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

test(codemode): keep only the Headers WPT cases that exercise the runtime
fix(codemode): let Headers methods report a bad receiver
2026-09-17 06:16:20 +00:00 · 2026-09-16 14:16:08 -05:00 · 2026-09-16 13:19:46 -05:00 · 2026-09-16 13:19:46 -05:00 · 2026-09-16 13:19:46 -05:00 · 2026-09-16 13:19:46 -05:00
68 changed files with 852 additions and 151 deletions
@@ -32,7 +32,7 @@
    },
    "packages/ai": {
      "name": "@opencode/ai",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@aws-sdk/credential-providers": "3.1057.0",
        "@opencode/schema": "workspace:*",
@@ -54,7 +54,7 @@
    },
    "packages/app": {
      "name": "@opencode/app",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@corvu/drawer": "catalog:",
        "@dnd-kit/abstract": "0.5.0",
@@ -113,7 +113,7 @@
    },
    "packages/cli": {
      "name": "@opencode/cli",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "bin": {
        "opencode2": "./bin/opencode2.cjs",
      },
@@ -177,7 +177,7 @@
    },
    "packages/client": {
      "name": "@opencode/client",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/protocol": "workspace:*",
        "@opencode/schema": "workspace:*",
@@ -203,7 +203,7 @@
    },
    "packages/codemode": {
      "name": "@opencode/codemode",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "acorn": "8.15.0",
        "effect": "catalog:",
@@ -217,7 +217,7 @@
    },
    "packages/console/app": {
      "name": "@opencode/console-app",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@cloudflare/vite-plugin": "1.15.2",
        "@ibm/plex": "6.4.1",
@@ -253,7 +253,7 @@
    },
    "packages/console/core": {
      "name": "@opencode/console-core",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@aws-sdk/client-sts": "3.782.0",
        "@jsx-email/render": "1.1.1",
@@ -280,7 +280,7 @@
    },
    "packages/console/function": {
      "name": "@opencode/console-function",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@openauthjs/openauth": "0.0.0-20250322224806",
        "@opencode/console-core": "workspace:*",
@@ -297,7 +297,7 @@
    },
    "packages/console/mail": {
      "name": "@opencode/console-mail",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@jsx-email/all": "2.2.3",
        "@jsx-email/cli": "1.4.3",
@@ -321,7 +321,7 @@
    },
    "packages/console/support": {
      "name": "@opencode/console-support",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@cloudflare/vite-plugin": "1.15.2",
        "@opencode/console-core": "workspace:*",
@@ -341,7 +341,7 @@
    },
    "packages/core": {
      "name": "@opencode/core",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@ai-sdk/cohere": "3.0.27",
        "@ai-sdk/gateway": "3.0.104",
@@ -409,7 +409,7 @@
    },
    "packages/desktop": {
      "name": "@opencode/desktop",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@zip.js/zip.js": "2.7.62",
        "electron-context-menu": "4.1.2",
@@ -461,7 +461,7 @@
    },
    "packages/enterprise": {
      "name": "@opencode/enterprise",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@hono/standard-validator": "catalog:",
        "@opencode-ai/sdk": "1.18.21",
@@ -498,7 +498,7 @@
    },
    "packages/function": {
      "name": "@opencode/function",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@octokit/auth-app": "8.0.1",
        "@octokit/rest": "catalog:",
@@ -514,7 +514,7 @@
    },
    "packages/http-recorder": {
      "name": "@opencode/http-recorder",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@effect/platform-node-shared": "4.0.0-rc.112",
      },
@@ -533,7 +533,7 @@
    },
    "packages/httpapi-codegen": {
      "name": "@opencode/httpapi-codegen",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "effect": "catalog:",
        "prettier": "3.6.2",
@@ -546,7 +546,7 @@
    },
    "packages/latex": {
      "name": "@opencode/latex",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/plugin": "workspace:*",
        "@opentui/core": "catalog:",
@@ -560,7 +560,7 @@
    },
    "packages/merman": {
      "name": "@opencode/merman",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/plugin": "workspace:*",
        "@opentui/core": "catalog:",
@@ -575,7 +575,7 @@
    },
    "packages/plugin": {
      "name": "@opencode/plugin",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@ai-sdk/provider": "3.0.8",
        "@opencode/ai": "workspace:*",
@@ -614,7 +614,7 @@
    },
    "packages/plugin-browser": {
      "name": "@opencode/plugin-browser",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/plugin": "workspace:*",
        "@opencode/schema": "workspace:*",
@@ -644,7 +644,7 @@
    },
    "packages/protocol": {
      "name": "@opencode/protocol",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/schema": "workspace:*",
        "effect": "catalog:",
@@ -659,7 +659,7 @@
    },
    "packages/schema": {
      "name": "@opencode/schema",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@standard-schema/spec": "catalog:",
        "effect": "catalog:",
@@ -683,7 +683,7 @@
    },
    "packages/sdk": {
      "name": "@opencode/sdk",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/client": "workspace:*",
        "@opencode/core": "workspace:*",
@@ -704,7 +704,7 @@
    },
    "packages/server": {
      "name": "@opencode/server",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@effect/platform-node": "catalog:",
        "@effect/platform-node-shared": "catalog:",
@@ -726,7 +726,7 @@
    },
    "packages/session-ui": {
      "name": "@opencode/session-ui",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@kobalte/core": "catalog:",
        "@opencode/client": "workspace:*",
@@ -761,7 +761,7 @@
    },
    "packages/simulation": {
      "name": "@opencode/simulation",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/ai": "workspace:*",
        "@opencode/core": "workspace:*",
@@ -781,7 +781,7 @@
    },
    "packages/stats/app": {
      "name": "@opencode/stats-app",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@ibm/plex": "6.4.1",
        "@kobalte/core": "catalog:",
@@ -815,7 +815,7 @@
    },
    "packages/stats/core": {
      "name": "@opencode/stats-core",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@aws-sdk/client-athena": "3.933.0",
        "@planetscale/database": "1.19.0",
@@ -834,7 +834,7 @@
    },
    "packages/stats/server": {
      "name": "@opencode/stats-server",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@aws-sdk/client-firehose": "3.933.0",
        "@effect/platform-node": "catalog:",
@@ -880,7 +880,7 @@
    },
    "packages/theme": {
      "name": "@opencode/theme",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opentui/core": "catalog:",
        "effect": "catalog:",
@@ -894,7 +894,7 @@
    },
    "packages/tui": {
      "name": "@opencode/tui",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@opencode/client": "workspace:*",
        "@opencode/core": "workspace:*",
@@ -929,7 +929,7 @@
    },
    "packages/ui": {
      "name": "@opencode/ui",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@kobalte/core": "catalog:",
        "@pierre/diffs": "catalog:",
@@ -964,7 +964,7 @@
    },
    "packages/util": {
      "name": "@opencode/util",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@effect/opentelemetry": "catalog:",
        "@effect/platform-node": "catalog:",
@@ -997,7 +997,7 @@
    },
    "packages/web": {
      "name": "@opencode/web",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "@astrojs/cloudflare": "12.6.3",
        "@astrojs/markdown-remark": "6.3.1",
@@ -1038,7 +1038,7 @@
    },
    "services/update": {
      "name": "@opencode/update",
-      "version": "2.0.4",
+      "version": "2.0.5",
      "dependencies": {
        "jose": "6.0.11",
        "semver": "catalog:",
@@ -2,7 +2,7 @@
  "$schema": "https://json.schemastore.org/package.json",
  "name": "opencode",
  "description": "AI-powered development tool",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "packageManager": "bun@1.4.2",
@@ -1,6 +1,6 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "name": "@opencode/ai",
  "type": "module",
  "license": "MIT",
@@ -336,12 +336,18 @@ export type OutputItem = StreamItem & { readonly id: string }
 // Responses-compatible providers put streaming error details at the top level or
 // under `error`, and response failures under `response.error`. Accept all three shapes.
 // https://www.openresponses.org/specification
-const OpenResponsesErrorPayload = Schema.Struct({
+const OpenResponsesErrorObject = Schema.Struct({
  type: optionalNull(Schema.String),
  code: optionalNull(Schema.String),
  message: optionalNull(Schema.String),
  param: optionalNull(Schema.String),
 })
+const OpenResponsesErrorPayload = Schema.Union([Schema.String, OpenResponsesErrorObject]).pipe(
+  Schema.decodeTo(OpenResponsesErrorObject, {
+    decode: SchemaGetter.transform((error) => (typeof error === "string" ? { message: error } : error)),
+    encode: SchemaGetter.passthrough(),
+  }),
+)
 type OpenResponsesErrorPayload = Schema.Schema.Type<typeof OpenResponsesErrorPayload>

