create_label

Instructions

Implementation Reference

• src/index.ts:447-452 (handler)

  Handler function for the 'create_label' tool that calls the Gmail API to create a new label by passing input params as the request body to gmail.users.labels.create, wrapped in shared handleTool for auth and error handling.

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

• src/index.ts:438-446 (schema)

  Zod input schema defining parameters for creating a Gmail label: required 'name', optional 'messageListVisibility', 'labelListVisibility', and 'color' object with text and background colors.

  {
    name: z.string().describe("The display name of the label"),
    messageListVisibility: z.enum(['show', 'hide']).optional().describe("The visibility of messages with this label in the message list"),
    labelListVisibility: z.enum(['labelShow', 'labelShowIfUnread', 'labelHide']).optional().describe("The visibility of the label in the label list"),
    color: z.object({
      textColor: z.string().describe("The text color of the label as hex string"),
      backgroundColor: z.string().describe("The background color of the label as hex string")
    }).optional().describe("The color settings for the label")
  },

• src/index.ts:436-453 (registration)

  Registration of the 'create_label' tool on the MCP server, including name, description, input schema, and handler function.

  server.tool("create_label",
    "Create a new label",
    {
      name: z.string().describe("The display name of the label"),
      messageListVisibility: z.enum(['show', 'hide']).optional().describe("The visibility of messages with this label in the message list"),
      labelListVisibility: z.enum(['labelShow', 'labelShowIfUnread', 'labelHide']).optional().describe("The visibility of the label in the label list"),
      color: z.object({
        textColor: z.string().describe("The text color of the label as hex string"),
        backgroundColor: z.string().describe("The background color of the label as hex string")
      }).optional().describe("The color settings for the label")
    },
    async (params) => {
      return handleTool(config, async (gmail: gmail_v1.Gmail) => {
        const { data } = await gmail.users.labels.create({ userId: 'me', requestBody: params })
        return formatResponse(data)
      })
    }
  )

• src/index.ts:50-80 (helper)

  Shared helper function used by all tools, including 'create_label', to handle OAuth2 client creation, credential validation, Gmail API client instantiation, API call execution, and specialized error handling for authentication issues.

  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)

  Utility function to format API responses into MCP content structure by JSON stringifying the response.

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