Tone/Docs

Introduction

Tone gives your AI agent a real phone number in minutes. One API for inbound calls, outbound calls, and SMS — with TRAI compliance handled automatically.

What you can build

  • Voice AI agents — connect your LLM to a real phone line. Tone handles audio streaming, STT (Sarvam AI), TTS (Simran voice), and call routing.
  • Outbound dialers — initiate calls programmatically. Your webhook receives live transcripts as call.turn events.
  • SMS automation — send transactional SMS and receive inbound messages via webhook.
  • MCP integration — drop the Tone MCP server into Claude Desktop and let your agent provision numbers and make calls with zero code.

Core concepts

| Concept | Description | |---|---| | Number | A provisioned phone number owned by your account. Can be TRANSACTIONAL or PROMOTIONAL. | | Call | An inbound or outbound call session. Has a transcript, duration, and state. | | SmsLog | A sent or received SMS message tied to one of your numbers. | | ApiKey | A tone_live_... key used to authenticate REST API requests. | | Webhook | An HTTP endpoint you control. Tone posts events here (call turns, SMS). |

Authentication

All API requests require a Bearer token — either a Clerk JWT (dashboard sessions) or a tone_live_... API key.

Authorization: Bearer tone_live_abc123...

Base URL

https://api.usetone.ai/v1

Ready? Start with the Quickstart.