Go gRPC

You are a Go backend developer. The user wants to set up a working gRPC server and client in Go with protocol buffers.

What to check first

• Run go version to confirm Go 1.13+ is installed
• Verify protoc is installed: protoc --version (if not, install from https://github.com/protocolbuffers/protobuf/releases)
• Run go install google.golang.org/protobuf/cmd/protoc-gen-go@latest and go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest to get Go code generators

Steps

1. Create a proto/ directory and write a .proto file defining your service messages and RPC methods using syntax = "proto3"
2. Generate Go code from .proto file using protoc --go_out=. --go-grpc_out=. proto/your_service.proto
3. Import "google.golang.org/grpc" and create a server struct that implements the generated service interface
4. Implement each RPC method defined in your proto file on the server struct, matching the exact signature from generated code
5. In main, create a TCP listener with net.Listen("tcp", ":port") and register your service with grpc.NewServer() then RegisterYourServiceServer()
6. Call server.Serve(listener) to start the server blocking on that port
7. For the client, use grpc.Dial(":port", grpc.WithInsecure()) to connect and create a client stub with the generated constructor
8. Call RPC methods on the stub with a context timeout using context.WithTimeout(context.Background(), 5*time.Second)

Code

// proto/greeter.proto
syntax = "proto3";

package helloworld;

option go_package = "github.com/example/greeter/gen/helloworld";

service Greeter {
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

message HelloRequest {
  string name = 1;
}

message HelloReply {
  string message = 1;
}

// server.go
package main

import (
	"context"
	"fmt"
	"log"
	"net"

	"google.golang.org/grpc"
	pb "github.com/example/greeter/gen/helloworld"
)

type server struct {
	pb.UnimplementedGreeterServer
}

func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
	return &pb.HelloReply{Message: fmt.Sprintf("Hello, %s!", in.Name)}, nil
}

func main() {
	lis, err := net.Listen("tcp", ":50051")
	if err !=

Note: this example was truncated in the source. See the GitHub repo for the latest full version.

Common Pitfalls

• Treating this skill as a one-shot solution — most workflows need iteration and verification
• Skipping the verification steps — you don't know it worked until you measure
• Applying this skill without understanding the underlying problem — read the related docs first

When NOT to Use This Skill

• When a simpler manual approach would take less than 10 minutes
• On critical production systems without testing in staging first
• When you don't have permission or authorization to make these changes

How to Verify It Worked

• Run the verification steps documented above
• Compare the output against your expected baseline
• Check logs for any warnings or errors — silent failures are the worst kind

Production Considerations

• Test in staging before deploying to production
• Have a rollback plan — every change should be reversible
• Monitor the affected systems for at least 24 hours after the change