Adopt Anthropic computer and browser toolsets

docs/architecture.md

@@ -178,14 +178,15 @@ Catalog compilation composes provider behavior rather than replacing the whole
 catalog:
 
 - Ordinary function tools stay ordinary.
-- Anthropic native browser/computer declarations replace only their own
-  placeholders and merge required beta headers with caller headers.
+- Anthropic's browser/computer client-toolset declarations replace only their
+  own placeholders; their member calls and results retain `toolset_name`
+  through pi's function-tool transcript.
 - OpenAI streams through pi's builtin Responses transport and its automatic
   prompt caching by default; a Browser Loop-owned adapter handles OpenAI's native
   computer tool and tool-search namespace round-trips.
-- Anthropic's native browser tool falls back to an equivalent function-tool
-  declaration when the active credential cannot access `browser_20260701`;
-  the selected tool identity, name, schema, and executor remain unchanged.
+- Anthropic's `computer_toolset_20260801` and `browser_toolset_20260801` may be
+  selected together; calls remain separated by their computer and viewport
+  coordinate frames.
 - Google's current predefined browser toolset serializes one `computer_use`
   declaration plus exact exclusions through the Browser Loop-owned Interactions API
   adapter. Excluded calls fail with a named catalog error instead of reaching

packages/browser-loop/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+- Update Anthropic's computer and browser integrations to use the
+  `computer_toolset_20260801` and `browser_toolset_20260801` client toolsets.
+  Member calls/results preserve `toolset_name`, sequential batches stop at the
+  first failure, and both toolsets may be selected together.
 - Rename the product and unpublished package to Browser Loop: the repository is
   prepared for `kernel/browser-loop`, the package is `@onkernel/browser-loop`,
   and release tags use `browser-loop/v*`. The public `loop` namespace, `Loop*`

packages/browser-loop/README.md

@@ -318,8 +318,8 @@ function tools.
 ```ts
 const tools = [
   loop.providers.anthropic.tools.computer({
-    version: "20260701",
-    enableZoom: true,
+    version: "20260801",
+    zoom: true,
   }),
   loop.tools.browser.snapshot(),
 ];
@@ -330,9 +330,9 @@ Available groups:
 ```ts
 loop.providers.openai.tools.computer();
 
-loop.providers.anthropic.source;
-loop.providers.anthropic.tools.computer({ version: "20260701" });
-loop.providers.anthropic.tools.browser({ version: "20260701" });
+loop.providers.anthropic.sources;
+loop.providers.anthropic.tools.computer({ version: "20260801" });
+loop.providers.anthropic.tools.browser({ version: "20260801" });
 
