, Bytes, IteratorObj, Obj } from "../interpreter/objects.js"
 import { describeValue } from "../interpreter/references.js"
 import type { Interpreter } from "../interpreter/interpreter.js"
 import { coerceToNumber, coerceToString } from "./value.js"
@@ -173,15 +173,21 @@ export const uint8ArrayGlobal = <R>(ctx: Interpreter<R>) => {
    ["toString", 0, (thisValue) => self(thisValue, "toString").bytes.join(",")],
    ["toBase64", 0, (thisValue) => self(thisValue, "toBase64").bytes.toBase64()],
    ["toHex", 0, (thisValue) => self(thisValue, "toHex").bytes.toHex()],
-    ["keys", 0, (thisValue) => wrapAll(Array.from(self(thisValue, "keys").bytes.keys()))],
-    ["values", 0, (thisValue) => wrapAll(Array.from(self(thisValue, "values").bytes.values()))],
+    ["keys", 0, (thisValue) => new IteratorObj(builtins.Iterator, self(thisValue, "keys").bytes.keys())],
+    ["values", 0, (thisValue) => new IteratorObj(builtins.Iterator, self(thisValue, "values").bytes.values())],
    [
      "entries",
      0,
      (thisValue) =>
-        wrapAll(Array.from(self(thisValue, "entries").bytes.entries(), ([index, byte]) => wrapAll([index, byte]))),
+        new IteratorObj(
+          builtins.Iterator,
+          self(thisValue, "entries")
+            .bytes.entries()
+            .map(([index, byte]) => wrapAll([index, byte])),
+        ),
    ],
  ])
+  define(proto, IteratorSymbol, get(proto, "values"), hidden)
  return uint8Array
 }

@@ -1,6 +1,6 @@
 import { Effect } from "effect"
 import { constructor, fn, type Method, methods, prototypeFrom, receiver, requiresNew } from "../interpreter/native.js"
-import { invalidData, typeError } from "../interpreter/model.js"
+import { invalidData, IteratorSymbol, typeError } from "../interpreter/model.js"
 import {
  define,
  defineAccessor,
@@ -9,6 +9,7 @@ import {
  hidden,
  isWrapper,
  Arr,
+  IteratorObj,
  MapObj,
  Obj,
  PromiseObj,
@@ -153,12 +154,18 @@ export const mapGlobal = <R>(ctx: Interpreter<R>) => {
        return undefined
      },
    ],
-    ["keys", 0, (thisValue) => wrap(Array.from(self(thisValue, "keys").map.keys()))],
-    ["values", 0, (thisValue) => wrap(Array.from(self(thisValue, "values").map.values()))],
+    ["keys", 0, (thisValue) => new IteratorObj(builtins.Iterator, self(thisValue, "keys").map.keys())],
+    ["values", 0, (thisValue) => new IteratorObj(builtins.Iterator, self(thisValue, "values").map.values())],
    [
      "entries",
      0,
-      (thisValue) => wrap(Array.from(self(thisValue, "entries").map.entries(), ([key, item]) => wrap([key, item]))),
+      (thisValue) =>
+        new IteratorObj(
+          builtins.Iterator,
+          self(thisValue, "entries")
+            .map.entries()
+            .map(([key, item]) => wrap([key, item])),
+        ),
    ],
    [
      "forEach",
@@ -173,6 +180,7 @@ export const mapGlobal = <R>(ctx: Interpreter<R>) => {
      },
    ],
  ])
+  define(proto, IteratorSymbol, get(proto, "entries"), hidden)
  return map
 }

@@ -218,7 +226,8 @@ const loadSetRecord = <R>(
      size: Math.max(Math.trunc(size), 0),
      has: (item: unknown) => Effect.map(ctx.call(has, source, [item]), Boolean),
      keys: () =>
-        Effect.flatMap(ctx.call(keys, source, []), (result) => {
+        Effect.flatMap(ctx.call(keys, source, []), (result): Effect.Effect<Iterable<unknown>> => {
+          if (result instanceof IteratorObj) return Effect.succeed(result.iterator)
          if (result instanceof Arr) return Effect.succeed(result.items)
          throw typeError(`Set.${name} expected 'keys' to return an iterator.`)
        }),
@@ -338,12 +347,18 @@ export const setGlobal = <R>(ctx: Interpreter<R>) => {
        return undefined
      },
    ],
-    ["keys", 0, (thisValue) => wrap(Array.from(self(thisValue, "keys").set.values()))],
-    ["values", 0, (thisValue) => wrap(Array.from(self(thisValue, "values").set.values()))],
+    ["keys", 0, (thisValue) => new IteratorObj(builtins.Iterator, self(thisValue, "keys").set.values())],
+    ["values", 0, (thisValue) => new IteratorObj(builtins.Iterator, self(thisValue, "values").set.values())],
    [
      "entries",
      0,
-      (thisValue) => wrap(Array.from(self(thisValue, "entries").set.values(), (item) => wrap([item, item]))),
+      (thisValue) =>
+        new IteratorObj(
+          builtins.Iterator,
+          self(thisValue, "entries")
+            .set.values()
+            .map((item) => wrap([item, item])),
+        ),
    ],
    [
      "forEach",
@@ -365,5 +380,6 @@ export const setGlobal = <R>(ctx: Interpreter<R>) => {
    operation("isSupersetOf"),
    operation("isDisjointFrom"),
  ])
+  define(proto, IteratorSymbol, get(proto, "values"), hidden)
  return set
 }
@@ -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 +1,132 @@
+import { Effect } from "effect"
+import { constructor, methods, prototypeFrom, receiver, requiresNew } from "../interpreter/native.js"
+import { IteratorSymbol, typeError } from "../interpreter/model.js"
+import { define, entries, get, hidden, Arr, HeadersObj, IteratorObj, 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)))
+      },
+    ],
+    // Iterator.from because Bun's Headers typings predate iterator helpers; the runtime iterators already have them.
