Hail — Claude Code MCP server: calls, SMS and email for agents
Hands your agent a real phone number and an inbox. It runs as a remote MCP endpoint with OAuth sign-in, so nothing gets installed locally.
claude mcp add --transport http hail-mcp https://mcp.hail.soWhat Hail does
Hail is a hosted MCP server that lets an agent place calls, exchange texts and handle email. The voice side — speech recognition, speech synthesis, knowing when someone has finished talking — lives in the service, while your agent supplies the reasoning. Point it at any OpenAI-compatible endpoint, or leave the conversation to the built-in Anthropic → OpenAI → Gemini chain. Texts and mail follow the same pattern: one endpoint, one key, one bill.
In Claude you add it with a single command aimed at https://mcp.hail.so. Sign-in happens over OAuth, and the client asks you to log into Hail the first time you use it. No API key, no local MCP runtime. The CLI is separate: hail login stores a key in ~/.hail/credentials.json.
Running it yourself takes Docker Compose. Voice calls also need LiveKit Cloud, a carrier, Deepgram, Cartesia and an LLM provider; without AWS SES there is no email. A public production setup wants a domain, HTTPS and managed Postgres — the local stack bundles its own database.
What it helps with
- call a person and reschedule an appointment by voice
- send a text and check whether it was delivered
- receive an inbound message and read the thread
- get a number in a specific country for voice and SMS
- send mail and pull an attachment out of an inbox
Example prompts for the agent
- Use Hail to find call-capable numbers in the UK, France and Canada, then compare monthly and setup fees.
- Call +14155550100 and remind them about the appointment, keep it short.
- Text +15551234567 that the order is ready and show me the delivery status.
How to install Hail
Platform CLI: remote server
claude mcp add --transport http hail-mcp https://mcp.hail.soPlatform CLI: remote server
codex mcp add mcp --url https://mcp.hail.soConfig file
{
"mcpServers": {
"mcp": {
"url": "https://mcp.hail.so"
}
}
}Config file
{
"servers": {
"mcp": {
"type": "http",
"url": "https://mcp.hail.so"
}
}
}Platform CLI: remote server
gemini mcp add -t http mcp https://mcp.hail.soStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about Hail
How do I install Hail in Claude Code?
Run claude mcp add --transport http hail-mcp https://mcp.hail.so, then complete the OAuth sign-in when the first request prompts you.
What does Hail do?
It gives an agent a phone number and an email inbox. Calls, texts and mail all go through one MCP endpoint, with the voice pipeline handled server-side.
Does Hail need an API key?
Not for the hosted server — OAuth covers authentication. A key only matters when you self-host, where it is set in .env as HAIL_API_KEY.
