Get a deposit back
Certified · $12.99Drafted
Draft a certified letter to Property LLC asking for my $1,400 deposit back. Show me, then send.Use case →
Send real mail from 
.
A letter, notecard or postcard. Your exact words, or drafted by Cline from your direction. You approve the exact price, and USPS delivers.
LetterNotecardPostcardYour exact wordsDrafted to your direction
You approve the exact total first
From $0.99 · postage included · no account needed
Cline MCP settingsExample
{ "mcpServers": { "paperplane": { "type": "streamableHttp", "url": "https://sendpaperplane.com/api/mcp" } }}
Agent · Cline
Draft a certified letter to Property LLC asking for my $1,400 deposit back, then send it.
Here’s my draft for you to read. I’ll get a quote before anything is sent.
Called quote_letter
LetterNotecardPostcardCertified
WordsDraftedExact text
Total, postage included$12.99
Token holds 30 minPayment required
Pay the link to send it. Nothing prints until you do. Order ord_8k2d.
How it works
From your ask to the mailbox.
Every piece is quoted, confirmed and sent, and gets a status page. Nothing prints until you approve the total.
Pipeline
Quote. Confirm. Send.
- Quote✓
quote_letter$0.99 · holds 30 min - Confirm✓
confirmation_tokenpayment authorized - Send✓
send_letterord_8k2d created
- At the print facility09:52
- In the mailWed 08:10
- Delivered—
Addresses
Corrected before it prints.
- Typed
- 1 main street apartment 4b richmond virginia
- Mailed as
- 1 MAIN ST APT 4B
RICHMOND VA 23220
Postage included.
- Letter$0.99
- Postcardfrom $0.99
- Notecardfrom $1.99
- Certified Mail$12.99
What arrives
A real envelope, at a real address.
- Your return address
- Mail class printed on it
- Certified Mail arrives with no paperplane branding
One endpoint
Cline quotes before it spends.
Set up
How do I send mail from Cline?
Install once, then ask in plain English.
1Add paperplane
Paste the block into Cline’s MCP settings.
- Your wordsDrafted
2Pick piece and words
Letter, notecard or postcard, in your exact text or drafted from your direction.
- Total, postage included$0.99Payment link
3Approve and it mails
Pay the link, USPS delivers, and you can track it.
Prefer to paste it? Add to
Cline’s MCP settings{ "mcpServers": { "paperplane": { "type": "streamableHttp", "url": "https://sendpaperplane.com/api/mcp" } } }Two choices, every send
What do you want to mail, and who writes it?
Cline asks both up front, so there are no surprises on the quote.
1
What are we mailing?
A letter, a notecard or a postcard. Say it in your ask, or let Cline pick the obvious one.
Letters can also go Certified, with a Return Receipt, or Priority.
2
Who writes it?
Give Cline the exact words, or give it a direction and let it write.
Your exact wordsSent verbatim
You
Send this exactly as written: Dear Maria, thank you for the renewal.
On the quoteThose words, unchanged. Cline does not rewrite them.
Drafted to your directionYou read it first
You
Write a firm but polite note asking for my deposit back.
ClineShows the draft. Ask for edits until it reads right.
Approved words are locked in. Change one afterward and the send is refused.
3
How should the words look?
Letters and postcards
Pick a font
Typed
Dear Maria, thank you.
Serif
Dear Maria, thank you.
Typewriter
Dear Maria, thank you.
Handwriting style
Dear Maria, thank you.
A few favorites. Letters have 5 fonts, postcards have 16 handwriting styles. See them all →
Notecards
Printed script, or a robot with a pen
Casual
Dear Maria, thank you.
Neat
Dear Maria, thank you.
12+ pen styles to choose from, $1 more. These are two of the most popular. See them all →
Want it actually handwritten? A robot writes it with a real pen for +$1.
What to ask
What can I ask Cline to send?