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

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

+it.effect("normalizes string errors in shared SSE and WebSocket decoding", () =>
+  Effect.gen(function* () {
+    for (const decode of [decodeEvent, OpenResponses.decodeChannelEvent]) {
+      expect(yield* decode(JSON.stringify({ type: "error", error: "Gateway failed" }))).toEqual({
+        type: "error",
+        error: { message: "Gateway failed" },
+      })
+      expect(
+        yield* decode(
+          JSON.stringify({ type: "response.failed", response: { id: "resp_failed", error: "Gateway failed" } }),
+        ),
+      ).toEqual({
+        type: "response.failed",
+        response: { id: "resp_failed", error: { message: "Gateway failed" } },
+      })
+    }
+  }),
+)
+
+for (const model of [
+  OpenAI.configure({ apiKey: "fixture" }).responses("gpt-5.6-sol"),
+  XAI.configure({ apiKey: "fixture" }).responses("grok-4.6"),
+  Azure.configure({ apiKey: "fixture", resourceName: "fixture" }).responses("deployment"),
+]) {
+  it.effect(`preserves string error messages and raw bodies through ${model.provider} Responses`, () =>
+    Effect.gen(function* () {
+      const raw = '{ "type": "error", "error": "Gateway rejected the request", "trace": "original" }'
+      const webSocket = WebSocketTransport.makeDirect({
+        open: () => Effect.succeed({ sendText: () => Effect.void, messages: Stream.make(raw), close: Effect.void }),
+      })
+      for (const options of [{ webSocket }, {}]) {
+        const error = yield* LLMClient.generate(LLM.request({ model, prompt: "Hello" }), options).pipe(
+          Effect.provide(fixedResponse(sseEvents(raw))),
+          Effect.flip,
+        )
+        expect(error.reason._tag).toBe("UnknownProvider")
+        expect(error.message).toBe("Gateway rejected the request")
+        expect(error.reason.body).toBe(raw)
+      }
+    }),
+  )
+}
+
 it.effect("retains classification and original error bodies through Meta and generic Responses routes", () =>
  Effect.gen(function* () {
    const raw = `{
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/app",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "description": "",
  "type": "module",
  "exports": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/cli",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "bin": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/client",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -13,8 +13,8 @@ The idea of code mode was originally introduced by Cloudflare. See

