# Agent Letter Desk

> AI apps write letters. Agent Letter Desk sends them as real post, with status, the post's delivery record where the post keeps one, and e-mail updates, one letter or many. A remote MCP server that mails paper letters for the user of an AI agent (Claude, ChatGPT, Grok, Mistral Vibe; not tested by us yet: Gemini custom apps in the US, Meta Muse custom connectors in the US (Canada later), Perplexity custom connectors on paid plans, background agents (Claude Duet, ChatGPT dots, Gemini Task mode (formerly Spark), Grok Bot), OpenClaw and Hermes Agent). The agent writes the letter with the user; the server checks it, lays it out, shows a PDF preview and the price, and mails it in the name of the signed-in account holder after the user approves.

- MCP server URL: https://agentletterdesk.com/mcp (Streamable HTTP, OAuth 2.1)
- Sign-up: letters are mailed now. Until the launch in early November 2026, only invited users can create an account. Other users can join the waitlist at https://agentletterdesk.com/waitlist.
- Destinations: 31 countries. Within the United States (Certified Mail with return receipt, or a standard letter); to 30 European countries from Europe or the US.
- Routes and prices: see the table “Routes” in https://agentletterdesk.com/llms-full.txt. It lists each destination with its postal services, what each records, the business days and the price of one page. One page costs from €2.20 in Europe and from $2.99 in the US. list_letter_types gives the same data, with the sender countries.
- What is recorded: every letter, the handover to the post (a standard letter records only that). A registered letter to the United States, Belgium, Germany and Spain (prepare_letter postal_service "registered", the default there) also records the delivery; in the United States and Spain also the signature. In Belgium, bpost records the posting and the delivery. On its own, the receipt is proof of posting, not proof of delivery. Proof of delivery needs an acknowledgement of receipt (avis de réception). We do not offer it yet. In Germany, Deutsche Post records the date on which the carrier reports the letter as put into the mailbox. On its own, this record is not proof of delivery in a German court. In the US it is Certified Mail with return receipt: the user gets the tracking number, the USPS tracking link (it shows the delivery) and our e-mail when USPS has the letter; we cannot get the signed return receipt for the user yet. To Austria, there are two standard letters. postal_service "standard": Austrian Post Brief, 2–3 business days, €2.90. "standard_next_day": Austrian Post Premium Brief, usually next business day, €3.20. Both record only the handover. Tell the user both prices and delivery times. Let the user choose. If the letter has a deadline, recommend "standard_next_day". To Germany, there are two standard letters. postal_service "standard": Deutsche Post Economy, 2–3 business days, €2.20. "standard_next_day": Deutsche Post Standardbrief, usually next business day, €3.20. Both record only the handover. Tell the user both prices and delivery times. Let the user choose. If the letter has a deadline, recommend "standard_next_day".
- prepare_letter quotes the price of each letter.
- Also for a reply to a letter that the user received, and for an objection to an official decision (Einspruch, Widerspruch). The agent reads the user's photo of the letter in the chat. Do not upload the photo to this server. Details: “When a letter is the right choice” in https://agentletterdesk.com/llms-full.txt.
- Also for agents that work in the background: a reminder by registered letter when an invoice stays unpaid, or a notice before a contract deadline. Prepare the letter when the trigger comes. Then ask the user to approve it. Give the user the order_url only after the user approved this letter, its recipient and its price.

## For AI agents

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. If the account has no address, ask the user for it and call save_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. Tell the user the note of the postal service: what it records and what it does not prove. A standard letter records only the handover, not the delivery.
6. Wait for the user’s clear yes. Then write the order_url from prepare_letter in the chat as text.
7. The user orders and pays on the order page. Then the server sends the letter. Do not call send_letter: it sends only a free resend.
8. After the order, call get_letter_status. Give the user the status and the tracking number, if the service has one. Call cancel_letter if the user wants to stop the letter before printing.

## Use with Gemini (US, English)

Gemini connects to this server as a custom app. Google sets these limits:

- The user is in the US and is 18 or older.
- The user uses Gemini in English.
- The user signs in to Gemini with a personal Google account. Work and school accounts cannot add custom apps.
- Keep Activity is on. If it is off, custom apps are not available.