 loop.providers.google.source;
 loop.providers.google.toolsets.browser({ exclude: ["right_click"] });
@@ -341,6 +341,16 @@ loop.providers.google.toolsets.browser({ exclude: ["right_click"] });
 loop.toolsets.browser();
 ```
 
+Anthropic's browser toolset leaves `javascript_exec` disabled unless it is
+enabled explicitly:
+
+```ts
+loop.providers.anthropic.tools.browser({
+  version: "20260801",
+  javascript: true,
+});
+```
+
 The Google browser set exposes the current predefined action names and uses
 normalized coordinates in `[0, 999]`. Its native `computer_use` declaration
 excludes every unselected browser action. If Google emits an excluded name
@@ -357,11 +367,12 @@ than on the wire. [Models and native surfaces](docs/supported-models.md) lists
 which models carry which surface.
 
 Provider-native caller-visible names are fixed by protocol. Version/tool/model
-mismatches fail during catalog compilation. If an Anthropic credential cannot
-access `browser_20260701`, Browser Loop retries with an equivalent `browser` function
-tool and remembers that choice for the credential and process. Every
-`loop.providers.*` tool surface exposes its first-party `source` (or versioned
-`sources`), and every returned provider spec carries the applicable URL.
+mismatches fail during catalog compilation. Anthropic's
+`computer_toolset_20260801` and `browser_toolset_20260801` declarations may be
+selected together; Browser Loop preserves member `toolset_name` fields and
+sequential batch semantics across pi's transcript.
+Every `loop.providers.*` tool surface exposes its first-party `source` or
+`sources`, and every returned provider spec carries the applicable URL.
 
 ## Catalog compilation
 
@@ -434,8 +445,8 @@ require different transports fails to compile.
   `openai-computer-use` api instead, which a Browser Loop adapter handles; that same
   adapter also covers tool-search namespace round-trips regardless of api,
   since pi's builtin transport does not replay them.
-- **Anthropic**: exact native declarations, beta-header composition, and
-  adaptive model preparation. No api fork — every Anthropic model streams
+- **Anthropic**: client-toolset declarations, member/result transcript
+  adaptation, and adaptive model preparation. Every Anthropic model streams
   through pi's builtin transport.
 - **Google**: a model selected without Google's native browser toolset streams
   through pi's builtin transport. Selecting

packages/browser-loop/docs/supported-models.md

@@ -22,8 +22,7 @@ models and need their own entry. Each cites first-party documentation.
 
 | provider | models | surfaces |
 | --- | --- | --- |
-| `anthropic` | `claude-opus-4-8`, `claude-opus-5`, `claude-sonnet-5` families | computer, browser |
-| `anthropic` | `claude-fable-5` family | computer |
+| `anthropic` | `claude-fable-5`, `claude-mythos-5`, `claude-opus-4-8`, `claude-opus-5`, `claude-sonnet-5` families | computer, browser |
 | `openai` | `gpt-5.6-sol`, `gpt-5.4`, `gpt-5.4-mini`, `gpt-5.5` | computer |
 | `google` | `gemini-3.6-flash`, `gemini-3.5-flash`, `gemini-3.5-flash-lite`, `gemini-2.5-computer-use-preview-10-2025` | browser |
 
@@ -93,9 +92,9 @@ npx tsx packages/browser-loop/scripts/native-action-probe.ts --provider openai -
 
 Update that provider's adapter under `src/pi/providers/` to execute the actions the
 probe returns, then add or adjust the `COMPUTER_USE_NATIVE_SURFACES` entry, citing the
-provider's documentation. Anthropic's computer tool version and its
-`computer-use-*` beta header are chosen by pi-ai per model, so a new dated
-version there usually means bumping pi-ai rather than editing this package.
+provider's documentation. Anthropic's client toolsets are adapted in
+`src/pi/providers/anthropic/toolsets.ts`; a new dated toolset version requires
+updating its declarations and member transcript adapter together.
 
 **A model rejects a tool Browser Loop sends.** Add a `LOOP_MODEL_QUIRKS` entry with the
 observed error as its `reason`, scoped as narrowly as the evidence supports: a

packages/browser-loop/examples/anthropic-native-smoke.ts

@@ -16,8 +16,8 @@ const CONFIGS: Record<string, readonly LoopAgentTool[]> = {
 	computer: loop.toolsets.computer(),
 	browser: loop.toolsets.browser(),
 	mixed: loop.toolsets.mixed(),
-	"native-computer": [loop.providers.anthropic.tools.computer({ version: "20260701", enableZoom: true })],
-	"native-browser": [loop.providers.anthropic.tools.browser({ version: "20260701" })],
+	"native-computer": [loop.providers.anthropic.tools.computer({ version: "20260801", zoom: true })],
+	"native-browser": [loop.providers.anthropic.tools.browser({ version: "20260801" })],
 };
 
 const PROMPT = [

packages/browser-loop/examples/shared/tools.ts

@@ -24,7 +24,7 @@ export function toolsForModel(model: LoopModelRef): LoopAgentTool[] {
