update_auto_forwarding

Instructions

Implementation Reference

• src/index.ts:886-899 (registration)

  Registers the MCP tool 'update_auto_forwarding' with description, Zod input schema, and handler function that calls the Gmail API via handleTool.

  server.tool("update_auto_forwarding",
    "Updates automatic forwarding settings",
    {
      enabled: z.boolean().describe("Whether all incoming mail is automatically forwarded to another address"),
      emailAddress: z.string().describe("Email address to which messages should be automatically forwarded"),
      disposition: z.enum(['leaveInInbox', 'archive', 'trash', 'markRead']).describe("The state in which messages should be left after being forwarded")
    },
    async (params) => {
      return handleTool(config, async (gmail: gmail_v1.Gmail) => {
        const { data } = await gmail.users.settings.updateAutoForwarding({ userId: 'me', requestBody: params })
        return formatResponse(data)
      })
    }
  )

• src/index.ts:893-898 (handler)

  The tool handler function. Uses the shared handleTool utility to authenticate, create Gmail client, call users.settings.updateAutoForwarding API with provided params, and format the response.

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

• src/index.ts:888-892 (schema)

  Zod schema for tool inputs: enabled (boolean), emailAddress (string), disposition (enum: leaveInInbox, archive, trash, markRead).

  {
    enabled: z.boolean().describe("Whether all incoming mail is automatically forwarded to another address"),
    emailAddress: z.string().describe("Email address to which messages should be automatically forwarded"),
    disposition: z.enum(['leaveInInbox', 'archive', 'trash', 'markRead']).describe("The state in which messages should be left after being forwarded")
  },

• src/index.ts:50-80 (helper)

  Shared helper function used by all Gmail API tools. Handles OAuth2 client creation/validation, Gmail client setup, API execution, error handling (esp. auth errors), and response formatting.

  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) {
      // Check for specific authentication errors
      if (
        error.message?.includes("invalid_grant") ||
        error.message?.includes("refresh_token") ||
        error.message?.includes("invalid_client") ||
        error.message?.includes("unauthorized_client") ||
        error.code === 401 ||
        error.code === 403
      ) {
        return formatResponse({
          error: `Authentication failed: ${error.message}. Please re-authenticate by running: npx @shinzolabs/gmail-mcp auth`,
        });
      }
  
      return formatResponse({ error: `Tool execution failed: ${error.message}` });
    }
  }