Hail

Overview

Hail is a communications platform for AI agents and backends, founded in 2025 in Sweden and run as a hosted service by Hail HQ. The whole platform is open source under AGPL-3.0 at github.com/hail-hq/hail and can be self-hosted with Docker Compose. It covers AI voice calls, SMS and email. It does not offer iMessage, RCS or WhatsApp.

Key features

• Saved agents that answer calls and texts on a number, with shared history across both
• Outbound AI calls with transcripts, recording, and handover of a live call to a person
• Bring your own OpenAI-compatible LLM for calls
• Two-way SMS (text only, no MMS) with automatic STOP and HELP handling
• Email on mail.hail.so or your own domain, with delivery and bounce events
• Numbers in 120+ countries, quoted live across Twilio, Telnyx and DIDWW
• Remote MCP server with OAuth, REST API, Go CLI, Python SDK and signed webhooks with redelivery

Pricing

Hail Cloud is prepaid with no subscription. Voice costs $0.10 a minute, including the phone connection, voice, transcription and language model, plus $0.01 a minute for recording. A US text costs $0.018, and email costs $1 per 1,000. Numbers are rented at carrier cost, from $0.50 a month. Self-hosting is free, but you pay LiveKit Cloud, your carrier and model providers.

How it compares to Linq

Linq is built around iMessage, with RCS and SMS fallback; Hail has no iMessage or RCS and sends SMS without MMS. Hail's API places and answers AI voice calls and handles email, while Linq's API does not place or answer calls and does not offer email. Hail charges per minute, text and email, while Linq charges a flat monthly fee from $260 with no per-message fees. Hail can be self-hosted from its AGPL source; Linq is a closed, fully managed service.

Best for

Teams building agents that need phone calls, SMS and email without iMessage, especially those who want to self-host or audit the code.

Sources

• hail.so
• hail.so/pricing
• hail.so/about
• hail.so/llms.txt
• hail.so/llms-full.txt
• hail.so/sms
• hail.so/voice
• hail.so/email
• hail.so/integrations
• hail.so/docs/mcp
• hail.so/docs/agents
• hail.so/docs/webhooks
• hail.so/docs/byo-llm
• hail.so/docs/cli
• hail.so/docs/self-host
• hail.so/docs/api
• hail.so/skill.md
• hail.so/legal/dpa
• hail.so/legal/terms
• github.com/hail-hq/hail