Certified Mail your software can hand a letter to

Your product or agent finishes a letter. Piloxa checks it, prices it and prepares it for the person to approve; the person pays and approves, and Piloxa prints it and mails it by USPS Certified Mail with tracking and the evidence kept. No key and no account to start.

Three ways in, all tested

Remote MCP at https://piloxa.com/mcp: for assistants and agents. Recipes.
REST described by https://piloxa.com/openapi.json. Recipes.
A link: https://piloxa.com/mail-a-letter-your-ai-wrote?src=partner:your-name. How the link works.

The tools

check_certified_letter (read only): Read only. Checks a draft letter or document before mailing: page count, recipient and sender address completeness, missing fields, placeholders, a deadline in the text, the recommended service and its exact price. Stores nothing.
quote_certified_letter (read only): Read only. The exact all-in total for a number of pages and a service.
prepare_certified_letter (prepares for approval; never mails or charges): Creates an unsent letter and returns the review link where the person reads it, pays and authorizes. Never prints, mails or charges.
get_certified_letter_status (read only): Read only. What USPS has reported about the letters prepared in the same conversation (or with the same API session).
search (read only): Read only. Searches Piloxa’s public Certified Mail guides; returns ids, titles, URLs and excerpts.
fetch (read only): Read only. The full text of one guide, with its URL and last-updated date.
compare_certified_mail_services (read only): Read only. Every service Piloxa offers, what it includes, when to use it and its exact current price for a page count.
explain_certified_mail_status (read only): Read only. A USPS tracking status or Piloxa state in plain words, with the next step and the guide that explains it.

Machine-readable descriptions

/agent-capabilities.json: services, operations, policies and current prices in one file.
/.well-known/mcp.json: the MCP server card.
/skills/index.json: workflow skills for agents.
/llms.txt and /for-ai-agents: the same facts in prose.

Partners are paid per letter

Add ?src=partner:your-name to the link or to the MCP address (https://piloxa.com/mcp?src=partner:your-name). Every paid letter that arrives that way is credited to you on the terms on /for-partners.

What no integration can do

Mail or charge anything. Nothing is printed, mailed or charged until a person reviews the exact document, the recipient and the total, and approves and pays on the review page. An assistant can check, quote and prepare; it cannot send.
Read a person’s past letters anonymously. Status answers only for letters prepared in the same session.
Decide a legal deadline. A deadline is the person’s to state; Piloxa only notices that a letter mentions one.