What it is
Vapi is a developer-first platform for building AI voice agents.
What you'd use it for
You would use Vapi to build a highly customised voice agent in code, choosing your own models, with sub-second response targets.
Examples of use
A developer wants a voice agent shaped to their own product. They build it in code with Vapi, choosing exactly which models it uses.
A team wants to test a phone support idea fast. They prototype a custom experience with Vapi's API.
A voice product needs to feel responsive. The team builds it on Vapi, which targets sub-second response.
The default model does not fit a particular use case. The team swaps in their own through Vapi's bring-your-own-model support.
A product needs a voice channel but the team does not want a finished platform. They add the channel with Vapi instead.
A startup engineering team would rather assemble the voice agent themselves. Vapi gives them the building blocks to do it.
How it works
Vapi is API-first, with bring-your-own-model support. The developer assembles the voice agent from its building blocks.
How it compares
Vapi is a builder's voice platform, like Retell AI. Both sell the parts; PolyAI and Replicant sell finished products.
What others say
A widely used voice-AI developer platform. No formal analyst evaluation was found.