Fast Mermaid Validator MCP

# Environment Variables Configuration Complete documentation of all environment variables for the Mermaid Validator API. ## 🌐 Server Configuration | Variable | Type | Default | Description | |----------|------|---------|-------------| | `PORT` | Integer | `8000` | HTTP server port | | `HOST` | String | `0.0.0.0` | HTTP server host binding | | `NODE_ENV` | String | `development` | Node.js environment (`development`, `production`, `test`) | | `API_VERSION` | String | `v1` | API version prefix | | `MAX_REQUEST_SIZE` | String | `50mb` | Maximum request body size | **Example:** ```bash PORT=8080 HOST=127.0.0.1 NODE_ENV=production API_VERSION=v1 MAX_REQUEST_SIZE=100mb ``` ## 🔒 Security Configuration | Variable | Type | Default | Description | |----------|------|---------|-------------| | `CORS_ORIGIN` | String | `*` | CORS allowed origins (comma-separated or `*`) | | `RATE_LIMIT_WINDOW_MS` | Integer | `900000` | Rate limit window in milliseconds (15 minutes) | | `RATE_LIMIT_MAX_REQUESTS` | Integer | `100` | Maximum requests per IP per window | | `HELMET_CSP_ENABLED` | Boolean | `true` | Enable Content Security Policy headers | | `TRUST_PROXY` | Boolean | `true` | Trust proxy headers for IP detection | **Example:** ```bash CORS_ORIGIN="https://app.example.com,https://admin.example.com" RATE_LIMIT_WINDOW_MS=300000 RATE_LIMIT_MAX_REQUESTS=50 HELMET_CSP_ENABLED=true TRUST_PROXY=true ``` ## 📁 File Upload Configuration | Variable | Type | Default | Description | |----------|------|---------|-------------| | `MAX_FILE_SIZE` | Integer | `10485760` | Maximum file size in bytes (10MB) | | `MAX_FILES` | Integer | `20` | Maximum number of files per request | | `ALLOWED_MIME_TYPES` | String | See config | Comma-separated list of allowed MIME types | | `ALLOWED_EXTENSIONS` | String | `.md,.markdown,.txt,.zip` | Comma-separated list of allowed file extensions | | `TEMP_DIR` | String | `./tmp` | Temporary directory for file uploads | | `CLEANUP_INTERVAL` | Integer | `3600000` | Temp file cleanup interval in milliseconds (1 hour) | **Example:** ```bash MAX_FILE_SIZE=20971520 # 20MB MAX_FILES=50 ALLOWED_MIME_TYPES="text/markdown,text/plain,application/zip" ALLOWED_EXTENSIONS=".md,.markdown,.txt,.zip" TEMP_DIR="/app/temp" CLEANUP_INTERVAL=1800000 # 30 minutes ``` ## ✅ Validation Configuration | Variable | Type | Default | Description | |----------|------|---------|-------------| | `VALIDATION_TIMEOUT` | Integer | `30000` | Validation timeout in milliseconds (30 seconds) | | `MAX_DIAGRAMS_PER_FILE` | Integer | `50` | Maximum diagrams allowed per file | | `MAX_TOTAL_DIAGRAMS` | Integer | `200` | Maximum total diagrams per request | | `ENABLE_SVG_GENERATION` | Boolean | `true` | Enable SVG generation for valid diagrams | | `SVG_MAX_SIZE` | Integer | `100000` | Maximum SVG size to store in response (100KB) | | `VALIDATION_METHOD` | String | `pure` | Validation method (`pure` or `browser`) | **Example:** ```bash VALIDATION_TIMEOUT=60000 # 1 minute MAX_DIAGRAMS_PER_FILE=100 MAX_TOTAL_DIAGRAMS=500 