First MCP Server

# CLAUDE.md This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository. ## Project Overview This is a TypeScript project named "first-mcp-server" - an MCP (Model Context Protocol) server implementation. The project includes modern TypeScript tooling, testing, linting, and formatting configurations. ## Development Commands **Build & Run:** - `npm run build` - Build project using tsup (generates CommonJS output with sourcemaps) - `npm start` - Run the built application from dist/ - `npm run start:dev` - Run development server with ts-node **Testing:** - `npm run test` - Run Jest tests - `npm run test:watch` - Run Jest in watch mode for development - `npm run test:coverage` - Run tests with coverage report **Code Quality:** - `npm run lint` - Run ESLint on source and test files - `npm run lint:fix` - Fix ESLint issues automatically - `npm run format` - Format code with Prettier - `npm run type-check` - Run TypeScript type checking without emitting files **Maintenance:** - `npm run audit:check` - Check for security vulnerabilities using audit-ci - `npm run dep:check` - Check for outdated dependencies - `npm run dep:update` - Update dependencies to latest versions - `npm run release` - Create a release using standard-version - `npm run snapshot` - Create a snapshot prerelease ## Project Architecture **Module System:** - Uses path mapping with `#src/*` aliases for clean imports (configured in tsconfig.json:5) - Jest configured with matching module name mapping for tests (jest.config.js:6-9) **Build Configuration:** - **tsup**: Currently builds CommonJS only (tsup.config.ts:6) - ESM and type definitions are commented out - **TypeScript**: Strict mode with enhanced checking including `noUncheckedIndexedAccess` (tsconfig.json:10) - **Target**: ES2022 with source maps and declarations enabled **Testing Setup:** - Jest with ts-jest preset and Node environment - Setup file at `test/setup.ts` for global test configuration - Coverage collection from all `src/` files with appropriate exclusions - Supports both `#src/` and `#test/` path aliases **Quality Tooling:** - Husky git hooks for commit validation (.husky/ directory) - lint-staged for pre-commit file processing (package.json:53-62) - Commitlint with conventional commits - Prettier and ESLint integration with auto-fixing **Package Structure:** - Main entry: `dist/index.js` (CommonJS) - Module entry: `dist/index.mjs` (currently not built) - Types: `dist/index.d.ts` (currently not generated) - Published files limited to `dist/` only - Current implementation: Basic console.log output (src/index.ts:5)