feat: add built-in browser tool

Add a first-class browser tool backed by agent-browser and enable it by default in coding sessions. Include CLI and system-prompt wiring plus focused coverage for the new tool. Co-authored-by: Codex <noreply@openai.com>
2026-04-15 07:04:45 +00:00 · 2026-03-08 12:50:02 -07:00 · 2026-03-08 12:50:02 -07:00 · 0720c47495
commit 0720c47495
parent df702d95a3
8 changed files with 797 additions and 15 deletions
--- a/packages/coding-agent/src/cli/args.ts
+++ b/packages/coding-agent/src/cli/args.ts
@ -5,7 +5,11 @@
 import type { ThinkingLevel } from "@mariozechner/pi-agent-core";
 import chalk from "chalk";
 import { APP_NAME, CONFIG_DIR_NAME, ENV_AGENT_DIR } from "../config.js";
-import { allTools, type ToolName } from "../core/tools/index.js";
+import {
+  allTools,
+  defaultCodingToolNames,
+  type ToolName,
+} from "../core/tools/index.js";

 export type Mode = "text" | "json" | "rpc";

@ -193,7 +197,11 @@ export function parseArgs(
 }

 export function printHelp(): void {
-  console.log(`${chalk.bold(APP_NAME)} - AI coding assistant with read, bash, edit, write tools
+  const defaultToolsText = defaultCodingToolNames.join(",");
+  const availableToolsText = Object.keys(allTools).join(", ");
+  const defaultToolsLabel = defaultCodingToolNames.join(", ");
+
+  console.log(`${chalk.bold(APP_NAME)} - AI coding assistant with read, bash, browser, edit, write tools

 ${chalk.bold("Usage:")}
  ${APP_NAME} [options] [@files...] [messages...]
@ -224,8 +232,8 @@ ${chalk.bold("Options:")}
  --models <patterns>            Comma-separated model patterns for Ctrl+P cycling
                                 Supports globs (anthropic/*, *sonnet*) and fuzzy matching
  --no-tools                     Disable all built-in tools
-  --tools <tools>                Comma-separated list of tools to enable (default: read,bash,edit,write)
-                                 Available: read, bash, edit, write, grep, find, ls
+  --tools <tools>                Comma-separated list of tools to enable (default: ${defaultToolsText})
+                                 Available: ${availableToolsText}
  --thinking <level>             Set thinking level: off, minimal, low, medium, high, xhigh
  --extension, -e <path>         Load an extension file (can be used multiple times)
  --no-extensions, -ne           Disable extension discovery (explicit -e paths still work)
@ -322,9 +330,10 @@ ${chalk.bold("Environment Variables:")}
  PI_SHARE_VIEWER_URL              - Base URL for /share command (default: https://pi.dev/session/)
  PI_AI_ANTIGRAVITY_VERSION        - Override Antigravity User-Agent version (e.g., 1.23.0)

-${chalk.bold("Available Tools (default: read, bash, edit, write):")}
+${chalk.bold(`Available Tools (default: ${defaultToolsLabel}):`)}
  read   - Read file contents
  bash   - Execute bash commands
+  browser - Browser automation with persistent state
  edit   - Edit files with find/replace
  write  - Write files (creates/overwrites)
  grep   - Search file contents (read-only, off by default)
--- a/packages/coding-agent/src/core/agent-session.ts
+++ b/packages/coding-agent/src/core/agent-session.ts
@ -111,7 +111,7 @@ import {
 } from "./slash-commands.js";
 import { buildSystemPrompt } from "./system-prompt.js";
 import type { BashOperations } from "./tools/bash.js";
-import { createAllTools } from "./tools/index.js";
+import { createAllTools, defaultCodingToolNames } from "./tools/index.js";

 // ============================================================================
 // Skill Block Parsing
@ -187,7 +187,7 @@ export interface AgentSessionConfig {
  customTools?: ToolDefinition[];
  /** Model registry for API key resolution and model discovery */
  modelRegistry: ModelRegistry;
-  /** Initial active built-in tool names. Default: [read, bash, edit, write] */
+  /** Initial active built-in tool names. Default: [read, bash, browser, edit, write] */
  initialActiveToolNames?: string[];
  /** Override base tools (useful for custom runtimes). */
  baseToolsOverride?: Record<string, AgentTool>;
@ -2447,7 +2447,7 @@ export class AgentSession {

