set_local_storage

Instructions

Implementation Reference

• src/tools/devtools-storage.ts:75-89 (handler)

  The tool handler function that executes set_local_storage logic. It takes key, value, optional tabId and apiKey, sends a 'set_local_storage' command via the WebSocket bridge, and returns success/error text.

  server.tool(
    'set_local_storage',
    'Set a localStorage entry on the current page',
    {
      key: z.string().describe('Storage key'),
      value: z.string().describe('Storage value'),
      tabId: z.number().optional().describe('Target tab ID (defaults to active tab)'),
      apiKey: z.string().optional().describe('API key for authentication'),
    },
    async ({ key, value, tabId, apiKey }) => {
      const result = await bridge.sendCommand({ command: 'set_local_storage', params: { key, value }, tabId, apiKey });
      if (!result.success) return { content: [{ type: 'text' as const, text: `Error: ${result.error?.message}` }], isError: true };
      return { content: [{ type: 'text' as const, text: `localStorage["${key}"] set` }] };
    }
  );

• src/tools/devtools-storage.ts:78-83 (schema)

  Input schema/validation for set_local_storage using Zod, defining required 'key' (string), required 'value' (string), optional 'tabId' (number), and optional 'apiKey' (string).

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

• src/tools/devtools-storage.ts:75-89 (registration)

  The tool is registered via server.tool() call on line 75 as 'set_local_storage' inside the registerDevtoolsStorageTools function.

  server.tool(
    'set_local_storage',
    'Set a localStorage entry on the current page',
    {
      key: z.string().describe('Storage key'),
      value: z.string().describe('Storage value'),
      tabId: z.number().optional().describe('Target tab ID (defaults to active tab)'),
      apiKey: z.string().optional().describe('API key for authentication'),
    },
    async ({ key, value, tabId, apiKey }) => {
      const result = await bridge.sendCommand({ command: 'set_local_storage', params: { key, value }, tabId, apiKey });
      if (!result.success) return { content: [{ type: 'text' as const, text: `Error: ${result.error?.message}` }], isError: true };
      return { content: [{ type: 'text' as const, text: `localStorage["${key}"] set` }] };
    }
  );

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

  The sendCommand method on WebSocketBridge that dispatches the 'set_local_storage' command over WebSocket to the Chrome extension.

  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));
    });
  }

• src/tools/index.ts:29-55 (registration)

  The registerAllTools function (called from server.ts) which calls registerDevtoolsStorageTools to register all storage tools including set_local_storage.

  export function registerAllTools(server: McpServer, bridge: WebSocketBridge) {
    registerNavigationTools(server, bridge);
    registerTabManagementTools(server, bridge);
    registerKeyboardTools(server, bridge);
    registerScreenshotTools(server, bridge);
    registerClickTools(server, bridge);
    registerInputTools(server, bridge);
    registerDragDropTools(server, bridge);
    registerHoverTools(server, bridge);
  
    registerDevtoolsSourcesTools(server, bridge);
    registerDevtoolsModifyTools(server, bridge);
    registerDevtoolsNetworkTools(server, bridge);
    registerDevtoolsStorageTools(server, bridge);
    registerDevtoolsConsoleTools(server, bridge);
  
    registerAccessibilityTools(server, bridge);
    registerEmulationTools(server, bridge);
    registerElementTools(server, bridge);
    registerAuditTools(server, bridge);
    registerInteractionTools(server, bridge);
    registerMonitoringTools(server, bridge);
    registerQaTools(server, bridge);
    registerGestureTools(server, bridge);
    registerMacroTools(server, bridge);
    registerVisualRegressionTools(server, bridge);
  }