 ## How it differs from JavaScript

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

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

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

 ### OpenAPI tools

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

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

 ## Extensions

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

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

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

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

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

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

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

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

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

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

+describe("Headers", () => {
+  test("constructs from records, pairs, Maps, and Headers; names fold to lowercase and values combine", async () => {
+    expect(
+      await value(`
+        const headers = new Headers({ "Content-Type": "text/plain", "X-Count": 1, "X-Null": null })
+        headers.append("Accept", "text/html")
+        headers.append("accept", "application/json")
+        headers.set("x-count", "2")
+        headers.delete("x-null")
+        const copy = new Headers(headers)
+        copy.set("content-type", "text/html")
+        return {
+          get: headers.get("content-type"),
+          missing: headers.get("x-missing"),
+          combined: headers.get("ACCEPT"),
+          has: [headers.has("Accept"), headers.has("x-null")],
+          count: headers.get("x-count"),
+          copied: [headers.get("content-type"), copy.get("content-type")],
+          pairs: [...new Headers([["b", "2"], ["A", "1"]])],
+          map: [...new Headers(new Map([["k", "v"]]))],
+          keys: headers.keys(),
+          values: headers.values(),
+          entries: headers.entries(),
+        }
+      `),
+    ).toEqual({
+      get: "text/plain",
+      missing: null,
+      combined: "text/html, application/json",
+      has: [true, false],
+      count: "2",
+      copied: ["text/plain", "text/html"],
+      pairs: [
+        ["a", "1"],
+        ["b", "2"],
+      ],
+      map: [["k", "v"]],
+      keys: ["accept", "content-type", "x-count"],
+      values: ["text/html, application/json", "text/plain", "2"],
+      entries: [
+        ["accept", "text/html, application/json"],
+        ["content-type", "text/plain"],
+        ["x-count", "2"],
+      ],
+    })
+  })
+
+  test("iterates in sorted order everywhere iteration is allowed, and getSetCookie keeps cookies apart", async () => {
+    expect(
+      await value(`
+        const headers = new Headers({ b: "2", a: "1" })
+        headers.append("Set-Cookie", "x=1")
+        headers.append("set-cookie", "y=2")
+        const seen = []
+        headers.forEach((value, name, self) => seen.push(name + "=" + value + ":" + (self === headers)))
+        const [first] = headers
+        function* pairs() { yield* headers }
+        return {
+          seen,
+          first,
+          spread: [...headers],
+          from: Array.from(headers).length,
+          generator: [...pairs()].length,
+          object: Object.fromEntries(headers),
+          cookies: headers.getSetCookie(),
+        }
+      `),
+    ).toEqual({
+      seen: ["a=1:true", "b=2:true", "set-cookie=x=1:true", "set-cookie=y=2:true"],
+      first: ["a", "1"],
+      spread: [
+        ["a", "1"],
+        ["b", "2"],
+        ["set-cookie", "x=1"],
+        ["set-cookie", "y=2"],
+      ],
+      from: 4,
+      generator: 4,
+      object: { a: "1", b: "2", "set-cookie": "y=2" },
+      cookies: ["x=1", "y=2"],
+    })
+  })
+
+  test("serializes as a name-to-value object at the boundary and in JSON; prints for console", async () => {
+    const result = await run(`
+      const headers = new Headers({ "X-A": "1", b: "2" })
+      console.log(headers)
+      return { headers, json: JSON.stringify({ headers }), text: String(headers), type: typeof headers, is: headers instanceof Headers }
+    `)
+    expect(result.ok && result.value).toEqual({
+      headers: { b: "2", "x-a": "1" },
+      json: '{"headers":{"b":"2","x-a":"1"}}',
+      text: "[object Headers]",
+      type: "object",
+      is: true,
+    })
+    expect(result.ok && result.logs?.[0]).toBe('Headers {"b":"2","x-a":"1"}')
+  })
+
+  test("rejects what it cannot build from, and invalid names and values, with TypeErrors the program can catch", async () => {
+    expect(
+      await value(`
+        function message(run) {
+          try { run(); return null } catch (error) { return error instanceof TypeError ? error.message : error }
+        }
+        const headers = new Headers()
+        return [
+          message(() => Headers()),
+          message(() => new Headers(null)),
+          message(() => new Headers(1)),
+          message(() => new Headers("a=1")),
+          message(() => new Headers(new Date())),
+          message(() => new Headers(() => 1)),
+          message(() => new Headers([["name"]])),
+          message(() => new Headers([["a", "b", "c"]])),
+          message(() => new Headers({ "bad name": "x" })),
+          message(() => new Headers({ name: "bad\u0000value" })),
+          message(() => headers.get("invalid\u0100")),
+          message(() => headers.has({})),
+          message(() => headers.set("a", "invalid\u0100")),
+          message(() => headers.append("a")),
+          message(() => headers.forEach()),
+          message(() => headers.forEach(1)),
+          message(() => { const get = headers.get; return get("a") }),
+        ]
+      `),
+    ).toEqual([
+      "Constructor Headers requires 'new'.",
+      "new Headers(...) expects a record of names to values, iterable [name, value] pairs, or Headers.",
+      "new Headers(...) expects a record of names to values, iterable [name, value] pairs, or Headers.",
+      "new Headers(...) expects a record of names to values, iterable [name, value] pairs, or Headers.",
+      "new Headers(...) expects a record of names to values, iterable [name, value] pairs, or Headers.",
+      "new Headers(...) expects a record of names to values, iterable [name, value] pairs, or Headers.",
+      "new Headers(...) expects iterable [name, value] pairs.",
+      "new Headers(...) expects iterable [name, value] pairs.",
+      expect.stringContaining("bad name"),
+      expect.stringContaining("invalid value"),
+      expect.stringContaining("Invalid header name"),
+      expect.stringContaining("[object Object]"),
+      expect.stringContaining("invalid value"),
+      "Headers.append requires 2 arguments.",
+      "Headers.forEach requires 1 argument.",
+      "Headers.forEach expects a function callback.",
+      "Headers.prototype.get called on incompatible receiver undefined.",
+    ])
+  })
+})
+
 describe("Map", () => {
  test("get/set/has/size with chaining", async () => {
    expect(
@@ -3,10 +3,13 @@
 * - html/webappapis/atob/base64.any.js (btoa reference encoder, input list, and atob WebIDL cases)
 * - fetch/data-urls/resources/base64.json (copied to fixtures/wpt-base64.json)
 * - WebCryptoAPI/randomUUID.https.any.js
+ * - fetch/api/headers/{headers-basic,headers-errors}.any.js
 *
 * Copyright © web-platform-tests contributors. Governed by the 3-Clause BSD license in LICENSE.wpt.
 *
 * `assert_throws_dom("InvalidCharacterError", …)` becomes a check for a TypeError: CodeMode has no DOMException.
+ * Headers cases that need `Symbol.iterator`, iterator objects from `keys()`/`values()`/`entries()` (CodeMode returns
+ * arrays), or a custom iterator on a Headers instance are left out.
 */
