Remove origin-keyed agent cluster requirement and update WPT

README.md

@@ -15,7 +15,7 @@ Then install the checkout in your app with `pnpm add /path/to/webmcp-polyfill`.
 
 ## Usage
 
-Use HTTPS or localhost. Some browsers need an `Origin-Agent-Cluster: ?1` header; current Chrome enables origin keying by default.
+Use HTTPS or localhost.
 
 Load the polyfill before registering tools:
 
@@ -75,8 +75,6 @@ import "webmcp-polyfill/auto";
 
 Next.js runs [client instrumentation](https://nextjs.org/docs/app/api-reference/file-conventions/instrumentation-client) before hydration. A Server Component import alone won't install the polyfill in the browser.
 
-Configure `Origin-Agent-Cluster` through Next.js [`headers()`](https://nextjs.org/docs/app/api-reference/config/next-config-js/headers) if your browser needs it.
-
 Both entry points are SSR-safe: installation does nothing without a document. Your pages can stay server-rendered; WebMCP runs in the browser.
 
 The package needs no `"use client"` directive. Use it on your [Client Components](https://nextjs.org/docs/app/api-reference/directives/use-client) and access `document.modelContext` in effects or event handlers. Pass an `AbortSignal` when registering in an effect, then abort it during cleanup.

TESTING.md

@@ -2,28 +2,29 @@
 
 ## Results
 
-**226 browser tests pass** across Chromium 153.0.8010.12, Firefox 155.0, and
+**223 browser tests pass** across Chromium 153.0.8010.12, Firefox 155.0, and
 Playwright WebKit 26.6. Package checks also pass: imports, types, SSR, and tarball contents.
 CI runs these checks plus WPT in Chrome, Firefox, and actual Safari. Safari runs on
 `macos-26`; Playwright WebKit is a separate build.
 
-WPT covers **all 67 WebMCP testharness files, 161 subtests**, with zero unexpected results:
+WPT covers **all 70 WebMCP testharness files, 190 subtests**, with zero unexpected results
+in Chrome and Firefox:
 
-| Subtest result | Chrome / Firefox | Safari |
-| --- | ---: | ---: |
-| PASS | 96 | 92 |
-| Expected FAIL | 23 | 27 |
-| Expected TIMEOUT | 24 | 24 |
-| Expected NOTRUN | 18 | 18 |
+| Subtest result | Count |
+| --- | ---: |
+| PASS | 92 |
+| Expected FAIL | 52 |
+| Expected TIMEOUT | 26 |
+| Expected NOTRUN | 20 |
 
-Tested with Chrome Canary 156.0.8068.0, Firefox Nightly 158.0a1 (20260922211342),
-Firefox 142.0.1, and Safari 26.6.2 (21624.5.1.11.3) on macOS 26.6.2.
-At the file level: 42 OK, 24 expected timeouts, one expected error.
+Tested with Chrome Canary 157.0.8080.0 and Firefox Nightly 159.0a1 (20260930214513).
+Safari has not yet run at this pin; none of the expectations are browser-specific.
+At the file level: 43 OK, 26 expected timeouts, one expected error.
 
 Expected failures are still failures. `NOTRUN` means an earlier timeout prevented
 the test from running, including three abort cases. Passing declarative checks only
-cover rejection or absence of tools. All 22 pinned IDL checks pass, but that IDL
-predates `debugging` and lifecycle events. This is not full conformance.
+cover rejection or absence of tools. Of the 38 pinned IDL checks, the 16 for lifecycle
+event handlers and interfaces fail. This is not full conformance.
 
 ## Run locally
 
@@ -41,7 +42,7 @@ native WebMCP. A separate Chromium test uses `--enable-features=WebMCP` to check
 that loading the polyfill preserves the native context and its tools.
 
