MCP

An MCP email server: your agent gets a real inbox in one config entry

Agents constantly need email — to receive a verification message, wait for a human reply, or get notified by a system that only speaks SMTP. Gmail OAuth is painful to set up and worse to demo. mxu.io is a remote MCP server (Streamable HTTP) that gives any MCP-capable agent — Claude Code, Claude Desktop, or your own framework — a live inbox at name@mxu.io with zero mail infrastructure.

Setup (Claude Code)

claude mcp add --transport http mxu \
  https://api.musicsupplies.com/functions/v1/mxu-mcp \
  --header "Authorization: Bearer mxu_live_YOUR_KEY"

Or in any MCP JSON config:

{
  "mcpServers": {
    "mxu": {
      "type": "http",
      "url": "https://api.musicsupplies.com/functions/v1/mxu-mcp",
      "headers": { "Authorization": "Bearer mxu_live_YOUR_KEY" }
    }
  }
}

The tools your agent gets

Tool	What it does
`create_inbox`	Mint `name@mxu.io` — live and receiving instantly
`wait_for_message`	Block up to 55s until mail arrives (the agent-loop killer feature)
`get_latest_message`	Newest message with `extracted.otp` / `extracted.verify_link`
`get_messages`	List messages, newest first, with extraction
`reply`	Answer in-thread with proper headers, DKIM-signed (paid plans)
`send_email`	Guardrailed outbound send (paid plans)
`list_inboxes` / `delete_inbox` / `account_info`	Housekeeping

What an agent loop looks like

create_inbox(name: "scout")            → scout@mxu.io, live
# agent signs up for a service with that address, or shares it with a human
wait_for_message(inbox: "scout")       → blocks until mail arrives
# message.extracted.otp = "482913" — the agent enters the code and continues
reply(message_id, text: "Confirmed — proceeding.")

Why extraction is deterministic (not AI)

The agent calling the tools already has a brain. What it lacks is structure: mxu parses OTP codes, links, and verification URLs with rules, so the values are exact, instant, and free — and your agent spends its tokens on the task, not on reading email HTML.

Free to start

The free plan is receive-only with 48-hour retention — perfect for OTP flows and demos. Paid plans from $9/month add sending, longer retention, and more inboxes. Pricing →

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