update_label

Instructions

Implementation Reference

• src/index.ts:525-531 (handler)

  Handler function for the 'update_label' tool. It destructures the params to separate the label ID and update data, uses handleTool for authentication and Gmail client creation, calls the Gmail API to update the label, and formats the response.

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

• src/index.ts:515-524 (schema)

  Zod schema defining the input parameters for the update_label tool: required 'id' for the label ID, optional fields for name, visibilities, and color object.

  {
    id: z.string().describe("The ID of the label to update"),
    name: z.string().optional().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:513-532 (registration)

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

  server.tool("update_label",
    "Update an existing label",
    {
      id: z.string().describe("The ID of the label to update"),
      name: z.string().optional().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) => {
      const { id, ...labelData } = params
      return handleTool(config, async (gmail: gmail_v1.Gmail) => {
        const { data } = await gmail.users.labels.update({ userId: 'me', id, requestBody: labelData })
        return formatResponse(data)
      })
    }
  )

• src/index.ts:50-80 (helper)

  Shared helper function handleTool used by update_label (and other tools) to handle OAuth2 authentication, Gmail client creation, API call execution, and error handling including auth-specific 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) {
      // 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 to format API responses into MCP content structure by stringifying the response as JSON text.

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