 WPT needs Python 3.11+ and a clean checkout at
-[`2699eaa`](https://github.com/web-platform-tests/wpt/commit/2699eaa2e5f906eda4d7443f7080c3de19e62365).
+[`fe52996`](https://github.com/web-platform-tests/wpt/commit/fe52996d4465f23617bce91927bdd58e6ce8f541).
 The [CI workflow](.github/workflows/test.yml) has the sparse-checkout and dependency setup.
 
 ```sh
@@ -50,10 +51,7 @@ WPT_ROOT=../wpt WPT_BROWSER=firefox pnpm test:wpt
 WPT_ROOT=../wpt WPT_BROWSER=safari pnpm test:wpt
 ```
 
-Firefox downloads Nightly unless `FIREFOX_BIN` is set. The runner enables
-`dom.origin_agent_cluster.default` in the test profile because the pinned pages
-assume origin keying without a header; [Firefox defaults to site keying](https://github.com/mozilla-firefox/firefox/blob/FIREFOX_142_0_1_RELEASE/modules/libpref/init/StaticPrefList.yaml#L5768-L5773).
-Local fixtures test explicit `Origin-Agent-Cluster` headers.
+Firefox downloads Nightly unless `FIREFOX_BIN` is set.
 Safari requires macOS, [Remote Automation, and WPT hosts-file setup](https://web-platform-tests.org/running-tests/safari.html).
 
 Set `WPT_PYTHON` or `WPT_VENV` to use an existing Python environment. Extra arguments
@@ -67,23 +65,18 @@ other non-testharness files are outside this suite.
 
 ## Draft alignment and limitations
 
-Checked against [draft `f5645e9`](https://github.com/webmachinelearning/webmcp/blob/f5645e9aea51eb589599f181d104a2f49430608e/index.bs)
+Checked against [draft `d61d0e6`](https://github.com/webmachinelearning/webmcp/blob/d61d0e6d297ddb6bff3510b1330dbb215c6ef43c/index.bs)
 and `webmcp-types@0.1.9`.
 
-- **Missing APIs:** declarative forms, CSS states, and lifecycle events are not
-  implemented. This includes both the draft's `ModelContext` events and the older
-  `window` events WPT expects.
+- **Missing APIs:** declarative forms, CSS states, and lifecycle events
+  (`toolactivated`/`toolcancel`, their handlers, and `ToolActivatedEvent`/`ToolCancelEvent`)
+  are not implemented.
 - **Draft differences:** results are JSON-serialized; some pinned tests expect raw
-  strings. Omitted or `undefined` input becomes `{}`, matching the types and pinned
-  IDL rather than the recorded draft. `null` and primitives reject.
+  strings. Omitted or `undefined` input becomes `{}`; `null` and primitives reject.
 - **Timing:** MessagePorts approximate native task ordering. Aborting before
   dispatch skips the callback; the draft dispatches and then aborts its signal.
   Delegated permission checks are asynchronous, so argument errors can precede
   `NotAllowedError`.
-- **Safari:** the tested version lacks `originAgentCluster`, so the polyfill skips
-  that check. Four WPT assertions fail with `NotAllowedError` instead of
-  `SecurityError`. [WebKit's implementation](https://github.com/WebKit/WebKit/pull/66162)
-  landed behind a flag.
 - **Frames:** each participating document must load the polyfill. Native contexts
   and WPT's uninstrumented blank helper documents cannot answer its messages.
   Opaque-origin handshakes and inaccessible cross-origin shadow frames are

src/index.ts

@@ -607,9 +607,6 @@ function requireActiveWindow(owner: Document): Window {
   if (!view) {
     throw new NativeDOMException("The document is not fully active", "InvalidStateError");
   }
-  if (view.originAgentCluster === false && view.location.protocol !== "file:") {
-    throw new NativeDOMException("An origin-keyed agent cluster is required", "SecurityError");
-  }
 
   // Synchronous where the browser exposes the policy; FrameBridge.allowed() covers the rest.
   if (readToolsPolicy(owner) === false) {

tests/fixtures/server.ts

@@ -45,7 +45,6 @@ const frameHtml = '<!doctype html><title>WebMCP frame</title><script src="/auto.
 const pages: Record<string, string> = {
   "/": blankHtml,
   "/health": blankHtml,
-  "/no-cluster": blankHtml,
   "/app": appHtml,
   "/frame": frameHtml,
   "/startup": startupHtml,
@@ -54,7 +53,6 @@ const pages: Record<string, string> = {
 
 createServer(async (request, response) => {
   const path = new URL(request.url ?? "/", "http://localhost").pathname;
-  response.setHeader("Origin-Agent-Cluster", path === "/no-cluster" ? "?0" : "?1");
   response.setHeader("Cache-Control", "no-store");
   const page = pages[path];
 

tests/index.test.ts

@@ -41,39 +41,6 @@ test("operations reject invalid receivers before reading arguments", async ({ pa
   expect(outcome).toEqual({ reads: 0, errors: Array(12).fill("TypeError") });
 });
 