    const defaultActiveToolNames = this._baseToolsOverride
      ? Object.keys(this._baseToolsOverride)
-      : ["read", "bash", "edit", "write"];
+      : defaultCodingToolNames;
    const baseActiveToolNames =
      options.activeToolNames ?? defaultActiveToolNames;
    this._refreshToolRegistry({
--- a/packages/coding-agent/src/core/sdk.ts
+++ b/packages/coding-agent/src/core/sdk.ts
@ -25,8 +25,11 @@ import { time } from "./timings.js";
 import {
  allTools,
  bashTool,
+  browserTool,
  codingTools,
+  defaultCodingToolNames,
  createBashTool,
+  createBrowserTool,
  createCodingTools,
  createEditTool,
  createFindTool,
@ -64,7 +67,7 @@ export interface CreateAgentSessionOptions {
  /** Models available for cycling (Ctrl+P in interactive mode) */
  scopedModels?: Array<{ model: Model<any>; thinkingLevel?: ThinkingLevel }>;

-  /** Built-in tools to use. Default: codingTools [read, bash, edit, write] */
+  /** Built-in tools to use. Default: codingTools [read, bash, browser, edit, write] */
  tools?: Tool[];
  /** Custom tools to register (in addition to built-in tools). */
  customTools?: ToolDefinition[];
@ -109,6 +112,7 @@ export {
  // Pre-built tools (use process.cwd())
  readTool,
  bashTool,
+  browserTool,
  editTool,
  writeTool,
  grepTool,
@ -122,6 +126,7 @@ export {
  createReadOnlyTools,
  createReadTool,
  createBashTool,
+  createBrowserTool,
  createEditTool,
  createWriteTool,
  createGrepTool,
@ -262,7 +267,7 @@ export async function createAgentSession(
    thinkingLevel = "off";
  }

-  const defaultActiveToolNames: ToolName[] = ["read", "bash", "edit", "write"];
+  const defaultActiveToolNames: ToolName[] = [...defaultCodingToolNames];
  const initialActiveToolNames: ToolName[] = options.tools
    ? options.tools
        .map((t) => t.name)
--- a/packages/coding-agent/src/core/system-prompt.ts
+++ b/packages/coding-agent/src/core/system-prompt.ts
@ -4,11 +4,14 @@

 import { getDocsPath, getReadmePath } from "../config.js";
 import { formatSkillsForPrompt, type Skill } from "./skills.js";
+import { defaultCodingToolNames } from "./tools/index.js";

 /** Tool descriptions for system prompt */
 const toolDescriptions: Record<string, string> = {
  read: "Read file contents",
  bash: "Execute bash commands (ls, grep, find, etc.)",
+  browser:
+    "Open websites, inspect pages with snapshot, click/fill/wait, take screenshots, and save/load browser state",
  edit: "Make surgical edits to files (find exact text and replace)",
  write: "Create or overwrite files",
  grep: "Search file contents for patterns (respects .gitignore)",
@ -19,7 +22,7 @@ const toolDescriptions: Record<string, string> = {
 export interface BuildSystemPromptOptions {
  /** Custom system prompt (replaces default). */
  customPrompt?: string;
-  /** Tools to include in prompt. Default: [read, bash, edit, write] */
+  /** Tools to include in prompt. Default: coding tools including browser */
  selectedTools?: string[];
  /** Optional one-line tool snippets keyed by tool name. */
  toolSnippets?: Record<string, string>;
@ -123,7 +126,7 @@ export function buildSystemPrompt(

  // Build tools list based on selected tools.
  // Built-ins use toolDescriptions. Custom tools can provide one-line snippets.
-  const tools = selectedTools || ["read", "bash", "edit", "write"];
+  const tools = selectedTools ?? defaultCodingToolNames;
  const toolsList =
    tools.length > 0
      ? tools
@ -147,6 +150,7 @@ export function buildSystemPrompt(
  };

  const hasBash = tools.includes("bash");
+  const hasBrowser = tools.includes("browser");
  const hasEdit = tools.includes("edit");
  const hasWrite = tools.includes("write");
  const hasGrep = tools.includes("grep");
@ -180,6 +184,12 @@ export function buildSystemPrompt(
    addGuideline("Use write only for new files or complete rewrites");
  }