Anything you would hand to a person who has a stamp. Each card shows the piece, the price and whose words. Browse all use cases →
Chase a late invoice
Letter · $0.99Exact text
Mail overdue-invoice.md exactly as written, first-class. Quote it first.Use case →
Thank a customer
Notecard · $1.99Drafted
Write a warm thank-you notecard for the customer in ticket 4821. Let me read it first.Use case →
Postcards to testers
Postcard · from $0.99Exact text
Send each address in beta-testers.csv a 4x6 postcard: “Thanks for the bug report.” Total first.Use case →
Send a condolence card
Notecard · $1.99Exact text
Send this notecard exactly as written: “Thinking of you and your family.” Address in contact-88.json.Use case →
Serve a formal notice
Certified · $12.99Exact text
Send notice-30-day.md word for word, Certified with Return Receipt. Do not rewrite it.Use case →
Steer it in plain English
“Draft it, don’t send yet”Shows you the text. Nothing is quoted or mailed.
“Make it a postcard instead”Re-quotes the same words as a postcard.
“Send it Certified”Adds a signed USPS delivery record and re-quotes.
“Where is order ord_8k2d?”Reads the live status, print facility to delivered.
Go deeper
The docs go further than this page.
Everything here is the short version. The full documentation has the rest.
Twenty guides, end to end.
Addresses, bulk sends from a CSV, credits, webhooks, templates, and a full demand letter.
Guides →POST /v1/quotesPOST /v1/ordersA full API.
An OpenAPI spec for all fifteen endpoints, Postman collections, and every error code.
API reference →Q
Extended FAQThe questions behind them.
Deliverability, USPS rules, what a Certified receipt proves, and the delivery guarantee.
Full FAQ →"sandbox": true$0.00Run it all for free.
Quote, address check and order all run. Nothing prints or is charged. Flip one flag to go live.
Sandbox guide →Questions
Sending mail from Cline: frequently asked questions
Can I tell Cline exactly what to write?
Yes. Say “send this exactly as written” and paste the words or point at a file. Cline passes them through unchanged, and the quote shows them so you can check before you pay. If you would rather it write, give it a direction like “a firm but polite note asking for my deposit back” and it shows you a draft first. Either way the approved words are locked into the confirmation token.
Are notecards really handwritten?
Two ways. The $1.99 notecard is printed in a handwriting-style script. For $1 more ($2.99), a robot writes it with a real pen, so the strokes are real ink on real card. Letters can use a professional typeface or a handwriting-style font, at the same price.
What stops Cline from mailing the wrong letter?
The quote. send_letter only works with the token quote_letter returns, and that token is bound to the exact recipient, content, class, format and price. If the agent changes a word or an address after you approved it, the send is refused and it has to quote again. The address is checked against USPS data before any charge.
Can Cline send a letter without asking me?
Not unless you hand it a prepaid credit code. quote_letter is free and creates nothing. send_letter refuses to run without the token that quote returns: single-use, good for 30 minutes, and bound to the exact recipient, content, class and price. Without a credit code, a live send returns a paperplane payment link and nothing prints until you pay it. A credit code cannot spend past its balance, and every connection has a default safety cap of $100 a day and $200 a month.
How much does it cost to mail a letter from Cline?
One all-in price, postage and printing included. Letters and 4x6 postcards start at $0.99 and notecards at $1.99. For $1 more, a robot writes your notecard by hand with a real pen. Certified Mail is $12.99 and Priority is $24.99. The quote shows the exact total before anything is sent, and sandbox runs are free.
Send your first piece of mail from .
A letter, notecard or postcard, in your words or drafted from your direction.
✓ You approve the exact total✓ No account neededFrom $0.99
Other ways to send
Not in Cline? Send it from wherever you work.
Same pieces, same choice of your words or ours, same quote and approval step. Only the front door changes.
Agents and editors
Ask any assistant
Every one gets the same tools and the same sandbox.
See all agents →
Integrations
Connect an automation
Trigger real mail from the tools you already run.
See all integrations →
Command lineAbout the CLI →
One command
Free with --sandbox.
$ npx paperplane send \ notice.pdf --sandbox