[lambdalisue]

Summary

Add a new Connect RPC echo server (echo-connectrpc) with the same interface as echo-grpc, supporting multiple protocols on a single port.

Key Features

• Multi-protocol support: Connect RPC, gRPC, and gRPC-Web
• Protocol control: Each protocol can be individually enabled/disabled via environment variables
• HTTP/1.1 and HTTP/2: Full support for both HTTP versions via h2c
• Dual encoding: JSON and Protocol Buffers
• Browser compatible: Built-in gRPC-Web support
• Reflection API: Full gRPC reflection (v1 and v1alpha) with version control
• 100% API compatible: Same .proto files and RPC interface as echo-grpc

Environment Variables

• DISABLE_CONNECTRPC, DISABLE_GRPC, DISABLE_GRPC_WEB - Protocol control
• DISABLE_REFLECTION_V1, DISABLE_REFLECTION_V1ALPHA - Reflection version control
• REFLECTION_INCLUDE_DEPENDENCIES - Dependency control (partially supported)

Implementation Details

• Uses connectrpc.com/connect for multi-protocol support
• Protocol filter middleware for runtime protocol control
• httptest-based unit tests (16 tests, all passing)
• Docker multi-arch build (linux/amd64, linux/arm64)
• GitHub Actions CI/CD workflows

Comparison with echo-grpc

Feature	echo-grpc	echo-connectrpc
gRPC	✅	✅ (configurable)
Connect RPC	❌	✅ (configurable)
gRPC-Web	❌	✅ (configurable)
HTTP/1.1	❌	✅
JSON	❌	✅
Browser support	❌	✅

Test Plan

• All unit tests pass (16/16, 1 skipped for HTTP/2 limitation)
• Integration tests pass (curl, grpcurl)
• Protocol filtering works (DISABLE_* env vars tested)
• Reflection version control works (v1/v1alpha tested)
• All protocols disabled correctly fails with error message
• just lint - 0 issues
• just test - all tests pass
• just build - successful build
• Docker Compose integration added (port 18081)
• GitHub Actions workflows created
• Documentation complete (README.md, CLAUDE.md, docs/api.md)

Files Added

• echo-connectrpc/ - Complete Connect RPC server implementation
• .github/workflows/build.echo-connectrpc.yml - Build workflow
• .github/workflows/docker.echo-connectrpc.yml - Docker publish workflow
• Updated root README.md, CLAUDE.md, justfile, compose.yaml