+  if (hasBrowser) {
+    addGuideline(
+      "Use browser for website tasks. Open the page, use snapshot to inspect interactive elements, then click, fill, wait, or screenshot as needed",
+    );
+  }
+
  // Output guideline (only when actually writing or executing)
  if (hasEdit || hasWrite) {
    addGuideline(
--- a/packages/coding-agent/src/core/tools/browser.ts
+++ b/packages/coding-agent/src/core/tools/browser.ts
@ -0,0 +1,505 @@
+import { spawn } from "node:child_process";
+import { randomBytes } from "node:crypto";
+import { existsSync, mkdirSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join, resolve } from "node:path";
+import type { AgentTool } from "@mariozechner/pi-agent-core";
+import { type Static, Type } from "@sinclair/typebox";
+import { getAgentDir } from "../../config.js";
+import { getShellEnv, killProcessTree, sanitizeBinaryOutput } from "../../utils/shell.js";
+
+const browserActions = [
+	"open",
+	"snapshot",
+	"click",
+	"fill",
+	"wait",
+	"screenshot",
+	"state_save",
+	"state_load",
+	"close",
+] as const;
+
+const browserSnapshotModes = ["interactive", "full"] as const;
+const browserLoadStates = ["load", "domcontentloaded", "networkidle"] as const;
+
+const DEFAULT_BROWSER_COMMAND = process.env.PI_AGENT_BROWSER_COMMAND || "agent-browser";
+const DEFAULT_BROWSER_TIMEOUT_SECONDS = 90;
+
+const browserSchema = Type.Object({
+	action: Type.Union(
+		browserActions.map((action) => Type.Literal(action)),
+		{ description: "Browser action to execute" },
+	),
+	url: Type.Optional(Type.String({ description: "URL to open, or URL glob to wait for" })),
+	mode: Type.Optional(
+		Type.Union(
+			browserSnapshotModes.map((mode) => Type.Literal(mode)),
+			{ description: "Snapshot mode. Defaults to interactive." },
+		),
+	),
+	ref: Type.Optional(
+		Type.String({
+			description: "Element ref from snapshot output, such as @e2",
+		}),
+	),
+	value: Type.Optional(Type.String({ description: "Text value to fill into a field" })),
+	text: Type.Optional(Type.String({ description: "Visible text to wait for" })),
+	ms: Type.Optional(
+		Type.Number({
+			description: "Milliseconds to wait",
+			minimum: 0,
+		}),
+	),
+	loadState: Type.Optional(
+		Type.Union(
+			browserLoadStates.map((state) => Type.Literal(state)),
+			{ description: "Page load state to wait for" },
+		),
+	),
+	path: Type.Optional(
+		Type.String({
+			description: "Output path for screenshots, relative to the current working directory if not absolute",
+		}),
+	),
+	fullPage: Type.Optional(Type.Boolean({ description: "Capture a full-page screenshot" })),
+	stateName: Type.Optional(
+		Type.String({
+			description: "Named browser state checkpoint stored under ~/.pi/agent/browser/states/",
+		}),
+	),
+});
+
+export type BrowserToolAction = (typeof browserActions)[number];
+export type BrowserSnapshotMode = (typeof browserSnapshotModes)[number];
+export type BrowserLoadState = (typeof browserLoadStates)[number];
+export type BrowserToolInput = Static<typeof browserSchema>;
+
+export interface BrowserToolDetails {
+	action: BrowserToolAction;
+	command: string;
+	args: string[];
+	profilePath: string;
+	screenshotPath?: string;
+	statePath?: string;
+}
+
+export interface BrowserOperations {
+	exec: (
+		command: string,
+		args: string[],
+		options: {
+			cwd: string;
+			env: NodeJS.ProcessEnv;
+			onData: (data: Buffer) => void;
+			signal?: AbortSignal;
+			timeout?: number;
+		},
+	) => Promise<{ exitCode: number | null }>;
+}
+
+const defaultBrowserOperations: BrowserOperations = {
+	exec: (command, args, { cwd, env, onData, signal, timeout }) => {
+		return new Promise((resolvePromise, rejectPromise) => {
+			const child = spawn(command, args, {
+				cwd,
+				detached: true,
+				env,
+				stdio: ["ignore", "pipe", "pipe"],
+			});
+
+			let timedOut = false;
+			let timeoutHandle: NodeJS.Timeout | undefined;
+
+			if (timeout !== undefined && timeout > 0) {
+				timeoutHandle = setTimeout(() => {
+					timedOut = true;
+					if (child.pid) {
+						killProcessTree(child.pid);
+					}
+				}, timeout * 1000);
+			}
+
+			if (child.stdout) {
+				child.stdout.on("data", onData);
+			}
+			if (child.stderr) {
+				child.stderr.on("data", onData);
+			}
+
+			const onAbort = () => {
+				if (child.pid) {
+					killProcessTree(child.pid);
+				}
+			};
+
+			if (signal) {
+				if (signal.aborted) {
+					onAbort();
+				} else {
+					signal.addEventListener("abort", onAbort, { once: true });
+				}
+			}
+
+			child.on("error", (error) => {
+				if (timeoutHandle) clearTimeout(timeoutHandle);
+				if (signal) signal.removeEventListener("abort", onAbort);
+				rejectPromise(error);
+			});
+
+			child.on("close", (code) => {
+				if (timeoutHandle) clearTimeout(timeoutHandle);
+				if (signal) signal.removeEventListener("abort", onAbort);
+
+				if (signal?.aborted) {
+					rejectPromise(new Error("aborted"));
+					return;
+				}
+
+				if (timedOut) {
+					rejectPromise(new Error(`timeout:${timeout}`));
+					return;
+				}
+
+				resolvePromise({ exitCode: code });
+			});
+		});
+	},
+};
+
+export interface BrowserToolOptions {
+	operations?: BrowserOperations;
+	command?: string;
+	defaultTimeoutSeconds?: number;
+	profileDir?: string;
+	stateDir?: string;
+	agentDir?: string;
+}
+
+interface BrowserCommandContext {
+	action: BrowserToolAction;
+	args: string[];
+	statusMessage: string;
+	successMessage: string;
