Vapi

Overview

Vapi is a comprehensive infrastructure platform that enables developers to build, test, and deploy intelligent voice AI agents. By abstracting the complexities of telephony, speech-to-text, and text-to-speech, it allows for fast integration into existing applications. The platform provides tools for managing sophisticated conversation workflows, enabling natural, human-like interactions for sales, support, and scheduling use cases at scale.

What it does

• Orchestrates STT, LLM, and TTS providers for real-time voice conversations.
• Enables complex agent behavior through customizable system prompts and function calling.
• Supports multi-agent 'Squads' for handling specialized, multi-step customer service workflows.
• Provides granular API-first control over latency, audio quality, and conversation state management.

Who it's for

• Software Developers
• Product Managers
• Enterprise Engineering Teams
• AI/LLM Application Builders

Why it works

• The platform offers a modular, architecture-agnostic approach that lets developers swap STT, LLM, and TTS providers to optimize for cost or performance.
• It significantly accelerates time-to-market by handling the low-level telephony and audio piping that typically requires specialized engineering resources.
• Strong API-first design and comprehensive documentation provide technical teams with the flexibility needed for high-volume, enterprise-grade production deployments.
• Built-in observability, testing suites, and experiment tracking allow teams to iterate on prompts and voice workflows with data-driven confidence.

Founder story

Founded in 2020 by Jordan Dearsley in San Francisco, Vapi was created to solve the gap between highly capable LLMs and human-like voice communication. Frustrated by the lack of developer-friendly tools to connect these models to telephony at scale, Dearsley built an infrastructure layer that allows businesses to deploy reliable, real-time voice agents that can actually resolve customer intents.

Alternatives

• Retell AI
• Bland AI
• Deepgram
• Synthflow

Comparison overview

• vs Retell AI: Vapi focuses on a more modular architecture that allows users to bring their own model keys for every layer of the voice stack.
• vs Bland AI: Vapi is generally perceived as more developer-centric and API-first, whereas Bland AI often emphasizes high-volume outbound automation out-of-the-box.