Connect mcpbrief to Claude

mcpbrief is a remote MCP server. Add the URL once as a connector, log in – and from then on you can send letters and registered mail from any chat.

Connector URL https://mcpbrief.de/mcp

Open Claude connectors ↗

Claude.ai · Claude Desktop · Claude Mobile

Add as a connector

Open Settings → Connectors in Claude (claude.ai or the desktop app).
Click “Add custom connector”.
Name: mcpbrief, URL: https://mcpbrief.de/mcp
Click Connect, log in to mcpbrief and approve access.
Then just write in the chat: “Send … by post to …”

In Team and Enterprise organizations, an admin may need to approve the connector. In ChatGPT it works the same way via Settings → Apps & Connectors.

Claude Code

Claude Code (terminal)

With browser login:

claude mcp add --transport http mcpbrief https://mcpbrief.de/mcp

Or with an API key:

claude mcp add --transport http mcpbrief https://mcpbrief.de/mcp \
  --header "Authorization: Bearer mbx_YOUR_KEY"

Create API keys under Account → API keys.

ChatGPT · Grok · Gemini

ChatGPT, Grok and Gemini

ChatGPT: Settings → Apps & Connectors → Create connector, enter URL https://mcpbrief.de/mcp, sign in with mcpbrief.
Grok: grok.com → Connectors → add your own MCP server, URL https://mcpbrief.de/mcp, authentication via header Authorization: Bearer mbx_… (API key from your account).
Gemini: custom MCP server via URL https://mcpbrief.de/mcp (Gemini Enterprise via admin with OAuth; personal accounts via “Connected Apps” where available).

Examples

„Send the attached invoice by post to Muster GmbH, Ringstraße 5, 1010 Wien.“

„Write a cancellation of my contract 4711 to the insurance company (address in the PDF) and send it as registered mail.“

„Has my registered letter from yesterday been handed over to the postal service yet? What is the tracking number?“

„How much balance do I have left?“

Available tools

Tool	Description	Type
`get_letter_price`	Checks the address, lays out the letter, counts pages, calculates the cost and returns a PDF preview. Sends nothing.	read-only
`send_letter`	Sends a letter by post (text, Markdown, PDF, DOCX, image – as content, Base64 or URL). Only after confirmation.	charged
`get_letter_status`	Returns the dispatch status and, for registered mail, the tracking number.	read-only
`get_letter_history`	Lists your recent letters.	read-only
`get_batch_price` · `send_letter_batch`	Mail merge: one letter per recipient with placeholders (check price or send).	charged
`resend_letter`	Sends a previous letter again with the stored document (only after confirmation).	charged
`cancel_letter`	Cancels a letter as long as it has not been printed yet (the amount is refunded).	refunded
`get_account_balance`	Shows balance, prices, sender and daily limit.	read-only

Passing letters

Claude passes the address as “recipient” and the letter text as “content” – mcpbrief turns them into a finished A4 letter with letterhead, the address in the envelope window, date and page numbers.

{
  "recipient": {
    "name": "Stadtwerke Musterstadt GmbH",
    "company": "Kundenservice",
    "street": "Hauptstraße 1",
    "zip": "10115",
    "city": "Berlin",
    "country": "DE"
  },
  "delivery": "registered",
  "subject": "Kündigung Vertrag 4711",
  "content": "Sehr geehrte Damen und Herren,\n\nhiermit kündige ich …\n\nMit freundlichen Grüßen\nMax Muster",
  "idempotency_key": "6f1c…"
}

Alternatively: file_base64 + file_name (PDF, DOCX, TXT, MD, JPG, PNG) or file_url (public https link) – an address sheet is then added in front.