Gmail MCP Server

Instructions

Implementation Reference

• src/index.ts:861-870 (registration)

  Registration of the 'get_vacation' tool, including empty input schema and inline handler function that retrieves Gmail vacation responder settings via the Gmail API after handling authentication.
  server.tool("get_vacation", "Get vacation responder settings", {}, async () => { return handleTool(config, async (gmail: gmail_v1.Gmail) => { const { data } = await gmail.users.settings.getVacation({ userId: 'me' }) return formatResponse(data) }) } )
• src/index.ts:864-869 (handler)

  Handler function for 'get_vacation' tool. Uses shared handleTool utility to authenticate and call Gmail API's users.settings.getVacation method, then formats the response.
  async () => { return handleTool(config, async (gmail: gmail_v1.Gmail) => { const { data } = await gmail.users.settings.getVacation({ userId: 'me' }) return formatResponse(data) }) }
• src/index.ts:50-66 (helper)

  Shared helper function handleTool used by get_vacation (and other tools) to handle OAuth2 authentication, create Gmail client, execute the API call, and handle errors.
  const handleTool = async (queryConfig: Record<string, any> | undefined, apiCall: (gmail: gmail_v1.Gmail) => Promise<any>) => { try { const oauth2Client = queryConfig ? createOAuth2Client(queryConfig) : defaultOAuth2Client if (!oauth2Client) throw new Error('OAuth2 client could not be created, please check your credentials') const credentialsAreValid = await validateCredentials(oauth2Client) if (!credentialsAreValid) throw new Error('OAuth2 credentials are invalid, please re-authenticate') const gmailClient = queryConfig ? google.gmail({ version: 'v1', auth: oauth2Client }) : defaultGmailClient if (!gmailClient) throw new Error('Gmail client could not be created, please check your credentials') const result = await apiCall(gmailClient) return result } catch (error: any) { return `Tool execution failed: ${error.message}` } }
• src/index.ts:48-49 (helper)

  Helper function formatResponse used to format API responses into MCP-compatible content structure.
  const formatResponse = (response: any) => ({ content: [{ type: "text", text: JSON.stringify(response) }] })