Puppeteer MCP Server

Instructions

Implementation Reference

• dist/tabs.js:183-202 (handler)

  Core implementation of switching to the specified tab: retrieves the page from state, sets it as active tab ID, brings the page to front, returns tab info on success or tabNotFound error.

  export async function switchTab(tabId) {
      const page = state.tabs.get(tabId);
      if (!page) {
          return err(tabNotFound(tabId));
      }
      state.activeTabId = tabId;
      try {
          // Bring page to front
          await page.bringToFront();
          return ok({
              id: tabId,
              url: page.url(),
              title: await page.title(),
              isActive: true,
          });
      }
      catch (error) {
          return err(tabNotFound(tabId));
      }
  }

• dist/schemas.js:15-17 (schema)

  Zod schema defining the input for the switch_tab tool: requires a tabId string.

  export const switchTabSchema = z.object({
      tabId: z.string().describe('Tab ID to switch to'),
  });

• dist/tools/tab-tools.js:31-34 (registration)

  Registers the 'switch_tab' MCP tool on the server, using the switchTabSchema for input validation and an inline async handler that delegates to switchTab and wraps the result with handleResult.

  server.tool('switch_tab', 'Switch to a different tab, making it the active tab for subsequent operations.', switchTabSchema.shape, async ({ tabId }) => {
      const result = await switchTab(tabId);
      return handleResult(result);
  });