SignalWire Docs

Build performant and scalable real-time communications applications on the programmable cloud platform built for developers.

Voice APIs that outperform the competition
Integrated ultra low-latency Voice AI for human-like interaction – intuitive routing and logic with SWML and API access with SWAIG serverless functions
Build with compatible REST APIs or next-generation WebSocket realtime APIs
Robust Chat, Fax, and Video APIs and SDKs
High-throughput Messaging backed by unmatched support to stay compliant and maximize delivery rates

Don't know where to start?

Talk to Sigmond! He is a helpful assistant that can answer questions and help you get started, and he's built using SignalWire APIs.

Explore applications

There are lots of ways to build on SignalWire. Check out a few starting points for popular applications below.

Relay Realtime SDK (Server)
Relay Browser SDK

Relay Realtime SDK (Server)

import { SignalWire } from "@signalwire/realtime-api";

// Initialize the SignalWire client
const client = await SignalWire({ project: "ProjectID Here", token: "Token Here" });

// Access video client from the main client
const videoClient = client.video;

// Setup listener for when a room starts
await videoClient.listen({
  onRoomStarted: async (roomSession) => {
    console.log("Room started", roomSession.displayName);

    roomSession.startStream({
      url: "rtmp://example.com/stream"
    })
  }
});

📚 RELAY docs View the full guide →

Relay Browser SDK

import * as SignalWire from "@signalwire/js";
import axios from "axios";

const rtmpUrl = "rtmp://example.com/live";

async function connect() {
    try {
        await navigator.mediaDevices.getUserMedia({ 
            video: true,
            audio: true
        });
    } catch (e) {
        console.error("Failed to get user media:", e);
        return;
    }

    const reply = await axios.post(
        "/get_token", // Make request to server to get video token from SignalWire Rest API
        {
            user_name: "user",
            room_name: "room"
        }
    )

    const roomSession = new SignalWire.Video.RoomSession({
        token: reply.data.token, // Obtained from SignalWire REST API
        rootElement: document.getElementById("video")
    })

    roomSession.on("stream.started", (m) => console.log(m));

    try {
        await roomSession.join()
        await roomSession.startStream({ url: rtmpUrl })
    } catch (e) {
        console.error("Failed to join room:", e);
    }
}

connect()

📚 RELAY docs View the full guide →

SWML
Call Flow Builder

SWML

version: 1.0.0
sections:
  main:
    - ai:
        post_prompt_url: https://example.com/my-post-prompt-url
        params:
          save_conversation: true
        prompt:
          text: |
            You are a knowledgeable developer. 
            Have an open-ended discussion with the caller about SignalWire and programmable communications.

📚 SWML docs View the full guide →

SWML
Call Flow Builder
Relay Realtime SDK (Server)
CXML

SWML

version: 1.0.0
sections:
  main:
    - play:
        url: 'say: Hello from SignalWire!'

📚 SWML docs `play` method reference

Relay Realtime SDK (Server)

import { SignalWire } from "@signalwire/realtime-api";

const client = await SignalWire({ project: "ProjectID Here", token: "Token Here" })

const voiceClient = client.voice;

// Listen for incoming calls
await voiceClient.listen({
  topics: ["office"],
  onCallReceived: async (call) => {
    console.log("Call received");
    // Answer the call
    call.answer();
    // Play TTS on the call
    await call.playTTS({
      text: "Hello from SignalWire!",
      }
    })
  }
});

📚 RELAY docs View the full guide →

CXML

<?xml version="1.0" encoding="UTF-8"?>
<Response>
     <Say>Hello from SignalWire!</Say>
</Response>

📚 CXML docs View the full guide →

SWML
Relay Realtime SDK (Server)
CXML
REST API

SWML

version: 1.0.0
sections:
  main:
    - send_sms:
        from_number: "+155512312345"
        to_number: "+15555554321"
        body: "Hello from SignalWire!"

