esl-lite v3.1.1
FreeSwitch Event Socket Client
esl-lite is a dedicated, optimized, simplified, client-only version of the esl package for Node.js.
This package is written in TypeScript, includes JsDoc inline documentation and extensive type definitions (including events), and exposes both CJS and ESM versions.
Like the venerable esl package (started in 2011), it is used in production worldwide.
Which package should I use?
Use esl only if server mode is required.
Use esl-lite otherwise. Event Socket server-mode does not scale well.
Installation
npm i esl-liteyarn add esl-liteGetting Started
import { FreeSwitchClient } from 'esl-lite'
import pino from 'pino'
const logger = pino.default()
const client = new FreeSwitchClient({ logger })
client.on('CHANNEL_CREATE', (msg) => {
  logger.info( msg.body.data, 'new call')
  const uuid = msg.body.uniqueID
  if (uuid) {
    // Send command to a specific channel!
    client.command_uuid(uuid, 'answer', '', 4000).catch( logger.error )
  }
})
// Send generic commands
await await.bgapi('originate sofia/profile/sip:destination@host &park')
// For CUSTOM messages with Event-Subclass, use the `.custom` event-emitter.
client.custom.on('conference::maintenance', (msg) => { … })Exception reporting
esl-lite should never throw or reject. Instead, all methods report errors using custom classes.
These are clearly listed in the TypeScript return types.
Documentation
FreeSwitchClient is the main class and provides most features.
Source
The primary repository is https://g.rie.re/shimaore/esl-lite
Also available on Github and Gitlab.
About
Written by Stéphane Alnet
Changelog
v3.0
- simplified: reconnection handling is now hidden- missed commands are automatically requeued upon reconnection
 
- expanded documentation
- added .logsevent emitter
v2.0
- added automatic event jsonwhen subscribing to events
- made .event_jsonmethod private since it is no longer needed — added.customevent-emitter to properly serve CUSTOM events