// the find
go-fuego/fuego
Golang Fuego - Web framework generating OpenAPI 3 spec from source code - Pluggable to existing Gin & Echo APIs
Fuego is a Go web framework that generates OpenAPI 3 specs directly from typed handler signatures using generics — no annotations, no YAML, no separate spec file to keep in sync. It wraps `net/http` with a thin typed layer, so existing middleware and handlers still work. Aimed at Go developers who want automatic API documentation without switching ecosystems.
The generics-based approach (`ContextWithBody[T]`) is the real thing here — the spec is derived from actual types at registration time, so drift between docs and implementation is structurally impossible. Full `net/http` compatibility means you can adopt it incrementally on an existing codebase, wrapping one route at a time. The `InTransform`/`OutTransform` hooks give you a clean place to normalize and validate input without polluting handler logic. RFC 9457 error responses out of the box is a nice default that most frameworks ignore.
At 1,734 stars and a 2025 roadmap still in discussion, this is not a stable API yet — expect breaking changes if you're on the early end. The Gin/Echo adaptor support is real but limited: you get OpenAPI generation for those routes, not the full Fuego context system, so it's a half-step. The `InTransform` interface requires a method on your request struct, which pushes validation logic into your data model — that coupling is going to hurt on larger projects where request types and domain types should stay separate. No streaming response support documented anywhere visible, which rules it out for SSE or chunked transfer use cases.