+    [
+      "keys",
+      0,
+      (thisValue) => new IteratorObj(builtins.Iterator, Iterator.from(self(thisValue, "keys").headers.keys())),
+    ],
+    [
+      "values",
+      0,
+      (thisValue) => new IteratorObj(builtins.Iterator, Iterator.from(self(thisValue, "values").headers.values())),
+    ],
+    [
+      "entries",
+      0,
+      (thisValue) =>
+        new IteratorObj(
+          builtins.Iterator,
+          Iterator.from(self(thisValue, "entries").headers.entries()).map(([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
+        })
+      },
+    ],
+  ])
+  define(proto, IteratorSymbol, get(proto, "entries"), hidden)
+  return headers
+}
@@ -0,0 +1,19 @@
+import { methods, receiver } from "../interpreter/native.js"
+import { IteratorObj, record } from "../interpreter/objects.js"
+import type { Interpreter } from "../interpreter/interpreter.js"
+
+// Every built-in collection iterator shares the Iterator prototype; JS gives each collection its own, which is only
+// observable through getPrototypeOf.
+export const iteratorGlobals = <R>(ctx: Interpreter<R>): void => {
+  const builtins = ctx.builtins
+  methods(builtins, builtins.Iterator, [
+    [
+      "next",
+      0,
+      (thisValue) => {
+        const step = receiver(IteratorObj, thisValue, "Iterator.prototype.next").iterator.next()
+        return record(builtins.Object, { value: step.value, done: Boolean(step.done) })
+      },
+    ],
+  ])
+}
@@ -1,8 +1,8 @@
 import { Effect } from "effect"
-import { constructor, type Method, methods } from "../interpreter/native.js"
+import { constructor, fn, type Method, methods } from "../interpreter/native.js"
 import { checkArrayLength, checkStringLength } from "../interpreter/limits.js"
-import { invalidData, rangeError, typeError } from "../interpreter/model.js"
-import { Arr, PromiseObj, RegExpObj, record } from "../interpreter/objects.js"
+import { invalidData, IteratorSymbol, rangeError, typeError } from "../interpreter/model.js"
+import { define, hidden, Arr, IteratorObj, PromiseObj, RegExpObj, record } from "../interpreter/objects.js"
 import { containsOpaqueReference, typeofValue } from "../interpreter/references.js"
 import { applyCollectionCallback, isSupportedCallback } from "../interpreter/callback.js"
 import type { Interpreter } from "../interpreter/interpreter.js"
@@ -258,5 +258,16 @@ export const stringGlobal = <R>(ctx: Interpreter<R>) => {
      return joined
    }),
  ])
+  define(
+    builtins.String,
+    IteratorSymbol,
+    fn(
+      builtins,
+      "[Symbol.iterator]",
+      0,
+      (thisValue) => new IteratorObj(builtins.Iterator, self(thisValue, "[Symbol.iterator]")[Symbol.iterator]()),
+    ),
+    hidden,
+  )
  return string
 }
@@ -1,7 +1,19 @@
 import { Effect } from "effect"
 import { constructor, fn, type Method, methods, prototypeFrom, receiver, requiresNew } from "../interpreter/native.js"
-import { PendingThrow, typeError, uriError } from "../interpreter/model.js"
-import { defineAccessor, entries, isWrapper, Arr, Obj, URLObj, URLSearchParamsObj } from "../interpreter/objects.js"
+import { IteratorSymbol, PendingThrow, typeError, uriError } from "../interpreter/model.js"
+import {
+  define,
+  defineAccessor,
+  entries,
+  get,
+  hidden,
+  isWrapper,
+  Arr,
+  IteratorObj,
+  Obj,
+  URLObj,
+  URLSearchParamsObj,
+} from "../interpreter/objects.js"
 import { isRuntimeReference } from "../interpreter/references.js"
 import { applyCollectionCallback, preserveConsumerError } from "../interpreter/callback.js"
 import type { Interpreter } from "../interpreter/interpreter.js"
@@ -107,12 +119,10 @@ 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 +136,29 @@ 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 +172,8 @@ 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.")
    }
@@ -249,13 +270,18 @@ export const urlSearchParamsGlobal = <R>(ctx: Interpreter<R>) => {
        return undefined
      },
    ],
-    ["keys", 0, (thisValue) => wrap(Array.from(self(thisValue, "keys").params.keys()))],
-    ["values", 0, (thisValue) => wrap(Array.from(self(thisValue, "values").params.values()))],
+    ["keys", 0, (thisValue) => new IteratorObj(builtins.Iterator, self(thisValue, "keys").params.keys())],
+    ["values", 0, (thisValue) => new IteratorObj(builtins.Iterator, self(thisValue, "values").params.values())],
    [
      "entries",
      0,
      (thisValue) =>
-        wrap(Array.from(self(thisValue, "entries").params.entries(), ([key, value]) => wrap([key, value]))),
+        new IteratorObj(
+          builtins.Iterator,
+          self(thisValue, "entries")
+            .params.entries()
+            .map(([key, value]) => wrap([key, value])),
+        ),
    ],
    ["toString", 0, (thisValue) => self(thisValue, "toString").params.toString()],
    [
@@ -272,5 +298,6 @@ export const urlSearchParamsGlobal = <R>(ctx: Interpreter<R>) => {
      },
    ],
  ])
+  define(proto, IteratorSymbol, get(proto, "entries"), hidden)
  return searchParams
 }
@@ -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.