 import { describe, expect, test } from "bun:test"
 import { Effect } from "effect"
@@ -166,3 +169,225 @@ describe("crypto.randomUUID WPT parity (WebCryptoAPI/randomUUID.https.any.js)",
    ).toEqual([true, true, true, 768])
  })
 })
+
+// Enough of testharness.js to run the Headers files close to verbatim; each `test` records its failure, if any.
+const testharness = `
+  const failures = []
+  function test(run, name) { try { run() } catch (error) { failures.push(name + ": " + (error && error.message ? error.message : error)) } }
+  function assert_equals(actual, expected, message) { if (actual !== expected) throw new Error((message || "") + " expected " + JSON.stringify(expected) + " got " + JSON.stringify(actual)) }
+  function assert_true(actual, message) { assert_equals(actual, true, message) }
+  function assert_false(actual, message) { assert_equals(actual, false, message) }
+  function assert_array_equals(actual, expected, message) { assert_equals(JSON.stringify(actual), JSON.stringify(expected), message) }
+  function assert_throws_js(type, run) { try { run() } catch (error) { if (error instanceof type) return; throw new Error("threw " + error.name) } throw new Error("did not throw") }
+  function assert_unreached() { throw new Error("unreachable") }
+`
+
+describe("Headers WPT parity (fetch/api/headers)", () => {
+  test("headers-basic.any.js", async () => {
+    expect(
+      await value(`
+        ${testharness}
+        test(function() { new Headers() }, "Create headers from no parameter")
+        test(function() { new Headers(undefined) }, "Create headers from undefined parameter")
+        test(function() { new Headers({}) }, "Create headers from empty object")
+        var parameters = [null, 1]
+        parameters.forEach(function(parameter) {
+          test(function() { assert_throws_js(TypeError, function() { new Headers(parameter) }) }, "Create headers with " + parameter + " should throw")
+        })
+        var headerDict = {"name1": "value1", "name2": "value2", "name3": "value3", "name4": null, "name5": undefined, "name6": 1, "Content-Type": "value4"}
+        var headerSeq = []
+        for (var name in headerDict) headerSeq.push([name, headerDict[name]])
+        test(function() {
+          var headers = new Headers(headerSeq)
+          for (name in headerDict) assert_equals(headers.get(name), String(headerDict[name]), "name: " + name + " has value: " + headerDict[name])
+          assert_equals(headers.get("length"), null, "init should be treated as a sequence, not as a dictionary")
+        }, "Create headers with sequence")
+        test(function() {
+          var headers = new Headers(headerDict)
+          for (name in headerDict) assert_equals(headers.get(name), String(headerDict[name]), "name: " + name + " has value: " + headerDict[name])
+        }, "Create headers with record")
+        test(function() {
+          var headers = new Headers(headerDict)
+          var headers2 = new Headers(headers)
+          for (name in headerDict) assert_equals(headers2.get(name), String(headerDict[name]), "name: " + name + " has value: " + headerDict[name])
+        }, "Create headers with existing headers")
+        test(function() {
+          var headers = new Headers()
+          for (name in headerDict) {
+            headers.append(name, headerDict[name])
+            assert_equals(headers.get(name), String(headerDict[name]), "name: " + name + " has value: " + headerDict[name])
+          }
+        }, "Check append method")
+        test(function() {
+          var headers = new Headers()
+          for (name in headerDict) {
+            headers.set(name, headerDict[name])
+            assert_equals(headers.get(name), String(headerDict[name]), "name: " + name + " has value: " + headerDict[name])
+          }
+        }, "Check set method")
+        test(function() {
+          var headers = new Headers(headerDict)
+          for (name in headerDict) assert_true(headers.has(name), "headers has name " + name)
+          assert_false(headers.has("nameNotInHeaders"), "headers do not have header: nameNotInHeaders")
+        }, "Check has method")
+        test(function() {
+          var headers = new Headers(headerDict)
+          for (name in headerDict) {
+            assert_true(headers.has(name), "headers have a header: " + name)
+            headers.delete(name)
+            assert_true(!headers.has(name), "headers do not have anymore a header: " + name)
+          }
+        }, "Check delete method")
+        test(function() {
+          var headers = new Headers(headerDict)
+          for (name in headerDict) assert_equals(headers.get(name), String(headerDict[name]), "name: " + name + " has value: " + headerDict[name])
+          assert_equals(headers.get("nameNotInHeaders"), null, "header: nameNotInHeaders has no value")
+        }, "Check get method")
+        var headerEntriesDict = {"name1": "value1", "Name2": "value2", "name": "value3", "content-Type": "value4", "Content-Typ": "value5", "Content-Types": "value6"}
+        var sortedHeaderDict = {}
+        var headerValues = []
+        var sortedHeaderKeys = Object.keys(headerEntriesDict).map(function(value) {
+          sortedHeaderDict[value.toLowerCase()] = headerEntriesDict[value]
+          headerValues.push(headerEntriesDict[value])
+          return value.toLowerCase()
+        }).sort()
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          assert_array_equals(headers.keys(), sortedHeaderKeys)
+          for (const key of headers.keys()) assert_true(sortedHeaderKeys.indexOf(key) != -1)
+        }, "Check keys method")
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          assert_array_equals(headers.values(), sortedHeaderKeys.map((key) => sortedHeaderDict[key]))
+          for (const value of headers.values()) assert_true(headerValues.indexOf(value) != -1)
+        }, "Check values method")
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          assert_array_equals(headers.entries(), sortedHeaderKeys.map((key) => [key, sortedHeaderDict[key]]))
+          for (const entry of headers.entries()) assert_equals(entry[1], sortedHeaderDict[entry[0]])
+        }, "Check entries method")
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          assert_array_equals([...headers], sortedHeaderKeys.map((key) => [key, sortedHeaderDict[key]]))
+        }, "Check Symbol.iterator method")
+        test(function() {
+          var headers = new Headers(headerEntriesDict)
+          var index = 0
+          headers.forEach(function(value, key, container) {
+            assert_equals(headers, container)
+            assert_equals(key, sortedHeaderKeys[index])
+            assert_equals(value, sortedHeaderDict[sortedHeaderKeys[index]])
+            index++
+          })
+          assert_equals(index, sortedHeaderKeys.length)
+        }, "Check forEach method")
+        test(() => {
+          const headers = new Headers({"foo": "2", "baz": "1", "BAR": "0"})
+          const actualKeys = []
+          const actualValues = []
+          for (const [header, value] of headers) {
+            actualKeys.push(header)
+            actualValues.push(value)
+            headers.delete("foo")
+          }
+          assert_array_equals(actualKeys, ["bar", "baz"])
+          assert_array_equals(actualValues, ["0", "1"])
+        }, "Iteration skips elements removed while iterating")
+        test(() => {
+          const headers = new Headers({"foo": "2", "baz": "1", "BAR": "0", "quux": "3"})
+          const actualKeys = []
+          const actualValues = []
+          for (const [header, value] of headers) {
+            actualKeys.push(header)
+            actualValues.push(value)
+            if (header === "baz") headers.delete("bar")
+          }
