INK POSTAL

Print + mail API for agents  ·  Early access

Your agent can now mail you things.

Ink Postal is a print-and-mail API for AI agents. Send a PDF and an address; we print it, fold it, stamp it, and USPS carries it the rest of the way. Prefilled DMV forms. Letters that need a wet signature. The folder your accountant keeps asking for. Works with Claude, Muse, or anything that can make an HTTP request.

Request a key Read how it works

From $1.25 a letter, postage included. No monthly minimum. Delete-after-print by default.

INK POSTAL PO Box 2140 San Francisco, CA 94126
TO James Maxwell 412 Hyde Street, Apt 3 San Francisco, CA 94109-3102
What arrives. Thursday, probably.

Agents can read the entire internet, fill in any form, and draft any letter. Then they hit a wall: the form has to be signed in person, the letter has to be certified, the document has to be on a desk. Ink Postal is the last step. It is also, for most agents, the first thing they've ever done that you can hold.

§ 01

Things worth putting on paper

  1. FORM 01

    The DMV form, prefilled.

    Tell your agent the registration lapsed. It finds the right form for your state, fills in what it already knows about you and the car, prints it, and mails it to your kitchen table. You sign it at the counter. That's the part that still needs you.

  2. FORM 02

    A letter that has to exist.

    Landlord disputes. Insurance appeals. Anything with the HOA. Some correspondence is only real when it's certified, with a green card that comes back. Your agent drafts it; we make it real.

  3. FORM 03

    The folder for the accountant.

    Your agent gathered every 1099 and receipt. Your accountant still wants paper. Thirty pages, duplex, stapled, shipped to her office with your name on the cover sheet.

  4. FORM 04

    A contract with a real signature.

    Two copies, tabs where you sign, a prepaid return envelope tucked in behind. The agent handles the negotiation; the pen is still yours.

  5. FORM 05

    A note to a person.

    The agent remembered the birthday. A card with a stamp on it says more than a calendar notification. Send it to yourself first if you want to read it before they do.

§ 02

Three steps. One of them is ours.

  1. 1

    Your agent sends a file.

    A PDF, or HTML we render for you. Plus a recipient. That's the whole request.

  2. 2

    We print it.

    Laser, black on 24 lb paper, folded into a #10 window envelope. Duplex, color, and heavier stock are flags.

  3. 3

    USPS carries it.

    First-Class in 3–5 business days. Certified with tracking. A webhook fires when it's scanned and when it lands.

request curl 
curl https://api.inkpostal.com/v1/mail \
  -H "Authorization: Bearer ik_live_…" \
  -F to="James Maxwell, 412 Hyde St Apt 3, San Francisco CA 94109" \
  -F file=@reg156-prefilled.pdf \
  -F service=first_class \
  -F duplex=true
response 201 
{
  "id": "ml_8f2kQpN7",
  "status": "queued",
  "pages": 2,
  "proof_url": "https://inkpostal.com/p/ml_8f2kQpN7",
  "expected_delivery": "2026-10-01",
  "cost_usd": 1.25
}

Also: an MCP server, so Claude and Muse can call it as a tool. npx inkpostal mcp

§ 03

Rules an agent has to follow

Mail is a real thing that arrives at a real door. We treat it that way.

Recipients are allow-listed.
By default an agent can only mail addresses its owner has confirmed. Usually that's you. No cold mail to strangers, ever, from any key.
You can look before it prints.
Every job gets a proof URL. Turn on hold-for-approval and nothing prints until you tap "okay" on your phone.
The file is deleted after printing.
We keep the tracking record. We do not keep your document. Encrypted in transit and at rest for the hours it exists with us.
Spend has a ceiling.
Per-key daily and monthly caps, set by you. An agent in a loop can't mail you four hundred copies of anything.
§ 04

Not yet. Soon.

§ 05

Priced like postage

Postage is included in every number below. No platform fee, no minimum.

Service Includes Price
Letter, First-Class Up to 6 pages b/w, #10 window envelope, 3–5 business days $1.25
Additional page Black and white. Color is $0.25. $0.10
Certified Mail Tracking, signature on delivery, electronic return receipt $11.50
Flat, 9×12 envelope Up to 60 pages, unfolded, for the accountant $4.90
Postcard 4×6, full color both sides $0.95

Volume pricing exists. Ask when you're past a few thousand a month.

§ 06

Get a key

We're letting people in a few at a time while the printers catch up. Tell us what your agent wants to mail and we'll send a key, plus a real letter, so you can see the paper.