@@ -298,21 +298,18 @@ const cases = [
  },
  {
    path: "test/built-ins/Array/prototype/keys/iteration.js",
-    code: `return ["a", "b", "c"].keys()`,
-    expected: [0, 1, 2],
+    code: `const it = ["a", "b", "c"].keys(); return [it.next(), it.next(), it.next(), it.next()]`,
+    expected: [{ value: 0, done: false }, { value: 1, done: false }, { value: 2, done: false }, { done: true }],
  },
  {
    path: "test/built-ins/Array/prototype/values/iteration.js",
-    code: `return ["a", "b", "c"].values()`,
-    expected: ["a", "b", "c"],
+    code: `const it = ["a", "b", "c"].values(); return [it.next(), it.next(), it.next(), it.next()]`,
+    expected: [{ value: "a", done: false }, { value: "b", done: false }, { value: "c", done: false }, { done: true }],
  },
  {
    path: "test/built-ins/Array/prototype/entries/iteration.js",
-    code: `return ["a", "b"].entries()`,
-    expected: [
-      [0, "a"],
-      [1, "b"],
-    ],
+    code: `const it = ["a", "b"].entries(); return [it.next(), it.next(), it.next()]`,
+    expected: [{ value: [0, "a"], done: false }, { value: [1, "b"], done: false }, { done: true }],
  },
  {
    path: "test/built-ins/Array/isArray/15.4.3.2-0-3.js",
@@ -15,6 +15,12 @@ const error = async (code: string) => {
  return result.error
 }

+describe("source syntax", () => {
+  test("rejects TypeScript-only syntax", async () => {
+    expect((await error(`const value: number = 1; return value`)).kind).toBe("ParseError")
+  })
+})
+
 describe("error identity", () => {
  test("awaiting the same rejected promise twice yields the same error object", async () => {
    expect(
@@ -101,7 +107,7 @@ describe("host errors escaping built-ins", () => {
  test("report the location of the call that raised them", async () => {
    const failure = await error(`return [1].map((n) => n.toFixed(200))`)
    expect(failure.kind).toBe("ExecutionFailure")
-    expect(failure.message).toBe("RangeError: toFixed() argument must be between 0 and 100 (line 1, col 23)")
+    expect(failure.message).toBe("RangeError: toFixed() argument must be between 0 and 100 (line 1, col 19)")
  })

  test("a built-in that rejects its arguments before doing any work is located at the call", async () => {
@@ -109,13 +115,13 @@ describe("host errors escaping built-ins", () => {
  })

  test("a rejection born inside a promise the built-in created is located at the creating call", async () => {
-    expect((await error(`return await Promise.all(1)`)).message).toEndWith("(line 1, col 14)")
-    expect((await error(`return await Promise.race([])`)).message).toEndWith("(line 1, col 14)")
+    expect((await error(`return await Promise.all(1)`)).message).toEndWith("(line 1, col 10)")
+    expect((await error(`return await Promise.race([])`)).message).toEndWith("(line 1, col 10)")
    expect((await error(`return await Promise.all({ [Symbol.iterator]: () => ({ next: 1 }) })`)).message).toEndWith(
-      "(line 1, col 14)",
+      "(line 1, col 10)",
    )
    expect((await error(`let p; p = Promise.resolve().then(() => p); return await p`)).message).toEndWith(
-      "(line 2, col 5)",
+      "(line 1, col 8)",
    )
  })

@@ -128,7 +134,7 @@ describe("host errors escaping built-ins", () => {

  test("a failure inside a built-in called by another built-in is located at the outer call", async () => {
    const failure = await error(`return Array.from({ [Symbol.iterator]: () => ({ next: 1 }) })`)
-    expect(failure.message).toBe("TypeError: Iterator next must be a function. (line 1, col 8)")
+    expect(failure.message).toBe("TypeError: Iterator next must be a function. (line 1, col 4)")
  })
 })

@@ -147,7 +153,7 @@ describe("call depth", () => {
  test("uncaught overflow reports the call that overflowed", async () => {
    const failure = await error(`const f = (n) => f(n + 1); return f(0)`)
    expect(failure.kind).toBe("ExecutionFailure")
-    expect(failure.message).toBe("RangeError: Maximum call stack size exceeded (line 1, col 18)")
+    expect(failure.message).toBe("RangeError: Maximum call stack size exceeded (line 1, col 14)")
  })

  test("the limit is 10000 nested calls", async () => {
@@ -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({
@@ -192,8 +220,9 @@ describe("values are converted at the boundary, never shared", () => {
    expect(held[1]).toBeInstanceOf(Error)
  })

-  test("functions, promises, and symbols cannot be passed in", async () => {
+  test("functions, promises, iterators, and symbols cannot be passed in", async () => {
    expect((await failure(`keep(() => 1)`)).message).toContain("Argument 1 to keep contains a function")
+    expect((await failure(`keep([1].keys())`)).message).toContain("Argument 1 to keep contains an iterator")
    expect((await failure(`keep(later(1))`)).message).toContain("un-awaited Promise")
    expect((await failure(`keep(Symbol.iterator)`)).message).toContain("Argument 1 to keep contains a symbol")
  })
@@ -122,10 +122,10 @@ describe("Map.groupBy Test262 parity", () => {
          grouped.get(1),
          grouped.get("1"),
          grouped.has(stringable),
-          grouped.keys().length,
+          [...grouped.keys()].length,
          parity.get("even"),
          parity.get("odd"),
-          lengths.keys(),
+          [...lengths.keys()],
          lengths.get(5),
          lengths.get(4),
        ]
@@ -162,7 +162,7 @@ describe("Map.groupBy Test262 parity", () => {
      await value(`
        const grouped = Map.groupBy("🥰💩🙏😈", (char) => char < "🙏" ? "before" : "after")
