Go SDK

About RELAY Realtime SDK v2

The SignalWire Realtime SDK v2 provides multi-language support for building real-time communication applications with persistent WebSocket connections.

Capabilities

• Voice (Calling): Make and receive calls, control call flow, play audio, record calls, detect answering machines, and implement complex IVR systems
• Messaging: Send and receive SMS/MMS messages with delivery tracking and media support
• Tasking: Queue and process background jobs with reliable delivery

SDK Components

The SDK provides three components for connecting to RELAY:

• Consumer: Long-running process for handling incoming events. Recommended for most use cases.
• Task: Queue jobs for Consumers from short-lived processes (e.g., web requests). Useful when you can’t maintain a persistent connection.
• Client: Lower-level connection for outbound-only scripts or when you need custom control over the connection.

Contexts

RELAY uses Contexts to route events to specific consumers. A context is a named string that categorizes requests, allowing you to:

• Write consumers for specific types of calls or messages
• Scale different workloads independently
• Separate traffic based on business rules

For example, configure a support phone number with the support context and a personal number with personal context. RELAY delivers events only to consumers listening for those contexts.

Getting Started

The RELAY SDK for Go enables Go developers to connect and use SignalWire’s RELAY APIs within their own Go code.

Installation

Install the package using “go get”.

$
go get github.com/signalwire/signalwire-golang

Minimum Requirements

The Go SDK requires Go 1.11 or greater installed on your system.

Using the SDK

To use the SDK, you need your project and token from your SignalWire dashboard.

RELAY Consumer

A Relay.Consumer creates a long running process, allowing you to respond to incoming requests and events in realtime. RELAY Consumers abstract all the setup of connecting to RELAY and automatically dispatches workers to handle requests; so you can concentrate on writing your code without having to worry about multi-threading or blocking, everything just works. Think of RELAY Consumers like a background worker system for all your calling and messaging needs.

RELAY Consumers can scale easily, simply by running multiple instances of your Relay.Consumer process. Each event will only be delivered to a single consumer, so as your volume increases, just scale up! This process works well whether you are using Docker Swarm, a Procfile on Heroku, your own webserver, and most other environments.

Setting up a new consumer is the easiest way to get up and running.

1
consumer := new(signalwire.Consumer)
2
// setup the Client
3
consumer.Setup(PProjectID, PTokenID, Contexts)
4
// register callback
5
consumer.Ready = MyReady
6
// start
7
if err := consumer.Run(); err != nil {
8
	signalwire.Log.Error("Error occurred while starting Signalwire Consumer\n")
9
}

Learn more about RELAY Consumers