+          assert_array_equals(actualKeys, ["bar", "baz", "quux"])
+          assert_array_equals(actualValues, ["0", "1", "3"])
+        }, "Removing elements already iterated over causes an element to be skipped during iteration")
+        test(() => {
+          const headers = new Headers({"foo": "2", "baz": "1", "BAR": "0", "quux": "3"})
+          const actualKeys = []
+          const actualValues = []
+          for (const [header, value] of headers) {
+            actualKeys.push(header)
+            actualValues.push(value)
+            if (header === "baz") headers.append("X-yZ", "4")
+          }
+          assert_array_equals(actualKeys, ["bar", "baz", "foo", "quux", "x-yz"])
+          assert_array_equals(actualValues, ["0", "1", "2", "3", "4"])
+        }, "Appending a value pair during iteration causes it to be reached during iteration")
+        test(() => {
+          const headers = new Headers({"foo": "2", "baz": "1", "BAR": "0", "quux": "3"})
+          const actualKeys = []
+          const actualValues = []
+          for (const [header, value] of headers) {
+            actualKeys.push(header)
+            actualValues.push(value)
+            if (header === "baz") headers.append("abc", "-1")
+          }
+          assert_array_equals(actualKeys, ["bar", "baz", "baz", "foo", "quux"])
+          assert_array_equals(actualValues, ["0", "1", "1", "2", "3"])
+        }, "Prepending a value pair before the current element position causes it to be skipped during iteration and adds the current element a second time")
+        return failures
+      `),
+    ).toEqual([])
+  })
+
+  test("headers-errors.any.js", async () => {
+    expect(
+      await value(`
+        ${testharness}
+        test(function() { assert_throws_js(TypeError, function() { new Headers([["name"]]) }) }, "Create headers giving an array having one string as init argument")
+        test(function() { assert_throws_js(TypeError, function() { new Headers([["invalid", "invalidValue1", "invalidValue2"]]) }) }, "Create headers giving an array having three strings as init argument")
+        test(function() { assert_throws_js(TypeError, function() { new Headers([["invalid\u0100", "Value1"]]) }) }, "Create headers giving bad header name as init argument")
+        test(function() { assert_throws_js(TypeError, function() { new Headers([["name", "invalidValue\u0100"]]) }) }, "Create headers giving bad header value as init argument")
+        var badNames = ["invalid\u0100", {}]
+        var badValues = ["invalid\u0100"]
+        badNames.forEach(function(name) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.get(name) }) }, "Check headers get with an invalid name " + name)
+        })
+        badNames.forEach(function(name) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.delete(name) }) }, "Check headers delete with an invalid name " + name)
+        })
+        badNames.forEach(function(name) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.has(name) }) }, "Check headers has with an invalid name " + name)
+        })
+        badNames.forEach(function(name) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.set(name, "Value1") }) }, "Check headers set with an invalid name " + name)
+        })
+        badValues.forEach(function(value) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.set("name", value) }) }, "Check headers set with an invalid value " + value)
+        })
+        badNames.forEach(function(name) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.append("invalid\u0100", "Value1") }) }, "Check headers append with an invalid name " + name)
+        })
+        badValues.forEach(function(value) {
+          test(function() { var headers = new Headers(); assert_throws_js(TypeError, function() { headers.append("name", value) }) }, "Check headers append with an invalid value " + value)
+        })
+        test(function() {
+          var headers = new Headers([["name", "value"]])
+          assert_throws_js(TypeError, function() { headers.forEach() })
+          assert_throws_js(TypeError, function() { headers.forEach(undefined) })
+          assert_throws_js(TypeError, function() { headers.forEach(1) })
+        }, "Headers forEach throws if argument is not callable")
+        test(function() {
+          var headers = new Headers([["name1", "value1"], ["name2", "value2"], ["name3", "value3"]])
+          var counter = 0
+          try {
+            headers.forEach(function(value, name) {
+              counter++
+              if (name == "name2") throw "error"
+            })
+          } catch (e) {
+            assert_equals(counter, 2)
+            assert_equals(e, "error")
+            return
+          }
+          assert_unreached()
+        }, "Headers forEach loop should stop if callback is throwing exception")
+        return failures
+      `),
+    ).toEqual([])
+  })
+})
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/console-app",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "scripts": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/console-core",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/console-function",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "$schema": "https://json.schemastore.org/package.json",
  "private": true,
  "type": "module",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/console-mail",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "dependencies": {
    "@jsx-email/all": "2.2.3",
    "@jsx-email/cli": "1.4.3",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/console-support",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "scripts": {
@@ -1,6 +1,6 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "name": "@opencode/core",
  "type": "module",
  "license": "MIT",
@@ -167,7 +167,8 @@ export const AzurePlugin = define({
                draft.settings.baseURL,
                resolveResourceName(draft.settings, resourceName) ?? resourceName,
              )
-            if (responsesWebSocketCapable(item.provider, draft)) draft.transport = "websocket"
+            if (responsesWebSocketCapable(item.provider, draft))
+              draft.transport = item.provider.transport ?? "websocket"
          })
        }
      }
@@ -270,7 +270,7 @@ export const OpenAIPlugin = define({
        // ChatGPT-plan tokens only authorize codex-eligible models, and the
        // subscription covers usage, so hide the rest and zero the cost.
        models.update(model.providerID, model.id, (draft) => {
-          draft.transport = "websocket"
+          draft.transport = models.provider.get(model.providerID)?.provider.transport ?? "websocket"
          if (!chatgpt) return
          if (Schema.is(Schema.Struct({ mode: Schema.Literal("pro") }))(draft.body?.reasoning)) {
            draft.enabled = false
@@ -98,7 +98,7 @@ export const XAIPlugin = define({
    yield* ctx.model.transform((models) => {
      for (const model of models.list(providerID)) {
        models.update(providerID, model.id, (draft) => {
-          draft.transport = "websocket"
+          draft.transport = models.provider.get(providerID)?.provider.transport ?? "websocket"
        })
      }
    })
@@ -10,6 +10,9 @@ import { Model } from "@opencode/core/model"
 import { ModelResolver } from "@opencode/core/model-resolver"
 import { Plugin } from "@opencode/core/plugin"
 import { PluginHost } from "@opencode/core/plugin/host"
+import { AzurePlugin } from "@opencode/core/plugin/provider/azure"
+import { OpenAIPlugin } from "@opencode/core/plugin/provider/openai"
+import { XAIPlugin } from "@opencode/core/plugin/provider/xai"
 import { Provider } from "@opencode/core/provider"
 import { withEnv } from "../fixture/env"
 import { testEffect } from "../lib/effect"
@@ -106,6 +109,50 @@ describe("ConfigProviderPlugin.Plugin", () => {
    }),
  )

