Mailtrap Email Sending

# CLAUDE.md This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository. ## Development Commands ### Build and Development - `npm run build` - Compile TypeScript to JavaScript in the `dist/` directory - `npm run dev` - Run the MCP server with the MCP Inspector for testing - `npm run prepublish` - Build the project and make the executable script executable ### Code Quality - `npm run lint` - Run both ESLint and TypeScript checks - `npm run lint:eslint` - Run ESLint for code style checking - `npm run lint:tsc` - Run TypeScript compiler for type checking ### Testing - `npm test` - Run all Jest tests - `npm run test:watch` - Run tests in watch mode during development - `npm run test:coverage` - Run tests with coverage reporting ## Project Architecture This is an MCP (Model Context Protocol) server that integrates with Mailtrap's email service. The architecture follows a modular pattern: ### Core Components - **src/index.ts**: Main MCP server entry point that registers all tools and handles the server lifecycle - **src/client.ts**: Mailtrap client configuration and initialization - **src/config/index.ts**: Server configuration constants ### Tool Architecture All tools follow a consistent pattern in the `src/tools/` directory: - Each tool has its own subdirectory (e.g., `sendEmail/`, `templates/`) - Tools export both their implementation function and Zod schema for validation - Template operations are grouped under `templates/` with individual files for each CRUD operation ### Tool Structure Pattern ``` src/tools/{toolName}/ ├── index.ts # Main tool export ├── schema.ts # Zod validation schema ├── {toolName}.ts # Tool implementation └── __tests__/ # Jest test files ``` ### Environment Variables Required - `MAILTRAP_API_TOKEN`: Required API token from Mailtrap - `DEFAULT_FROM_EMAIL`: Default sender email address - `MAILTRAP_ACCOUNT_ID`: Optional account ID for multi-account setups ### Testing Setup - Uses Jest with TypeScript support via ts-jest - Test files are located in `__tests__/` directories within each tool - Environment variables are set up via `jest/setEnvVars.js` - Coverage reports exclude test files and type definitions ### Build Configuration - TypeScript compilation targets ES2022 with CommonJS modules - Separate build config (`tsconfig.build.json`) excludes test files from distribution - Output goes to `dist/` directory with proper executable permissions ### Available MCP Tools 1. **send-email**: Send transactional emails through Mailtrap 2. **create-template**: Create new email templates 3. **list-templates**: List all email templates 4. **update-template**: Update existing email templates 5. **delete-template**: Delete email templates Each tool uses Zod schemas for input validation and follows the MCP protocol for response formatting.