        const empty = Map.groupBy([], () => { throw new Error("not called") })
-        return [grouped.keys(), grouped.get("before"), grouped.get("after"), empty.size]
+        return [[...grouped.keys()], grouped.get("before"), grouped.get("after"), empty.size]
      `),
    ).toEqual([["after", "before"], ["💩", "😈"], ["🥰", "🙏"], 0])
  })
@@ -502,9 +502,9 @@ describe("CodeMode-specific array behavior", () => {
    expect(err.message).toContain("circular")
  })

-  test("keys/values/entries return arrays usable with for...of and spread", async () => {
+  test("keys/values/entries return iterators usable with for...of and spread", async () => {
    expect(await value(`return [...["x","y","z"].keys()]`)).toEqual([0, 1, 2])
-    expect(await value(`return ["x","y"].values()`)).toEqual(["x", "y"])
+    expect(await value(`return [...["x","y"].values()]`)).toEqual(["x", "y"])
    expect(
      await value(`
      const out = []
@@ -198,10 +198,10 @@ describe("Set composition Test262 parity", () => {
          keys: () => [-0],
        }
        return [
-          1 / new Set([1]).union(setlike).values()[1] === Infinity,
-          1 / new Set([0, 1, 2]).intersection(setlike).values()[0] === Infinity,
+          1 / [...new Set([1]).union(setlike)][1] === Infinity,
+          1 / [...new Set([0, 1, 2]).intersection(setlike)][0] === Infinity,
          [...new Set([0, 1]).difference(setlike)],
-          1 / new Set([1, 2]).symmetricDifference(setlike).values()[2] === Infinity,
+          1 / [...new Set([1, 2]).symmetricDifference(setlike)][2] === Infinity,
        ]
      `),
    ).toEqual([true, true, [1], true])
@@ -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(
@@ -668,18 +816,28 @@ describe("Map", () => {
    expect((await error(`return new Map(["flat"])`)).message).toMatch(/\[key, value\] pairs/)
  })

-  test("keys/values/entries return arrays", async () => {
+  test("keys/values/entries return live iterators", async () => {
    expect(
      await value(`
      const m = new Map([["a", 1], ["b", 2]])
-      return { keys: m.keys(), values: m.values(), entries: m.entries() }
+      const keys = m.keys()
+      const first = keys.next()
+      m.set("c", 3)
+      return { first, rest: [...keys], values: [...m.values()], entries: [...m.entries()], same: [...m[Symbol.iterator]()] }
    `),
    ).toEqual({
-      keys: ["a", "b"],
-      values: [1, 2],
+      first: { value: "a", done: false },
+      rest: ["b", "c"],
+      values: [1, 2, 3],
      entries: [
        ["a", 1],
        ["b", 2],
+        ["c", 3],
+      ],
+      same: [
+        ["a", 1],
+        ["b", 2],
+        ["c", 3],
      ],
    })
  })
@@ -971,6 +1129,108 @@ describe("TextEncoder and TextDecoder", () => {
  })
 })

+describe("built-in iterators", () => {
+  test("keys/values/entries and [Symbol.iterator] step with next() and stay live", async () => {
+    expect(
+      await value(`
+        const items = ["a"]
+        const it = items.entries()
+        items.push("b")
+        const steps = [it.next(), it.next(), it.next()]
+        items.push("c")
+        return { steps, after: it.next(), same: items[Symbol.iterator] === items.values }
+      `),
+    ).toEqual({
+      steps: [{ value: [0, "a"], done: false }, { value: [1, "b"], done: false }, { done: true }],
+      after: { done: true },
+      same: true,
+    })
+    expect(
+      await value(`
+        const s = new Set([1, 2])
+        const u = new URLSearchParams("a=1&b=2")
+        const h = new Headers({ b: "2", a: "1" })
+        const bytes = new Uint8Array([7, 8])
+        return [
+          [...s.entries()], [...s[Symbol.iterator]()], s[Symbol.iterator] === s.values,
+          [...u.keys()], [...u[Symbol.iterator]()], u[Symbol.iterator] === u.entries,
+          [...h.values()], [...h[Symbol.iterator]()], h[Symbol.iterator] === h.entries,
+          [...bytes.entries()], [...bytes[Symbol.iterator]()], bytes[Symbol.iterator] === bytes.values,
+          [..."ab"[Symbol.iterator]()],
+        ]
+      `),
+    ).toEqual([
+      [
+        [1, 1],
+        [2, 2],
+      ],
+      [1, 2],
+      true,
+      ["a", "b"],
+      [
+        ["a", "1"],
+        ["b", "2"],
+      ],
+      true,
+      ["1", "2"],
+      [
+        ["a", "1"],
+        ["b", "2"],
+      ],
+      true,
+      [
+        [0, 7],
+        [1, 8],
+      ],
+      [7, 8],
+      true,
+      ["a", "b"],
+    ])
+  })
+
+  test("iterators are consumed once by every iteration site", async () => {
+    expect(
+      await value(`
+        const it = [1, 2, 3, 4].values()
+        const picked = []
+        for (const item of it) { picked.push(item); if (item === 2) break }
+        const [third] = it
+        return { picked, third, rest: [...it], spent: Array.from(it), again: it[Symbol.iterator]() === it }
+      `),
+    ).toEqual({ picked: [1, 2], third: 3, rest: [4], spent: [], again: true })
+    expect(
+      await value(`
+        const m = new Map([["a", 1], ["b", 2]])
+        return [
+          Object.fromEntries(m.entries()), Array.from(m.keys(), (k) => k + "!"), new Set(m.values()).size,
+          await Promise.all([Promise.resolve(1), 2].values()),
+        ]
+      `),
+    ).toEqual([{ a: 1, b: 2 }, ["a!", "b!"], 2, [1, 2]])
+    expect(await value(`let s = 0; for await (const v of [Promise.resolve(1), 2].values()) s += v; return s`)).toBe(3)
+    expect(