+  for (const builtin of [
+    { id: "openai", model: "gpt-5.6-sol", package: "@opencode/ai/providers/openai/responses", plugin: OpenAIPlugin },
+    { id: "xai", model: "grok-4.6", package: "@opencode/ai/providers/xai", plugin: XAIPlugin },
+    { id: "azure", model: "gpt-5.6-sol", package: "@opencode/ai/providers/azure/responses", plugin: AzurePlugin },
+    { id: "custom-azure", model: "deployment", package: "@opencode/ai/providers/azure/responses", plugin: AzurePlugin },
+  ]) {
+    it.live(`provider transport overrides ${builtin.id} defaults while model overrides still win`, () =>
+      Effect.gen(function* () {
+        const providers = yield* Provider.Service
+        const models = yield* Model.Service
+        const plugin = yield* Plugin.Service
+        const host = yield* PluginHost.make(plugin)
+        const providerID = Provider.ID.make(builtin.id)
+        const modelID = Model.ID.make(builtin.model)
+        yield* providers.transform((editor) => {
+          editor.update(providerID, (provider) => {
+            provider.activation = "enabled"
+            provider.package = builtin.package
+          })
+          editor.models.update(providerID, modelID, () => {})
+        })
+        yield* builtin.plugin.effect(host)
+        expect((yield* models.get(providerID, modelID))?.transport).toBe("websocket")
+
+        yield* addPlugin([
+          new Document({
+            type: "document",
+            info: decode({
+              providers: {
+                [builtin.id]: {
+                  transport: "http",
+                  models: { override: { modelID: builtin.model, transport: "websocket" } },
+                },
+              },
+            }),
+          }),
+        ])
+
+        expect((yield* models.get(providerID, modelID))?.transport).toBe("http")
+        expect((yield* models.get(providerID, Model.ID.make("override")))?.transport).toBe("websocket")
+      }),
+    )
+  }
+
  it.effect("adds key auth for custom providers without env credentials", () =>
    Effect.gen(function* () {
      const integrations = yield* Integration.Service
@@ -586,26 +586,26 @@ describe("OpencodePlugin", () => {
          expect(yield* websearch.default()).toBeUndefined()

