get_attachment
Retrieve specific attachments from Gmail messages by providing the message ID and attachment ID. Simplify email attachment management using the Gmail MCP server.
Instructions
Get a message attachment
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | The ID of the attachment | |
| messageId | Yes | ID of the message containing the attachment |
Implementation Reference
- src/index.ts:708-713 (handler)The handler function for the 'get_attachment' tool. It uses handleTool for authentication and calls the Gmail API to retrieve the specified attachment from a message.async (params) => { return handleTool(config, async (gmail: gmail_v1.Gmail) => { const { data } = await gmail.users.messages.attachments.get({ userId: 'me', messageId: params.messageId, id: params.id }) return formatResponse(data) }) }
- src/index.ts:704-707 (schema)Zod input schema defining parameters 'messageId' and 'id' for the get_attachment tool.{ messageId: z.string().describe("ID of the message containing the attachment"), id: z.string().describe("The ID of the attachment"), },
- src/index.ts:702-714 (registration)Registration of the 'get_attachment' tool using McpServer.tool() method, including description, schema, and handler function.server.tool("get_attachment", "Get a message attachment", { messageId: z.string().describe("ID of the message containing the attachment"), id: z.string().describe("The ID of the attachment"), }, async (params) => { return handleTool(config, async (gmail: gmail_v1.Gmail) => { const { data } = await gmail.users.messages.attachments.get({ userId: 'me', messageId: params.messageId, id: params.id }) return formatResponse(data) }) } )
- src/index.ts:50-80 (helper)Shared helper function 'handleTool' used by get_attachment (and other tools) to handle OAuth2 authentication, client creation, and error handling before executing the Gmail API call.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}` }); } }
- src/index.ts:48-48 (helper)Helper function 'formatResponse' used to format the API response into MCP content format.const formatResponse = (response: any) => ({ content: [{ type: "text", text: JSON.stringify(response) }] })