+	profilePath: string;
+	screenshotPath?: string;
+	statePath?: string;
+}
+
+function resolveCommandPath(cwd: string, inputPath: string): string {
+	return resolve(cwd, inputPath);
+}
+
+function getBrowserRootDir(options?: BrowserToolOptions): string {
+	const baseAgentDir = options?.agentDir ?? getAgentDir();
+	return join(baseAgentDir, "browser");
+}
+
+function getBrowserProfilePath(cwd: string, options?: BrowserToolOptions): string {
+	const profilePath = options?.profileDir ?? join(getBrowserRootDir(options), "profile");
+	return resolveCommandPath(cwd, profilePath);
+}
+
+function getBrowserStateDir(cwd: string, options?: BrowserToolOptions): string {
+	const stateDir = options?.stateDir ?? join(getBrowserRootDir(options), "states");
+	return resolveCommandPath(cwd, stateDir);
+}
+
+function createTempScreenshotPath(): string {
+	const id = randomBytes(8).toString("hex");
+	return join(tmpdir(), `pi-browser-screenshot-${id}.png`);
+}
+
+function normalizeOutput(chunks: Buffer[]): string {
+	return sanitizeBinaryOutput(Buffer.concat(chunks).toString("utf-8")).trim();
+}
+
+function sanitizeStateName(stateName: string): string {
+	const trimmed = stateName.trim();
+	if (trimmed.length === 0) {
+		throw new Error("stateName is required for browser state actions");
+	}
+
+	const withoutJsonSuffix = trimmed.endsWith(".json") ? trimmed.slice(0, -".json".length) : trimmed;
+	const sanitized = withoutJsonSuffix.replace(/[^a-zA-Z0-9._-]+/g, "-").replace(/^-+|-+$/g, "");
+
+	if (sanitized.length === 0) {
+		throw new Error(`Invalid browser state name: "${stateName}"`);
+	}
+
+	return sanitized;
+}
+
+function ensureBrowserDirs(profilePath: string, stateDir: string): void {
+	mkdirSync(profilePath, { recursive: true });
+	mkdirSync(stateDir, { recursive: true });
+}
+
+function buildWaitArgs(input: BrowserToolInput): { args: string[]; status: string } {
+	const targets = [
+		input.ref !== undefined ? "ref" : undefined,
+		input.url !== undefined ? "url" : undefined,
+		input.text !== undefined ? "text" : undefined,
+		input.ms !== undefined ? "ms" : undefined,
+		input.loadState !== undefined ? "loadState" : undefined,
+	].filter((target): target is string => target !== undefined);
+
+	if (targets.length !== 1) {
+		throw new Error("browser wait requires exactly one of ref, url, text, ms, or loadState");
+	}
+
+	if (input.ref) {
+		return { args: ["wait", input.ref], status: `Waiting for ${input.ref}...` };
+	}
+	if (input.url) {
+		return {
+			args: ["wait", "--url", input.url],
+			status: `Waiting for URL ${input.url}...`,
+		};
+	}
+	if (input.text) {
+		return {
+			args: ["wait", "--text", input.text],
+			status: `Waiting for text "${input.text}"...`,
+		};
+	}
+	if (input.ms !== undefined) {
+		return {
+			args: ["wait", String(input.ms)],
+			status: `Waiting ${input.ms}ms...`,
+		};
+	}
+
+	return {
+		args: ["wait", "--load", input.loadState!],
+		status: `Waiting for load state ${input.loadState}...`,
+	};
+}
+
+function buildBrowserCommand(
+	cwd: string,
+	input: BrowserToolInput,
+	options?: BrowserToolOptions,
+): BrowserCommandContext {
+	const profilePath = getBrowserProfilePath(cwd, options);
+	const stateDir = getBrowserStateDir(cwd, options);
+	ensureBrowserDirs(profilePath, stateDir);
+
+	const baseArgs = ["--profile", profilePath];
+
+	switch (input.action) {
+		case "open": {
+			if (!input.url) {
+				throw new Error("browser open requires url");
+			}
+			return {
+				action: input.action,
+				args: [...baseArgs, "open", input.url],
+				statusMessage: `Opening ${input.url}...`,
+				successMessage: `Opened ${input.url}`,
+				profilePath,
+			};
+		}
+		case "snapshot": {
+			const mode = input.mode ?? "interactive";
+			const args = mode === "interactive" ? [...baseArgs, "snapshot", "-i"] : [...baseArgs, "snapshot"];
+			return {
+				action: input.action,
+				args,
+				statusMessage: "Capturing browser snapshot...",
+				successMessage: "Captured browser snapshot",
+				profilePath,
+			};
+		}
+		case "click": {
+			if (!input.ref) {
+				throw new Error("browser click requires ref");
+			}
+			return {
+				action: input.action,
+				args: [...baseArgs, "click", input.ref],
+				statusMessage: `Clicking ${input.ref}...`,
+				successMessage: `Clicked ${input.ref}`,
+				profilePath,
+			};
+		}
+		case "fill": {
+			if (!input.ref || input.value === undefined) {
+				throw new Error("browser fill requires ref and value");
+			}
+			return {
+				action: input.action,
+				args: [...baseArgs, "fill", input.ref, input.value],
+				statusMessage: `Filling ${input.ref}...`,
+				successMessage: `Filled ${input.ref}`,
+				profilePath,
+			};
+		}
+		case "wait": {
+			const wait = buildWaitArgs(input);
+			return {
+				action: input.action,
+				args: [...baseArgs, ...wait.args],
+				statusMessage: wait.status,
+				successMessage: "Browser wait condition satisfied",
+				profilePath,
+			};
+		}
+		case "screenshot": {
+			const screenshotPath = input.path ? resolveCommandPath(cwd, input.path) : createTempScreenshotPath();
+			const args = [...baseArgs, "screenshot"];
+			if (input.fullPage) {
+				args.push("--full");
+			}
+			args.push(screenshotPath);
+
+			return {
+				action: input.action,
+				args,
+				statusMessage: "Taking browser screenshot...",
+				successMessage: `Saved browser screenshot to ${screenshotPath}`,
+				profilePath,
