Development runner

The runner package runs a bot and everything around it: the HTTP server, WebRTC signaling, LiveKit tokens, and the WebSocket endpoints telephony providers and WebSocket clients connect to. A bot is one function, called once per session:

func bot(ctx context.Context, args runner.Arguments) error {
	t, err := runner.CreateTransport(ctx, args, runner.TransportParams{
		WebRTC: transport.DefaultParams,
		Twilio: func() runner.WebSocketParams {
			return runner.WebSocketParams{Params: wsserver.DefaultParams()}
		},
	})
	if err != nil {
		return err
	}
	// Build the pipeline around t.Input() and t.Output(), then run it with ctx.
	return nil
}

func main() { runner.Main(bot) }

go run . serves every transport on http://localhost:7860 . A client says which transport it wants in the transport field of POST /start; the session then arrives on that transport and the runner calls bot.

Transports

CreateTransport builds the transport from the session’s arguments, with the parameters from the matching TransportParams field. A transport whose field is nil cannot be used.

On /ws the provider is detected from its first messages. CreateTransport then sets TransportType and CallData on the arguments (call id, numbers, custom parameters) and builds the provider’s serializer, with its credentials from the environment (TWILIO_ACCOUNT_SID, TWILIO_AUTH_TOKEN, TELNYX_API_KEY, PLIVO_AUTH_ID, PLIVO_AUTH_TOKEN). A plain WebSocket client needs a serializer of your choosing in TransportParams.WebSocket.

Command line

The runner loads a .env file from the working directory if there is one. Your own flags go on flag.CommandLine before runner.Main, and the parsed runner flags reach the bot as args.Base().CLIArgs. Add routes of your own to runner.App before runner.Main.

Unlike the rest of jargo, which takes explicit Config structs, the runner reads the command line and the environment: it is an application’s entry point, not a library a program configures.

The browser client

The runner serves a ready-made browser client at /client, and / redirects there: the published build of pipecat-ai-prebuilt , embedded by the github.com/gojargo/jargo-web/prebuilt module. It connects over WebRTC and shows the conversation, events and metrics, which makes it a debugging UI. Set runner.Frontend before runner.Main to serve your own handler instead, or to nil to serve none.

Not available

Daily, Vonage and MoQ have no jargo transport, so the runner does not serve them. File uploads and the eval harness’s connection on /ws are not served yet.