Esl

This module has been superseded by the esl-lite module.

esl-lite provides:

• better documentation
• better performance
• automatic reconnection to FreeSwitch
• better LSP integration and safer operations due to precise typing of all operations
• integrated support for CUSTOM events
• integrated support for FreeSwitch logging
• updated extensive test suite

esl-lite is based on the esl module, which was started in 2011 and has served the community well over the years. esl-lite is geared towards supporting large scale deployments for the foreseeable future!

Overview

This module was a promise-based client ('inbound' event socket) and server ('outbound' event socket) for FreeSwitch, written entirely in Javascript.

The new esl-lite module provides only a client ('inbound') API, since the server API does not scale well.

Support

Commercial support is available as well from the author.

Migrating to esl-lite

If you have been using the esl module in client ('inbound') mode, migrating to esl-lite is simple.

• No need to manage disconnection/reconnections anymore. The client will reconnect transparently and re-establish event triggers.
• All APIs are now available directly on the client. You explicitly provide the Unique-ID for uuid commands. Per-operation timeouts are required.

const client = new FreeSwitchClient({ logger })
client.on('CHANNEL_CREATE', (msg) => {
  …
  client.command_uuid(msg.body.uniqueId, 'answer', '', 4000).catch( logger.error )
})
await client.bgapi('originate sofia/profile/sip:destination@host &park')
client.custom.on('conference::maintenance', (msg) => { … })

• APIs no longer throw — inspect the outcome of the commands instead.

const outcome = await client.bgapi('originate …')
if (outcome instanceof Error) {
  // failed
} else {
  // success
}

If you have been using the esl module in server ('outbound') mode, migrating to esl-lite isn't too difficult either.

• Replace your dialplan with inline:park (instead of inline:'socket:… async full').
• Your application should use FreeSwitchClient instead of FreeSwitchServer.
• Replace .on( 'connection', … ) with a proper handler for ingress calls.

client.on('CHANNEL_CREATE', (msg) => {
  if (msg.body.data['Direction'] !== 'inbound') {
    return
  }
  // Your code here
})

• All APIS are now available directly on the client. You explicitely provide the Unique-ID for uuid commands. Per-operation timeouts are required.
• APIs no longer throw — inspect the outcome of the commands instead

Head over to the online documentation for additional details.