Google MCP

Instructions

Implementation Reference

• handlers/drive.ts:31-44 (handler)

  Handler function that validates input arguments and delegates to GoogleDrive.getFileContent to execute the tool logic.

  export async function handleDriveGetFileContent(
    args: any,
    googleDriveInstance: GoogleDrive
  ) {
    if (!isGetFileContentArgs(args)) {
      throw new Error("Invalid arguments for google_drive_get_file_content");
    }
    const { fileId } = args;
    const result = await googleDriveInstance.getFileContent(fileId);
    return {
      content: [{ type: "text", text: result }],
      isError: false,
    };
  }

• utils/drive.ts:49-103 (helper)

  Core implementation in GoogleDrive class that interacts with Google Drive API to fetch file content, handling various MIME types appropriately.

  async getFileContent(fileId: string) {
    try {
      // First get the file metadata to check its type
      const fileMetadata = await this.drive.files.get({
        fileId: fileId,
        fields: "name,mimeType",
      });
  
      const { name, mimeType } = fileMetadata.data;
  
      // Handle text files directly
      if (
        mimeType === "text/plain" ||
        mimeType === "application/json" ||
        mimeType.includes("text/") ||
        mimeType.includes("application/javascript")
      ) {
        const response = await this.drive.files.get({
          fileId: fileId,
          alt: "media",
        });
  
        return `File: ${name}\nContent:\n\n${response.data}`;
      }
  
      // For Google Docs, get the content as plain text
      else if (
        mimeType === "application/vnd.google-apps.document" ||
        mimeType === "application/vnd.google-apps.spreadsheet"
      ) {
        let exportMimeType = "text/plain";
        if (mimeType === "application/vnd.google-apps.spreadsheet") {
          exportMimeType = "text/csv";
        }
  
        const response = await this.drive.files.export({
          fileId: fileId,
          mimeType: exportMimeType,
        });
  
        return `File: ${name}\nContent (exported as ${exportMimeType}):\n\n${response.data}`;
      }
  
      // For other file types, just return metadata
      else {
        return `File: ${name}\nType: ${mimeType}\nThis file type cannot be displayed as text. You can access it via Google Drive directly.`;
      }
    } catch (error) {
      throw new Error(
        `Failed to get file content: ${
          error instanceof Error ? error.message : String(error)
        }`
      );
    }
  }

• tools/drive/index.ts:32-45 (schema)

  Tool schema defining the name, description, and input schema (requiring fileId).

  export const GET_FILE_CONTENT_TOOL: Tool = {
    name: "google_drive_get_file_content",
    description: "Get the content of a file from Google Drive",
    inputSchema: {
      type: "object",
      properties: {
        fileId: {
          type: "string",
          description: "ID of the file to retrieve",
        },
      },
      required: ["fileId"],
    },
  };

• server-setup.ts:186-190 (registration)

  Registration in the main server switch statement that routes tool calls to the appropriate handler.

  case "google_drive_get_file_content":
    return await driveHandlers.handleDriveGetFileContent(
      args,
      googleDriveInstance
    );

• utils/helper.ts:253-257 (schema)

  Type guard function for runtime validation of tool input arguments.

  export function isGetFileContentArgs(args: any): args is {
    fileId: string;
  } {
    return args && typeof args.fileId === "string";
  }