Steps for the user:

1. Open gemini.google.com.
2. Open Settings › Connected Apps › Custom apps.
3. Select “Add a custom app”.
4. Enter the MCP server URL https://agentletterdesk.com/mcp. Do not add a slash at the end.
5. Select Next.
6. Sign in on our page.
7. Allow the access.

If Gemini does not use the app, type @ in the chat. Select Agent Letter Desk.

Gemini asks the user to confirm each write action. This confirmation does not replace the user’s approval of the preview and the price. The inline preview possibly does not show in Gemini. Always give the user the preview link.

## Use with Mistral Vibe (formerly Le Chat)

Mistral Vibe connects to this server as a custom connector. All plans can add one. This includes the free plan. On a Team or Enterprise plan, an administrator adds it.

Steps for the user:

1. Open https://chat.mistral.ai/connections (the Connectors page of chat.mistral.ai).
2. Select “+ Add Connector”.
3. Select “Custom MCP Connector”.
4. Enter a name without spaces, for example AgentLetterDesk.
5. Enter the server URL https://agentletterdesk.com/mcp. Do not add a slash at the end.
6. Select Connect. Mistral Vibe finds the OAuth sign-in by itself.
7. Sign in on our page.
8. Allow the access.

In each chat for a letter, select + › Connectors › Agent Letter Desk. If the user does not select it, Mistral Vibe can write the letter itself. Then nothing is mailed.

Mistral Vibe asks the user to approve each write action. This approval does not replace the user’s approval of the preview and the price. Mistral Vibe shows no inline preview. Before the approval, always give the user the preview link, the postal service and the full price.

## Use with Meta Muse (US and Canada)

Muse connects to this server as a custom connector. Meta sets this limit: the user is in the US or in Canada and is 18 or older. Meta does not review custom connectors.

Steps for the user:

1. Open Muse.
2. Send Muse this message: “Create a custom connector for Agent Letter Desk. It is a remote MCP server at https://agentletterdesk.com/mcp. It uses OAuth.”
3. Sign in on our page.
4. Allow the access.

Then ask Muse for a letter.

A sender in Canada cannot send a letter yet. We do not know if Muse shows the inline preview. Before the approval, always give the user the preview link, the postal service and the full price.

## Use with Perplexity (paid plans)

Perplexity connects to this server as a custom remote connector. Perplexity offers custom connectors on Pro, Max and Enterprise, not on the free plan. On Enterprise, an administrator must allow custom connectors.

Steps for the user:

1. Open Account settings › Connectors.
2. Select “+ Custom connector”. Then select Remote.
3. Enter the name Agent Letter Desk and the server URL https://agentletterdesk.com/mcp.
4. Tick the acknowledgement box. Select Add.
5. Select the new connector card.
6. Sign in on our page in the window that opens.
7. Allow the access.

In a chat, select Agent Letter Desk in the connector picker, or type @ and select it. The sources of the chat must include apps.

Perplexity can ask the user to approve actions that write. This approval does not replace the user’s approval of the preview and the price. We do not know if Perplexity shows the inline preview. Before the approval, always give the user the preview link, the postal service and the full price.

## Use with background agents (Claude Duet, ChatGPT dots, Gemini Task mode (formerly Spark), Grok Bot)

These agents work for the user without a new chat. Claude Duet, ChatGPT dots and Gemini Task mode use the connections of the user's AI app. Grok Bot has its own connections. We have not tested these agents yet.

- Claude Duet (US, Pro and Max, research preview): Duet uses the connectors of the user's Claude account. Connect Agent Letter Desk in Claude first.
- ChatGPT dots (Pro outside the EEA, Switzerland and the UK; Business Premium): a dot uses the apps of the user's ChatGPT account. Connect Agent Letter Desk in ChatGPT first.
- Gemini Task mode (formerly Spark; US, Google AI Pro or Ultra): Task mode uses the custom apps of the user's Gemini account. Add Agent Letter Desk as a custom app first. See “Use with Gemini (US, English)”.
- Grok Bot: Grok Bot has its own plugins. It does not use the connectors of grok.com. In Grok Bot, open Connect apps. Add a custom MCP server (Remote HTTPS) with the URL https://agentletterdesk.com/mcp. Sign in on our page when Grok Bot asks.

Some agents can act without asking the user. Do not send a letter that way. Prepare the letter when the event happens. Then ask the user to approve this letter, its recipient and its price. Give the user the order_url only after that approval. The user orders and pays on the order page.