 			// Claude 5 can use Anthropic's native browser tool; older models use portable
 			// Loop tools plus the explicit semantic action-plan surface.
 			return loop.providers.anthropic.supports.browser(modelId)
-				? [loop.providers.anthropic.tools.browser({ version: "20260701", javascript: true })]
+				? [loop.providers.anthropic.tools.browser({ version: "20260801", javascript: true })]
 				: structuredBrowserTools();
 		case "google":
 			// Current Gemini computer-use models expect Google's predefined browser actions.

packages/browser-loop/src/core/actions/browser.ts

@@ -23,15 +23,20 @@ export const BROWSER_ACTION_TYPES = [
 	"browser_find",
 	"browser_click",
 	"browser_hover",
+	"browser_mouse_down",
+	"browser_mouse_up",
 	"browser_drag",
 	"browser_fill",
 	"browser_scroll_to",
 	"browser_scroll",
 	"browser_type",
 	"browser_key",
+	"browser_hold_key",
 	"browser_navigate",
 	"browser_list_tabs",
 	"browser_new_tab",
+	"browser_switch_tab",
+	"browser_close_tab",
 	"browser_screenshot",
 	"browser_evaluate",
 ] as const;
@@ -138,6 +143,20 @@ export interface BrowserActionHover {
 	tab_id?: string;
 }
 
+export interface BrowserActionMouseDown {
+	type: "browser_mouse_down";
+	x: number;
+	y: number;
+	tab_id?: string;
+}
+
+export interface BrowserActionMouseUp {
+	type: "browser_mouse_up";
+	x: number;
+	y: number;
+	tab_id?: string;
+}
+
 export interface BrowserActionDrag {
 	type: "browser_drag";
 	from: { x: number; y: number };
@@ -180,9 +199,16 @@ export interface BrowserActionKey {
 	tab_id?: string;
 }
 
+export interface BrowserActionHoldKey {
+	type: "browser_hold_key";
+	text: string;
+	duration: number;
+	tab_id?: string;
+}
+
 export interface BrowserActionNavigate {
 	type: "browser_navigate";
-	/** A URL, or the sentinels "back" / "forward" for history navigation. */
+	/** A URL, or the sentinels "back", "forward", or "reload". */
 	url: string;
 	tab_id?: string;
 }
@@ -195,6 +221,16 @@ export interface BrowserActionNewTab {
 	type: "browser_new_tab";
 }
 
+export interface BrowserActionSwitchTab {
+	type: "browser_switch_tab";
+	tab_id: string;
+}
+
+export interface BrowserActionCloseTab {
+	type: "browser_close_tab";
+	tab_id: string;
+}
+
 export interface BrowserActionScreenshot {
 	type: "browser_screenshot";
 	/** Optional crop region, [x0, y0, x1, y1] in viewport pixels. */
@@ -216,15 +252,20 @@ export type BrowserAction =
 	| BrowserActionFind
 	| BrowserActionClick
 	| BrowserActionHover
+	| BrowserActionMouseDown
+	| BrowserActionMouseUp
 	| BrowserActionDrag
 	| BrowserActionFill
 	| BrowserActionScrollTo
 	| BrowserActionScroll
 	| BrowserActionTypeText
 	| BrowserActionKey
+	| BrowserActionHoldKey
 	| BrowserActionNavigate
 	| BrowserActionListTabs
 	| BrowserActionNewTab
+	| BrowserActionSwitchTab
+	| BrowserActionCloseTab
 	| BrowserActionScreenshot
 	| BrowserActionEvaluate;
 
@@ -403,6 +444,14 @@ export function createBrowserActionSchemaByType(options: BrowserActionSchemaOpti
 			},
 			{ additionalProperties: false },
 		),
+		browser_mouse_down: Type.Object(
+			{ type: Type.Literal("browser_mouse_down"), x: Type.Number(), y: Type.Number(), tab_id: TabId() },
+			{ additionalProperties: false },
+		),
+		browser_mouse_up: Type.Object(
+			{ type: Type.Literal("browser_mouse_up"), x: Type.Number(), y: Type.Number(), tab_id: TabId() },
+			{ additionalProperties: false },
+		),
 		browser_drag: Type.Object(
 			{
 				type: Type.Literal("browser_drag"),
@@ -459,16 +508,33 @@ export function createBrowserActionSchemaByType(options: BrowserActionSchemaOpti
 			},
 			{ additionalProperties: false },
 		),
+		browser_hold_key: Type.Object(
+			{
+				type: Type.Literal("browser_hold_key"),
+				text: Type.String({ description: "Key or chord to hold." }),
+				duration: Type.Number({ minimum: 0, maximum: 30 }),
+				tab_id: TabId(),
+			},
+			{ additionalProperties: false },
+		),
 		browser_navigate: Type.Object(
 			{
 				type: Type.Literal("browser_navigate"),
-				url: Type.String({ description: "URL to navigate to, or \"back\" / \"forward\" for history navigation." }),
+				url: Type.String({ description: "URL to navigate to, or \"back\", \"forward\", or \"reload\"." }),
 				tab_id: TabId(),
 			},
 			{ additionalProperties: false },
 		),
 		browser_list_tabs: Type.Object({ type: Type.Literal("browser_list_tabs") }, { additionalProperties: false }),
 		browser_new_tab: Type.Object({ type: Type.Literal("browser_new_tab") }, { additionalProperties: false }),
+		browser_switch_tab: Type.Object(
+			{ type: Type.Literal("browser_switch_tab"), tab_id: Type.String() },
+			{ additionalProperties: false },
+		),
+		browser_close_tab: Type.Object(
+			{ type: Type.Literal("browser_close_tab"), tab_id: Type.String() },