📚 SWML docs View the full guide →

Relay Realtime SDK (Server)

import { SignalWire } from "@signalwire/realtime-api";

const client = await SignalWire({ project: "ProjectID Here", token: "Token Here"})

let messageClient = client.messaging;

const sendResult = await messageClient.send({
    from: "+155512312345",
    to: "+15555554321",
    body: "Hello from SignalWire!"
});

📚 RELAY docs View the full guide →

CXML

<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Message>
        <Body>Hello from SignalWire!</Body>
    </Message>
</Response>

📚 CXML docs View the full guide →

REST API

curl -L 'https://<YOUR_SPACE>.signalwire.com/api/laml/2010-04-01/Accounts/<PROJECT_ID_HERE>/Messages' \
-H 'Content-Type: application/x-www-form-urlencoded' \
-H 'Accept: application/json' \
-H 'Authorization: Basic <BASE64 ENCODED AUTHENTICATION STRING>' \
-d 'To=%2B155512312345' \
-d 'From=%2B15555554321' \
-d 'Body=Hello%20from%20SignalWire!'

📚 SignalWire API docs View the full guide →

SWML
CXML

SWML

version: 1.0.0
sections:
  main:
    - receive_fax: {}

📚 SWML docs View the full guide →

CXML

<?xml version="1.0" encoding="UTF-8"?>
<Response>
  <Receive></Receive>
</Response>

📚 CXML docs View the full guide →

Relay Realtime SDK (Server)
Relay Browser SDK

Relay Realtime SDK (Server)

import { SignalWire } from "@signalwire/realtime-api";

const client = await SignalWire({ project: "ProjectID Here", token: "Token Here" })

const chatClient = client.chat;

await chatClient.listen({
  channels: ["channel1"],
  onMessageReceived: async (message) => {
    console.log(message.content);
  }
});

await chatClient.publish({
        channel: "channel1",
        content: `Hello from SignalWire!`
    })

📚 RELAY docs View the full guide →

Relay Browser SDK

import { Chat } from "@signalwire/js";

const chatClient = new Chat.Client({
  token: "<your_chat_token>", // get this from the REST APIs
});

await chatClient.subscribe(["mychannel1", "mychannel2"]);

chatClient.on("message", (message) => {
  console.log("Received", message.content,
              "on", message.channel,
              "at", message.publishedAt);
});

await chatClient.publish({
  channel: "mychannel1",
  content: `Hello from SignalWire!`,
});

📚 RELAY docs View the full guide →

Relay Realtime SDK (Server)
Relay Browser SDK

Relay Realtime SDK (Server)

import { SignalWire } from '@signalwire/realtime-api'

const client = await SignalWire({ project: "ProjectID Here", token: "Token Here" })

const pubSubClient = client.pubSub;

await pubSubClient.listen({
  channels: ["mychannel1"],
  onMessageReceived: (message) => {
    console.log(message);
  }
});

await pubSubClient.publish({
  channel: "mychannel1",
  content: "Hello from SignalWire!"
});

📚 RELAY docs View the full guide →

Relay Browser SDK

import { PubSub } from "@signalwire/js";

const pubSubClient = new PubSub.Client({
  token: "<your chat token>", // get this from the REST APIs
});

await pubSubClient.subscribe(["mychannel1", "mychannel2"]);

pubSubClient.on("message", (message) => {
  console.log("Received", message.content,
              "on", message.channel,
              "at", message.publishedAt);
});

await pubSubClient.publish({
  channel: "mychannel1",
  content: "Hello from SignalWire!",
});

📚 RELAY docs View the full guide →

Relay Realtime SDK (Server)
Relay Browser SDK

Relay Realtime SDK (Server)

import { SignalWire } from "@signalwire/realtime-api";

// Initialize the SignalWire client
const client = await SignalWire({ project: "ProjectID Here", token: "Token Here" });

// Access video client from the main client
const videoClient = client.video;

// Setup listener for when a room starts
await videoClient.listen({
  onRoomStarted: async (roomSession) => {
    console.log("Room started", roomSession.displayName);

    roomSession.startStream({
      url: "rtmp://example.com/stream"
    })
  }
});