## Use with OpenClaw or Hermes Agent

OpenClaw and Hermes Agent run on the user's own computer or server. Both connect to remote MCP servers with OAuth. We have not tested them yet.

Steps for OpenClaw:

1. Open Settings › MCP in the OpenClaw Control UI.
2. Select “Add server”. Enter the name agent-letter-desk.
3. Select Streamable HTTP.
4. Enter the server URL https://agentletterdesk.com/mcp. Select “Add server”.
5. In the config editor, set `auth: "oauth"` for this server.
6. Select “Sign in” for this server. Sign in on our page and allow the access.
7. Check the server with `openclaw mcp doctor agent-letter-desk --probe`.

Steps for Hermes Agent:

1. Open `~/.hermes/config.yaml`.
2. Under `mcp_servers`, add `agent_letter_desk` with `url: "https://agentletterdesk.com/mcp"` and `auth: oauth`.
3. Run `hermes mcp login agent_letter_desk`.
4. Sign in on our page in the browser. Allow the access.
5. In a Hermes session, run `/reload-mcp`.

We do not know if OpenClaw or Hermes Agent shows the inline preview. Before the approval, always give the user the preview link, the postal service and the full price.

## Docs

- [Full facts for agents](https://agentletterdesk.com/llms-full.txt): tools, routes, prices, rules, sign-in and privacy in one file
- [Home page](https://agentletterdesk.com/index.md): what the service does, how to connect, where letters go (for the United States)
- [Privacy policy](https://agentletterdesk.com/privacy.md): what is stored and for how long
- [Terms of use](https://agentletterdesk.com/terms.md): the service, liability, no legal advice
- [Support](https://agentletterdesk.com/support.md): help, cancel a letter, disconnect an app, delete the account

## Pages by market

The same service and the same prices on every page; each page leads with its market's routes and examples. Send people to the page of their country.

- [United States](https://agentletterdesk.com/index.md) (https://agentletterdesk.com/): Certified Mail with return receipt, or a standard letter; prices in dollars, from $2.99.
- [Europe, in English](https://agentletterdesk.com/eu.md) (https://agentletterdesk.com/eu): registered and standard letters to 30 European countries; prices in euros, from €2.20.
- [Europe, in German](https://agentletterdesk.com/de/index.md) (https://agentletterdesk.com/de): the page for Europe in German.

## Guides

When a postal letter is better than e-mail, and how to send one. The links are the Markdown versions; each HTML page has the same URL without ".md". Index: https://agentletterdesk.com/guides

