Test modeNo letter goes into the mail. No money is charged.What this means
Agent Letter Desk

For Claude, ChatGPT and, soon, Meta Muse

Your AI writes the letter. We put it in the post.

Ask your AI for a cancellation, a dispute or a complaint. Agent Letter Desk checks the letter, lays it out for the post, shows you a preview and the price. When you approve, it mails the letter in your name.

Connect your AI How it works
Destinations
31 countries
In the US
USPS Certified Mail
Proof of delivery
US, BE, DE, ES
Page one of an A4 letter as the server lays it out: the address in the envelope window, the sender in the letterhead, the text below, the page number at the foot.85.525.5TEST MODENOT MAILED · NOT CHARGED1234

Page one of an A4 letter

  1. The address sits in the envelope window, 85.5 × 25.5 mm. The post reads it there.
  2. The sender is you: the name from your account.
  3. The text your AI wrote with you, checked before it gets a price.
  4. Page numbers and enclosures, set by the server.

01How it works

Three steps. You approve the last one.

  1. Connect once.

    Add Agent Letter Desk to Claude or ChatGPT with one URL. Sign in and enter your name. Every letter carries that name.

  2. Ask your AI.

    Say what you need, in your own words. Your AI writes the letter with you. The server checks it and lays it out for the post.

    “Cancel my gym membership. Send it by registered mail.”

  3. Approve the preview and the price.

    Open the PDF. Check the recipient and the price. Then tell your AI to send it. You can cancel until the letter is printed.

02Safeguards

Rules the server keeps.

An AI can make mistakes. These checks run on our server for every letter, whatever the AI says. They are code, not instructions to the AI.

  1. Preview before send

    A letter can only be sent after the server prepared it: checked, laid out, priced, with a PDF preview for you.

  2. The price you saw

    The send must carry the exact price of the preview. A different price is refused.

  3. The recipient you saw

    The send must name the recipient of the preview. A different name is refused.

  4. A pause for a person

    A letter cannot be sent in the first 10 seconds after its preview. An AI that prepares and sends in one step is stopped.

  5. Never twice

    Each letter is sent once. The same letter to the same recipient again is refused, unless you ask for a second copy.

  6. No blanks, no examples

    A letter with a blank such as [Name], or with an example address, is refused. Your AI must ask you for the real value.

  7. Your name, from your account

    The sender is the account holder. The name comes from your account page. An AI cannot change it.

  8. Cancel until printing

    Cancel a prepared letter at any time. A sent letter can be cancelled until the printer starts on it.

Every letter and every enclosure also passes an automatic content check for threats, harassment, extortion and hate before it gets a price. One sender can mail the same recipient at most 3 times in 30 days.

03Destinations

Where letters go.

Within the United States by USPS Certified Mail. To 30 European countries, from Europe or the US. The recipient’s country decides the postal service.

Proof of delivery

Only letters to United States, Belgium, Germany and Spain come with proof of delivery. Every other route has no tracking and no proof. Your AI must tell you before you approve the letter.

With proof of delivery

Recipient inPostal serviceWhat you getBusiness daysTest price
United States USPS Certified Mail with electronic return receipt Tracking and the recipient’s signature 3–5 $14.99
Belgium bpostRegistered Standard (legal mailing receipt)Or a standard letter, without proof: €4.90 Tracking and proof of delivery, no signature 1–2 €13.90
Germany Deutsche PostEinschreiben EinwurfOr a standard letter, without proof: €4.90 Tracking and proof of delivery, no signature 1 €6.90
Spain CorreosCarta Certificada (with receipt)Or a standard letter, without proof: €4.90 Tracking and the recipient’s signature 2–4 €9.90

By the local post, without proof

Recipient inPostal serviceBusiness daysTest price
Austria Austrian PostPremium Brief 1 €4.90
Luxembourg bpost / Post LuxembourgEconomy Letter 2–3 €4.90
Netherlands PostNLStandaard 1–2 €4.90
Switzerland Swiss PostA Mail 1 €4.90
United Kingdom Royal Mail1st Class 1 €6.90

International priority letter by DHL, without proof

22 countries, 2–11 business days.

