Web Calling

Web Calling is loaded by a single <script> tag on your site. The script injects an iframe pinned to the bottom-right of the page. When a visitor clicks the launcher, the widget requests microphone access, opens a WebSocket to PolyAI’s WebRTC gateway, and starts an Opus 48 kHz audio call with your agent.

Two endpoints are involved:

• HTTPS to PolyAI’s widget script endpoint, which loads the widget JS.
• WSS to the WebRTC gateway, which carries signaling and Opus audio to your agent.

Only one Web Calling call can be active per browser at a time. The widget enforces this with a cross-tab lock so a visitor with multiple tabs open cannot start parallel calls.

The widget script also exposes a window.PolyphoneAPI object that lets your page drive the call programmatically, useful when you want to trigger Web Calling from a custom button, an in-app event, or an existing chat experience.

// Open the widget and start a call in one step.
window.PolyphoneAPI.connectAndCall();
// Pass context to the agent mid-call.
window.PolyphoneAPI.sendInfo("user_signed_in", { userId: "abc123" });
// React to lifecycle events.
window.PolyphoneAPI.onConnected(() => console.log("Call connected"));
window.PolyphoneAPI.onEnded(() => console.log("Call ended"));
// Remove a handler when you're done.
window.PolyphoneAPI.off("connected", myHandler);

Available commands: connect, disconnect, startCall, endCall, connectAndCall, mute, unmute, sendInfo, isConnected, getCurrentSession, destroy. Event registration uses dedicated methods: onReady, onConnecting, onConnected, onDisconnected, onRegistered, onUnregistered, onRinging, onAnswered, onEnded, onFailed, onMuted, onUnmuted, onCaptureAudio, onAudioEnded, onInfoSent, onInfoReceived, onTranscription, onError. Use off(eventName, handler) to remove a registered handler.

Web Calling uses standard WebRTC primitives. Verified browsers:

Visitors on unsupported browsers see a disabled call button with a brief explanation. Mobile-browser and in-app-webview behavior can vary, so test in your intended deployment environment before launch.