📚 RELAY docs View the full guide →

Relay Browser SDK

import * as SignalWire from "@signalwire/js";
import axios from "axios";

const rtmpUrl = "rtmp://example.com/live";

async function connect() {
    try {
        await navigator.mediaDevices.getUserMedia({ 
            video: true,
            audio: true
        });
    } catch (e) {
        console.error("Failed to get user media:", e);
        return;
    }

    const reply = await axios.post(
        "/get_token", // Make request to server to get video token from SignalWire Rest API
        {
            user_name: "user",
            room_name: "room"
        }
    )

    const roomSession = new SignalWire.Video.RoomSession({
        token: reply.data.token, // Obtained from SignalWire REST API
        rootElement: document.getElementById("video")
    })

    roomSession.on("stream.started", (m) => console.log(m));

    try {
        await roomSession.join()
        await roomSession.startStream({ url: rtmpUrl })
    } catch (e) {
        console.error("Failed to join room:", e);
    }
}

connect()

📚 RELAY docs View the full guide →

SWML
Call Flow Builder

SWML

version: 1.0.0
sections:
  main:
    - ai:
        post_prompt_url: https://example.com/my-post-prompt-url
        params:
          save_conversation: true
        prompt:
          text: |
            You are a knowledgeable developer. 
            Have an open-ended discussion with the caller about SignalWire and programmable communications.

📚 SWML docs View the full guide →

SWML
Call Flow Builder
Relay Realtime SDK (Server)
CXML

SWML

version: 1.0.0
sections:
  main:
    - play:
        url: 'say: Hello from SignalWire!'

📚 SWML docs `play` method reference

Relay Realtime SDK (Server)

import { SignalWire } from "@signalwire/realtime-api";

const client = await SignalWire({ project: "ProjectID Here", token: "Token Here" })

const voiceClient = client.voice;

// Listen for incoming calls
await voiceClient.listen({
  topics: ["office"],
  onCallReceived: async (call) => {
    console.log("Call received");
    // Answer the call
    call.answer();
    // Play TTS on the call
    await call.playTTS({
      text: "Hello from SignalWire!",
      }
    })
  }
});

📚 RELAY docs View the full guide →

CXML

<?xml version="1.0" encoding="UTF-8"?>
<Response>
     <Say>Hello from SignalWire!</Say>
</Response>

📚 CXML docs View the full guide →

SWML
Relay Realtime SDK (Server)
CXML
REST API

SWML

version: 1.0.0
sections:
  main:
    - send_sms:
        from_number: "+155512312345"
        to_number: "+15555554321"
        body: "Hello from SignalWire!"

📚 SWML docs View the full guide →

Relay Realtime SDK (Server)

import { SignalWire } from "@signalwire/realtime-api";

const client = await SignalWire({ project: "ProjectID Here", token: "Token Here"})

let messageClient = client.messaging;

const sendResult = await messageClient.send({
    from: "+155512312345",
    to: "+15555554321",
    body: "Hello from SignalWire!"
});

📚 RELAY docs View the full guide →

CXML

<?xml version="1.0" encoding="UTF-8"?>
<Response>
    <Message>
        <Body>Hello from SignalWire!</Body>
    </Message>
</Response>

📚 CXML docs View the full guide →

REST API

curl -L 'https://<YOUR_SPACE>.signalwire.com/api/laml/2010-04-01/Accounts/<PROJECT_ID_HERE>/Messages' \
-H 'Content-Type: application/x-www-form-urlencoded' \
-H 'Accept: application/json' \
-H 'Authorization: Basic <BASE64 ENCODED AUTHENTICATION STRING>' \
-d 'To=%2B155512312345' \
-d 'From=%2B15555554321' \
-d 'Body=Hello%20from%20SignalWire!'

📚 SignalWire API docs View the full guide →

SWML
CXML

SWML

version: 1.0.0
sections:
  main:
    - receive_fax: {}

📚 SWML docs View the full guide →

CXML

<?xml version="1.0" encoding="UTF-8"?>
<Response>
  <Receive></Receive>
</Response>

📚 CXML docs View the full guide →

Relay Realtime SDK (Server)
Relay Browser SDK

Relay Realtime SDK (Server)

import { SignalWire } from "@signalwire/realtime-api";

const client = await SignalWire({ project: "ProjectID Here", token: "Token Here" })

const chatClient = client.chat;

await chatClient.listen({
  channels: ["channel1"],
  onMessageReceived: async (message) => {
    console.log(message.content);
  }
});

await chatClient.publish({
        channel: "channel1",
        content: `Hello from SignalWire!`
    })

