Open alternatives3
Open-source apps that replace Twilio
LiveKit is a server that lets people, devices and AI agents talk by voice, video and data in the same online room. It is for developers who want to build calling, video or voice AI features into their own apps and run them on their own servers.
Fonoster is a self-hostable platform for building voice apps and AI voice agents that make and answer real phone calls, with PBX features and SDKs. It is for developers who want programmable phone calls without relying on a closed service, and it can also be used through Fonoster Cloud.
OpenVidu is a self-hosted video and audio system that lets you run your own video conferencing app or build custom video features. It is aimed at organisations and developers who want to keep their calls on their own servers.
What's missing
What people still miss here, and wish existed. Upvote what matters to you.
Before you build
Planning something for phone & voice APIs? See what exists first, so you can reuse parts or explain what's different. Paste this into any AI assistant:
Fix the list itself
A project or closed app missing from this list, or a mistake on it? These open a short form on GitHub, and a mod reviews it. To say what a project can't do, use What's missing.
About this page
Replaces fully means it does the main job of these apps; Replaces partly means it covers some of it.
Licenses: every project here uses an open-source license (what each one means). Open core means some parts are paid or under another license.
GitHub stars are shown for reference. They measure popularity, not whether it replaces anything.
Verified means r/TrueOpenSource mods checked it: open-source license, maintained, and it really does the job.
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