gRPC Swagger vs grpcmock-go

gRPC Swagger is a free, open-source debugging tool for discovering and calling gRPC methods through Swagger UI. It uses server reflection to scan a registered endpoint, identified by host and port, and then displays available services, method definitions, and parameters. Users can invoke methods with Swagger UI’s “Try it out” control, supplying request data and headers as JSON; the headers are passed to the gRPC server as metadata. Reflection must be enabled on the gRPC service, but the setup instructions say proto files and related implementations do not need modification. The project runs from a released JAR or from source and defaults to port 8080. Configuration can show registered services and expire inactive registrations after a chosen number of seconds. Documented endpoints cover registration, service listing, method calls, and Swagger documentation. It is self-hosted, available for API and web use, and licensed under MIT.

grpcmock-go is a free, MIT-licensed Go module providing gRPC testing utilities. It helps tests mock gRPC servers, configure expectations for methods, headers, and payloads, and invoke client calls. Supported methods include unary, client-streaming, server-streaming, and bidirectional-streaming patterns. Request matching can use exact values, regular expressions, JSON, or custom matchers. Mock responses may return payloads, errors, or custom-handler results, and streaming client invocations can use custom handlers. Services can be registered from generated Go code, service instances, or individual methods when generated code is unavailable. The project recommends MockServerWithBufConn for in-memory application testing, with examples using bufconn listeners and context dialers. Installation uses `go get go.nhat.io/grpcmock`, and Go 1.25 or later is required. GitHub lists v0.34.0, released December 12, 2025, as the latest release. The Open-source Go module plan costs nothing.