GripMock vs grpcmock-go

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.

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.