+				screenshotPath,
+			};
+		}
+		case "state_save": {
+			if (!input.stateName) {
+				throw new Error("browser state_save requires stateName");
+			}
+			const statePath = join(stateDir, `${sanitizeStateName(input.stateName)}.json`);
+			return {
+				action: input.action,
+				args: [...baseArgs, "state", "save", statePath],
+				statusMessage: `Saving browser state "${input.stateName}"...`,
+				successMessage: `Saved browser state "${input.stateName}" to ${statePath}`,
+				profilePath,
+				statePath,
+			};
+		}
+		case "state_load": {
+			if (!input.stateName) {
+				throw new Error("browser state_load requires stateName");
+			}
+			const statePath = join(stateDir, `${sanitizeStateName(input.stateName)}.json`);
+			if (!existsSync(statePath)) {
+				throw new Error(`Saved browser state "${input.stateName}" not found at ${statePath}`);
+			}
+			return {
+				action: input.action,
+				args: [...baseArgs, "state", "load", statePath],
+				statusMessage: `Loading browser state "${input.stateName}"...`,
+				successMessage: `Loaded browser state "${input.stateName}" from ${statePath}`,
+				profilePath,
+				statePath,
+			};
+		}
+		case "close":
+			return {
+				action: input.action,
+				args: [...baseArgs, "close"],
+				statusMessage: "Closing browser...",
+				successMessage: "Closed browser",
+				profilePath,
+			};
+		default: {
+			const unsupportedAction: never = input.action;
+			throw new Error(`Unsupported browser action: ${unsupportedAction}`);
+		}
+	}
+}
+
+function buildBrowserErrorMessage(action: BrowserToolAction, output: string, exitCode: number | null): string {
+	const base =
+		exitCode === null
+			? `Browser action "${action}" failed`
+			: `Browser action "${action}" exited with code ${exitCode}`;
+	return output.length > 0 ? `${output}\n\n${base}` : base;
+}
+
+function getMissingBrowserCommandMessage(command: string): string {
+	return [
+		`Browser tool could not find "${command}".`,
+		"Install agent-browser so the first-class browser tool can run.",
+		"Recommended setup:",
+		"  npm install -g agent-browser",
+		"  agent-browser install",
+		"If Chromium lives at a custom path, set AGENT_BROWSER_EXECUTABLE_PATH.",
+	].join("\n");
+}
+
+export function createBrowserTool(cwd: string, options?: BrowserToolOptions): AgentTool<typeof browserSchema> {
+	const operations = options?.operations ?? defaultBrowserOperations;
+	const command = options?.command ?? DEFAULT_BROWSER_COMMAND;
+	const defaultTimeoutSeconds = options?.defaultTimeoutSeconds ?? DEFAULT_BROWSER_TIMEOUT_SECONDS;
+
+	return {
+		name: "browser",
+		label: "browser",
+		description:
+			"Use a persistent browser for websites: open pages, inspect them with snapshot, click or fill elements, wait for changes, take screenshots, and save or load named browser state.",
+		parameters: browserSchema,
+		execute: async (_toolCallId, input, signal, onUpdate) => {
+			const commandContext = buildBrowserCommand(cwd, input, options);
+			const details: BrowserToolDetails = {
+				action: commandContext.action,
+				command,
+				args: commandContext.args,
+				profilePath: commandContext.profilePath,
+				screenshotPath: commandContext.screenshotPath,
+				statePath: commandContext.statePath,
+			};
+
+			onUpdate?.({
+				content: [{ type: "text", text: commandContext.statusMessage }],
+				details,
+			});
+
+			const chunks: Buffer[] = [];
+
+			try {
+				const { exitCode } = await operations.exec(command, commandContext.args, {
+					cwd,
+					env: getShellEnv(),
+					onData: (data) => chunks.push(data),
+					signal,
+					timeout: defaultTimeoutSeconds,
+				});
+
+				const output = normalizeOutput(chunks);
+				if (exitCode !== 0 && exitCode !== null) {
+					throw new Error(buildBrowserErrorMessage(commandContext.action, output, exitCode));
+				}
+
+				if (commandContext.action === "snapshot") {
+					if (output.length === 0) {
+						throw new Error("Browser snapshot returned no output");
+					}
+					return {
+						content: [{ type: "text", text: output }],
+						details,
+					};
+				}
+
+				const text = output.length > 0 ? output : commandContext.successMessage;
+				return {
+					content: [{ type: "text", text }],
+					details,
+				};
+			} catch (error) {
+				if (error instanceof Error && "code" in error && error.code === "ENOENT") {
+					throw new Error(getMissingBrowserCommandMessage(command));
+				}
+				if (error instanceof Error && error.message === "aborted") {
+					throw new Error(`Browser action "${commandContext.action}" aborted`);
+				}
+				if (error instanceof Error && error.message.startsWith("timeout:")) {
+					const seconds = error.message.split(":")[1];
+					throw new Error(`Browser action "${commandContext.action}" timed out after ${seconds} seconds`);
+				}
+				throw error;
+			}
+		},
+	};
+}
+
+export const browserTool = createBrowserTool(process.cwd());
--- a/packages/coding-agent/src/core/tools/index.ts
+++ b/packages/coding-agent/src/core/tools/index.ts
@ -8,6 +8,17 @@ export {
  bashTool,
  createBashTool,
 } from "./bash.js";
+export {
+  type BrowserLoadState,
+  type BrowserOperations,
+  type BrowserSnapshotMode,
+  type BrowserToolAction,
+  type BrowserToolDetails,
+  type BrowserToolInput,
+  type BrowserToolOptions,
+  browserTool,
+  createBrowserTool,
+} from "./browser.js";
 export {
  createEditTool,
  type EditOperations,
@ -68,6 +79,11 @@ export {

