// the find
grpc-ecosystem/grpc-gateway
gRPC to JSON proxy generator following the gRPC HTTP spec
gRPC-Gateway generates a reverse-proxy server that translates HTTP/JSON requests into gRPC calls, letting you serve both protocols from a single gRPC implementation. You annotate your .proto files with google.api.http options, run the code generator, and get a working REST API automatically. It's the standard solution for teams that want gRPC internally but need to expose a REST API for clients that can't speak gRPC.
SLSA Level 3 supply chain attestation on releases — rare for ecosystem tooling and worth noting if you care about software provenance. The external gRPC API Configuration file option is genuinely useful: you can add HTTP mappings to proto files you don't own without forking them. PATCH-to-FieldMask translation is automatic and saves real boilerplate. Active maintenance with 20k stars and production deployments processing millions of daily requests since 2018.
OpenAPI 3.1 output (protoc-gen-openapiv3) is alpha and explicitly unstable — the JSON shape for oneofs, enums, and wrappers will change between minor releases, so you can't use it if you depend on spec stability. No support for true bidirectional streaming, HTTP headers as method parameters, or trailer metadata — these aren't edge cases for everyone. The protoc plugin toolchain (four binaries, buf.yaml, googleapis deps, PATH management) has real setup friction compared to frameworks that handle this in-band. Constrained path templates like {name=projects/*} silently rename to {name_1} in OpenAPI output, which can surprise clients doing URL encoding.