+      await value(`return new Set([1, 2]).union({ size: 1, has: () => false, keys: () => new Set([3]).keys() })`),
+    ).toEqual([1, 2, 3])
+  })
+
+  test("iterators are opaque references", async () => {
+    expect(await value(`return [1].keys()`)).toEqual({})
+    expect(await value(`return JSON.stringify({ it: [1].keys() })`)).toBe('{"it":{}}')
+    expect(await value(`return [typeof [1].keys(), Array.isArray([1].keys()), Object.keys([1].keys())]`)).toEqual([
+      "object",
+      false,
+      [],
+    ])
+    const logged = await run(`console.log([1].keys()); return null`)
+    expect(logged.logs?.[0]).toBe("[opaque reference]")
+    expect((await error(`return [1].keys() + ""`)).message).toContain("Binary operators require data values")
+    expect((await error(`return [1].keys().next.call({})`)).message).toContain("is not a function")
+    expect((await error(`const it = [1].keys(); const next = it.next; return next()`)).message).toContain(
+      "Iterator.prototype.next called on incompatible receiver undefined",
+    )
+  })
+})
+
 describe("stdlib integration", () => {
  test("constructor follows own keys, shadowing, writes, and new", async () => {
    expect(
@@ -13,8 +13,6 @@ built-ins/Array/prototype/copyWithin/coerced-values-target.js  # Array.copyWithi
 built-ins/Array/prototype/copyWithin/return-abrupt-from-end.js  # Expected a Test262Error but got a TypeError
 built-ins/Array/prototype/copyWithin/return-abrupt-from-start.js  # Expected a Test262Error but got a TypeError
 built-ins/Array/prototype/copyWithin/return-abrupt-from-target.js  # Expected a Test262Error but got a TypeError
-built-ins/Array/prototype/entries/iteration-mutable.js  # .next is not a function.
-built-ins/Array/prototype/entries/iteration.js  # .next is not a function.
 built-ins/Array/prototype/every/15.4.4.16-7-6.js  # res Expected SameValue(«true», «false») to be true
 built-ins/Array/prototype/every/15.4.4.16-7-c-i-8.js  # [, , , ].every(callbackfn) Expected SameValue(«true», «false») to be true
 built-ins/Array/prototype/every/15.4.4.16-8-10.js  # … cannot be constructed: user-defined constructors and classes are not supported. Call it as a funct
@@ -86,8 +84,6 @@ built-ins/Array/prototype/join/S15.4.4.5_A3.1_T2.js  # Array.join expects zero a
 built-ins/Array/prototype/join/S15.4.4.5_A3.2_T2.js  # x.join() must return "*" Expected SameValue(«"[object Object]"», «"*"») to be true
 built-ins/Array/prototype/join/S15.4.4.5_A4_T3.js  # Array.prototype.join called on incompatible receiver a data object.
 built-ins/Array/prototype/join/S15.4.4.5_A5_T1.js  # #1: Array.prototype[1] = 1; x = [0]; x.length = 2; x.join() === "0,1". Actual: 0,
-built-ins/Array/prototype/keys/iteration-mutable.js  # .next is not a function.
-built-ins/Array/prototype/keys/iteration.js  # .next is not a function.
 built-ins/Array/prototype/lastIndexOf/15.4.4.15-5-1.js  # Array.lastIndexOf expects start index to be a number.
 built-ins/Array/prototype/lastIndexOf/15.4.4.15-5-15.js  # Array.lastIndexOf expects start index to be a number.
 built-ins/Array/prototype/lastIndexOf/15.4.4.15-5-16.js  # Array.lastIndexOf expects start index to be a number.
@@ -241,9 +237,6 @@ built-ins/Array/prototype/unshift/S15.4.4.13_A2_T3.js  # Array.prototype.unshift
 built-ins/Array/prototype/unshift/S15.4.4.13_A3_T2.js  # Array.prototype.unshift called on incompatible receiver a data object.
 built-ins/Array/prototype/unshift/S15.4.4.13_A4_T1.js  # Array.prototype.unshift called on incompatible receiver a data object.
 built-ins/Array/prototype/unshift/S15.4.4.13_A4_T2.js  # #3: Array.prototype[0] = 1; x = []; x.length = 1; x.unshift(0); x[1] === 1. Actual: undefined
-built-ins/Array/prototype/values/iteration-mutable.js  # .next is not a function.
-built-ins/Array/prototype/values/iteration.js  # .next is not a function.
-language/statements/async-function/rest-params-trailing-comma-early-error.js  # expected SyntaxError but the program ran
 language/statements/async-generator/dflt-params-abrupt.js  # Expected a Test262Error to be thrown but no exception was thrown at all
 language/statements/async-generator/dflt-params-ref-later.js  # Expected a ReferenceError to be thrown but no exception was thrown at all
 language/statements/async-generator/dflt-params-ref-self.js  # Expected a ReferenceError to be thrown but no exception was thrown at all
@@ -291,16 +284,13 @@ language/statements/async-generator/dstr/obj-ptrn-prop-id-init-throws.js  # Expe
 language/statements/async-generator/dstr/obj-ptrn-prop-id-init-unresolvable.js  # Expected a ReferenceError to be thrown but no exception was thrown at all
 language/statements/async-generator/dstr/obj-ptrn-prop-obj-value-null.js  # Expected a TypeError to be thrown but no exception was thrown at all
 language/statements/async-generator/dstr/obj-ptrn-prop-obj-value-undef.js  # Expected a TypeError to be thrown but no exception was thrown at all
-language/statements/async-generator/rest-params-trailing-comma-early-error.js  # expected SyntaxError but the program ran
 language/statements/async-generator/return-undefined-implicit-and-explicit.js  # Actual ["tick 1", "tick 2", "g1 ret", "g2 ret", "g3 ret", "g4 ret"] and expected ["tick 1", "g1 ret"
 language/statements/const/dstr/ary-init-iter-get-err-array-prototype.js  # Expected a TypeError to be thrown but no exception was thrown at all
-language/statements/for-await-of/async-func-decl-dstr-array-elem-init-in.js  # Failed to parse TypeScript: '…' expected.
