ai voice agent platforms

speech, model and synthesis in one websocket api

phone agents for inbound call handling and appointment booking

outbound and inbound ai calling built on a contact-centre stack

the only vendor whose headline band already includes telephony, stt, tts and the llm — with the sub-rates printed underneath.

apache 2.0 top to bottom — self-host it and the platform fee simply stops existing.

bsd-licensed, provider-agnostic, and free if you run it yourself — the framework the others are competing with.

bundles the llm, stt and tts with no token charges — the simplest bill here, with telephony left outside it.

five cents a minute for vapi, and everything that makes a phone call work costs extra.

calls its rate 'all-in' on a page that lists telephony and llm tokens as separate charges.

the best voices in the business, sold without an agent price anywhere on the site.

the lowest teaser rate in the category, on a pricing page that returns 404.

free to build, undisclosed to run, and $30,000 a year to buy properly.