list_labels
Retrieve all labels from a Gmail mailbox to organize and manage email workflows efficiently using the Gmail MCP server.
Instructions
List all labels in the user's mailbox
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Implementation Reference
- src/index.ts:481-490 (registration)Registration of the 'list_labels' MCP tool. Includes empty input schema and inline handler that uses handleTool to authenticate and call Gmail API's users.labels.list to retrieve all labels.server.tool("list_labels", "List all labels in the user's mailbox", {}, async () => { return handleTool(config, async (gmail: gmail_v1.Gmail) => { const { data } = await gmail.users.labels.list({ userId: 'me' }) return formatResponse(data) }) } )
- src/index.ts:484-489 (handler)Inline handler function for 'list_labels' tool. Delegates to shared handleTool for OAuth2 auth and API call to list Gmail labels, then formats the response.async () => { return handleTool(config, async (gmail: gmail_v1.Gmail) => { const { data } = await gmail.users.labels.list({ userId: 'me' }) return formatResponse(data) }) }
- src/index.ts:50-80 (helper)Shared helper function handleTool used by all Gmail tools, including list_labels. Handles OAuth2 authentication, client validation, Gmail client creation, executes the provided API callback, and formats errors appropriately.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 by list_labels handler to format the API response into MCP content structure.const formatResponse = (response: any) => ({ content: [{ type: "text", text: JSON.stringify(response) }] })