OSRS MCP Server

Instructions

Implementation Reference

• index.ts:182-203 (handler)

  The core handler function that implements the logic for the 'get_file_details' tool, retrieving file existence, size, line count, and modification timestamps.

  function getFileDetails(filename: string): any {
      try {
          const filePath = path.join(DATA_DIR, filename);
          if (!fs.existsSync(filePath)) {
              return { exists: false };
          }
  
          const stats = fs.statSync(filePath);
          const lineCount = getFileLineCount(filePath);
  
          return {
              exists: true,
              size: stats.size,
              lineCount,
              created: stats.birthtime,
              lastModified: stats.mtime
          };
      } catch (error) {
          console.error(`Error getting file details for ${filename}:`, error);
          return { exists: false, error: 'Error getting file details' };
      }
  }

• index.ts:62-64 (schema)

  Zod schema defining the input validation for the 'get_file_details' tool (filename parameter).

  const FileDetailsSchema = z.object({
      filename: z.string().describe("The filename to get details for in the data directory")
  });

• index.ts:328-332 (registration)

  Registration of the 'get_file_details' tool in the MCP server's listTools response.

  {
      name: "get_file_details",
      description: "Get details about a file in the data directory.",
      inputSchema: convertZodToJsonSchema(FileDetailsSchema),
  },

• index.ts:424-433 (handler)

  Dispatch handler in the CallToolRequestSchema that validates input, performs security checks, calls getFileDetails, and formats the response.

  case "get_file_details":
      const { filename: detailsFilename } = FileDetailsSchema.parse(args);
      
      // Security check to prevent directory traversal
      if (detailsFilename.includes('..') || detailsFilename.includes('/') || detailsFilename.includes('\\')) {
          throw new Error('Invalid filename');
      }
      
      const details = getFileDetails(detailsFilename);
      return responseToString(details);

• index.ts:210-218 (helper)

  Helper utility function used by getFileDetails to compute the line count of the file.

  function getFileLineCount(filePath: string): number {
      try {
          const content = fs.readFileSync(filePath, 'utf8');
          return content.split('\n').length;
      } catch (error) {
          console.error(`Error counting lines in ${filePath}:`, error);
          return 0;
      }
  }