Firefox MCP Server

Instructions

Implementation Reference

• index-multi-debug.js:1038-1048 (handler)

  The primary handler for the 'navigate' MCP tool. Retrieves the target browser page (by tabId or active tab), navigates to the provided URL using Playwright's page.goto(), and returns a confirmation message.

  async navigate(args) {
    this.ensureBrowserRunning();
    const { url, tabId } = args;
    const page = this.getPage(tabId);
    
    await page.goto(url);
    
    return {
      content: [{ type: 'text', text: `Tab '${tabId || this.activeTabId}' navigated to: ${url}` }]
    };
  }

• index-multi-debug.js:86-97 (schema)

  Input schema definition for the 'navigate' tool, specifying required 'url' parameter and optional 'tabId'.

  {
    name: 'navigate',
    description: 'Navigate to a URL',
    inputSchema: {
      type: 'object',
      properties: {
        url: { type: 'string' },
        tabId: { type: 'string' }
      },
      required: ['url']
    }
  },

• index-multi-debug.js:407-408 (registration)

  Registration and dispatch of the 'navigate' tool within the CallToolRequestSchema request handler switch statement.

  case 'navigate':
    return await this.navigate(args);

• index-multi-debug.js:1021-1033 (helper)

  Helper method used by navigate (and other tools) to retrieve the browser Page object for a given tabId or the active tab.

  getPage(tabId) {
    if (tabId) {
      if (!this.pages.has(tabId)) {
        throw new Error(`Tab '${tabId}' not found`);
      }
      return this.pages.get(tabId);
    } else {
      if (!this.activeTabId || !this.pages.has(this.activeTabId)) {
        throw new Error('No active tab. Use create_tab or set_active_tab first.');
      }
      return this.pages.get(this.activeTabId);
    }
  }