Vapi

Vapi (vapi.ai) is a voice AI orchestration layer that sits between your phone system and your AI models. You connect a speech-to-text provider (Deepgram, AssemblyAI, Whisper), a language model (GPT-4o, Claude, Gemini), and a text-to-speech engine (ElevenLabs, Azure, Play.ht), and Vapi handles the real-time call pipeline — turn-taking, interruptions, backchanneling, and tool calls — at sub-500ms latency. The platform is API-first: every configuration is programmable, making it the go-to infrastructure layer for developer teams building production voice agents.

Key Features

• Bring Your Own Stack — mix and match STT, LLM, and TTS providers; full API control over every component
• Real-time call handling — endpointing, interrupt detection, backchanneling, and emotion cues built in
• Squads — chain multiple specialized agents in a single call with handoffs between roles
• Function calling — trigger external APIs mid-call for CRM updates, booking, or lookups
• Knowledge base (RAG) — upload PDFs and docs for agents to reference live during calls
• Webhooks & analytics — call transcripts, cost breakdowns, and per-component usage dashboards

Vapi Pricing

• Free trial — $10 in credits at signup, 60 free minutes. No credit card required.
• Pay-As-You-Go — $0.05/min platform fee + separate charges for STT, LLM, and TTS providers. Real-world all-in cost typically lands between $0.15–$0.33/min depending on model choices.
• Enterprise — custom pricing — volume discounts, HIPAA compliance ($1,000/mo add-on), dedicated support, SSO, and extended call history.Pricing is subject to change. Always check the latest rates on the official website. For more AI tool reviews, visit aitoolscoop.com.

Who Should Use Vapi?

Vapi is the right platform for developer and engineering teams that want maximum control over every layer of their voice agent stack. If your team already has contracts with OpenAI, Deepgram, and ElevenLabs and wants a production-grade orchestration layer on top, Vapi provides that without vendor lock-in. Teams that need predictable all-in pricing or no-code setup will find Retell AI a simpler alternative.