sequin-go

A Go SDK for consuming messages from a consumer group in Sequin.

See the docs on pkg.go.dev.

Installing

Install the library:

go get github.com/sequinstream/sequin-go

Usage

The sequin-go SDK provides a high-level Processor for consuming messages from Sequin consumer groups. Here's a simple example:

// Initialize the client
client := sequin.NewClient(&sequin.ClientOptions{
    Token: "your-token",
})

// Create a processor
processor, err := sequin.NewProcessor(
    client,
    "your-consumer-group",
    func(ctx context.Context, msgs []sequin.Message) error {
        // Process each message in the batch
        for _, msg := range msgs {
            fmt.Printf("Received message: %s\n", string(msg.Record))
        }
        return nil
    },
    sequin.ProcessorOptions{
        MaxBatchSize: 10,           // Process up to 10 messages at once
        MaxConcurrent: 3,           // Run up to 3 processors concurrently
        FetchBatchSize: 20,         // Fetch 20 messages at a time from server
        Prefetching: &sequin.PrefetchingOptions{
            BufferSize: 100,        // Buffer up to 100 messages
        },
    },
)
if err != nil {
    log.Fatal(err)
}

// Run the processor (blocks until context is cancelled)
ctx := context.Background()
if err := processor.Run(ctx); err != nil {
    log.Fatal(err)
}

Configuration

The Processor supports several configuration options:

• MaxBatchSize: Maximum number of messages to process in a single batch
• MaxConcurrent: Maximum number of concurrent batch processors
• FetchBatchSize: Number of messages to request from server in a single call
• Prefetching: Optional message prefetching configuration
  • BufferSize: How many messages to prefetch and buffer

Examples

For complete working examples, see:

• Simple consumer - Basic message processing to stdout/file
• Audit logging - More complex example with database integration

Environment Variables

By default, the Client connects to Sequin Cloud at https://api.sequinstream.com. To use a local Sequin instance, set:

export SEQUIN_URL=http://localhost:7376