 language/statements/for-await-of/async-func-decl-dstr-obj-empty-bool.js  # TypeError: Object destructuring requires a data object or array value, received a boolean.
 language/statements/for-await-of/async-func-decl-dstr-obj-empty-num.js  # TypeError: Object destructuring requires a data object or array value, received a number.
 language/statements/for-await-of/async-func-decl-dstr-obj-empty-string.js  # TypeError: Object destructuring requires a data object or array value, received a string.
 language/statements/for-await-of/async-func-decl-dstr-obj-rest-number.js  # TypeError: Object destructuring requires a data object or array value, received a number.
 language/statements/for-await-of/async-func-decl-dstr-obj-rest-str-val.js  # TypeError: Object destructuring requires a data object or array value, received a string.
-language/statements/for-await-of/async-gen-decl-dstr-array-elem-init-in.js  # Failed to parse TypeScript: '…' expected.
 language/statements/for-await-of/async-gen-decl-dstr-array-elem-iter-rtrn-close-null.js  # "Promise incorrectly fulfilled."
 language/statements/for-await-of/async-gen-decl-dstr-obj-empty-bool.js  # TypeError: Object destructuring requires a data object or array value, received a boolean.
 language/statements/for-await-of/async-gen-decl-dstr-obj-empty-num.js  # TypeError: Object destructuring requires a data object or array value, received a number.
@@ -308,8 +298,6 @@ language/statements/for-await-of/async-gen-decl-dstr-obj-empty-string.js  # Type
 language/statements/for-await-of/async-gen-decl-dstr-obj-rest-number.js  # TypeError: Object destructuring requires a data object or array value, received a number.
 language/statements/for-await-of/async-gen-decl-dstr-obj-rest-str-val.js  # TypeError: Object destructuring requires a data object or array value, received a string.
 language/statements/for-in/head-lhs-member.js  # Unsupported for...in binding.
-language/statements/for-of/Array.prototype.Symbol.iterator.js  # The called value is not a function.
-language/statements/for-of/dstr/array-elem-init-in.js  # Failed to parse TypeScript: '…' expected.
 language/statements/for-of/dstr/array-elem-iter-rtrn-close-err.js  # Iterator next must be a function.
 language/statements/for-of/dstr/array-elem-iter-rtrn-close-null.js  # Expected a TypeError to be thrown but no exception was thrown at all
 language/statements/for-of/dstr/array-elem-iter-thrw-close-err.js  # Expected SameValue(«1», «0») to be true
@@ -355,7 +343,6 @@ language/statements/function/S14_A5_T1.js  # Identifier '…' has already been d
 language/statements/function/S14_A5_T2.js  # Identifier '…' has already been declared.
 language/statements/function/dstr/ary-init-iter-get-err-array-prototype.js  # Expected a TypeError to be thrown but no exception was thrown at all
 language/statements/function/dstr/dflt-ary-init-iter-get-err-array-prototype.js  # Expected a TypeError to be thrown but no exception was thrown at all
-language/statements/function/rest-params-trailing-comma-early-error.js  # expected SyntaxError but the program ran
 language/statements/generators/dflt-params-abrupt.js  # Expected a Test262Error to be thrown but no exception was thrown at all
 language/statements/generators/dflt-params-ref-later.js  # Expected a ReferenceError to be thrown but no exception was thrown at all
 language/statements/generators/dflt-params-ref-self.js  # Expected a ReferenceError to be thrown but no exception was thrown at all
@@ -406,8 +393,6 @@ language/statements/generators/dstr/obj-ptrn-prop-obj-value-undef.js  # Expected
 language/statements/generators/has-instance.js  # The right-hand side of '…' has no '…' object.
 language/statements/generators/prototype-typeof.js  # Expected SameValue(«"undefined"», «"object"») to be true
 language/statements/generators/prototype-uniqueness.js  # Expected true but got false
-language/statements/generators/rest-params-trailing-comma-early-error.js  # expected SyntaxError but the program ran
-language/statements/labeled/value-await-non-module-escaped.js  # Failed to parse TypeScript: Keywords cannot contain escape characters.
 language/statements/labeled/value-await-non-module.js  # Failed to parse TypeScript: Expression expected.
 language/statements/let/dstr/ary-init-iter-get-err-array-prototype.js  # Expected a TypeError to be thrown but no exception was thrown at all
 language/statements/return/S12.9_A1_T1.js  # expected SyntaxError but the program ran
@@ -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.
+ * `checkIteratorProperties` (prototype chain and property descriptors) and the custom iterator on a Headers
+ * instance are left out.
