Does the agent need an API key or signup?

No. The mailbox and its token are created on demand by the create_mailbox tool. There's no account, no key, and nothing to configure beyond adding the server. That's the main thing that sets smails apart from key-gated MCP email servers.

Which MCP clients work?

Any MCP client. The server runs over stdio via npx, so Claude Desktop, Claude Code, Cursor, and others all work with the same config.

Does it extract the verification code for me?

It returns the full parsed message; the agent reads the code or magic link out of the body — something LLM agents do reliably. For scripts, parse the returned text or HTML.

Can a human see the same inbox?

Yes. The CLI, the REST API, the MCP server, and the website all drive the same mailbox, so you can watch what your agent receives.

Can the agent send email?

Not yet — smails is receive-only. It's built for inbound verification codes, magic links, and confirmations, not outbound or two-way threads.

MCP · Free · No API key · No signup

A free disposable email MCP server for your AI agent.

Sign-ups and logins gate AI agents behind email verification codes. The smails MCP server gives your agent its own throwaway inbox — no API key, no signup — so it can create an address and read the codes, magic links, and confirmations it receives on its own.

Add the server Try the web inbox

Why this one

Other MCP email servers make you register and pass an API key. smails doesn't.

No API key — the agent provisions its own mailbox at runtime.
No signup, no account, no card. Free.
Same mailbox across MCP, CLI, REST API, and the web — watch what your agent receives.
Runs over stdio via npx — nothing to install or host.

Set it up

The server ships with the @smails/cli npm package and runs over stdio — no install, no key.

Claude Code

terminal

claude mcp add smails -- npx -y @smails/cli mcp

Claude Desktop / Cursor / any MCP client

Add this to your MCP config (e.g. ~/.claude/mcp.json):

mcp.json

{
  "mcpServers": {
    "smails": {
      "command": "npx",
      "args": ["@smails/cli", "mcp"]
    }
  }
}

Tools the agent gets

create_mailbox

Create a fresh disposable address and start receiving — no key.

get_address

Return the agent's current mailbox address.

list_messages

List messages in the mailbox (sender, subject, preview).

read_message

Read a message's full parsed body — the agent extracts the code or link.

delete_message

Delete a message once the agent is done with it.

How an agent reads a verification code

1
Agent calls create_mailbox and gets an address like a8f3@smails.dev.
2
It pastes that address into the sign-up form it's automating.
3
The service emails a verification code; smails receives it instantly.
4
Agent calls list_messages, then read_message, and reads the code straight out of the body.
5
It submits the code and finishes the flow — no human in the loop.

Prefer raw HTTP or a shell? The same flow works over the REST API and is walked through end to end in reading verification codes.

FAQ

Give your agent an inbox.

Open the web app for a live inbox, or wire up the MCP server above and let your agent handle email itself.

Open smails GitHub