snapshot_page_state

Instructions

Implementation Reference

• src/tools/qa.ts:167-187 (registration)

  The tool 'snapshot_page_state' is registered via server.tool() in the registerQaTools function. It defines the tool name, description, schema (optional tabId and apiKey), and the handler logic.

  server.tool(
    'snapshot_page_state',
    'Capture a complete snapshot of the page state: HTML, localStorage, sessionStorage, cookies, scroll position, and form values. Use with restore_page_state to return to this exact state.',
    {
      tabId: z.number().optional().describe('Target tab ID (defaults to currently active tab)'),
      apiKey: z.string().optional().describe('API key for authentication if enabled'),
    },
    async ({ tabId, apiKey }) => {
      const result = await bridge.sendCommand({
        command: 'snapshot_page_state',
        params: {},
        tabId,
        apiKey,
        timeout: LONG_TIMEOUT,
      });
      if (!result.success) {
        return { content: [{ type: 'text', text: `Error: ${result.error?.message}` }], isError: true };
      }
      return { content: [{ type: 'text', text: JSON.stringify(result.data, null, 2) }] };
    }
  );

• src/tools/qa.ts:174-186 (handler)

  The handler function for 'snapshot_page_state' asyncronously sends a command via bridge.sendCommand with command 'snapshot_page_state', empty params, optional tabId/apiKey, and a long timeout. It returns the result data or an error.

  async ({ tabId, apiKey }) => {
    const result = await bridge.sendCommand({
      command: 'snapshot_page_state',
      params: {},
      tabId,
      apiKey,
      timeout: LONG_TIMEOUT,
    });
    if (!result.success) {
      return { content: [{ type: 'text', text: `Error: ${result.error?.message}` }], isError: true };
    }
    return { content: [{ type: 'text', text: JSON.stringify(result.data, null, 2) }] };
  }

• src/tools/qa.ts:170-173 (schema)

  Input schema for 'snapshot_page_state': tabId (optional number) and apiKey (optional string), both described via Zod schemas.

  {
    tabId: z.number().optional().describe('Target tab ID (defaults to currently active tab)'),
    apiKey: z.string().optional().describe('API key for authentication if enabled'),
  },

• src/types.ts:1-16 (helper)

  BridgeCommand interface defines the structure of commands sent to the WebSocket bridge, including the 'command' field which is set to 'snapshot_page_state'.

  export interface BridgeCommand {
    command: string;
    params: Record<string, unknown>;
    tabId?: number;
    apiKey?: string;
    timeout?: number;
  }
  
  export interface BridgeResponse {
    success: boolean;
    data?: unknown;
    error?: {
      code: string;
      message: string;
    };
  }

• src/websocket-bridge.ts:63-103 (helper)

  WebSocketBridge.sendCommand is the messaging method that sends the command to the browser extension over a WebSocket and returns a BridgeResponse promise.

  async sendCommand(cmd: BridgeCommand): Promise<BridgeResponse> {
    if (!this.isConnected()) {
      return {
        success: false,
        error: {
          code: 'NOT_CONNECTED',
          message: 'Chrome extension is not connected. Ensure the extension is installed, enabled, and the browser is running.',
        },
      };
    }
  
    const id = crypto.randomUUID();
    const timeout = cmd.timeout ?? DEFAULT_TIMEOUT;
  
    return new Promise<BridgeResponse>((resolve, reject) => {
      const timer = setTimeout(() => {
        this.pending.delete(id);
        resolve({
          success: false,
          error: {
            code: 'TIMEOUT',
            message: `Command '${cmd.command}' timed out after ${timeout}ms`,
          },
        });
      }, timeout);
  
      this.pending.set(id, { resolve, reject, timer });
  
      const message = {
        id,
        type: 'request',
        command: cmd.command,
        params: cmd.params,
        tabId: cmd.tabId,
        apiKey: cmd.apiKey,
        timestamp: Date.now(),
      };
  
      this.client!.send(JSON.stringify(message));
    });
  }