 */
 import { describe, expect, test } from "bun:test"
 import { Effect } from "effect"
@@ -166,3 +169,256 @@ 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)
+          var actual = headers.keys()
+          sortedHeaderKeys.forEach(function(key) {
+            const entry = actual.next()
+            assert_false(entry.done)
+            assert_equals(entry.value, key)
+          })
+          assert_true(actual.next().done)
+          assert_true(actual.next().done)
+          for (const key of headers.keys()) assert_true(sortedHeaderKeys.indexOf(key) != -1)
+        }, "Check keys method")
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          var actual = headers.values()
+          sortedHeaderKeys.forEach(function(key) {
+            const entry = actual.next()
+            assert_false(entry.done)
+            assert_equals(entry.value, sortedHeaderDict[key])
+          })
+          assert_true(actual.next().done)
+          assert_true(actual.next().done)
+          for (const value of headers.values()) assert_true(headerValues.indexOf(value) != -1)
+        }, "Check values method")
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          var actual = headers.entries()
+          sortedHeaderKeys.forEach(function(key) {
+            const entry = actual.next()
+            assert_false(entry.done)
+            assert_equals(entry.value[0], key)
+            assert_equals(entry.value[1], sortedHeaderDict[key])
+          })
+          assert_true(actual.next().done)
+          assert_true(actual.next().done)
+          for (const entry of headers.entries()) assert_equals(entry[1], sortedHeaderDict[entry[0]])
+        }, "Check entries method")
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          var actual = headers[Symbol.iterator]()
+          sortedHeaderKeys.forEach(function(key) {
+            const entry = actual.next()
+            assert_false(entry.done)
+            assert_equals(entry.value[0], key)
+            assert_equals(entry.value[1], sortedHeaderDict[key])
+          })
+          assert_true(actual.next().done)
+          assert_true(actual.next().done)
+        }, "Check Symbol.iterator method")
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          var reference = sortedHeaderKeys[Symbol.iterator]()
+          headers.forEach(function(value, key, container) {
+            assert_equals(headers, container)
+            const entry = reference.next()
+            assert_false(entry.done)
+            assert_equals(key, entry.value)
+            assert_equals(value, sortedHeaderDict[entry.value])
+          })
+          assert_true(reference.next().done)
+        }, "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": "2.0.8",
+  "version": "2.0.10",
  "type": "module",
  "license": "MIT",
  "scripts": {
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
LukeParkerDev	6a57105b2c	refactor(app): keep the SSH contract schemas out of the renderer The Effect schemas move to servers/ssh/schema.ts, imported by the desktop main process for its RPC server; the renderer gets types only. The SSH attempt controller tracks its one in-flight request per server with a cancellation flag instead of Effect fibers, with the same settle-on-cancel behaviour.	2026-09-20 16:37:02 +10:00
LukeParkerDev	7930c5f676	refactor(app): port the model selection and terminal stores to plain codecs	2026-09-20 16:37:02 +10:00
LukeParkerDev	a440d0bced	refactor(app): port language, drafts, pairing, review panel, open-in-app and upsell stores to plain codecs Also replaces the Effect Iterable pipeline in the provider catalog with array methods.	2026-09-20 16:37:01 +10:00
LukeParkerDev	169ababd60	refactor(app): port command, notification, highlights, home, file-view and workspace-tip stores to plain codecs Session import keeps validating against the shared Effect schema through a dynamic import, so the shared schema and Effect load only when a file is imported. Persisted notification errors are checked structurally instead of through the shared schema. composer/schema.ts carries Effect twins of the file selection shapes until it is ported.	2026-09-20 16:37:00 +10:00
LukeParkerDev	10638d1d9f	refactor(app): port the settings store to plain codecs Migration shapes use preserving structs so undeclared stored fields survive, as Effect's onExcessProperty preserve did at every level; explicit-but-invalid legacy values still decode to null rather than absent; persisted() encodes through encodeOrThrow so an invalid in-memory value fails instead of being written.	2026-09-20 16:37:00 +10:00
LukeParkerDev	faa72aea3a	refactor(app): port the server, model, vcs and project stores to plain codecs Migrations keep their behaviour: URL strings and bare HTTP blocks become server objects, canonical-local project buckets move under local, invalid map entries are dropped individually. Migrated definitions now preserve stored fields the migration does not mention, as Effect's onExcessProperty preserve did. The Effect ServerKey is gone; the codec one in runtime/server/key.ts carries the same brand.	2026-09-20 16:36:59 +10:00
LukeParkerDev	211ce5e9f8	refactor(app): port the layout store to plain codecs Same shapes, defaults and migration as before (workspaces flag to map, review panel flag inherited from the file tree, legacy file-tree width), expressed with the codec module instead of Effect Schema.	2026-09-20 16:36:59 +10:00
LukeParkerDev	3858b11bf9	refactor(app): plain codecs for persisted state, starting with tabs Adds an Effect-free codec module for persisted stores with the same recovery semantics as the Persistence helpers, lets persisted() accept either a Schema or a codec while stores migrate, and ports the tab storage schemas as the first store. ServerKey keeps its brand type on both sides so ServerConnection.Key stays one type. Effect leaves the renderer's initial module graph once the remaining stores are ported.	2026-09-20 16:36:58 +10:00
