The heating is off, there is mould, or water comes through the ceiling. As a tenant in Germany, you must tell your landlord about a defect without delay (§ 536c (1) BGB). You describe it in English; your AI writes the defect notice (Mängelanzeige) in German, the landlord's language, and shows you what it says. We send it in your name as a registered letter.
Why a letter, not e-mail
- You need to show that the landlord got it. A tenants' association in Munich writes that an e-mail alone is not suitable proof of receipt (Mieterverein München, fact sheet, in German).
- Without a notice, you can lose rights. A tenant who does not report a defect can owe damages and lose the rent reduction for that time (§ 536c (2) BGB).
- Many private landlords give no e-mail address. A letter reaches them, and the landlord does not have to sign for it or pick it up. The post's mailbox record helps, but on its own it is no proof in court (What a registered letter proves).
Example to copy
I rent a flat in Germany. Since Monday the heating in the living room is cold. Write a defect notice in German to my landlord, with a deadline of two weeks, and say that I pay the rent under reservation. Show me an English translation. Then send it as an Einschreiben.
Your AI asks for the landlord's name and address, the address of the flat and the details of the defect. Photos can go with it as enclosures; each page raises the price, which you see before you say yes.
What the notice should contain
The Mieterverein München names four points:
- The defect: what, where, since when, clearly enough for a stranger.
- The effect: how it limits your use of the flat.
- The reservation: you pay the rent from now on under reservation (unter Vorbehalt).
- The deadline: a concrete date, usually two weeks. Allow for printing and the post.
Not possible: ending the lease. In Germany it needs a handwritten signature (§ 568 BGB), so our server refuses it.
FAQ
Why in German?
The letter goes to a landlord in Germany. A letter in German avoids any doubt about what it says. Your AI shows you an English version before you approve.
May I reduce the rent?
That depends on the defect and the case. The Mieterverein advises to get advice first and to pay the rent under reservation until then. We give no advice on it.
Does the notice need my signature?
The law sets no form for the notice. Our letter carries your name in print. If your lease asks for a signed notice, our letter is not enough for that: we cannot sign for you.
Sources
Checked on 17 October 2026.
- § 536c BGB, § 568 BGB (official English translation); the German text: § 536c, § 568
- Mieterverein München: Merkblatt zur richtigen Mängelanzeige für Mitglieder (October 2023, in German)
- Deutsche Post: Einschreiben (in German)
- Federal Labour Court: 2 AZR 184/25 (7 May 2026), report by beck-aktuell, in German
Use it with Claude, ChatGPT, Grok or Mistral Vibe
Before the launch, only invited testers can create an account. Everyone else can join the waitlist.
Add Agent Letter Desk to your AI app once, with this server URL: https://
- Claude (claude.ai, desktop and mobile): Add to Claude opens Claude with the name and the URL filled in. Select Add, then Connect. Sign in and allow access. In a chat, select + › Connectors and turn on Agent Letter Desk. By hand: Customize › Connectors › + Add › Add custom connector, then paste the URL.
- ChatGPT (chatgpt.com): copy the URL and open ChatGPT. Plugins › Add › Add custom MCP server. Paste the URL, choose OAuth, sign in and allow access. Worked on the Free plan when we checked (13 October 2026). OpenAI decides which plans can add one.
- Grok (grok.com): copy the URL and open Grok's connectors. New connector › Custom. Enter a name and paste the URL. Sign in and allow access in the window that opens. In a chat, type @ and pick Agent Letter Desk (Grok uses a connector only when you select it).
- Mistral Vibe (chat.mistral.ai, formerly Le Chat): copy the URL and open Mistral Vibe's connectors. + Add Connector › Custom MCP Connector. Enter a name without spaces, such as AgentLetterDesk, and paste the URL. Sign in and allow access. In a chat, select + › Connectors › Agent Letter Desk (without this step, Mistral Vibe may write the letter itself). Works on the free plan.
You sign in with your e-mail address or your Google account. Then ask your AI for the letter. You check the preview and the price. Nothing goes out without your yes.
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