firefox-devtools-mcp

Instructions

Implementation Reference

• src/tools/pages.ts:141-168 (handler)

  The main handler function that executes the 'navigate_page' tool. It validates the 'url' input, gets the Firefox instance, refreshes tabs, checks the selected tab, navigates to the URL, and returns a success response.

  export async function handleNavigatePage(args: unknown): Promise<McpToolResponse> {
    try {
      const { url } = args as { url: string };
  
      if (!url || typeof url !== 'string') {
        throw new Error('url parameter is required and must be a string');
      }
  
      const { getFirefox } = await import('../index.js');
      const firefox = await getFirefox();
  
      // Refresh tabs to get latest list
      await firefox.refreshTabs();
      const tabs = firefox.getTabs();
      const selectedIdx = firefox.getSelectedTabIdx();
      const page = tabs[selectedIdx];
  
      if (!page) {
        throw new Error('No page selected');
      }
  
      await firefox.navigate(url);
  
      return successResponse(`✅ [${selectedIdx}] → ${url}`);
    } catch (error) {
      return errorResponse(error as Error);
    }
  }

• src/tools/pages.ts:33-46 (schema)

  The schema definition for the 'navigate_page' tool, specifying the name, description, and input schema requiring a 'url' string.

  export const navigatePageTool = {
    name: 'navigate_page',
    description: 'Navigate selected tab to URL.',
    inputSchema: {
      type: 'object',
      properties: {
        url: {
          type: 'string',
          description: 'Target URL',
        },
      },
      required: ['url'],
    },
  };

• src/index.ts:110-110 (registration)

  Registration of the 'navigate_page' handler in the toolHandlers Map, mapping the tool name to its execution function.

  ['navigate_page', tools.handleNavigatePage],

• src/index.ts:154-154 (registration)

  Registration of the 'navigate_page' tool schema in the allTools array, used for listing available tools.

  tools.navigatePageTool,

• src/tools/index.ts:6-17 (registration)

  Re-export of the 'navigate_page' tool schema (navigatePageTool) and handler (handleNavigatePage) from pages.ts, making them available centrally.

  export {
    listPagesTool,
    newPageTool,
    navigatePageTool,
    selectPageTool,
    closePageTool,
    handleListPages,
    handleNewPage,
    handleNavigatePage,
    handleSelectPage,
    handleClosePage,
  } from './pages.js';