- [When a letter is the right choice (and when e-mail is enough)](https://agentletterdesk.com/guides/letter-or-email.md): E-mail is often enough. A letter is better with no e-mail address, a deadline to prove, or a law that says 'in writing'. Some letters need your signature.
- [Ask for your security deposit back by Certified Mail](https://agentletterdesk.com/guides/security-deposit-demand-letter.md): Ask your former landlord for your deposit by USPS Certified Mail. Your AI writes the letter; we mail it for $17.99. No post office.
- [Answer a letter you received, with your AI](https://agentletterdesk.com/guides/answer-a-letter-with-ai.md): Add a photo of the letter to the chat. Your AI reads it and writes the reply with you. You approve preview and price, we print and post it.
- [Cancel a gym membership by Certified Mail](https://agentletterdesk.com/guides/cancel-gym-membership-certified-mail.md): Your gym contract says to cancel by mail? Your AI writes the cancellation letter; we mail it by USPS Certified Mail for $17.99. No post office.
- [Dispute a credit card billing error by Certified Mail](https://agentletterdesk.com/guides/credit-card-billing-error-letter.md): Send a written billing error notice to your card issuer within 60 days. Your AI writes it; we mail it by USPS Certified Mail, $17.99.
- [Dispute a debt and request validation by Certified Mail](https://agentletterdesk.com/guides/debt-validation-letter-certified-mail.md): Dispute a debt in writing before the end date on the collector's notice. Your AI writes the letter with you; we mail it by Certified Mail. No debt relief.
- [Defect notice to your landlord in Germany, in English](https://agentletterdesk.com/guides/defect-notice-landlord-germany.md): Renting in Germany? Your AI writes the defect notice (Mängelanzeige) in German; we send it as an Einschreiben for €6.30.
- [GDPR access request when e-mail does not work](https://agentletterdesk.com/guides/gdpr-access-request-registered-letter.md): No privacy contact or no answer? Your AI writes the GDPR access request; we send it as a registered letter to Germany for €6.30.
- [Send a registered letter to Belgium](https://agentletterdesk.com/guides/registered-letter-to-belgium.md): Registered letter to Belgium from your AI app: bpost records the posting and the delivery. €15.90, preview first, no post office.
- [Send a registered letter to Spain](https://agentletterdesk.com/guides/registered-letter-to-spain.md): Registered letter with signature to Spain from your AI app: Correos carta certificada for €9.50. Check the preview first. No post office.
- [Ask a debt collector to stop contacting you, by Certified Mail](https://agentletterdesk.com/guides/stop-debt-collector-contact-letter.md): Tell a debt collector in writing to stop contacting you. Your AI writes the letter; we mail it by USPS Certified Mail, $17.99. No debt relief.
- [What a registered letter proves](https://agentletterdesk.com/guides/what-a-registered-letter-proves.md): What the post records for each of our services, and when that record alone is not proof of delivery: Germany, Belgium, Spain, the US, standard letters.
- [Withdraw from a contract with a company in another EU country](https://agentletterdesk.com/guides/withdraw-contract-eu-company.md): Withdraw within 14 days from a contract with a company in another EU country. Your AI writes it; we mail it, as a registered letter where we offer one.
- [Send a real letter from Claude](https://agentletterdesk.com/guides/send-letter-from-claude.md): Add Agent Letter Desk to Claude once. Claude writes the letter with you, you approve preview and price, we print and post it. 31 countries.
- [Send a registered letter from ChatGPT](https://agentletterdesk.com/guides/send-registered-letter-from-chatgpt.md): Connect once, ask ChatGPT, check the preview and price, say yes. We print and post it. US Certified Mail; registered mail to Germany, Belgium and Spain.

## Card guides

Greeting cards for recipients in the United States. Make a card at https://agentletterdesk.com/cards. Index: https://agentletterdesk.com/cards/guides

- [When to mail Christmas cards in 2026](https://agentletterdesk.com/cards/guides/christmas-card-mailing-deadlines-2026.md): USPS says mail First-Class Christmas cards by Thursday, December 17, 2026. Order cards from your AI chat by December 14 (our estimate).
- [A Christmas card with your own photo](https://agentletterdesk.com/cards/guides/photo-christmas-card.md): Put a family photo on the front of a printed Christmas card from your AI chat: which photos print well, the people's consent, and how to upload.
- [Send one card to many people](https://agentletterdesk.com/cards/guides/send-one-card-to-many-people.md): One card, one order, one approval for up to 100 people in the US, each card with its own greeting name. Prices from $5.49 a card, and tips for your list.
- [Turn a photo into a Christmas card drawing](https://agentletterdesk.com/cards/guides/turn-a-photo-into-a-christmas-card-drawing.md): Turn a photo of your family or pet into a painted Christmas card: which photos work, styles that fit, likeness tips and the consent of the people in it.
- [What to write in a Christmas card](https://agentletterdesk.com/cards/guides/what-to-write-in-a-christmas-card.md): Christmas card wording for family, friends, colleagues, neighbors and someone who had a hard year, religious or not, with short sign-offs.
- [What to write in a sympathy card](https://agentletterdesk.com/cards/guides/what-to-write-in-a-sympathy-card.md): Sympathy card wording for a friend, a colleague, a neighbor or family, short or longer, religious or not, what to avoid, and what to write when it is late.
- [What to write in a wedding thank-you card](https://agentletterdesk.com/cards/guides/what-to-write-in-a-wedding-thank-you-card.md): Wedding thank-you card wording for a gift, a money gift, a guest who travelled, helpers and group gifts, when to send, and how to thank many guests.

## German pages

The website in German, for people who read German. The German terms (https://agentletterdesk.com/de/terms) are a German text. The German privacy policy and imprint (https://agentletterdesk.com/de/privacy, https://agentletterdesk.com/de/imprint) keep their English text until a lawyer reviews a German version (the imprint's data sources are in German).

