Vatel Go SDK

Use the Vatel Call Agent Builder from Go: manage agents over the REST API and run real-time voice sessions over WebSockets.

Installation

go get github.com/Devpro-Software/vatel-go-sdk

Quick start

Create a client with your API base URL and organization API key, then open a call session:

package main

import (
	"context"
	"log"

	"github.com/Devpro-Software/vatel-go-sdk"
)

func main() {
	client := vatel.New("https://api.vatel.ai", "your-org-api-key")
	ctx := context.Background()

	tokenResp, err := client.SessionToken(ctx, "agent-uuid")
	if err != nil {
		log.Fatal(err)
	}

	conn, err := client.DialConnection(ctx, tokenResp.Token)
	if err != nil {
		log.Fatal(err)
	}
	defer conn.Close()

	for msg := range conn.Messages() {
		data, _ := msg.ParseData()
		switch msg.Type {
		case vatel.TypeSessionStarted:
			if d, ok := data.(vatel.SessionStartedData); ok {
				log.Println("session started", d.ID)
			}
		case vatel.TypeResponseAudio:
			if d, ok := data.(vatel.ResponseAudioData); ok {
				// Decode d.Audio (base64) and play PCM 16 24kHz mono
				_ = d
			}
		case vatel.TypeToolCall:
			if d, ok := data.(vatel.ToolCallData); ok {
				conn.SendToolCallOutput(d.ToolCallID, "result")
			}
		case vatel.TypeSessionEnded:
			return
		}
	}
}

REST API

Use the same client to call the REST API:

• List agents — client.ListAgents(ctx) returns all agents for your organization.
• Session token — client.SessionToken(ctx, agentID) returns a short-lived JWT. Use this token to open a WebSocket connection for that agent.

You can pass a custom HTTP client:

client := vatel.New("https://api.vatel.ai", apiKey, vatel.WithHTTPClient(myHTTPClient))

WebSocket (call session)

After you have a session token:

1. Connect — client.DialConnection(ctx, tokenResp.Token) opens the WebSocket. You can also build the URL with client.ConnectionURL(token) and call vatel.DialConnection(ctx, url, nil) if you need a custom dialer.
2. Send — Use conn.SendInputAudio(base64PCM) or conn.SendInputAudioBytes(pcm) for microphone audio (PCM 16-bit 24 kHz mono). Use conn.SendToolCallOutput(toolCallID, output) when the server sends a tool call.
3. Receive — Read one message with conn.Receive(), or consume all messages with conn.Messages(). Each message has a Type and optional Data; call msg.ParseData() to get typed structs such as SessionStartedData, ResponseAudioData, ToolCallData, etc.

When you’re done, call conn.Close() (or conn.CloseWithReason(code, text)).

Error handling

• REST errors are returned as *vatel.APIError with StatusCode and Body. Check the status code and body to handle 4xx/5xx responses.
• If you send on a closed WebSocket connection, you get vatel.ErrConnectionClosed.