initial commit of the call agent

Author: programmerraja

agent.js

@@ -0,0 +1,181 @@
+const express = require("express");
+const { WebSocketServer } = require("ws");
+const Twilio = require("twilio");
+const { createServer } = require("http");
+
+const app = express();
+app.use(express.json());
+
+const server = createServer(app);
+
+const websocket = new WebSocketServer({ noServer: true });
+
+// Endpoint to initiate an outbound call
+app.get("/outbound-call", (req, res) => {
+ const twilioClient = new Twilio(
+ process.env.TWILIO_ACC, // Twilio Account SID from environment variables
+ process.env.TWILIO_KEY // Twilio Auth Token from environment variables
+ );
+
+ const twimlResponse = `<?xml version="1.0" encoding="UTF-8"?>
+ <Response>
+ <Connect>
+ <Stream url="wss://${process.env.SERVER_URL}/outbound-stream" />
+ </Connect>
+ </Response>`;
+
+ // Create the call using Twilio API and initiate the WebSocket stream
+ twilioClient.calls
+ .create({
+ from: process.env.FROM_NUMBER,
+ to: req.query.toNumber,
+ twiml: twimlResponse, // The TwiML response containing WebSocket stream information
+ })
+ .then((call) => {
+ res.send({
+ success: true,
+ message: "Call initiated",
+ callSid: call.sid,
+ });
+ })
+ .catch((error) => {
+ res.status(500).send({
+ success: false,
+ message: "Failed to initiate call",
+ error: error.message,
+ });
+ });
+});
+
+server.on("upgrade", (request, socket, head) => {
+ const pathname = new URL(request.url, `http://${request.headers.host}`)
+ .pathname;
+
+ console.log("RECEIVED UPGRADE ON", pathname);
+
+ if (pathname === "/outbound-stream") {
+ websocket.handleUpgrade(request, socket, head, (ws) => {
+ websocket.emit("connection", ws, request);
+ });
+
+ // Handle WebSocket connection from Twilio
+ websocket.on("connection", async (ws) => {
+ console.log("Stream connected from Twilio");
+
+ // Set up the Eleven Labs WebSocket
+ await setupElevenLabs();
+
+ // Handle WebSocket errors
+ ws.on("error", (err) => console.log("Error on Twilio WebSocket:", err));
+
+ // Handle incoming messages from Twilio
+ ws.on("message", (message) => {
+ try {
+ const msg = JSON.parse(message);
+ switch (msg.event) {
+ case "start":
+ streamSid = msg.start.streamSid;
+ console.log(`Started StreamSid ${streamSid}`);
+ break;
+
+ case "media":
+ if (elevenWs?.readyState === WebSocket.OPEN) {
+ console.log(
+ `Received media from Twilio: StreamSid ${streamSid}`
+ );
+ const audioMessage = {
+ user_audio_chunk: Buffer.from(
+ msg.media.payload,
+ "base64"
+ ).toString("base64"),
+ };
+ elevenWs.send(JSON.stringify(audioMessage));
+ }
+ break;
+
+ case "stop":
+ if (elevenWs?.readyState === WebSocket.OPEN) elevenWs.close();
+ console.log("Stream ended");
+ break;
+
+ default:
+ console.log(`Unhandled event: ${msg.event}`);
+ }
+ } catch (error) {
+ console.error("Error processing Twilio message:", error, streamSid);
+ }
+ });
+
+ // Close connection
+ ws.on("close", () => {
+ console.log("Connection closed by Twilio");
+ if (elevenWs?.readyState === WebSocket.OPEN) elevenWs.close();
+ });
+
+ // Set up Eleven Labs WebSocket
+ async function setupElevenLabs() {
+ try {
+ const { data } = await axios.get(
+ `https://api.elevenlabs.io/v1/convai/conversation/get_signed_url?agent_id=${process.env.AGENT_ID}`,
+ { headers: { "xi-api-key": process.env.API_KEY } }
+ );
+ elevenWs = new WebSocket(data.signed_url);
+
+ elevenWs.on("open", () => console.log("Connected to Eleven Labs"));
+ elevenWs.on("message", (data) =>
+ handleElevenLabsMessages(JSON.parse(data))
+ );
+ elevenWs.on("error", (error) =>
+ console.error("Error with Eleven Labs WebSocket:", error)
+ );
+ elevenWs.on("close", () =>
+ console.log("Disconnected from Eleven Labs")
+ );
+ } catch (error) {
+ console.error("Error setting up Eleven Labs WebSocket:", error);
+ }
+ }
+
+ // Handle Eleven Labs WebSocket messages
+ function handleElevenLabsMessages(message) {
+ switch (message.type) {
+ case "audio":
+ if (streamSid) {
+ const audioData = {
+ event: "media",
+ streamSid,
+ media: {
+ payload:
+ message.audio.chunk || message.audio_event.audio_base_64,
+ },
+ };
+ ws.send(JSON.stringify(audioData));
+ }
+ break;
+ case "interruption":
+ ws.send(JSON.stringify({ event: "clear", streamSid }));
+ break;
+ case "ping":
+ if (message.ping_event?.event_id) {
+ elevenWs.send(
+ JSON.stringify({
+ type: "pong",
+ event_id: message.ping_event.event_id,
+ })
+ );
+ }
+ break;
+ default:
+ console.log(
+ `Unhandled message type from Eleven Labs: ${message.type}`
+ );
+ }
+ }
+ });
+ }
+});
+
+// Start the server on port 8080
+server.listen(8080, () => {
+ console.log(`Server is running on port 8080`);
+});