Claude Code, Cursor and others

Programs that run on your computer or your server connect with an agent key: you create the agent in mailrust, choose its rights, and paste the key into the program.

Create an agent

1. Open Agents in the side panel and go to New agent.
2. Give it a name you will recognise, for example Claude Code on my laptop.
3. Choose its rights and, if you want, the mailboxes it may see and how long it may work.
4. Press Create agent.

The key starts with mra_ and is shown once. Copy it right away: mailrust keeps only its fingerprint, so a lost key cannot be shown again; create a new agent instead.

Claude Code

claude mcp add --transport http mailrust https://mail.example.com/mcp \
  --header "Authorization: Bearer mra_..."

Cursor

In ~/.cursor/mcp.json:

{
  "mcpServers": {
    "mailrust": {
      "url": "https://mail.example.com/mcp",
      "headers": { "Authorization": "Bearer mra_..." }
    }
  }
}

Any other program

Send the key in every request:

POST /mcp HTTP/1.1
Host: mail.example.com
Authorization: Bearer mra_...
Content-Type: application/json
Accept: application/json, text/event-stream

The same address serves the 2026-07-28 protocol and the earlier versions that start with initialize.

Keep keys safe

• One agent per program and machine: revoking one does not stop the others.
• Give an expiry to keys you hand to experiments.
• A key in a repository or a shared file is a key for anyone: revoke it and create a new one.