Telephony GitHub Repositories (2026) · Open Source Tools

Open source voice AI platform. Self-hosted alternative to Vapi and Retell. On Prem, BYOK across Speech to Speech or LLM/STT/TTS, with a visual workflow builder, MCP native and telephony support.

Open-source realtime voice agent server in Go with WebRTC (WHIP), barge-in, streaming STT/LLM/TTS pipelines, plugin system, multi-language SDKs, SIP telephony, ESP32 support & fully local mode.

Modern open-source multi-tenant PBX built on FreeSWITCH, Laravel and Vue. An alternative to FusionPBX, FreePBX and 3CX.

One binary. One YAML. Zero exposed PBX. FreeSBC is a pure-Go SBC that keeps FreeSWITCH/Asterisk off the public internet—SIP proxy, RTP/SRTP relay, WebRTC gateway, and built-in SIP security.

Modern and flexible SIP/VoIP cli tool

A complete voice AI building block with telephony integration, featuring real-time speech-to-text, text-to-speech, and LLM-powered conversational agents.

Modern Android dialer with built-in contacts, fast call history, AMOLED themes, dual-SIM support, privacy-focused calling, and rich contact management — a powerful alternative to Google Phone

MikoPBX — free open-source PBX for small business, built on Asterisk 22, PHP 8.4, and Phalcon 5. Deploy as ISO, Docker, LXC, or in the cloud.

A Java library for communicating with the Twilio REST API and generating TwiML.

Self-hosted, API-first AI call center. Realtime voice bots answer every call, human agents take over without a drop. Full REST + SSE API with OpenAPI spec to embed in your product. FreeSWITCH + OpenAI Realtime / Qwen, one Go binary.

IVOZ Provider - Multitenant solution for VoIP telephony providers

The world's only Open Source CPaaS with a Twilio compatible API

Make and receive phone calls through a paired Bluetooth phone, from your KDE desktop

Twilio C#/.NET Helper Library for .NET6+.