Open PBX (OPBX)

OPBX is Cloudonix's Open Source business phone system and contact center suite. Simple, fast and FREE to use with Cloudonix.

OPBX - the magical phone system

Business phone systems no longer need technical skills. Cloudonix’s OPBX project makes them easy for anyone to use—just like managing a web server. Your customers want fast answers, and missed calls mean lost revenue. Cloudonix gives your business smart, flexible tools to handle calls at scale.

OPBX includes AI voice agents integrations, IVR menus, call queues, conference rooms, and automated dialers. There are no licensing fees, hidden charges, or integration costs—just a simple system you can run on‑premise or in the cloud.

up and running in 5 minutes

  1. Register with Cloudonix — Create your FREE Cloudonix account at https://cockpit.cloudonix.com. Then, create a new API Key in your default domain.
  2. Create an OPBX organization — Create you FREE OPBX organization at https://opbx.cloudonix.cloud. Configure your Cloudonix API Key in OPBX to start your setup.
  3. Connect the MCP Server — Connect your AI agent to the OPBX MCP server, using the same API Key. Tell your AI what your PBX requirements are, and watch it go.

Visit the OPBX Public Repository at https://github.com/greenfieldtech-nirs/opbx

Open Source built for MSPs and Agencies

OPBX is a native multi‑tenant platform, so you can manage any number of organizations without extra integration or licensing.”

We created OPBX with MSPs in mind, allowing MSPs to start small and scale rapidly - without incurring a hefty licensing cost or operational expense. Using an inexpensive virtual machine and a $69 Cloudonix starter subscription, an MSP can support up to 50 customers and more than 2,000 extensions.

Native Voice agent routing

OPBX makes connecting to your favorite Voice Agent platform quick and simple. With over 30 different voice agent platforms, both commercial and Open Source, voice agents are at your finger tips.

Inbound or outbound, OPBX handles both with simple call routing workflows and voice agents load distribution between multiple voice agent providers.

real-time notifications and more

OPBX has business automation in mind, with full outbound webhook integration to any of your favorite automation tools. n8n, Make, Zapier, Active Pieces, just point OPBX to your integration endpoint - OPBX will actively report any call, any state change, any event.

Use Claude Code or Codex, and the OPBX MCP server to manage your system with AI, all features available at no extra cost.

human designed, ai crafted, free and open for everyone

See how Cloudonix can fit your operations and support your growth. Our team will help you identify high-value use cases, map the customer journey, and design a voice strategy that improves response times, agent productivity, and customer satisfaction. Ready to replace slow, siloed calling processes with an intelligent platform built for modern communication? Book a Cloudonix conversation and discover how AI-first voice orchestration can unlock your next wave of growth.

schedule a demo with an opbx expert

Are you an MSP or agency? schedule a call with an OPBX expert at Cloudonix, and see how OPBX can help you close more deals and improve your business outcome.

Book a meeting (Schedule a Demo, 45 min) on this page.

Frequently asked questions

What is Open PBX (OPBX)?

Open PBX (OPBX) is Cloudonix's open-source business phone system and contact center suite. It is designed to be simple, fast, and completely free to use with Cloudonix.

How does Cloudonix help businesses handle customer calls at scale?

Cloudonix provides the intelligence and flexibility to respond immediately to customer inquiries, helping to secure missed revenue opportunities. It orchestrates every voice interaction through AI-powered workflows designed to qualify, assist, escalate, and convert.

How does Cloudonix replace traditional static menus and manual routing?

Instead of relying on static menus, manual routing, or fragmented tools, Cloudonix automates interactions using intelligent, AI-powered workflows. This ensures a seamless customer experience without the need for manual routing.

How can the Cloudonix team help improve my operations and customer satisfaction?

The Cloudonix team will help you identify high-value use cases, map the customer journey, and design a custom voice strategy. This tailored approach is designed to improve response times, boost agent productivity, and increase customer satisfaction.

What are the key benefits of replacing slow, siloed calling processes with Cloudonix?

Replacing legacy systems with Cloudonix gives you an intelligent platform built for modern, scalable communication. It allows you to orchestrate voice interactions dynamically to convert prospects and assist customers more efficiently.

Is Open PBX free to use?

Yes, Open PBX is a simple, fast, and free open-source business phone system. It is completely free to use when you run it with the Cloudonix platform.