Vapi
Developer platform for building, testing, and deploying voice and chat AI agents at scale with full-stack control over the entire pipeline.
Overview
Vapi is a developer-first platform for building voice and chat AI agents that actually work in production. Rather than forcing you to stitch together separate speech-to-text, LLM, and text-to-speech services yourself, Vapi orchestrates the entire pipeline — handling the tricky latency optimization, turn-taking, and interruption detection that make voice agents feel natural rather than robotic.
The platform is built for engineers who need full control. You define your agent's behavior through a clean API or dashboard, wire up function calls for real-time actions (booking appointments, checking databases, transferring calls), and choose your own providers for each layer of the stack. Want GPT-4o for reasoning but ElevenLabs for voice? Swap them in without touching your agent logic. That modularity is what sets Vapi apart from more opinionated competitors.
With over 400,000 calls processed daily and consistently ranking among the top voice AI platforms in 2026, Vapi has proven itself in high-volume production environments. It's particularly strong for customer support automation, appointment scheduling, and outbound calling — anywhere you need an AI agent to handle real phone conversations at scale.
Key features
Voice AI Agents
Build conversational voice agents for inbound and outbound phone calls. The platform handles real-time speech recognition, natural turn-taking, interruption handling, and endpointing so conversations flow naturally.
Full-Stack Orchestration
Vapi manages the entire pipeline — STT, LLM inference, and TTS — with optimized latency between each step. No need to build and maintain your own orchestration layer.
Multi-Provider Flexibility
Bring your own LLM (OpenAI, Anthropic, Groq, open-source), voice provider (ElevenLabs, Deepgram, PlayHT), and telephony (Twilio, Vonage, SIP). Swap any component without rewriting agent code.
Function Calling & Tool Use
Define custom functions your agent can call mid-conversation — check inventory, book appointments, query CRMs, or transfer to a human. Supports parallel and sequential tool execution.
Pricing
Free tier: Free tier with limited minutes for prototyping and testing — no credit card required to start
| Plan | Price | What's included |
|---|---|---|
| Free | Free | Limited minutes to test and prototype, full API access, all core features |
| Pay As You Go | ~$0.05/min + provider costs | Usage-based pricing, no monthly minimum, full feature access, community support |
| Pro | $100/mo + usage | Lower per-minute rates, priority support, advanced analytics, team features |
| Enterprise | Custom | Volume discounts, dedicated support, SLAs, custom deployment options, HIPAA compliance |
Limited minutes to test and prototype, full API access, all core features
Usage-based pricing, no monthly minimum, full feature access, community support
Lower per-minute rates, priority support, advanced analytics, team features
Volume discounts, dedicated support, SLAs, custom deployment options, HIPAA compliance
Pros & cons
Pros
- ✓Provider-agnostic architecture lets you swap LLMs, voices, and telephony without code changes
- ✓Production-proven at scale with 400k+ daily calls across diverse use cases
- ✓Clean developer experience with well-documented APIs, SDKs, and a visual dashboard
- ✓Built-in function calling makes it straightforward to connect agents to external systems
Cons
- ×Developer-oriented — non-technical users will struggle without coding experience
- ×Per-minute costs add up fast at high volumes since you also pay underlying provider fees
- ×Voice quality depends on your chosen TTS provider, not Vapi itself
- ×Newer chat agent features are less mature than the core voice platform