- [Home page in German](https://agentletterdesk.com/de/index.md): the same facts as the English home page
- [Support in German](https://agentletterdesk.com/de/support.md): help, cancel a letter, disconnect an app, delete the account

## Guides in German

Index: https://agentletterdesk.com/de/ratgeber

- [Wann ein Brief die richtige Wahl ist (und wann eine E-Mail reicht)](https://agentletterdesk.com/de/ratgeber/brief-oder-e-mail.md): Oft reicht eine E-Mail. Ein Brief lohnt sich ohne E-Mail-Adresse, bei einer Frist mit Zugangsnachweis oder wenn ein Gesetz ihn verlangt.
- [Einen erhaltenen Brief mit der KI beantworten](https://agentletterdesk.com/de/ratgeber/brief-mit-ki-beantworten.md): Fügen Sie ein Foto des Briefs in den Chat ein. Ihre KI schreibt die Antwort mit Ihnen. Sie geben Vorschau und Preis frei, wir drucken und versenden.
- [DSGVO-Auskunft per Einschreiben: wenn die E-Mail nicht reicht](https://agentletterdesk.com/de/ratgeber/dsgvo-auskunft-per-einschreiben.md): Unternehmen ohne Datenschutz-Kontakt oder ohne Antwort? Ihre KI schreibt den DSGVO-Antrag, wir senden ihn als Einschreiben für 6,30 €.
- [Einschreiben nach Belgien verschicken](https://agentletterdesk.com/de/ratgeber/einschreiben-nach-belgien.md): Einschreiben nach Belgien aus Ihrer KI-App: bpost dokumentiert Einlieferung und Zustellung. 15,90 €, erst die Vorschau, ohne Postamt.
- [Einschreiben nach Spanien verschicken](https://agentletterdesk.com/de/ratgeber/einschreiben-nach-spanien.md): Einschreiben mit Unterschrift nach Spanien aus Ihrer KI-App: Correos carta certificada für 9,50 €. Erst die Vorschau prüfen. Ohne Postamt.
- [Mängelanzeige an den Vermieter per Einschreiben mit KI](https://agentletterdesk.com/de/ratgeber/maengelanzeige-vermieter-per-einschreiben.md): Wohnungsmangel? Ihre KI schreibt die Mängelanzeige mit Frist, wir senden sie als Einschreiben (Einwurf) für 6,30 €. Die Post dokumentiert den Einwurf.
- [Was ein Einschreiben belegt](https://agentletterdesk.com/de/ratgeber/was-belegt-ein-einschreiben.md): Was die Post bei jeder unserer Versandarten dokumentiert und wann der Beleg allein kein Zustellnachweis ist: Deutschland, Belgien, Spanien, USA.
- [Widerruf per Einschreiben: Telefon- und Haustürverträge](https://agentletterdesk.com/de/ratgeber/widerruf-per-einschreiben.md): Vertrag am Telefon oder an der Haustür geschlossen? Ihre KI schreibt den Widerruf, wir senden ihn als Einschreiben (Einwurf) für 6,30 €.
- [Einschreiben aus ChatGPT verschicken](https://agentletterdesk.com/de/ratgeber/einschreiben-aus-chatgpt-verschicken.md): Einmal verbinden, ChatGPT fragen, Vorschau und Preis prüfen, Ja sagen. Einschreiben (Einwurf) nach Deutschland 6,30 €. Nach Österreich nur Standardbrief.

## Discovery

- [MCP server card](https://agentletterdesk.com/mcp/server-card): name, version and endpoint (SEP-2127)
- [AI catalog](https://agentletterdesk.com/.well-known/ai-catalog.json): points to the server card
- [API catalog](https://agentletterdesk.com/.well-known/api-catalog): the MCP endpoint and its descriptions (RFC 9727)
- [auth.md](https://agentletterdesk.com/auth.md): how an agent connects a user (OAuth 2.1)
- [Agent skills index](https://agentletterdesk.com/.well-known/agent-skills/index.json): one skill, [SKILL.md](https://agentletterdesk.com/.well-known/agent-skills/agent-letter-desk-mcp/SKILL.md): connect and send a letter with the user's approval
- [OAuth protected resource metadata](https://agentletterdesk.com/.well-known/oauth-protected-resource/mcp)

## Optional

- [Imprint](https://agentletterdesk.com/imprint.md): who runs the service
- [Our bot](https://agentletterdesk.com/bot.md): AgentLetterDeskBot reads the companies' address pages of our recipient list about once a month and follows robots.txt
- [Sitemap](https://agentletterdesk.com/sitemap.xml)