Developers

Build voice systems with familiar developer primitives.

Explore API, SDK, WebSocket, webhook, SIP and example concepts through a developer-first surface. Illustrative syntax is clearly labeled until stable contracts are published.

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Illustrative REST example ILLUSTRATIVE

// Illustrative API syntax — example only, not a final contract
const response = await fetch("https://api.4vf.example/v1/agents", {
  method: "POST",
  headers: {
    "content-type": "application/json",
    "authorization": "Bearer <token>"
  },
  body: JSON.stringify({
    name: "Support Agent",
    language: "en",
    tools: ["lookup_order"]
  })
});

const agent = await response.json();

Developer Surface

A small set of composable integration concepts.

Explore the core developer primitives through concise examples while stable API contracts continue to evolve.

REST API

Model voice resources and operations through conventional HTTP boundaries.

SDKs

Wrap common client and server integration patterns with typed developer ergonomics.

WebSocket

Support event-oriented real-time interaction where streaming transport is appropriate.

Webhooks

Notify your systems about lifecycle and workflow events at configured endpoints.

SIP

Connect voice infrastructure using established telephony interoperability patterns.

Examples

Use clearly labeled illustrative code to understand architecture without presenting unstable syntax as a final contract.

Real-time Events

React to conversation state as it changes.

Streaming transport can expose useful runtime events for applications that need to coordinate UI or downstream logic with a voice session.

Speech states

Observe when voice input starts or stops.

Agent events

Track model or tool lifecycle events exposed by the runtime.

Application updates

Keep your UI synchronized with the conversation when appropriate.

Illustrative WebSocket example ILLUSTRATIVE

// Illustrative event handling
socket.addEventListener("message", (event) => {
  const message = JSON.parse(event.data);

  if (message.type === "speech.detected") {
    console.log("caller is speaking");
  }
});

Webhooks + SIP

Connect asynchronous events and voice infrastructure.

Use webhooks for event delivery and SIP for telephony interoperability where supported by the deployed platform boundary.

Explore Telephony

WebhookEvent payload → application endpoint

4VFVoice runtime boundary

SIPTelephony interoperability

Start from the docs, then connect the runtime.

Explore concepts and examples in the documentation as stable interfaces continue to evolve.

Read the Docs