  • Bulgaria3–5€4.90
  • Croatia3–5€4.90
  • Cyprus6–10€4.90
  • Czechia2–4€4.90
  • Denmark3–6€4.90
  • Estonia3–7€4.90
  • Finland3–7€4.90
  • France3–7€4.90
  • Greece7–11€4.90
  • Hungary2–5€4.90
  • Ireland3–5€5.90
  • Italy2–5€4.90
  • Latvia3–5€4.90
  • Lithuania2–5€4.90
  • Malta8–10€6.90
  • Norway3–7€4.90
  • Poland2–5€4.90
  • Portugal2–5€4.90
  • Romania4–9€4.90
  • Slovakia2–5€4.90
  • Slovenia2–6€4.90
  • Sweden3–6€4.90

PricesTest prices for a one-page letter, as the server quotes them today. Nothing is charged. In Europe, more pages cost more; your AI shows the exact price of each letter before you approve it.

SendersA letter to the United States needs a sender in the United States. A letter to Europe can come from any of 33 countries: the EU, Iceland, Liechtenstein, Norway, Switzerland, the United Kingdom and the United States.

ReturnsIf the post cannot deliver a letter in Europe, the post destroys it. It does not come back. The status then shows “undeliverable”.

04Connect

Connect your AI.

Agent Letter Desk is a remote MCP server. Add it to your AI app with this address.

Server URL

https://agentletterdesk.com/mcp

Claude

claude.ai, desktop and mobile

  1. Open SettingsConnectors.
  2. Choose Add custom connector.
  3. Enter a name and paste the server URL. Select Connect.
  4. Sign in and allow access. Then turn the connector on in a chat.

ChatGPT

chatgpt.com

  1. Open PluginsAdd.
  2. Choose Add custom MCP server.
  3. Paste the server URL. Choose OAuth.
  4. Sign in and allow access.

Custom MCP servers are not available on every ChatGPT plan.

Meta Muse

Coming

Muse has no custom connectors. A connection needs Meta’s review first. It is not available yet.

You sign in with your e-mail address. On the consent page you can give read-only access: untick “Prepare, send and cancel letters”.

05For AI agents

If you are an AI agent, read this.

Follow these steps for every letter. The server enforces the important ones.

  1. Connect to the MCP server at https://agentletterdesk.com/mcp (Streamable HTTP). It uses OAuth 2.1: the user signs in on our page and approves the access.

  2. Call get_account first. The sender of every letter is the account holder. Use the default sender address.

  3. Write the letter with the user. Ask the user for every name, number, date and address. Do not use placeholders or example values.

  4. Call prepare_letter. It checks the letter, lays it out and returns a PDF preview link and the price.

  5. Show the user the preview link, the recipient, the postal service and the price. Say so when the route has no proof of delivery.

  6. Wait for the user’s clear yes. Do not call send_letter in the same answer as prepare_letter.

  7. Call send_letter with the letter_id, the recipient name, the price and the number of enclosures that the user approved.

  8. Give the user the status and the tracking number. Call cancel_letter if the user wants to stop the letter before printing.

This is a test system. Tell the user that no letter goes into the mail and that nothing is charged.

06Privacy

Your letter is kept only until it is done.

The text of a letter and its enclosures stay on our server only until the letter reaches a final state: sent, failed, cancelled or expired. Then they are deleted. We never store the PDF; the preview is drawn each time you open it. After sending, we keep the record that you need: recipient name, status, price and tracking number. The pages you are reading set no cookies, use no trackers and load nothing from other servers.

Read the privacy policy

07Test mode

Every step runs, except the post.

Agent Letter Desk is in test mode. Letters go to the test systems of our print and mail partners, which never print or mail them. No money is charged; the prices are what the test service quotes. Paid mailing starts later, with full terms.

Read the terms of the test