 import type { AgentTool } from "@mariozechner/pi-agent-core";
 import { type BashToolOptions, bashTool, createBashTool } from "./bash.js";
+import {
+  browserTool,
+  createBrowserTool,
+  type BrowserToolOptions,
+} from "./browser.js";
 import { createEditTool, editTool } from "./edit.js";
 import { createFindTool, findTool } from "./find.js";
 import { createGrepTool, grepTool } from "./grep.js";
@ -78,9 +94,6 @@ import { createWriteTool, writeTool } from "./write.js";
 /** Tool type (AgentTool from pi-ai) */
 export type Tool = AgentTool<any>;

-// Default tools for full access mode (using process.cwd())
-export const codingTools: Tool[] = [readTool, bashTool, editTool, writeTool];
-
 // Read-only tools for exploration without modification (using process.cwd())
 export const readOnlyTools: Tool[] = [readTool, grepTool, findTool, lsTool];

@ -88,6 +101,7 @@ export const readOnlyTools: Tool[] = [readTool, grepTool, findTool, lsTool];
 export const allTools = {
  read: readTool,
  bash: bashTool,
+  browser: browserTool,
  edit: editTool,
  write: writeTool,
  grep: grepTool,
@ -97,11 +111,26 @@ export const allTools = {

 export type ToolName = keyof typeof allTools;

