How to send a physical letter from Claude
Claude can't mail anything on its own, but connected to Sendpaper it can. Add one connector, ask Claude to send a letter, a PDF or a postcard, check the preview, and pay. We print it and mail it by USPS.
- Works in
- Claude Code, Claude Desktop and claude.ai. Setup steps for each are below.
- Account or API key
- None. Sendpaper's connector needs no sign-in; you pay per piece.
- What Claude can send
- Postcards from $2.99, letters from $4.99, your own PDF (up to 6 pages), and Certified Mail from $14.99. US addresses only.
- Who pays
- You do, at a checkout link. In Claude Code with Stripe's Link CLI set up, Claude can instead pay with a one-time payment you approve for that amount.
- Tested
- Claude Code 2.1.290 on October 8, 2026: setup, and a PDF letter ordered up to the checkout link (against a test copy of Sendpaper; nothing was mailed).
Set it up
Claude Code
Run this once in your terminal; --scope user makes it available in every project. Then claude mcp list should show sendpaper as Connected.
claude mcp add --scope user --transport http sendpaper https://sendmypaper.com/mcpclaude.ai and Claude Desktop
Open Customize, then Connectors. Click + Add, choose Add custom connector, name it Sendpaper and paste this URL. For authentication, choose No sign in. In a chat, make sure Sendpaper is switched on under + then Connectors. Custom connectors work on every Claude plan (the Free plan allows one); on Team and Enterprise plans an Owner adds them in Organization settings.
https://sendmypaper.com/mcpHow it works
01Ask in plain words
Say what to send, to whom and from which return address. Claude fills in Sendpaper's create_letter or create_postcard tool; for your own document, give it a public link to the PDF.
02Approve the tool call
Claude asks before it uses a connector tool. Read what it's about to send and allow it; only choose Allow always for tools you're comfortable running unsupervised.
03Check the preview and pay
Claude gets back a preview link and a checkout link. Open the preview to see the exact print, then pay at the checkout link. Nothing is printed until the order is paid. (This walkthrough was tested up to the checkout link.)
04We review, print and mail it
A person reviews every piece before it's printed. It goes by USPS First-Class unless you chose Express or Certified Mail. Ask Claude for the order status any time; certified letters get a USPS tracking number.
What to include
- The recipient's full US mailing address
- Your return address (it's required, and shows through the envelope window)
- The message, or a public https link to a PDF you want mailed
- Certified Mail, if you need proof of delivery
Ask your agent
With Sendpaper connected to Codex, Muse or Claude, paste this and fill in the brackets:
Common questions
Do I need a Sendpaper account or API key?
No. The connector needs no authentication. Each order comes with its own checkout link, so you pay per piece.
Can Claude spend money without me?
Not by default: Claude gives you a checkout link and you pay. The exception is Claude Code with Stripe's Link CLI set up, where Claude can pay using a one-time payment that you approve in Link for that exact amount. Either way, avoid choosing Allow always for Sendpaper's pay_order tool if you want to approve each payment yourself.
Can Claude mail my own PDF?
Yes, if the PDF is at a public https link: Claude passes it to create_letter and we fetch it, fit each page to 8.5×11 and add an address page. Up to 6 pages. For a file on your computer, upload it on the website instead.
Can I cancel?
Claude can cancel an order that hasn't been paid. Once it's paid, email support before it's printed.
How do I know it was mailed?
Ask Claude to check the order: its status moves from paid to printing to mailed. Certified letters also get a USPS tracking number.
Sendpaper prints and mails what you or your agent writes. We're not a law firm or tax preparer and don't give legal or tax advice; for deadlines and the right address, check the notice itself, the agency, or a professional.