Hail documentation

Hail is a universal communication platform for AI agents — outbound phone calls, SMS, and email behind one MCP endpoint, one API key, one invoice. Most people use Hail Cloud; the whole stack is also self-hostable (AGPLv3).

Using Hail Cloud

• MCP clients — connect Claude.ai, ChatGPT, Cursor, or any MCP client. Paste a URL, click Allow, done.
• Webhooks — signed JSON events for inbound mail, SMS, delivery reports, and call outcomes.
• Bring your own LLM — point voice calls at your own OpenAI-compatible endpoint.
• CLI reference — the hail binary's email and webhooks surface.
• API reference — every REST endpoint, generated from the OpenAPI spec.

Understanding Hail

• Architecture — the three Python services, the Go CLI, and how LiveKit Cloud fits in.

Running it yourself

• Self-hosting — the umbrella: one-VM deploy, provider setup (LiveKit, Twilio, SES), SMTP inbound, and the operations runbook.
• Contributing — dev environment, regenerating OpenAPI, PR flow.

Source lives at github.com/hail-hq/hail. Every page here is also plain markdown in docs/public/ — anything in that folder is published, anything outside it is not.