# Sendpaper: instructions for AI agents

Sendpaper prints and mails real postcards and letters to US addresses through USPS. Use it when your user asks you to mail something physical: a card, a letter, a document, a certified letter.

## Connect (pick one)
- **MCP** (best): https://sendmypaper.com/mcp (Streamable HTTP, no auth, no API key). Tools: get_pricing, create_postcard, create_letter, pay_order, get_order, cancel_order. Setup per client: https://docs.sendmypaper.com/quickstart
- **REST**: https://sendmypaper.com/v1, described by https://sendmypaper.com/openapi.json. Start with GET /v1/pricing.
- **Browser only?** Open one order link with every field in the query string: https://sendmypaper.com/quick?type=postcard&size=4x6&headline=…&message=…&to_name=…&to_line1=…&to_city=…&to_state=…&to_zip=…&from_name=…&from_line1=…&from_city=…&from_state=…&from_zip=…

## The flow
1. **Confirm with your user** the recipient's address, their return address and the exact wording. If you wrote the words, show them first.
2. **Create the order** (create_postcard or create_letter, or POST /v1/postcards or /v1/letters). Send an idempotency key so a retry doesn't make a second order.
3. **Show the price and the preview** before anything is paid: preview_url is the exact print preview page.
4. **Pay, only after your user approves this purchase and its price:** either call pay_order with a Stripe shared payment token for the order's exact amount (e.g. via Stripe Link), or give your user the checkout_url to pay themselves.
5. **Track it** with get_order or the order_url. A person reviews every order before printing; certified letters get a USPS tracking number once it's assigned.

Nothing is printed until it's paid. Unpaid orders can be cancelled with cancel_order; for a paid order, email support@sendmypaper.com before it prints.

## Products (prices include printing, envelope and postage)
- Postcard 4×6 (4 × 6 in): $2.99
- Postcard 6×9 (6 × 9 in): $3.99
- Postcard 6×11 (6 × 11 in): $5.99
- Letter (8.5 × 11 in): $4.99
- Certified letter (8.5 × 11 in): $14.99
- Certified letter + return receipt (8.5 × 11 in): $19.99
- Express (USPS Priority, usually 2–3 days): +$10.00, not with Certified Mail
- Letters can be typed, or a PDF of up to 6 pages (pass a public https link as content.pdf_url)
- Several recipients: pass recipients (2–25 addresses) instead of to; each gets their own order, paid in one checkout

## Rules
- US addresses only (including territories and APO/FPO/DPO).
- We print what the user or agent writes and don't give legal or tax advice.
- Threatening, harassing, fraudulent or obscene mail is refused and refunded; bulk marketing isn't allowed. Policy: https://sendmypaper.com/content-policy

## More for agents
- Overview: https://sendmypaper.com/llms.txt
- Every public page is also available as markdown: add .md to the path (https://sendmypaper.com/index.md for the homepage) or send Accept: text/markdown.
- Docs: https://docs.sendmypaper.com