Vapi
by Vapi AI
Developer platform for voice agents. Build, deploy, and operate phone-first AI with code, in days not months.
Agents
Vapi
Added 17 May 2026
Overview
Vapi is the developer-flavoured voice agent platform. Compose a voice agent from your choice of STT, LLM, and TTS providers, wire in tools and webhooks, and Vapi handles call orchestration, telephony, and observability. The closest thing to a Stripe for voice agents.
Best for
Best for
Developers shipping custom voice agents in a real product
Use cases
- Build a custom voice agent in a few hundred lines of code
- Swap STT, LLM, or TTS provider without rewriting plumbing
- Outbound and inbound campaigns with full call observability
- Add voice as an interface to an existing tool-calling agent
Notes
Why it matters
Vapi is the platform answer for teams that want to build a voice agent, not buy a finished one. It is the Stripe-shaped layer the voice-agent stack needed.
How teams use it in production
Start with one tightly scoped flow, instrument latency end to end, then add a second flow. Vapi’s strongest feature is the observability that makes that loop possible.
What to watch
The competitive set with Retell and Bland is converging on a similar API shape. Vapi’s lead is the developer experience and the observability layer.
Pros
- Provider-agnostic, swap LLM or voice without lock-in
- Strong webhook + tool calling model
- Call observability is genuinely useful, not a stat dashboard
- Fast iteration loop from dashboard to deploy
Cons
- Developer-first, no non-engineer authoring path
- Costs stack across STT, LLM, TTS, and Vapi itself
- Latency tuning still needs engineering taste
Pairs with
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