-test("every operation rejects when the server opts out of origin-keyed agent clustering", async ({
-  page,
-}) => {
-  await page.goto("http://127.0.0.1:8793/no-cluster");
-  await page.addScriptTag({ url: "/auto.js" });
-  const outcome = await page.evaluate(async () => {
-    const context = document.modelContext!;
-    const errors = [];
-    for (const operation of [
-      () => context.getTools(),
-      () => context.registerTool({ name: "x", description: "X", execute: () => null }),
-      () =>
-        context.executeTool(
-          { name: "x", title: "", description: "X", window, origin: location.origin },
-          {},
-        ),
-    ]) {
-      try {
-        await operation();
-        errors.push("resolved");
-      } catch (error) {
-        if (!(error instanceof Error)) {
-          throw error;
-        }
-        errors.push(error.name);
-      }
-    }
-    return errors;
-  });
-
-  expect(outcome).toEqual(["SecurityError", "SecurityError", "SecurityError"]);
-});
-
 test("origin filters accept only potentially trustworthy origins", async ({ page }) => {
   await page.addScriptTag({ url: "/auto.js" });
   const outcome = await page.evaluate(async () => {

wpt/metadata/webmcp/declarative/executeTool-detach-toolactivated.https.html.ini

@@ -0,0 +1,5 @@
+# Declarative form registration is unsupported; waitForTool() never resolves.
+[executeTool-detach-toolactivated.https.html]
+  expected: TIMEOUT
+  [toolactivated is not dispatched when filling out a declarative tool form detaches the tool document]
+    expected: TIMEOUT

wpt/metadata/webmcp/idlharness.https.window.js.ini

@@ -0,0 +1,35 @@
+# Lifecycle events are unsupported: ModelContext has no ontoolactivated/ontoolcancel
+# handlers, and ToolActivatedEvent/ToolCancelEvent are not defined.
+[idlharness.https.window.html]
+  [ModelContext interface: attribute ontoolactivated]
+    expected: FAIL
+  [ModelContext interface: attribute ontoolcancel]
+    expected: FAIL
+  [ToolActivatedEvent interface: existence and properties of interface object]
+    expected: FAIL
+  [ToolActivatedEvent interface object length]
+    expected: FAIL
+  [ToolActivatedEvent interface object name]
+    expected: FAIL
+  [ToolActivatedEvent interface: existence and properties of interface prototype object]
+    expected: FAIL
+  [ToolActivatedEvent interface: existence and properties of interface prototype object's "constructor" property]
+    expected: FAIL
+  [ToolActivatedEvent interface: existence and properties of interface prototype object's @@unscopables property]
+    expected: FAIL
+  [ToolActivatedEvent interface: attribute toolName]
+    expected: FAIL
+  [ToolCancelEvent interface: existence and properties of interface object]
+    expected: FAIL
+  [ToolCancelEvent interface object length]
+    expected: FAIL
+  [ToolCancelEvent interface object name]
+    expected: FAIL
+  [ToolCancelEvent interface: existence and properties of interface prototype object]
+    expected: FAIL
+  [ToolCancelEvent interface: existence and properties of interface prototype object's "constructor" property]
+    expected: FAIL
+  [ToolCancelEvent interface: existence and properties of interface prototype object's @@unscopables property]
+    expected: FAIL
+  [ToolCancelEvent interface: attribute toolName]
+    expected: FAIL

wpt/metadata/webmcp/imperative/executeTool-detach-toolactivated.https.html.ini

@@ -0,0 +1,7 @@
+# WPT injection does not install the polyfill in /common/blank.html helper frames, so
+# their document.modelContext is undefined.
+[executeTool-detach-toolactivated.https.html]
+  [toolactivated is not dispatched when a tool execute callback from another realm detaches the tool document]
+    expected: FAIL
+  [toolactivated is not dispatched when a tool execute callback detaches its own document]
+    expected: FAIL

wpt/metadata/webmcp/imperative/executeTool-detach-toolcancel.https.html.ini

@@ -0,0 +1,7 @@
+# WPT injection does not install the polyfill in /common/blank.html helper frames, so
+# their document.modelContext is undefined.
+[executeTool-detach-toolcancel.https.html]
+  [toolcancel is not dispatched when a tool abort handler from another realm detaches the tool document]
+    expected: FAIL
+  [toolcancel is not dispatched when a tool abort handler detaches its own document]
+    expected: FAIL

