CNCF Atlas

English

日本語

English

日本語

Appearance

Getting Started ​

Based on the README example at commit 765b3c6, with v1.20.0 the nearest tag. Commands assume a Unix-like shell and a Go 1.25 toolchain (src/go.mod:3).

Prerequisites ​

  • Go 1.25 or newer.
  • The buf CLI for code generation.
  • The protoc-gen-go and protoc-gen-connect-go plugins for generating messages and Connect stubs.

Install ​

Add the library, then install the code-generation tools:

bash
go get connectrpc.com/connect
go install github.com/bufbuild/buf/cmd/buf@latest
go install connectrpc.com/connect/cmd/protoc-gen-connect-go@latest
go install google.golang.org/protobuf/cmd/protoc-gen-go@latest

A first working setup ​

The shortest path that runs is a Go server and a Go client for one service. Point the generated import path at your own Go module path.

Step 1, define the service in a .proto file, then generate code with buf generate. Your buf.gen.yaml lists protoc-gen-go and protoc-gen-connect-go side by side, which produces the message types and a *.connect.go file with NewXxxServiceHandler and NewXxxServiceClient.

bash
buf generate

Step 2, mount the generated handler on an http.ServeMux and serve it. The README example listens on localhost:8080:

go
mux := http.NewServeMux()
path, handler := greetv1connect.NewGreetServiceHandler(&greetServer{})
mux.Handle(path, handler)
http.ListenAndServe("localhost:8080", mux)

If gRPC clients must reach this server over cleartext HTTP/2 (h2c), enable it on the server's http.Protocols with SetUnencryptedHTTP2(true).

Step 3, build a client against that address and call the method directly:

go
client := greetv1connect.NewGreetServiceClient(
    http.DefaultClient, "http://localhost:8080/")
res, err := client.Greet(context.Background(),
    connect.NewRequest(&greetv1.GreetRequest{Name: "World"}))

Verify it works ​

Because a unary Connect call is plain HTTP, you can check the server with curl and no generated client at all. Against the public demo service:

bash
curl \
    --header "Content-Type: application/json" \
    --data '{"sentence": "I feel happy."}' \
    https://demo.connectrpc.com/connectrpc.eliza.v1.ElizaService/Say

A JSON response body means the handler, codec, and protocol negotiation are wired correctly. Point the same request at your own localhost:8080 service to confirm it locally.

Where to go next ​

The official Go getting-started guide covers streaming, interceptors, and error handling in depth (https://connectrpc.com/docs/go/getting-started/). For production concerns such as TLS, compression, and observability with otelconnect, follow the Connect documentation rather than the plaintext defaults used here.