Go Examples

Complex Service (Interceptors, Headers, Multi-Version)

Source code →

Demonstrates multiple services with interceptors, headers, and API versioning:

• ProductService — CRUD with logging + metrics interceptors
• OrderService v1 & v2 — Side-by-side API versions
• JSONService / BinaryService — JSON vs protobuf encoding

cd examples/complex-go
go mod tidy
go run server.go    # start server
go run client.go    # run client demo

KV Store & Object Store

Source code →

Demonstrates auto-persistence of RPC responses to NATS KV and Object stores:

• SaveProfile — Persists to KV bucket user_profiles with key user.{id}
• GenerateReport — Persists to Object Store bucket reports with key report.{id}
• Client reads cached data directly from stores

cd examples/kvstore-go
go mod tidy
go run cmd/server/server.go    # start server
go run cmd/client/client.go    # run client demo

Streaming RPC

Source code →

Demonstrates all four RPC patterns:

• Ping — Standard unary RPC
• CountUp — Server-streaming (server sends 5 numbers)
• Sum — Client-streaming (client sends values, server aggregates)
• Chat — Bidirectional streaming (echo service)

cd examples/streaming-go
go mod tidy
go run cmd/server/main.go    # start server (terminal 1)
go run cmd/client/main.go    # run client demo (terminal 2)

Server Implementation

// Server-streaming: emit numbers
func (s *streamService) CountUp(ctx context.Context, req *CountUpRequest, stream *StreamDemoService_CountUp_Stream) error {
    for i := int32(0); i < req.Count; i++ {
        stream.Send(&CountUpResponse{Number: req.Start + i})
        time.Sleep(200 * time.Millisecond)
    }
    return nil
}

// Client-streaming: aggregate
func (s *streamService) Sum(ctx context.Context, stream *StreamDemoService_Sum_Stream) (*SumResponse, error) {
    var total int64
    var count int32
    for {
        msg, err := stream.Recv(ctx)
        if err != nil { break }
        total += msg.Value
        count++
    }
    return &SumResponse{Total: total, Count: count}, nil
}

// Bidi: echo
func (s *streamService) Chat(ctx context.Context, stream *StreamDemoService_Chat_Stream) error {
    for {
        msg, err := stream.Recv(ctx)
        if err != nil { break }
        stream.Send(&ChatMessage{User: "server", Text: "echo: " + msg.Text})
    }
    return nil
}