So we wrote the entire code and open sourced it as a Visual drag-and-drop for voice agents ( same as vapi or n8n for voice). Built on a Pipecat fork and BSD-2, no strings attached. Tool calls, knowledge base, variable extraction, voicemail detection, call transfer to humans, multilingual support, post-call QA, background noise suppression, and a website widget are all included. You're not paying per-minute fees to a middleman wrapping the same APIs you'd call directly.

You can set it up with a simple docker command. It comes pre-wired with Deepgram, Cartesia, OpenAI , Speechmatics Sarvam for STT, same for TTS, and OpenAI, Gemini, groq, Openrouter, Azure on the LLM side. Telephony works out of the box with Twilio, Vonage , CLoudonix and Asterisk for both inbound and outbound.

There's a hosted version at app.dograh.com if self-hosting isn't your thing.

Repo: github.com/dograh-hq/dograh Video walkthrough: https://youtu.be/sxiSp4JXqws

We built this out of frustration, not a thesis. The tool is free to use and fully open source (and will always remain so), happy to answer questions about the data or how we built it.