Grok

Grok wrote the letter. Piloxa mails it and keeps the record.

Grok takes a custom connector by address, on the web, on iPhone and on Android, and Piloxa is one. Tested on 15 September 2026: Grok quoted the price correctly, wrote the letter, handed it over, and returned a review link with the recipient, the service and the total already filled in. Nothing was printed or charged until a person approved it.

Already have the letter? Mail it now.

Paste it, or attach the finished PDF. Piloxa prints it, envelopes it, buys the postage and sends it USPS Certified. You see the pages, the recipient and one total before you pay.

Your first letter is $9.95 all in: one or two pages by Certified Mail with USPS tracking, with printing, the envelope, postage and the certified fee included. No subscription, no minimum, no trip to the Post Office.

Mail my letter Start it in Grok

Connecting Grok to Piloxa

Open grok.com and go to Connectors.
Choose “New Connector”, then “Custom”.
Paste the address https://piloxa.com/mcp.
Leave the authentication step empty if Grok offers one. Piloxa asks for no sign-in of its own.

xAI's documentation says connectors are available to all Grok users; one third-party guide says custom connectors sit on the paid tiers, so a free account may not see the option. On Grok Business and Enterprise a team administrator has to add the connector in xAI's console before anyone else on the team can use it. The full requirements, for every assistant.

Grok Bot

A Grok Bot takes connectors as plugins from Marketplace in its sidebar, and those plugins come from the Cursor Marketplace. Piloxa's plugin carries the connector and the instructions for writing and handing over a letter, and needs no key and no sign-in. Cursor reviews every listing by hand, and Piloxa is not listed yet; until it is, add the connector by its address instead.

Open Marketplace in the Grok Bot sidebar, search for Piloxa and choose Add. If it is not listed yet, add https://piloxa.com/mcp as a custom connector.
Leave any authentication step empty.
In a task, type @ and pick Piloxa, or just ask the bot to mail the letter by Certified Mail.

The bot prepares the mailing and sends you the review link. It cannot pay or mail anything itself, even on a schedule: every letter waits for a person to open the link and authorize it.

Building on the xAI API or Grok Build

Agents built on the xAI API reach Piloxa as a remote MCP tool, with no key and no account:

from xai_sdk.tools import mcp
chat = client.chat.create(
    model="grok-4.7",
    tools=[mcp(server_url="https://piloxa.com/mcp", server_label="piloxa")],
)

With the OpenAI-compatible Responses API, pass {"type": "mcp", "server_url": "https://piloxa.com/mcp", "server_label": "piloxa"} in tools. In Grok Build, one command adds it:

grok mcp add --transport http piloxa https://piloxa.com/mcp

If you are building a product on top of it, add ?src=partner:your-name to the address and you are paid a share of every letter it sends; the terms.

Then say this

“Prepare this letter for Certified Mail with electronic return receipt.”

Grok passes the finished letter to Piloxa in one call and gives you back a link. You open it, read the exact pages as they will print, check the recipient after the postal address check, see one total, and authorize with your card. The letter leaves only at that moment.

No connector? The paste path is the same price

Copy the letter out of the chat, open piloxa.com/app, paste it, and fill in who it is from and who it goes to. Same review page, same total, same record afterwards. The connector saves a copy and a paste; it buys nothing else.

What Grok cannot do

Start it in the assistant you already use

Create your letter with

Each button opens your assistant with the request already written in, Piloxa and its connector address included, and copies the same words to your clipboard in case the assistant opens with an empty box. Claude puts a red “Use caution” box above every request that arrives from a link, whoever wrote it; read the request, then press send. Nothing is printed or mailed until you read the review page and pay. How to connect your assistant

The button opens the assistant with the request already written in. Ask for the letter, copy it out, and paste it at https://piloxa.com/app — or, if your assistant has the connector, say “Prepare this letter for Certified Mail with return receipt.”

Piloxa is the connector the assistant calls. Its address is https://piloxa.com/mcp. The assistant cannot mail anything: it hands you a review link. You open it, read the exact pages that will be printed, check the recipient, see one total, and authorize with your card. Only then does the letter leave.

Mail my letter How to connect your assistant

Status, September 2026: Live mailing is open for letters to any US address. You see the exact letter, the recipient and the total before you pay, and nothing is printed or mailed until you authorize it. Questions: support@piloxa.com.

What you end up holding

You are buying USPS Certified Mail, so the Postal Service keeps its own delivery record. Piloxa asks the printing partner for that history on its own, without anyone pressing anything, and adds each scan to your record as it is reported, naming where it came from. If you chose the return receipt, the signature of whoever accepted the letter is recorded the same way once USPS releases it. Where nothing has come back, the record says “no record yet” rather than guessing. The sample record shows every state, including the incomplete ones.

Certified Mail proves that something was delivered. It does not prove what was inside. Keeping the approved letter beside the mailing record is what closes that gap, and it is the whole reason this exists. See a filled-in record.

Common questions

Can Grok send mail by itself?

No. The connector prepares a draft and returns a review link, and that is all it can do. A person must open the link, read the document and pay before anything is printed or mailed.

Does the Grok connector need a key?

No. Piloxa asks for no key, no OAuth and no account to connect. If Grok offers an authentication step, leave it empty.

Has this actually been tested?

Yes, on 15 September 2026. Grok quoted the exact price, wrote the letter, handed it over through the connector and returned a review link with the recipient, the service and the total already filled in.

What does it cost?

$12.97 all in for a one-page letter by USPS Certified Mail, or $15.97 all in with the electronic return receipt. Printing, envelope and postage are included. There is no subscription and no minimum.

Does it work in a Grok Bot?

A Grok Bot takes remote connectors like Piloxa’s. Piloxa’s plugin for the Grok Bot and Cursor Marketplace is built but not listed yet, so for now add the connector by its address. Tested end to end so far: Grok on grok.com. The Grok Bot and xAI API routes use the same connector address and have not yet been run end to end by us.

Can I use it from the Grok app on my phone?

Yes. Grok takes a custom connector by address on the web, on iPhone and on Android, and the review link opens in a phone browser.

What proof do I get that it was mailed?

The exact document with its fingerprint, the printed recipient address, the service that was bought, and the mailing record showing when it was handed over to be printed and mailed. You are buying USPS Certified Mail, so the Postal Service keeps its own delivery record and, with the electronic return receipt, the signature; pulling that USPS history into your own record automatically is still being built.

Primary sources

Legal and postal references last reviewed September 18, 2026. Requirements vary by claim and jurisdiction.