The Strictly
Payment API
A complete REST API for payments, subscriptions, terminals, and invoicing. Integrate card, ACH, and recurring billing into your application in minutes.
Everything you need
From one-time charges to complex recurring billing — the Strictly API has you covered.
Payments
Charge, refund, void, and capture credit cards. Support for bulk charges and pre-authorization.
ACH Transfers
Process bank transfers via ACH. Supports charge, refund, and void operations.
Customer Vault
Store and manage customer payment profiles securely. Support for multiple cards and bank accounts per customer.
Subscriptions
Create recurring billing plans and subscriptions with flexible billing cycles.
Invoicing
Generate, send, and manage invoices. Includes line items, taxes, and delivery via email.
Terminal
Integrate physical payment terminals (BridgePay & Strictly) for in-person payments.
Payment Links
Create shareable payment links for one-time or recurring payments without a checkout page.
Webhooks
Receive real-time event notifications for payment status changes and other activity.
Reports
Access transaction and deposit reports to reconcile payments and monitor your business.
Up and running in minutes
Authenticate with HTTP Basic auth and your key-hash header. Every request to api.paywithzero.net/v1 is secured with these two credentials.
curl -X POST \
https://api.paywithzero.net/v1 \
/public/payment/charge \
-u "email:password" \
-H "key-hash: YOUR_KEY_HASH" \
-H "Content-Type: application/json" \
-d '{
"amount": 1000,
"currency": "USD",
"cardNumber": "4111111111111111",
"expirationDate": "12/26",
"cvv": "123"
}'Ready to integrate?
Use the sandbox environment to test your integration before going live. No approval needed.