Gmail MCP Server

Instructions

Implementation Reference

• src/index.ts:1144-1155 (registration)

  Registration of the 'get_send_as' MCP tool, including input schema, description, and handler function that calls the Gmail API to retrieve a specific send-as alias.
  server.tool("get_send_as", "Gets the specified send-as alias", { sendAsEmail: z.string().describe("The send-as alias to be retrieved") }, async (params) => { return handleTool(config, async (gmail: gmail_v1.Gmail) => { const { data } = await gmail.users.settings.sendAs.get({ userId: 'me', sendAsEmail: params.sendAsEmail }) return formatResponse(data) }) } )
• src/index.ts:1149-1154 (handler)

  The handler function for the 'get_send_as' tool. It uses the shared handleTool helper to authenticate, create a Gmail client, call users.settings.sendAs.get with the provided sendAsEmail, and format the response.
  async (params) => { return handleTool(config, async (gmail: gmail_v1.Gmail) => { const { data } = await gmail.users.settings.sendAs.get({ userId: 'me', sendAsEmail: params.sendAsEmail }) return formatResponse(data) }) }
• src/index.ts:1146-1148 (schema)

  Input schema for the 'get_send_as' tool, requiring a single string parameter 'sendAsEmail'.
  { sendAsEmail: z.string().describe("The send-as alias to be retrieved") },
• src/index.ts:50-66 (helper)

  Shared helper function used by all tools, including 'get_send_as', to handle OAuth2 authentication, Gmail client creation, API call execution, and error handling.
  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:48-48 (helper)

  Helper function to format tool responses as MCP content blocks with JSON-stringified data.
  const formatResponse = (response: any) => ({ content: [{ type: "text", text: JSON.stringify(response) }] })