A physical step for every attempt
Each verification requires a card sent through the U.S. mail.
A physical checkpoint for online accounts
We mail POST cardsto verify your users.
POST Request mails a verification code to a U.S. address. When your user scans and confirms, you get a signed webhook and one more reason to believe they (probably) aren’t an AI. (For now.)
- Rates from
- $1.50 / attempt
- Standard schedule
- 5–7 business days
- Completion
- Signed webhook
POST RequestForm PR-01
Your card has arrivedWhat your user receives
A better reason to check the mail.
The card carries a QR credential for one verification. It can complete that verification once; the completed page may remain available until the record is purged.
- 01 / Delivery
A POST card arrives
Its QR code is a credential: anyone who can see or copy it can use it unless you also require email binding.
- 02 / Verification
They scan and confirm
The QR code opens a short verification page. With email binding enabled, they also enter a code sent to their email as a second factor.
- 03 / Return
Signed and returned
They see the green VERIFIED postmark. Your server receives the signed webhook.
POST RequestCompletion receipt
FORM PR-01 / COPY BCredential record
- XMail progressed
- XCredential opened
- XVerification completed
- Card
- ...7F3A
- Binding
- Email OTP
- Event
- verification.verified
The delivery loop
One request. One physical checkpoint.
One API call sends the card. A signed webhook records completion of its credential.
- 01
Submit an address
Your server sends a domestic mailing address. We validate it, debit your postage balance, and create a single-use credential.
POST /api/v1/verifications - 02
We print and mail
We print the card and send it by U.S. mail.
PRINTED -> IN TRANSIT - 03
Your user closes the loop
They scan the card and confirm receipt. Email-bound cards also require the account code. We sign a webhook when complete.
verification.verified
Fraud resistance
Add a physical step to signup.
Each live attempt buys a mailpiece and adds postal delay. You pay the postage unless you pass the fee through; shared addresses and forwarded credentials are still possible.
Pair the card with email
If you enable email binding, your user confirms with the card and a code sent to their account.
One card, one completion
A credential completes its verification once. It does not establish a unique person or prevent that person from using other cards.
Domestic rates / July 2026
Postage, not seats.
Prepay a dollar balance. Each mailpiece debits its rate. Credits do not expire.
| Class | Format and schedule | Rate |
|---|---|---|
| Standard Default | Postcard / mailed next day / 5–7 business daysThe default. A postcard dispatched the next business day — the everyday checkpoint for most integrations. | $1.50 |
| Sealed | Sealed letter / mailed next day / 5–7 business daysA letter in a security-tinted envelope, with the code inside. Less exposed than a postcard, but not confidential from anyone who opens it. Sealed is not Certified Mail or a compliance certification. | $4.00 |
Credits never expire — buy postage now, spend it whenever.Postage is non-refundable once created, with two exceptions: a print rejection is credited in full; an undeliverable Sealed piece is credited 50%.
Integration
A request now. A webhook later.
1 / Create verificationHTTP
curl https://postrequest.dev/api/v1/verifications \
-H "Authorization: Bearer pr_live_..." \
-H "Idempotency-Key: signup-user-8123-v1" \
-H "Content-Type: application/json" \
-d '{
"address": {
"line1": "1600 EXAMPLE ST",
"city": "SEATTLE",
"state": "WA",
"zip": "98101"
},
"class": "standard",
"binding": "email_otp",
"email": "[email protected]",
"external_id": "user_8123"
}'2 / Receive completionWEBHOOK
{
"event_id": "evt_67b8c2735ab5de033a",
"occurred_at": "2026-07-17T15:02:11Z",
"type": "verification.verified",
"id": "01JZ3NVJ4M8Q",
"external_id": "user_8123",
"status": "verified",
"verified_at": "2026-07-17T15:02:11Z",
"binding": "email_otp"
}Start the clock