Luke Parker	717f81ce08	chore(desktop): attribute renderer CPU profiles to source files (#50114 )	2026-09-20 16:30:35 +10:00
Luke Parker	5fdfcc7a80	perf(desktop): hand the window its persisted stores before the first render (#50113 )	2026-09-20 16:29:02 +10:00
Luke Parker	0530c8e512	perf(desktop): talk to the main process without the Effect runtime in the renderer (#50112 )	2026-09-20 16:26:08 +10:00
Luke Parker	1d8cf4564b	perf(desktop): move startup work that the first window does not need off its path (#50111 )	2026-09-20 16:23:37 +10:00
Luke Parker	7e88f6bb18	perf(desktop): bundle the renderer's initial module graph as one chunk (#50110 )	2026-09-20 16:19:28 +10:00
Luke Parker	af592fb779	perf(desktop): serve the renderer's first assets before evaluating the main bundle (#50109 )	2026-09-20 16:18:50 +10:00
Luke Parker	7fc3f68007	perf(desktop): boot the renderer alongside the main bundle (#50108 )	2026-09-20 16:15:58 +10:00
opencode-agent[bot]	cdcbb0047e	chore(core): refresh bundled models.dev snapshot	2026-09-20 05:38:29 +00:00
opencode-agent[bot]	a1956a7522	chore(core): refresh bundled models.dev snapshot	2026-09-20 04:42:05 +00:00
opencode-agent[bot]	55bc7fd403	chore(core): refresh bundled models.dev snapshot	2026-09-20 03:43:32 +00:00
opencode-agent[bot]	3049b1e684	chore(core): refresh bundled models.dev snapshot	2026-09-20 02:45:23 +00:00
opencode-agent[bot]	1f36a7aff8	chore(core): refresh bundled models.dev snapshot	2026-09-20 01:31:11 +00:00
Aiden Cline	eb0e26b974	feat(codemode): return live iterators from keys, values, and entries (#50061 )	2026-09-19 18:46:35 -05:00
opencode-agent[bot]	6f2b0e7833	chore(core): refresh bundled models.dev snapshot	2026-09-19 23:38:19 +00:00
opencode-agent[bot]	f153255942	chore(core): refresh bundled models.dev snapshot	2026-09-19 22:37:11 +00:00
opencode-agent[bot]	fef2fad76f	chore(core): refresh bundled models.dev snapshot	2026-09-19 22:15:20 +00:00
Aiden Cline	f30d06ea34	fix(core): pin the session to http after repeated websocket stream losses (#50031 )	2026-09-19 16:45:54 -05:00
Kit Langton	dfa44e94e8	fix(tui): use focused action token for question form border (#50037 )	2026-09-19 19:07:10 +00:00
Aiden Cline	b81e10a461	fix(core): re-read models.dev catalog after subscribing to Refreshed (#50012 )	2026-09-19 13:31:38 -05:00
Aiden Cline	65c93b69ed	fix(ai): never fail decoding on Responses error frames (#49402 )	2026-09-19 13:27:05 -05:00
Aiden Cline	b073b052d3	fix(ai): remove bounded websocket inbound queues (#50026 )	2026-09-19 13:26:37 -05:00
Aiden Cline	728b2b6052	fix(core): honor session permissions in skill and MCP discovery (#50015 )	2026-09-19 12:59:09 -05:00
Aiden Cline	cc3ce20ab4	feat(codemode): add the Headers built-in (#49280 )	2026-09-19 12:35:14 -05:00
Aiden Cline	4ad5001be2	chore(core): refresh bundled models.dev snapshot (#50009 )	2026-09-19 12:24:10 -05:00
Matt SimpsonandAiden Cline	14b3c2ea4b	feat(cli): support Vite+ installations (#49624 ) Co-authored-by: Aiden Cline <63023139+rekram1-node@users.noreply.github.com>	2026-09-19 12:16:47 -05:00
opencode-agent[bot]andrekram1-node	558bd54c9b	fix(tui): use muted autocomplete label text (#50008 ) Co-authored-by: rekram1-node <rekram1-node@users.noreply.github.com>	2026-09-19 12:16:41 -05:00
Filip	7e70f7e1ab	feat(tui): label mention autocomplete options (#48551 )	2026-09-19 16:05:03 +02:00
opencode	cb6d95b7ef	sync release versions for v2.0.10	2026-09-19 13:40:59 +00:00
opencode-agent[bot]andBrendonovich	7020944359	fix(app): restore mobile tab interactions (#49964 ) Co-authored-by: Brendonovich <14191578+Brendonovich@users.noreply.github.com>	2026-09-19 21:00:45 +08:00
Shoubhit Dash	4b00dd2713	feat(tui): session-scoped plugin toasts (#49962 )	2026-09-19 18:24:38 +05:30
Chris YangandBrendan Allan	b447627f5f	fix(app): keep shortcuts search field focused while typing (#49779 ) Co-authored-by: Brendan Allan <14191578+Brendonovich@users.noreply.github.com>	2026-09-19 20:43:58 +08:00
opencode-agent[bot]andBrendonovich	5848ee0d24	fix(app): restore attachment classification (#49932 ) Co-authored-by: Brendonovich <14191578+Brendonovich@users.noreply.github.com>	2026-09-19 09:13:29 +00:00
Dax Raad	839aa25c3e	feat(cli): publish Homebrew formula	2026-09-19 04:37:36 -04:00
Dax Raad	c42f1c9232	Revert "feat(web): add v2 announcement banner to legacy docs" This reverts commit `7b7a67080e`.	2026-09-19 03:24:40 -04:00
Kit Langton	417f6d234d	fix(tui): restore running and unread status hue aliases (#49907 )	2026-09-19 02:05:53 -04:00
opencode	45a13af0ee	sync release versions for v2.0.9	2026-09-19 05:13:01 +00:00
Luke Parker	e50d845451	fix(desktop): run WSL commands with --exec so inline scripts are not pre-expanded (#49902 )	2026-09-19 14:36:04 +10:00
Kit Langton	56816621f8	fix(tui): restore foreground hue step for tab status colors (#49899 )	2026-09-19 04:33:23 +00:00
Luke Parker	7125f5f8b5	chore(desktop): measure the startup bench from the screen (#49894 )	2026-09-19 14:06:58 +10:00
opencode-agent[bot]	01a6ed8d97	chore: update nix node_modules hashes	2026-09-19 02:49:44 +00:00
opencode-agent[bot]rekram1-node Aiden Cline	004583d598	refactor(codemode): remove TypeScript stripping (#49870 ) Co-authored-by: rekram1-node <rekram1-node@users.noreply.github.com> Co-authored-by: Aiden Cline <aidenpcline@gmail.com>	2026-09-18 21:24:11 -05:00
Aiden Cline	cbd911368e	refactor(schema): separate provider and model settings (#49850 )	2026-09-18 21:20:08 -05:00
opencode-agent[bot]	8bfb247854	chore: update nix node_modules hashes	2026-09-19 02:20:04 +00:00