📚 RELAY docs View the full guide →

Relay Browser SDK

import { Chat } from "@signalwire/js";

const chatClient = new Chat.Client({
  token: "<your_chat_token>", // get this from the REST APIs
});

await chatClient.subscribe(["mychannel1", "mychannel2"]);

chatClient.on("message", (message) => {
  console.log("Received", message.content,
              "on", message.channel,
              "at", message.publishedAt);
});

await chatClient.publish({
  channel: "mychannel1",
  content: `Hello from SignalWire!`,
});

📚 RELAY docs View the full guide →

Relay Realtime SDK (Server)
Relay Browser SDK

Relay Realtime SDK (Server)

import { SignalWire } from '@signalwire/realtime-api'

const client = await SignalWire({ project: "ProjectID Here", token: "Token Here" })

const pubSubClient = client.pubSub;

await pubSubClient.listen({
  channels: ["mychannel1"],
  onMessageReceived: (message) => {
    console.log(message);
  }
});

await pubSubClient.publish({
  channel: "mychannel1",
  content: "Hello from SignalWire!"
});

📚 RELAY docs View the full guide →

Relay Browser SDK

import { PubSub } from "@signalwire/js";

const pubSubClient = new PubSub.Client({
  token: "<your chat token>", // get this from the REST APIs
});

await pubSubClient.subscribe(["mychannel1", "mychannel2"]);

pubSubClient.on("message", (message) => {
  console.log("Received", message.content,
              "on", message.channel,
              "at", message.publishedAt);
});

await pubSubClient.publish({
  channel: "mychannel1",
  content: "Hello from SignalWire!",
});

📚 RELAY docs View the full guide →

Relay Realtime SDK (Server)
Relay Browser SDK

Relay Realtime SDK (Server)

import { SignalWire } from "@signalwire/realtime-api";

// Initialize the SignalWire client
const client = await SignalWire({ project: "ProjectID Here", token: "Token Here" });

// Access video client from the main client
const videoClient = client.video;

// Setup listener for when a room starts
await videoClient.listen({
  onRoomStarted: async (roomSession) => {
    console.log("Room started", roomSession.displayName);

    roomSession.startStream({
      url: "rtmp://example.com/stream"
    })
  }
});

📚 RELAY docs View the full guide →

Relay Browser SDK

import * as SignalWire from "@signalwire/js";
import axios from "axios";

const rtmpUrl = "rtmp://example.com/live";

async function connect() {
    try {
        await navigator.mediaDevices.getUserMedia({ 
            video: true,
            audio: true
        });
    } catch (e) {
        console.error("Failed to get user media:", e);
        return;
    }

    const reply = await axios.post(
        "/get_token", // Make request to server to get video token from SignalWire Rest API
        {
            user_name: "user",
            room_name: "room"
        }
    )

    const roomSession = new SignalWire.Video.RoomSession({
        token: reply.data.token, // Obtained from SignalWire REST API
        rootElement: document.getElementById("video")
    })

    roomSession.on("stream.started", (m) => console.log(m));

    try {
        await roomSession.join()
        await roomSession.startStream({ url: rtmpUrl })
    } catch (e) {
        console.error("Failed to join room:", e);
    }
}

connect()

📚 RELAY docs View the full guide →

Core products

Want to get started with a specific channel? Start here.

AI

Integrated, powerful, scalable AI agents for your application

Voice

High-performance realtime and compatible APIs

Video

Fully customizable audio/video conferencing apps

Chat

Implement seamless in-browser chat using PubSub

Messaging

Programmable, high- throughput, compliant SMS & MMS

Fax

Programmable fax, certified SOC 2 Type II and HIPAA compliant

APIs, SDKs, and Tools

APIs and SDKs for SignalWire services that unify voice, video, chat, fax, and messaging.

Call Flow Builder

Build drag-and-drop calling apps without code

Click to Call

Embed one-click calling to phone numbers, AI Agents, and more on your website

SWSH CLI

SignalWire Shell command-line interface

WireStarter

Quick-start templates for SignalWire applications

AI

SignalWire AI services weave together LLMs, text-to-speech, speech-to-text and other AI services with PSTN, SIP, and WebRTC using a powerful underlying Call Fabric architecture and a comprehensive markup language called SWML.

AI Agents can call functions and connect to APIs with SWAIG

, utilize the Datasphere RAG stack, and programmatically adjust their own prompts using POM.