Trace MCP

Instructions

Implementation Reference

• src/index.ts:285-309 (handler)

  The main execution handler for the 'extract_schemas' tool. It validates input with Zod, invokes extractProducerSchemas on the specified directory, and returns the extracted ProducerSchemas as JSON.
  case 'extract_schemas': { const input = ExtractSchemasInput.parse(args); log(`Extracting schemas from: ${input.rootDir}`); const schemas = await extractProducerSchemas({ rootDir: input.rootDir, include: input.include, exclude: input.exclude, }); log(`Found ${schemas.length} tool definitions`); return { content: [ { type: 'text', text: JSON.stringify({ success: true, count: schemas.length, schemas, }, null, 2), }, ], }; }
• src/index.ts:45-49 (schema)

  Zod schema for validating the input parameters to the extract_schemas tool (rootDir, include globs, exclude globs).
  const ExtractSchemasInput = z.object({ rootDir: z.string().describe('Root directory of MCP server source code'), include: z.array(z.string()).optional().describe('Glob patterns to include (default: **/*.ts)'), exclude: z.array(z.string()).optional().describe('Glob patterns to exclude (default: node_modules, dist)'), });
• src/index.ts:130-142 (registration)

  Registration of the extract_schemas tool in the ListTools response, defining its name, description, and JSON input schema.
  { name: 'extract_schemas', description: 'Extract MCP tool definitions (ProducerSchemas) from server source code. Scans for server.tool() calls and parses their Zod schemas.', inputSchema: { type: 'object', properties: { rootDir: { type: 'string', description: 'Root directory of MCP server source code' }, include: { type: 'array', items: { type: 'string' }, description: 'Glob patterns to include' }, exclude: { type: 'array', items: { type: 'string' }, description: 'Glob patterns to exclude' }, }, required: ['rootDir'], }, },
• src/extract/index.ts:24-44 (helper)

  Helper function extractProducerSchemas that wraps language-specific parsers. Defaults to TypeScript parser and delegates the extraction.
  export async function extractProducerSchemas( options: ExtractorOptions ): Promise<ProducerSchema[]> { // For backward compatibility, default to TypeScript const language = options.language || 'typescript'; // Get parser from registry if (!hasParser(language)) { throw new Error( `No parser available for language: ${language}. Make sure to call bootstrapLanguageParsers() at startup.` ); } const parser = getParser(language); return parser.extractSchemas({ rootDir: options.rootDir, include: options.include, exclude: options.exclude, }); }
• src/languages/typescript.ts:18-57 (helper)

  Core TypeScript parser implementation for extractSchemas. Uses ts-morph to scan files for server.tool() calls, parse Zod schemas into JSON Schema, and collect ProducerSchema objects.
  async extractSchemas(options: ExtractOptions): Promise<ProducerSchema[]> { console.log(`[TypeScript] Scanning: ${options.rootDir}`); const project = new Project({ tsConfigFilePath: undefined, skipAddingFilesFromTsConfig: true, }); // Add source files const patterns = options.include || this.filePatterns; const excludePatterns = options.exclude || ['**/node_modules/**', '**/dist/**']; project.addSourceFilesAtPaths( patterns.map(p => `${options.rootDir}/${p}`) ); const schemas: ProducerSchema[] = []; for (const sourceFile of project.getSourceFiles()) { const filePath = sourceFile.getFilePath(); // Skip excluded patterns if (excludePatterns.some(pattern => filePath.includes(pattern.replace('**/', '')))) { continue; } // Find all server.tool() calls const toolCalls = this.findToolCalls(sourceFile); for (const toolCall of toolCalls) { const schema = this.parseToolCall(toolCall, filePath); if (schema) { schemas.push(schema); } } } console.log(`[TypeScript] Found ${schemas.length} tool definitions`); return schemas; }