ENABLE_SVG_GENERATION=true SVG_MAX_SIZE=200000 VALIDATION_METHOD=pure ``` ## 📊 Logging Configuration | Variable | Type | Default | Description | |----------|------|---------|-------------| | `LOG_LEVEL` | String | `info` | Logging level (`error`, `warn`, `info`, `debug`) | | `LOG_FORMAT` | String | `combined` | Log format (`combined`, `common`, `dev`, `short`, `tiny`) | | `LOG_TO_FILE` | Boolean | `false` | Enable file logging | | `LOG_FILE` | String | `logs/app.log` | Log file path | | `LOG_MAX_FILES` | Integer | `5` | Maximum number of log files to keep | | `LOG_MAX_SIZE` | String | `10m` | Maximum log file size | **Example:** ```bash LOG_LEVEL=debug LOG_FORMAT=json LOG_TO_FILE=true LOG_FILE="/var/log/mermaid-validator/app.log" LOG_MAX_FILES=10 LOG_MAX_SIZE=50m ``` ## 🏥 Health Check Configuration | Variable | Type | Default | Description | |----------|------|---------|-------------| | `MEMORY_THRESHOLD` | Integer | `90` | Memory usage threshold percentage for health checks | | `DISK_THRESHOLD` | Integer | `90` | Disk usage threshold percentage for health checks | | `HEALTH_CHECK_INTERVAL` | Integer | `30000` | Health check interval in milliseconds | | `READINESS_TIMEOUT` | Integer | `5000` | Readiness probe timeout in milliseconds | **Example:** ```bash MEMORY_THRESHOLD=85 DISK_THRESHOLD=85 HEALTH_CHECK_INTERVAL=60000 READINESS_TIMEOUT=10000 ``` ## 🎨 Mermaid Configuration | Variable | Type | Default | Description | |----------|------|---------|-------------| | `MERMAID_THEME` | String | `default` | Default Mermaid theme (`default`, `dark`, `forest`, `neutral`) | | `MERMAID_LOG_LEVEL` | String | `error` | Mermaid internal log level | | `MERMAID_SECURITY_LEVEL` | String | `strict` | Mermaid security level (`strict`, `loose`, `antiscript`) | | `MERMAID_MAX_TEXT_SIZE` | Integer | `50000` | Maximum text size for Mermaid diagrams | | `MERMAID_MAX_EDGES` | Integer | `500` | Maximum number of edges in diagrams | | `MERMAID_MAX_VERTICES` | Integer | `200` | Maximum number of vertices in diagrams | **Example:** ```bash MERMAID_THEME=dark MERMAID_LOG_LEVEL=warn MERMAID_SECURITY_LEVEL=strict MERMAID_MAX_TEXT_SIZE=100000 MERMAID_MAX_EDGES=1000 MERMAID_MAX_VERTICES=500 ``` ## 🚀 Production Environment Variables ### Minimal Production Configuration ```bash # Required NODE_ENV=production PORT=8000 HOST=0.0.0.0 # Security CORS_ORIGIN="https://yourdomain.com" RATE_LIMIT_MAX_REQUESTS=50 RATE_LIMIT_WINDOW_MS=900000 # File Limits MAX_FILE_SIZE=10485760 MAX_FILES=10 MAX_TOTAL_DIAGRAMS=100 # Logging LOG_LEVEL=warn LOG_TO_FILE=true LOG_FILE=/var/log/mermaid-validator/app.log # Health MEMORY_THRESHOLD=80 DISK_THRESHOLD=80 ``` ### High-Performance Production Configuration ```bash # Performance optimized NODE_ENV=production PORT=8000 HOST=0.0.0.0 MAX_REQUEST_SIZE=100mb # Aggressive rate limiting RATE_LIMIT_MAX_REQUESTS=200 RATE_LIMIT_WINDOW_MS=300000 # Higher limits for enterprise use MAX_FILE_SIZE=52428800 # 50MB MAX_FILES=50 MAX_DIAGRAMS_PER_FILE=100 MAX_TOTAL_DIAGRAMS=1000 # Extended timeouts VALIDATION_TIMEOUT=120000 # 2 minutes