asyncio powered FreeSWITCH cluster control
Clone or download



asyncio powered FreeSWITCH cluster control using pure Python 3.5+

pypi travis versions license docs

switchio (pronounced Switch Ee OoH) is the next evolution of switchy (think Bulbasaur -> Ivysaur) which leverages modern Python's new native coroutine syntax and, for now, asyncio.

API-wise the project intends to be the flask for VoIP but with a focus on performance and scalability more like sanic.

Use the power of async and await!

Build a routing system using Python's new coroutine syntax:

from switchio.apps.routers import Router

router = Router(
        'Call-Direction': 'inbound',
        'variable_sofia_profile': 'external'},
    subscribe=('PLAYBACK_START', 'PLAYBACK_STOP'),

async def welcome(sess, match, router):
    """Say hello to inbound calls.
    await sess.answer()  # resumes once call has been fully answered"Answered call to {}".format(match.groups(0)))

    sess.playback(  # non-blocking
    await sess.recv("PLAYBACK_START")"Playing welcome message")

    await sess.recv("PLAYBACK_STOP")
    await sess.hangup()  # resumes once call has been fully hungup

Run this app (assuming it's in from the shell:

$ switchio serve fs-host1 fs-host2 fs-host3 --app ./

You can also run it from your own script:

if __name__ == '__main__':
    from switchio import Service
    service = Service(['fs-host1', 'fs-host2', 'fs-host3'])
    service.apps.load_app(router, app_id='default')

Spin up an auto-dialer

Run thousands of call flows to stress test your service system using the built-in auto-dialer:

$ switchio dial fs-tester1 fs-tester2 --profile external --proxy --rate 100 --limit 3000


pip install switchio


Oh we've got them docs!

How do I deploy my FreeSWITCH cluster?

See the docs for the deats!

What's included?

  • A slew of built-in apps
  • A full blown auto-dialer originally built for stress testing VoIP service systems
  • Super detailed ESL event logging

How can I contribute?

Have an idea for a general purpose switchio app or helper? Make a PR here on GitHub!

Also, if you like switchio let us know on Riot!

Wait, how is switchio different from other ESL clients?

switchio differentiates itself by supporting FreeSWITCH process cluster control as well as focusing on leveraging the most modern Python language features. switchio takes pride in being a batteries included framework that tries to make all the tricky things about FreeSWITCH a cinch.

What if I'm stuck on Python 2?

Check out these other great projects:

Performance monitoring

If you'd like to record performance measurements using the CDR app, some optional numerical packages can be used:

Feature Dependency Installation
Metrics Capture pandas pip install switchio[metrics]
Graphing matplotlib pip install switchio[graphing]
HDF5 pytables [1] pip install switchio[hdf5]
[1]pytables support is a bit shaky and not recommended unless you intend to locally process massive data sets worth of CDRs. The default CSV backend is usually sufficient on a modern file system.


All files that are part of this project are covered by the following license, except where explicitly noted.

This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at