Swag is a code generation tool that automatically produces Swagger 2.0 API documentation from Go source code annotations.
The tool solves the problem of keeping API documentation synchronized with implementation by parsing declarative comments embedded directly in Go code. Developers annotate their API handlers with structured comments describing endpoints, parameters, request bodies, responses, and security requirements. Swag then generates a complete Swagger 2.0 specification and integrates it with popular Go web frameworks through dedicated plugins, allowing the documentation to be served alongside the running application via Swagger UI.
Swag suits projects where developers want to maintain API documentation close to the code that implements it, reducing the friction of keeping specs in sync with changes. It works with established Go web frameworks through framework-specific plugins. The tool supports advanced features including custom type mappings through struct tags, field exclusion, multi-line descriptions, generic types, security annotations, and enum documentation. Teams should choose this approach if they prefer annotation-driven documentation over maintaining separate specification files, and if they want generated docs to be part of their build process rather than a manual step.
The project maintains active development with regular commits addressing bug fixes and feature additions. Pull requests receive timely review and integration. The codebase shows consistent attention to test coverage and code quality. Documentation is comprehensive and regularly updated to reflect new capabilities and usage patterns.
