Gmail MCP

Instructions

Implementation Reference

• src/index.ts:809-818 (registration)

  Registration of the 'get_imap' tool, including its description, empty input schema, and handler function that uses handleTool to call Gmail API's users.settings.getImap and formats the response.

  server.tool("get_imap",
    "Gets IMAP settings",
    {},
    async () => {
      return handleTool(config, async (gmail: gmail_v1.Gmail) => {
        const { data } = await gmail.users.settings.getImap({ userId: 'me' })
        return formatResponse(data)
      })
    }
  )

• src/index.ts:812-818 (handler)

  Handler function for 'get_imap' tool: invokes Gmail API to retrieve IMAP settings for the user and returns formatted response.

    async () => {
      return handleTool(config, async (gmail: gmail_v1.Gmail) => {
        const { data } = await gmail.users.settings.getImap({ userId: 'me' })
        return formatResponse(data)
      })
    }
  )

• src/index.ts:49-65 (helper)

  Shared helper function handleTool used by get_imap (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:47-47 (helper)

  Helper function to format API responses into MCP-compatible content structure, used by get_imap.

  const formatResponse = (response: any) => ({ content: [{ type: "text", text: JSON.stringify(response) }] })