REST and gRPC API design patterns for Go services. Covers HTTP handlers, middleware, routing, request/response patterns, versioning, pagination, graceful shutdown, and OpenAPI documentation. Use when designing APIs, writing HTTP handlers, implementing middleware, structuring REST endpoints, or setting up gRPC services. Trigger examples: "design API", "REST endpoints", "HTTP handler", "middleware pattern", "graceful shutdown", "gRPC service", "API versioning". Do NOT use for general architecture (use go-architecture-review) or concurrency in handlers (use go-concurrency-review).
Review Go project architecture: package structure, dependency direction, layering, separation of concerns, domain modeling, and module boundaries. Use when reviewing architecture, designing package layout, evaluating dependency graphs, or refactoring monoliths into modules. Trigger examples: "review architecture", "package structure", "project layout", "dependency direction", "clean architecture Go", "module boundaries". Do NOT use for code-level style (use go-coding-standards) or API endpoint design (use go-api-design).
Build command-line tools in Go: flag handling, subcommands, stdin/stdout discipline, exit codes, signal handling, and when Cobra/Viper earn their weight over the standard library. Use when: "build a CLI", "add a subcommand", "parse flags", "exit codes", "handle Ctrl+C", "cobra command", "read from stdin", "CLI UX". Do NOT use for: HTTP API design (use go-api-design), project scaffolding in general (use go-project-layout), or configuration of services (use go-architecture-review).
Dependency injection in Go: constructor injection, wiring in main, avoiding global state, and when frameworks (wire, fx, dig) earn their complexity. Use when: "dependency injection", "wire up dependencies", "inject this", "remove global state", "singleton in Go", "use google/wire", "uber fx", "make this testable". Do NOT use for: interface design principles (use go-interface-design), project directory structure (use go-project-layout), or test doubles and mocks (use go-test-quality).
Idiomatic Go design patterns: functional options, builder, factory, strategy, middleware chain, pub/sub, and other patterns adapted for Go's type system. Use when: "design pattern", "functional options", "builder pattern", "factory pattern", "strategy pattern", "middleware chain", "option pattern", "how to structure this". Do NOT use for: interface design principles (use go-interface-design), package layout (use go-architecture-review), or concurrency patterns (use go-concurrency-review).
gRPC services in Go beyond the basics: proto design, status codes and error details, interceptors, deadlines, streaming, health checks, and graceful shutdown. Use when: "gRPC service", "proto design", "gRPC error handling", "interceptor", "gRPC streaming", "gRPC deadline", "grpc health check", "gRPC status codes". Do NOT use for: REST/HTTP handler design (use go-api-design), protobuf-agnostic API layering (use go-architecture-review), or TLS hardening details (use go-security-audit).
Go interface design patterns: implicit interfaces, consumer-side definition, interface compliance verification, composition, the accept-interfaces-return-structs principle, and common pitfalls. Use when designing interfaces, decoupling packages, defining contracts, reviewing interface usage, or refactoring for testability. Trigger examples: "design interface", "accept interfaces return structs", "interface compliance", "consumer-side interface", "interface composition". Do NOT use for HTTP handler patterns (use go-api-design) or general code review (use go-code-review).
Scaffold new Go projects and services: directory structure, cmd/ and internal/ conventions, when to use a flat layout, module naming, and main package wiring. Use when: "new Go project", "scaffold a service", "create project structure", "start a Go module", "how do I organize a new service", "set up folder structure". Do NOT use for: reviewing an existing architecture (use go-architecture-review), dependency injection wiring details (use go-dependency-injection), or CI pipeline setup (use go-ci).