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.

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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 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 docsView the full guide →

Relay Browser SDK

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 docsView the full guide →

SWML

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 docsView the full guide →

Call Flow Builder

Call Flow Builder

📚 Call Flow Builder docsView the full guide →

SWML

SWML

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

📚 SWML docs`play` method reference

Call Flow Builder

Call Flow Builder

📚 Call Flow Builder docsView the full guide →

Relay Realtime SDK (Server)

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 docsView the full guide →

CXML

CXML

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

📚 CXML docsView the full guide →

SWML

SWML

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

📚 SWML docsView the full guide →

Relay Realtime SDK (Server)

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 docsView the full guide →

CXML

CXML

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

📚 CXML docsView the full guide →

REST API

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 docsView the full guide →

SWML

SWML

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

📚 SWML docsView the full guide →

CXML

CXML

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

📚 CXML docsView the full guide →

Relay Realtime SDK (Server)

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 docsView the full guide →

Relay Browser SDK

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 docsView the full guide →

Relay Realtime SDK (Server)

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 docsView the full guide →

Relay Browser SDK

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 docsView the full guide →

Relay Realtime SDK (Server)

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 docsView the full guide →

Relay Browser SDK

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 docsView the full guide →

SWML

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 docsView the full guide →

Call Flow Builder

Call Flow Builder

📚 Call Flow Builder docsView the full guide →

SWML

SWML

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

📚 SWML docs`play` method reference

Call Flow Builder

Call Flow Builder

📚 Call Flow Builder docsView the full guide →

Relay Realtime SDK (Server)

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 docsView the full guide →

CXML

CXML

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

📚 CXML docsView the full guide →

SWML

SWML

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

📚 SWML docsView the full guide →

Relay Realtime SDK (Server)

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 docsView the full guide →

CXML

CXML

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

📚 CXML docsView the full guide →

REST API

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 docsView the full guide →

SWML

SWML

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

📚 SWML docsView the full guide →

CXML

CXML

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

📚 CXML docsView the full guide →

Relay Realtime SDK (Server)

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 docsView the full guide →

Relay Browser SDK

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 docsView the full guide →

Relay Realtime SDK (Server)

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 docsView the full guide →

Relay Browser SDK

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 docsView the full guide →

Relay Realtime SDK (Server)

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 docsView the full guide →

Relay Browser SDK

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 docsView the full guide →

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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

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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

SignalWire AI Gateway

, utilize the Datasphere RAG

Retrieval Automated Generation

stack, and programmatically adjust their own prompts using POM

Prompt Object Model

.

AI Agents

Create and manage AI agents for voice, video, and text interactions

SWML AI method

Create and manage AI agents for voice, video, and text interactions using SWML

SWAIG

A serverless function framework that connects Voice AI agents to APIs

Datasphere

SignalWire RAG: upload, manipulate, and retrieve information in the context of a SignalWire application

Prompt Object Model

A structured data format and accompanying Python SDK for composing, organizing, and rendering prompt instructions for LLMs

Tools

Tools to help you make the most of SignalWire services efficiently.

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

Compatibility

Use SignalWire services using APIs and SDKs with compatibility APIs that facilitate transition from other providers and legacy systems.

Compatibility REST APIs

REST APIs for compatibility services

Compatibility SDKs

SDKs for compatibility services

cXML

XML specification for handling calls and messages to your phone number, compatible with legacy systems

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