+			{ additionalProperties: false },
+		),
 		browser_screenshot: Type.Object(
 			{
 				type: Type.Literal("browser_screenshot"),

packages/browser-loop/src/core/anthropic-native.ts

@@ -14,7 +14,7 @@ function asNativeInput(args: unknown): NativeInput {
 
 const MAX_KEY_REPEAT = 100;
 
-/** Map one `computer_20260701` tool input onto canonical computer-plane actions. */
+/** Map one Anthropic computer toolset member onto canonical computer-plane actions. */
 export function mapNativeComputerInput(input: NativeInput): ComputerUseAction[] {
 	switch (input.action) {
 		case "screenshot":
@@ -52,19 +52,19 @@ export function mapNativeComputerInput(input: NativeInput): ComputerUseAction[]
 		}
 		case "hold_key":
 			// Canonical keypress duration is milliseconds; the native tool speaks seconds.
-			return [{ type: "keypress", keys: [text(input)], duration: durationSeconds(input) * 1000 }];
+			return [{ type: "keypress", keys: [text(input)], duration: durationSeconds(input, 300) * 1000 }];
 		case "wait":
-			return [{ type: "wait", ms: durationSeconds(input) * 1000 }];
+			return [{ type: "wait", ms: durationSeconds(input, 300) * 1000 }];
 		case "cursor_position":
 			return [{ type: "cursor_position" }];
 		case "zoom":
 			return [{ type: "zoom", region: region(input.region) }];
 		default:
-			throw new Error(`unsupported computer_20260701 action "${input.action}"`);
+			throw new Error(`unsupported computer toolset member "${input.action}"`);
 	}
 }
 
-/** Map one `browser_20260701` tool input onto canonical browser-plane actions. */
+/** Map one Anthropic browser toolset member onto canonical browser-plane actions. */
 export function mapNativeBrowserInput(input: NativeInput): ComputerUseAction[] {
 	const tab = tabId(input);
 	switch (input.action) {
@@ -100,12 +100,20 @@ export function mapNativeBrowserInput(input: NativeInput): ComputerUseAction[] {
 			return [{ type: "browser_click", ...pageTarget(input.target), ...modifiers(input.modifiers), ...tab }];
 		case "right_click":
 			return [{ type: "browser_click", ...pageTarget(input.target), button: "right", ...modifiers(input.modifiers), ...tab }];
+		case "middle_click":
+			return [{ type: "browser_click", ...pageTarget(input.target), button: "middle", ...modifiers(input.modifiers), ...tab }];
 		case "double_click":
 			return [{ type: "browser_click", ...pageTarget(input.target), num_clicks: 2, ...modifiers(input.modifiers), ...tab }];
 		case "triple_click":
 			return [{ type: "browser_click", ...pageTarget(input.target), num_clicks: 3, ...modifiers(input.modifiers), ...tab }];
 		case "hover":
 			return [{ type: "browser_hover", ...pageTarget(input.target), ...tab }];
+		case "mouse_move":
+			return [{ type: "browser_hover", ...coordinateTarget(input.target, "target"), ...tab }];
+		case "left_mouse_down":
+			return [{ type: "browser_mouse_down", ...coordinateTarget(input.target, "target"), ...tab }];
+		case "left_mouse_up":
+			return [{ type: "browser_mouse_up", ...coordinateTarget(input.target, "target"), ...tab }];
 		case "left_click_drag":
 			return [{ type: "browser_drag", from: coordinateTarget(input.from, "from"), to: coordinateTarget(input.target, "target"), ...tab }];
 		case "scroll":
@@ -124,12 +132,18 @@ export function mapNativeBrowserInput(input: NativeInput): ComputerUseAction[] {
 			const repeat = clampRepeat(input.repeat);
 			return Array.from({ length: repeat }, () => ({ type: "browser_key" as const, text: text(input), ...tab }));
 		}
+		case "hold_key":
+			return [{ type: "browser_hold_key", text: text(input), duration: durationSeconds(input, 30), ...tab }];
 		case "wait":
-			return [{ type: "wait", ms: durationSeconds(input) * 1000 }];
+			return [{ type: "wait", ms: durationSeconds(input, 30) * 1000 }];
+		case "switch_tab":
+			return [{ type: "browser_switch_tab", tab_id: requireString(input.tab_id, "tab_id") }];
+		case "close_tab":
+			return [{ type: "browser_close_tab", tab_id: requireString(input.tab_id, "tab_id") }];
 		case "javascript_exec":
 			return [{ type: "browser_evaluate", code: text(input), ...tab }];
 		default:
-			throw new Error(`unsupported browser_20260701 action "${input.action}"`);
+			throw new Error(`unsupported browser toolset member "${input.action}"`);
 	}
 }
 
@@ -191,10 +205,10 @@ function requireString(value: unknown, field: string): string {
 	return value;
 }
 
-function durationSeconds(input: NativeInput): number {
+function durationSeconds(input: NativeInput, maximum: number): number {
 	const value = input.duration;
 	if (typeof value !== "number" || !Number.isFinite(value) || value < 0) throw new Error("invalid duration: expected a non-negative number");
-	return Math.min(value, 100);
+	return Math.min(value, maximum);
 }
 
 function clampRepeat(value: unknown): number {