Show HN: Hail.so – Send and receive emails, calls, SMS via a single MCP/API/CLI

Category: devtools

Tags: api, ai-agents, communication, voice-calls, sms, email, mcp, twilio, open-source

Score: 7.3/10 (Innovation: 7, Technical: 7, Documentation: 8, Utility: 7)

Hail is an open-source universal communication platform that provides a unified API, CLI, and MCP server for AI agents to send and receive phone calls, SMS, and emails. It combines multiple communication channels into a single stream and features a pluggable voice pipeline with support for various STT/TTS providers and LLM backends, making it an innovative tool for building voice and messaging capabilities into AI agents.

Target audience: backend developers, AI engineers, devops

Repository: https://hail.so/ · Python · AGPL-3.0 · 3 stars

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