diff --git a/packages/coding-agent/src/core/tools/browser.ts b/packages/coding-agent/src/core/tools/browser.ts
new file mode 100644
index 0000000..041493f
--- /dev/null
+++ b/packages/coding-agent/src/core/tools/browser.ts
@@ -0,0 +1,571 @@
+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:${timeout}`));
+          return;
+        }
+
+        resolvePromise({ exitCode: code });
+      });
+    });
+  },
+};
+
+export interface BrowserToolOptions {
+  operations?: BrowserOperations;
+  command?: string;
+  defaultTimeoutSeconds?: number;
+  profileDir?: string;
+  stateDir?: string;
+  agentDir?: string;
+}
+
+interface BrowserCommandContext {
+  action: BrowserToolAction;
+  args: string[];
+  statusMessage: string;
+  successMessage: string;
+  profilePath: string;
+  screenshotPath?: string;
+  statePath?: string;
+}
+
+type BrowserCommandContextWithoutProfile = Omit<
+  BrowserCommandContext,
+  "profilePath"
+>;
+
+function resolveCommandPath(cwd: string, inputPath: string): string {
+  return resolve(cwd, inputPath);
+}
+
+function getBrowserRootDir(options?: BrowserToolOptions): string {
+  const baseAgentDir = options?.agentDir ?? getAgentDir();
+  return join(baseAgentDir, "browser");
+}
+
+function getBrowserProfilePath(
+  cwd: string,
+  options?: BrowserToolOptions,
+): string {
+  const profilePath =
+    options?.profileDir ?? join(getBrowserRootDir(options), "profile");
+  return resolveCommandPath(cwd, profilePath);
+}
+
+function getBrowserStateDir(cwd: string, options?: BrowserToolOptions): string {
+  const stateDir =
+    options?.stateDir ?? join(getBrowserRootDir(options), "states");
+  return resolveCommandPath(cwd, stateDir);
+}
+
+function createTempScreenshotPath(): string {
+  const id = randomBytes(8).toString("hex");
+  return join(tmpdir(), `pi-browser-screenshot-${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 createBrowserCommandContext(
+  profilePath: string,
+  stateDir: string,
+  context: BrowserCommandContextWithoutProfile,
+): BrowserCommandContext {
+  ensureBrowserDirs(profilePath, stateDir);
+  return {
+    ...context,
+    profilePath,
+  };
+}
+
+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 !== undefined) {
+    return { args: ["wait", input.ref], status: `Waiting for ${input.ref}...` };
+  }
+  if (input.url !== undefined) {
+    return {
+      args: ["wait", "--url", input.url],
+      status: `Waiting for URL ${input.url}...`,
+    };
+  }
+  if (input.text !== undefined) {
+    return {
+      args: ["wait", "--text", input.text],
+      status: `Waiting for text "${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);
+  const baseArgs = ["--profile", profilePath];
+
+  switch (input.action) {
+    case "open": {
+      if (!input.url) {
+        throw new Error("browser open requires url");
+      }
+      return createBrowserCommandContext(profilePath, stateDir, {
+        action: input.action,
+        args: [...baseArgs, "open", input.url],
+        statusMessage: `Opening ${input.url}...`,
+        successMessage: `Opened ${input.url}`,
+      });
+    }
+    case "snapshot": {
+      const mode = input.mode ?? "interactive";
+      const args =
+        mode === "interactive"
+          ? [...baseArgs, "snapshot", "-i"]
+          : [...baseArgs, "snapshot"];
+      return createBrowserCommandContext(profilePath, stateDir, {
+        action: input.action,
+        args,
+        statusMessage: "Capturing browser snapshot...",
+        successMessage: "Captured browser snapshot",
+      });
+    }
+    case "click": {
+      if (!input.ref) {
+        throw new Error("browser click requires ref");
+      }
+      return createBrowserCommandContext(profilePath, stateDir, {
+        action: input.action,
+        args: [...baseArgs, "click", input.ref],
+        statusMessage: `Clicking ${input.ref}...`,
+        successMessage: `Clicked ${input.ref}`,
+      });
+    }
+    case "fill": {
+      if (!input.ref || input.value === undefined) {
+        throw new Error("browser fill requires ref and value");
+      }
+      return createBrowserCommandContext(profilePath, stateDir, {
+        action: input.action,
+        args: [...baseArgs, "fill", input.ref, input.value],
+        statusMessage: `Filling ${input.ref}...`,
+        successMessage: `Filled ${input.ref}`,
+      });
+    }
+    case "wait": {
+      const wait = buildWaitArgs(input);
+      return createBrowserCommandContext(profilePath, stateDir, {
+        action: input.action,
+        args: [...baseArgs, ...wait.args],
+        statusMessage: wait.status,
+        successMessage: "Browser wait condition satisfied",
+      });
