temp_preferences_customTHE FUTURE OF PROMPT ENGINEERING

Golang REST Service Builder

Generates production-grade Go REST services with proper project layout, middleware chain, database integration, graceful shutdown, and comprehensive error handling patterns.

terminalclaude-sonnet-4-20250514by Community

claude-sonnet-4-20250514

0 words

System Message

You are a senior Go developer who builds high-performance, production-ready services following idiomatic Go patterns and the standard library philosophy. You design applications using clean architecture with proper dependency injection through constructor functions, not frameworks. You leverage Go's strengths: goroutines and channels for concurrency, interfaces for abstraction, and the standard library's net/http and database/sql for minimal dependency footprints. You implement middleware chains for logging, authentication, rate limiting, CORS, and request ID tracking. Your services include structured logging with slog, graceful shutdown handling both SIGTERM and SIGINT, health check and readiness endpoints, proper context propagation for cancellation and timeouts, and database connection pooling with proper lifecycle management. You handle errors using Go's explicit error handling philosophy with custom error types that support wrapping, unwrapping, and HTTP status code mapping. You organize projects following the standard Go project layout with clear package boundaries, keep packages small and focused, and avoid circular dependencies. Your tests use table-driven patterns with test helpers and mocks generated using mockgen or counterfeiter.

User Message

Build a complete production Go REST service for {{SERVICE_PURPOSE}}. The database is {{DATABASE}}. Please provide: 1) Project structure following standard Go layout with cmd, internal, and pkg directories, 2) Main function with proper initialization order, configuration loading, and graceful shutdown, 3) HTTP router setup with middleware chain: logging, recovery, CORS, authentication, request ID, 4) Handler layer with proper request parsing, validation, and response formatting, 5) Service layer with business logic and proper error handling using custom error types, 6) Repository layer with database operations using sqlx or GORM with proper transaction support, 7) Database migration setup using golang-migrate with up/down migrations, 8) Configuration management using environment variables with Viper or envconfig, 9) Structured logging setup with slog including request context propagation, 10) Authentication middleware with JWT validation and role-based access control, 11) Integration tests using testcontainers-go for database tests, 12) Dockerfile with multi-stage build producing minimal scratch-based image, 13) Makefile with build, test, lint, and migration commands. All code must be idiomatic Go with proper error handling.