CLEANUP_INTERVAL=1800000 # 30 minutes # Comprehensive logging LOG_LEVEL=info LOG_TO_FILE=true LOG_FORMAT=json LOG_MAX_FILES=30 LOG_MAX_SIZE=100m # Mermaid optimizations MERMAID_MAX_TEXT_SIZE=200000 MERMAID_MAX_EDGES=2000 MERMAID_MAX_VERTICES=1000 ``` ## 🐳 Container Environment Variables ### Docker Environment ```dockerfile # In Dockerfile ENV NODE_ENV=production \ PORT=8000 \ HOST=0.0.0.0 \ LOG_LEVEL=info \ LOG_TO_FILE=true \ TEMP_DIR=/app/tmp \ VALIDATION_METHOD=pure \ ENABLE_SVG_GENERATION=true ``` ### Docker Compose Environment ```yaml # In docker-compose.yml environment: - NODE_ENV=production - PORT=8000 - HOST=0.0.0.0 - LOG_LEVEL=info - LOG_TO_FILE=true - MAX_FILE_SIZE=10485760 - MAX_FILES=20 - VALIDATION_TIMEOUT=30000 - ENABLE_SVG_GENERATION=true - RATE_LIMIT_MAX_REQUESTS=100 - CORS_ORIGIN=* - MEMORY_THRESHOLD=90 - DISK_THRESHOLD=90 ``` ### Kubernetes Environment ```yaml # In k8s deployment env: - name: NODE_ENV value: "production" - name: PORT value: "8000" - name: LOG_LEVEL value: "info" - name: MAX_FILE_SIZE valueFrom: configMapKeyRef: name: mermaid-config key: max-file-size - name: DATABASE_URL valueFrom: secretKeyRef: name: mermaid-secrets key: database-url ``` ## 🔧 Development Environment Variables ### Local Development ```bash NODE_ENV=development PORT=8001 HOST=127.0.0.1 LOG_LEVEL=debug LOG_TO_FILE=false CORS_ORIGIN=* RATE_LIMIT_MAX_REQUESTS=1000 VALIDATION_TIMEOUT=60000 ENABLE_SVG_GENERATION=true VALIDATION_METHOD=pure ``` ### Testing Environment ```bash NODE_ENV=test PORT=0 # Random available port LOG_LEVEL=silent LOG_TO_FILE=false TEMP_DIR=./test-tmp CLEANUP_INTERVAL=10000 MAX_FILES=5 MAX_TOTAL_DIAGRAMS=20 VALIDATION_TIMEOUT=5000 ``` ## 📋 Environment Variable Validation The application validates all environment variables on startup: - **Type checking**: Ensures integers are valid numbers - **Range validation**: Checks values are within acceptable ranges - **Required variables**: Fails fast if critical variables are missing - **Default values**: Provides sensible defaults for optional variables ## 🚨 Security Considerations ### Sensitive Variables Never expose these in logs or client-side code: - Database credentials (if added) - API keys (if added) - JWT secrets (if added) - File paths containing sensitive data ### Production Security ```bash # Use restrictive CORS CORS_ORIGIN="https://yourdomain.com" # Lower rate limits RATE_LIMIT_MAX_REQUESTS=50 # Disable debug logging LOG_LEVEL=warn # Enable all security features HELMET_CSP_ENABLED=true TRUST_PROXY=true # Lower resource limits MEMORY_THRESHOLD=80 DISK_THRESHOLD=80 ``` ## ✅ Environment Variable Checklist Before deployment, verify: - [ ] `NODE_ENV` is set to `production` - [ ] `PORT` matches your deployment configuration - [ ] `CORS_ORIGIN` is properly configured - [ ] Rate limiting is appropriate for your use case - [ ] File size limits match your requirements - [ ] Logging configuration is suitable - [ ] Health check thresholds are appropriate - [ ] All paths (temp dir, log file) are writable - [ ] No sensitive information is exposed