+export const defaultCodingToolNames: ToolName[] = [
+  "read",
+  "bash",
+  "browser",
+  "edit",
+  "write",
+];
+
+// Default tools for full access mode (using process.cwd())
+export const codingTools: Tool[] = defaultCodingToolNames.map(
+  (toolName) => allTools[toolName],
+);
+
 export interface ToolsOptions {
  /** Options for the read tool */
  read?: ReadToolOptions;
  /** Options for the bash tool */
  bash?: BashToolOptions;
+  /** Options for the browser tool */
+  browser?: BrowserToolOptions;
 }

 /**
@ -111,6 +140,7 @@ export function createCodingTools(cwd: string, options?: ToolsOptions): Tool[] {
  return [
    createReadTool(cwd, options?.read),
    createBashTool(cwd, options?.bash),
+    createBrowserTool(cwd, options?.browser),
    createEditTool(cwd),
    createWriteTool(cwd),
  ];
@ -141,6 +171,7 @@ export function createAllTools(
  return {
    read: createReadTool(cwd, options?.read),
    bash: createBashTool(cwd, options?.bash),
+    browser: createBrowserTool(cwd, options?.browser),
    edit: createEditTool(cwd),
    write: createWriteTool(cwd),
    grep: createGrepTool(cwd),
--- a/packages/coding-agent/src/index.ts
+++ b/packages/coding-agent/src/index.ts
@ -181,6 +181,7 @@ export {
  // Factory
  createAgentSession,
  createBashTool,
+  createBrowserTool,
  // Tool factories (for custom cwd)
  createCodingTools,
  createEditTool,
@ -244,7 +245,16 @@ export {
  type BashToolInput,
  type BashToolOptions,
  bashTool,
+  type BrowserLoadState,
+  type BrowserOperations,
+  type BrowserSnapshotMode,
+  type BrowserToolAction,
+  type BrowserToolDetails,
+  type BrowserToolInput,
+  type BrowserToolOptions,
+  browserTool,
  codingTools,
+  defaultCodingToolNames,
  DEFAULT_MAX_BYTES,
  DEFAULT_MAX_LINES,
  type EditOperations,
--- a/packages/coding-agent/test/browser-tool.test.ts
+++ b/packages/coding-agent/test/browser-tool.test.ts
@ -0,0 +1,212 @@
+import { mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, describe, expect, it } from "vitest";
+import { parseArgs } from "../src/cli/args.js";
+import { buildSystemPrompt } from "../src/core/system-prompt.js";
+import {
+	type BrowserOperations,
+	type BrowserToolDetails,
+	createAllTools,
+	createBrowserTool,
+	defaultCodingToolNames,
+} from "../src/core/tools/index.js";
+
+interface TextBlock {
+	type: "text";
+	text: string;
+}
+
+type ToolContentBlock = TextBlock | { type: string };
+
+interface ToolResultLike {
+	content: ToolContentBlock[];
+	details?: unknown;
+}
+
+interface BrowserExecCall {
+	command: string;
+	args: string[];
+	cwd: string;
+	env: NodeJS.ProcessEnv;
+	timeout?: number;
+}
+
+function getTextOutput(result: ToolResultLike): string {
+	return result.content
+		.filter((block): block is TextBlock => block.type === "text")
+		.map((block) => block.text)
+		.join("\n");
+}
+
+function createMockBrowserOperations(
+	output = "",
+	exitCode = 0,
+): {
+	calls: BrowserExecCall[];
+	operations: BrowserOperations;
+} {
+	const calls: BrowserExecCall[] = [];
+
+	return {
+		calls,
+		operations: {
+			exec: async (command, args, options) => {
+				calls.push({
+					command,
+					args,
+					cwd: options.cwd,
+					env: options.env,
+					timeout: options.timeout,
+				});
+				if (output.length > 0) {
+					options.onData(Buffer.from(output, "utf-8"));
+				}
+				return { exitCode };
+			},
+		},
+	};
+}
+
+describe("browser tool", () => {
+	const tempDirs: string[] = [];
+
+	afterEach(() => {
+		while (tempDirs.length > 0) {
+			const tempDir = tempDirs.pop();
+			if (tempDir) {
+				rmSync(tempDir, { recursive: true, force: true });
+			}
+		}
+	});
+
+	function createTempDir(prefix: string): string {
+		const tempDir = mkdtempSync(join(tmpdir(), prefix));
+		tempDirs.push(tempDir);
+		return tempDir;
+	}
+
+	it("opens pages through agent-browser with a shared profile", async () => {
+		const cwd = createTempDir("coding-agent-browser-open-");
+		const profileDir = join(cwd, "profile");
+		const stateDir = join(cwd, "states");