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

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

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

          state.advertised = false
-          yield* TestClock.adjust("10 minutes")
+          yield* TestClock.adjust("1 minute")
          yield* drain
          expect(state.requests).toBe(4)
          expect(rebuilds).toEqual({ provider: initial.provider + 2, websearch: initial.websearch + 2 })
@@ -1,7 +1,7 @@
 {
  "name": "@opencode/desktop",
  "private": true,
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "homepage": "https://opencode.ai",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/enterprise",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/function",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "$schema": "https://json.schemastore.org/package.json",
  "private": true,
  "type": "module",
@@ -1,6 +1,6 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "name": "@opencode/http-recorder",
  "description": "Record and replay Effect HTTP and WebSocket traffic with deterministic cassettes",
  "type": "module",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/httpapi-codegen",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "exports": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/latex",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "exports": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/merman",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "exports": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/plugin-browser",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "description": "OpenCode's desktop browser plugin",
  "type": "module",
  "license": "MIT",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/plugin",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "scripts": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/protocol",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/schema",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -1,6 +1,6 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "name": "@opencode/sdk",
  "type": "module",
  "license": "MIT",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/server",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/session-ui",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/simulation",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/stats-app",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/stats-core",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "license": "MIT",
@@ -1,5 +1,5 @@
 import { describe, expect, test } from "bun:test"
-import { toGeoAggregate, toModelAggregate, toProviderAggregate } from "./inference"
+import { buildStatsQuery, toGeoAggregate, toModelAggregate, toProviderAggregate } from "./inference"
 import { modelAuthor, normalizeInferenceModel, statModel, statProvider } from "./model-normalization"