wpt/metadata/webmcp/imperative/executeTool-events.https.html.ini

@@ -1,6 +1,10 @@
-# Lifecycle events are unsupported. This test waits for window events; the current
-# draft places toolactivated/toolcancel on ModelContext.
+# Lifecycle events are unsupported. The first case waits for a toolactivated event
+# that is never dispatched, so the later cases do not run.
 [executeTool-events.https.html]
   expected: TIMEOUT
-  [toolactivated and toolcancel events are dispatched on window during tool execution and cancellation]
+  [toolactivated and toolcancel events are dispatched on document.modelContext during tool execution and cancellation]
     expected: TIMEOUT
+  [toolactivated is dispatched at the ModelContext of the tool target document]
+    expected: NOTRUN
+  [toolcancel is dispatched at the ModelContext of the tool target document]
+    expected: NOTRUN

wpt/metadata/webmcp/imperative/executeTool-target-detachment.https.html.ini

@@ -1,4 +1,10 @@
-# The draft rejects a removed target with UnknownError; the test expects InvalidStateError.
+# The draft rejects a removed target with UnknownError; the first case expects
+# InvalidStateError. The last two cases register in /common/blank.html helper frames,
+# where WPT injection does not install the polyfill.
 [executeTool-target-detachment.https.html]
   [executeTool() rejects when target frame is detached before execution]
     expected: FAIL
+  [executeTool() rejects cleanly when tool callback synchronously detaches its own frame]
+    expected: FAIL
+  [executeTool() abort cleanly handles synchronous frame detachment inside options.signal abort listener]
+    expected: FAIL

wpt/metadata/webmcp/tool-activated-event.https.html.ini

@@ -0,0 +1,11 @@
+# Lifecycle events are unsupported: ToolActivatedEvent is not defined and executeTool()
+# dispatches no toolactivated event.
+[tool-activated-event.https.html]
+  [ToolActivatedEvent constructor with default event init dictionary]
+    expected: FAIL
+  [ToolActivatedEvent constructor with an event init dictionary]
+    expected: FAIL
+  [ontoolactivated is invoked for synthetic toolactivated events dispatched at ModelContext]
+    expected: FAIL
+  [ontoolactivated is invoked when a tool is activated]
+    expected: FAIL

wpt/metadata/webmcp/tool-cancel-event.https.html.ini

@@ -0,0 +1,12 @@
+# Lifecycle events are unsupported: ToolCancelEvent is not defined, and the last case
+# waits for a toolcancel event that is never dispatched.
+[tool-cancel-event.https.html]
+  expected: TIMEOUT
+  [ToolCancelEvent constructor with default event init dictionary]
+    expected: FAIL
+  [ToolCancelEvent constructor with an event init dictionary]
+    expected: FAIL
+  [ontoolcancel is invoked for synthetic toolcancel events dispatched at ModelContext]
+    expected: FAIL
+  [ontoolcancel is invoked when a tool invocation is canceled]
+    expected: TIMEOUT

wpt/revision.txt

@@ -1 +1 @@
-2699eaa2e5f906eda4d7443f7080c3de19e62365
+fe52996d4465f23617bce91927bdd58e6ce8f541

wpt/run.ts

@@ -28,7 +28,7 @@ switch (browser) {
   }
   case "firefox": {
     const binary = process.env.FIREFOX_BIN;
-    browserArguments.push("--headless", "--setpref=dom.origin_agent_cluster.default=true");
+    browserArguments.push("--headless");
     browserArguments.push(
       ...(binary
         ? ["--channel=stable", "--binary", binary]
@@ -114,11 +114,11 @@ const subtests = results.flatMap((fileResult) => fileResult.subtests);
 const uniqueFiles = new Set(results.map((fileResult) => fileResult.test));
 
 // These counts belong to the pinned revision; an incomplete run must not pass.
-assert.equal(results.length, 67, "Expected all 67 WebMCP testharness files at the pin");
+assert.equal(results.length, 70, "Expected all 70 WebMCP testharness files at the pin");
 assert.equal(uniqueFiles.size, results.length, "WPT repeated a test file");
 assert.equal(
   subtests.length,
-  161,
+  190,
   "WPT subtest count changed; inspect the report and expectations",
 );
 const statusCounts = { PASS: 0, FAIL: 0, TIMEOUT: 0, NOTRUN: 0, PRECONDITION_FAILED: 0 };