+		const { calls, operations } = createMockBrowserOperations();
+
+		const browserTool = createBrowserTool(cwd, {
+			operations,
+			command: "agent-browser-test",
+			profileDir,
+			stateDir,
+		});
+
+		const result = (await browserTool.execute("browser-open", {
+			action: "open",
+			url: "https://example.com",
+		})) as ToolResultLike;
+
+		expect(calls).toHaveLength(1);
+		expect(calls[0]).toMatchObject({
+			command: "agent-browser-test",
+			args: ["--profile", profileDir, "open", "https://example.com"],
+			cwd,
+			timeout: 90,
+		});
+		expect(getTextOutput(result)).toBe("Opened https://example.com");
+
+		const details = result.details as BrowserToolDetails | undefined;
+		expect(details?.profilePath).toBe(profileDir);
+	});
+
+	it("uses interactive snapshots by default and returns snapshot text", async () => {
+		const cwd = createTempDir("coding-agent-browser-snapshot-");
+		const profileDir = join(cwd, "profile");
+		const stateDir = join(cwd, "states");
+		const { calls, operations } = createMockBrowserOperations("main [ref=@e1]\nbutton [ref=@e2] Sign in");
+
+		const browserTool = createBrowserTool(cwd, {
+			operations,
+			profileDir,
+			stateDir,
+		});
+
+		const result = (await browserTool.execute("browser-snapshot", {
+			action: "snapshot",
+		})) as ToolResultLike;
+
+		expect(calls[0]?.args).toEqual(["--profile", profileDir, "snapshot", "-i"]);
+		expect(getTextOutput(result)).toContain("button [ref=@e2] Sign in");
+	});
+
+	it("validates wait targets before spawning agent-browser", async () => {
+		const cwd = createTempDir("coding-agent-browser-wait-");
+		const profileDir = join(cwd, "profile");
+		const stateDir = join(cwd, "states");
+		const { calls, operations } = createMockBrowserOperations();
+
+		const browserTool = createBrowserTool(cwd, {
+			operations,
+			profileDir,
+			stateDir,
+		});
+
+		await expect(
+			browserTool.execute("browser-wait-missing", {
+				action: "wait",
+			}),
+		).rejects.toThrow("browser wait requires exactly one of ref, url, text, ms, or loadState");
+
+		await expect(
+			browserTool.execute("browser-wait-ambiguous", {
+				action: "wait",
+				ref: "@e2",
+				text: "Done",
+			}),
+		).rejects.toThrow("browser wait requires exactly one of ref, url, text, ms, or loadState");
+
+		expect(calls).toHaveLength(0);
+	});
+
+	it("stores named state under the managed browser state directory", async () => {
+		const cwd = createTempDir("coding-agent-browser-state-");
+		const profileDir = join(cwd, "profile");
+		const stateDir = join(cwd, "states");
+		const { calls, operations } = createMockBrowserOperations();
+
+		const browserTool = createBrowserTool(cwd, {
+			operations,
+			profileDir,
+			stateDir,
+		});
+
+		const result = (await browserTool.execute("browser-state-save", {
+			action: "state_save",
+			stateName: "my session/prod",
+		})) as ToolResultLike;
+
+		const expectedStatePath = join(stateDir, "my-session-prod.json");
+		expect(calls[0]?.args).toEqual(["--profile", profileDir, "state", "save", expectedStatePath]);
+
+		const details = result.details as BrowserToolDetails | undefined;
+		expect(details?.statePath).toBe(expectedStatePath);
+		expect(getTextOutput(result)).toContain(expectedStatePath);
+	});
+
+	it("accepts browser in --tools and exposes it in default tool wiring", () => {
+		const parsed = parseArgs(["--tools", "browser,read"]);
+		expect(parsed.tools).toEqual(["browser", "read"]);
+
+		expect(defaultCodingToolNames).toContain("browser");
+		expect(createAllTools(process.cwd()).browser.name).toBe("browser");
+	});
+
+	it("mentions browser in the default system prompt", () => {
+		const prompt = buildSystemPrompt();
+
+		expect(prompt).toContain(
+			"- browser: Open websites, inspect pages with snapshot, click/fill/wait, take screenshots, and save/load browser state",
+		);
+		expect(prompt).toContain(
+			"Use browser for website tasks. Open the page, use snapshot to inspect interactive elements, then click, fill, wait, or screenshot as needed",
+		);
+	});
+});