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

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

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

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

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

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

 export type Resolved = Omit<Info, "attention" | "cursor" | "keybinds" | "leader" | "mouse" | "session" | "tabs"> & {
  attention: {
-    enabled: boolean
    notifications: boolean
    sound: boolean
    volume: number
@@ -285,9 +283,8 @@ export function resolve(input: Info, options: { terminalSuspend: boolean }): Res
  return {
    ...input,
    attention: {
-      enabled: input.attention?.enabled ?? false,
-      notifications: input.attention?.notifications ?? true,
-      sound: input.attention?.sound ?? true,
+      notifications: input.attention?.notifications ?? false,
+      sound: input.attention?.sound ?? false,
      volume: input.attention?.volume ?? 0.4,
      sound_pack: input.attention?.sound_pack ?? "opencode.default",
      sounds: input.attention?.sounds ?? {},
@@ -1,6 +1,6 @@
 {
  "name": "@opencode/ui",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/util",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "type": "module",
  "license": "MIT",
  "repository": {
@@ -2,7 +2,7 @@
  "name": "@opencode/web",
  "type": "module",
  "license": "MIT",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "scripts": {
    "dev": "astro dev",
    "dev:remote": "VITE_API_URL=https://api.opencode.ai astro dev",
@@ -2,7 +2,7 @@
  "name": "opencode",
  "displayName": "opencode",
  "description": "opencode for VS Code",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "publisher": "sst-dev",
  "repository": {
    "type": "git",
@@ -1,7 +1,7 @@
 {
  "$schema": "https://json.schemastore.org/package.json",
  "name": "@opencode/update",
-  "version": "2.0.4",
+  "version": "2.0.5",
  "private": true,
  "type": "module",
  "scripts": {
@@ -108,12 +108,11 @@ Set scroll speed and acceleration:

 ## Attention

-Configure notifications and sounds:
+Configure notifications and sounds. Both are off by default and can be enabled independently:

 ```json title="cli.json"
 {
  "attention": {
-    "enabled": true,
    "notifications": true,
    "sound": true,
    "volume": 0.4,
@@ -127,8 +126,7 @@ Configure notifications and sounds:

 | Field           | Values                 | Description                                                                                          |
 | --------------- | ---------------------- | ---------------------------------------------------------------------------------------------------- |
-| `enabled`       | boolean                | Enables attention alerts.                                                                            |
-| `notifications` | boolean                | Shows system notifications.                                                                          |
+| `notifications` | boolean                | Shows system notifications when the terminal is not focused.                                         |
 | `sound`         | boolean                | Plays attention sounds.                                                                              |
 | `volume`        | number from `0` to `1` | Sets sound volume.                                                                                   |
 | `sound_pack`    | string                 | Selects the active sound pack.                                                                       |
Author	SHA1	Message	Date
Aiden Cline	c635a03165	refactor(codemode): check the Headers receiver before calling the host	2026-09-16 14:16:08 -05:00
Aiden Cline	99084d8a9b	test(codemode): keep only the Headers WPT cases that exercise the runtime	2026-09-16 13:19:46 -05:00
Aiden Cline	c3d278a906	fix(codemode): let Headers methods report a bad receiver	2026-09-16 13:19:46 -05:00
Aiden Cline	e919bcc308	docs(codemode): replace the stale Values section with Extension.make	2026-09-16 13:19:46 -05:00
Aiden Cline	0880378abb	feat(codemode): add the Headers built-in	2026-09-16 13:19:46 -05:00
Shoubhit Dash	2cdd938152	fix: honor provider transport overrides and preserve errors (#49350 )	2026-09-16 22:42:23 +05:30
opencode	4d73b40e59	sync release versions for v2.0.5	2026-09-16 16:35:05 +00:00
opencode-agent[bot]andadamdotdevin	276f2eef3e	fix(stats): hide Union Alpha provider (#49355 ) Co-authored-by: adamdotdevin <2363879+adamdotdevin@users.noreply.github.com>	2026-09-16 10:58:41 -05:00
Dax Raad	8806d34ed4	feat(tui): make notification and sound alerts independent toggles Remove the attention.enabled master switch. Notifications and sounds are now enabled independently and both default to off. Existing enabled keys are ignored; there is no migration.	2026-09-16 11:39:09 -04:00
Shoubhit Dash	cda2bc5100	test(core): match the one minute Console config refresh interval (#49327 )	2026-09-16 17:37:14 +05:30