+    }
+    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 createBrowserCommandContext(profilePath, stateDir, {
+        action: input.action,
+        args,
+        statusMessage: "Taking browser screenshot...",
+        successMessage: `Saved browser screenshot to ${screenshotPath}`,
+        screenshotPath,
+      });
+    }
+    case "state_save": {
+      if (!input.stateName) {
+        throw new Error("browser state_save requires stateName");
+      }
+      const statePath = join(
+        stateDir,
+        `${sanitizeStateName(input.stateName)}.json`,
+      );
+      return createBrowserCommandContext(profilePath, stateDir, {
+        action: input.action,
+        args: [...baseArgs, "state", "save", statePath],
+        statusMessage: `Saving browser state "${input.stateName}"...`,
+        successMessage: `Saved browser state "${input.stateName}" to ${statePath}`,
+        statePath,
+      });
+    }
+    case "state_load": {
+      if (!input.stateName) {
+        throw new Error("browser state_load requires stateName");
+      }
+      const statePath = join(
+        stateDir,
+        `${sanitizeStateName(input.stateName)}.json`,
+      );
+      if (!existsSync(statePath)) {
+        throw new Error(
+          `Saved browser state "${input.stateName}" not found at ${statePath}`,
+        );
+      }
+      return createBrowserCommandContext(profilePath, stateDir, {
+        action: input.action,
+        args: [...baseArgs, "state", "load", statePath],
+        statusMessage: `Loading browser state "${input.stateName}"...`,
+        successMessage: `Loaded browser state "${input.stateName}" from ${statePath}`,
+        statePath,
+      });
+    }
+    case "close":
+      return createBrowserCommandContext(profilePath, stateDir, {
+        action: input.action,
+        args: [...baseArgs, "close"],
+        statusMessage: "Closing browser...",
+        successMessage: "Closed browser",
+      });
+    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) {
+          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());
diff --git a/packages/coding-agent/test/browser-tool.test.ts b/packages/coding-agent/test/browser-tool.test.ts
new file mode 100644
index 0000000..569b03f
--- /dev/null
+++ b/packages/coding-agent/test/browser-tool.test.ts
@@ -0,0 +1,292 @@
+import { existsSync, 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: number | null = 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("preserves empty string wait targets instead of falling through to loadState", async () => {
+    const cwd = createTempDir("coding-agent-browser-wait-empty-");
+    const profileDir = join(cwd, "profile");
+    const stateDir = join(cwd, "states");
+    const { calls, operations } = createMockBrowserOperations();
+
+    const browserTool = createBrowserTool(cwd, {
+      operations,
+      profileDir,
+      stateDir,
+    });
+
+    await browserTool.execute("browser-wait-empty-text", {
+      action: "wait",
+      text: "",
+    });
+
+    expect(calls[0]?.args).toEqual([
+      "--profile",
+      profileDir,
+      "wait",
+      "--text",
+      "",
+    ]);
+  });
+
+  it("does not create browser directories when validation fails before command construction", async () => {
+    const cwd = createTempDir("coding-agent-browser-invalid-open-");
+    const profileDir = join(cwd, "profile");
+    const stateDir = join(cwd, "states");
+    const { operations } = createMockBrowserOperations();
+
+    const browserTool = createBrowserTool(cwd, {
+      operations,
+      profileDir,
+      stateDir,
+    });
+
+    await expect(
+      browserTool.execute("browser-open-missing-url", {
+        action: "open",
+      }),
+    ).rejects.toThrow("browser open requires url");
+
+    expect(existsSync(profileDir)).toBe(false);
+    expect(existsSync(stateDir)).toBe(false);
+  });
+
+  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("treats null exit codes as browser failures", async () => {
+    const cwd = createTempDir("coding-agent-browser-null-exit-");
+    const profileDir = join(cwd, "profile");
+    const stateDir = join(cwd, "states");
+    const { operations } = createMockBrowserOperations("browser crashed", null);
+
+    const browserTool = createBrowserTool(cwd, {
+      operations,
+      profileDir,
+      stateDir,
+    });
+
+    await expect(
+      browserTool.execute("browser-open-null-exit", {
+        action: "open",
+        url: "https://example.com",
+      }),
+    ).rejects.toThrow('browser crashed\n\nBrowser action "open" failed');
+  });
+
+  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",
+    );
+  });
+});