Claude
ChatGPT
CursorSend real mail from your code.
Letters, Certified Mail and postcards through USPS, from $1.99. No API key, no account. Quote, confirm, send.
Free to preview. The sandbox is free and mails nothing.
The facts, before the price
$1.99
starting price, postage and envelope included
3–5
business days for First-Class or Certified to arrive
1
business day from order to USPS handoff
USPS
every piece, no other carrier
USPS
Stripe securedHow it works.
- ComposedPaste text or upload a PDF — typeset automatically.
- SubmittedAddress verified, paid, sent to print.
- MailedPrinted, sealed, handed to USPS.
- DeliveredTracked to the mailbox, receipt emailed.
$ claude mcp add --transport http \ paperplane \ https://sendpaperplane.com/api/mcp✓ Added paperplane > Mail notice.pdf to Property LLC, 1 Main St, Richmond VA 23220, by Certified Mail. quote_letter certified · 1 page · $12.99 send_letter
POST /v1/orders{ "mail_class": "certified", "to": { "name": "Property LLC", "line1": "1 Main St", "city": "Richmond", "state": "VA", "zip": "23220" }, "pdf_url": "https://…/notice.pdf"}
Send it from wherever you are.
The same letter, from whatever surface you are already in: web, agent, email, or your own site.
The old way, and this one
Same USPS service, same proof of mailing; it comes from USPS either way. Everything around it is what changes.
| What | paperplane | At the counter |
|---|---|---|
| Printer, envelope | not needed | yours |
| PS Form 3800 | done for you | by hand |
| Address check | before you pay | Not available |
| Time | 2 min | 10 min + line |
| Proof of mailing | emailed, kept | a paper slip |
| Price, all in | $12.99 | fees + your costs |
›See the long version
The old way
Certified Mail, at the counter
- Write the letter, print it, and find an envelope that fits it.
- Address it by hand — including a return address, which USPS requires on every certified piece.
- Drive to the post office during opening hours and join the line.
- Fill in PS Form 3800 at the counter, peel it, and stick it on the envelope yourself.
- Decide at the window: the paper green card (PS Form 3811) or the electronic Return Receipt.
- Pay at the window, in cash or card, plus your own printing and envelope.
- Keep the stamped Form 3800 somewhere you will still have it in a year. It is your only proof of mailing.
Ten minutes at the counter with no line. Then do it again for the next recipient.
This way
Certified Mail, from where you are
- Paste the letter, or upload the PDF.The composer renders the exact pages that will print — fonts, pagination, everything.
- Type the two addresses.Both are checked against USPS data before you are asked to pay.
- Pay $12.99, or $14.99 with the electronic Return Receipt.We print it, seal it, and hand it to USPS the next business day. Tracking number by email.
About two minutes. No form, no line, nothing to lose.
Or hand it to an assistant: the same send runs over MCP, the API, or the CLI.
Who ends up sending letters here
Three jobs, one send flow. Everything below works today — the deeper guide is one tap away.
People who need it to hold up
The letter is the evidence: Certified Mail, a checked address, and a tracking page you can hand to a lawyer.
For the letter that has to hold up →People mailing for other people
Upload a CSV of clients or tenants; every row becomes its own individually addressed letter.
For mailing a list without mail-merge →Developers and AI agents
An MCP endpoint and REST API a human still approves the payment on, with a free sandbox.
For the agent and developer docs →
Illustrative scenarios · not customer reviews
What a send actually looks like
We haven't launched, so there is no one to quote yet. These are written examples of jobs the product does today: the people are made up, the capabilities are not.
A solo founder sending a contract notice
The agreement says notice by certified mail, return receipt requested — so that is exactly what gets picked, and the receipt records both the mailing and who signed for it. Certified envelopes never carry our mark, so the letter arrives looking like it came from the company that sent it.
A property manager mailing 40 tenants the same notice
A CSV export becomes 40 individually addressed First-Class letters in one pass — no mail-merge document, no campaign platform. Rows with a repaired ZIP or a missing city are flagged before anything prints, and each letter is tracked on its own afterwards.
A tenant chasing a security deposit
The demand goes Certified with an electronic Return Receipt, which is what makes the statutory clock provable rather than merely started. That receipt records who signed for it and when — the exact record a security-deposit dispute turns on.
An engineer wiring mail into an agent
The agent quotes the letter for free, then calls send and gets back a payment link for a human to approve — it cannot spend on its own. The same path runs end to end in the sandbox, free, with nothing printed.
Tracked from the print floor to the mailbox.
Every mailed piece has a status page: at the print facility, in the mail, delivered. Certified letters carry the USPS tracking number and, with the electronic Return Receipt, the signed delivery record. Share the link with a lawyer or a landlord; no login on either end.
How tracking works
One price. Postage included.
Printing, the envelope and USPS postage are in the number. No account, no plan, nothing added at checkout.
$1.99
First-Class letter
1 page, black and white, envelope and postage included
Extra pages $0.25 · Color +$0.50/page · Tracking +$0.99
Most sent
$12.99
Certified Mail
Proof of mailing and USPS tracking
The one landlords, courts and the IRS take seriously
$14.99
Certified + Return Receipt
Adds a signed electronic proof of delivery
Others charge $20 to $24 for the same piece
$24.99
Priority Mail
Flat-rate envelope, 1 to 3 day delivery
For the letter that cannot wait
$1.99
Postcard
4x6, message only, printing and postage included
6x9 $2.99 · 6x11 $3.49 · no envelope, no tracking
$5.99
Card
Folded notecard, handwriting script, printing and postage included
Enclosed like a greeting card, not open like a postcard
Extra pages $0.25 each. Color $0.50 a page. Tracking on First-Class $0.99. Full detail on the pricing page.
Connect your agent.
Pick your client, paste one config, and ask it to send this certified. Your assistant prepares the letter, you approve the payment link, USPS does the rest.
Step 1
Connect
claude mcp add --transport http paperplane https://sendpaperplane.com/api/mcpTry it: free, nothing mailed
Tell your agent:
Using the paperplane tools, quote a 1-page certified letter to Property LLC, 1 Main St, Richmond VA 23220, then send it in sandbox mode.Questions.
How does this work?
Upload a PDF or paste your letter text. We typeset it if needed, print it, seal it in a windowed envelope and hand it to USPS, usually the next business day. You get an email receipt and a status page.
Do I need an account?
No. Pay per letter with a card or Apple Pay. Your email gets a receipt and a private tracking link, and that is the entire relationship.
What is Certified Mail and when do I need it?
Certified Mail is a USPS service that gives you proof you mailed something and proof it arrived. Use it for security deposit demands, notice to a landlord, IRS correspondence, insurance disputes and anything a court might ask about. The electronic Return Receipt adds the recipient’s delivery record.
Why is your certified price lower than other sites?
We price Certified Mail as a letter with a USPS extra service on top, not as a premium product. $12.99, or $14.99 with the electronic Return Receipt, printing and envelope included. Others charge $20 to $24 for the same piece.
Is my letter private?
Documents are encrypted in transit and at rest, are never used for anything except printing your letter, and are deleted 30 days after delivery. An automated screen, with human review only when flagged, checks for fraud and threats, for the same reason the post office has rules.
Can AI assistants use this?
Yes. Claude, ChatGPT and custom agents can quote and send letters through the MCP endpoint, with a free sandbox mode. Your assistant hands you a payment link; you approve; we mail it.
Send it however you already work
We support your method too — web, email, text or the CLI, one all-in price either way.