GripMock vs gRPC Swagger

GripMock is a mock server for gRPC services that returns responses defined in YAML or JSON without requiring a backend. It supports unary, server-streaming, client-streaming, and bidirectional calls. Stubs can match request inputs and headers using rules such as equals, contains, matches, anyOf, and glob; dynamic templates can form responses from request payloads, headers, and stream position. Stubs can also return gRPC status errors or delayed responses for timeout testing. The web dashboard lists used and unused stubs and allows them to be created, edited, or deleted while the server runs. GripMock loads .proto files or compiled .pb descriptors, including descriptors supplied to a running server, and can start from a Buf Schema Registry module reference. Deployment options include Docker, release binaries, Homebrew, shell scripts, and Go; a Go SDK embeds it in a test process. It also supports native TLS, optional mutual TLS, OTLP traces, a /metrics endpoint, and MCP endpoints for AI agents. It is free and MIT-licensed.

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.