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Strictly / PayWithZero API

The Strictly payment API is a REST API that gives you full control over payments, recurring billing, customer management, and terminal operations — through a single integration.

What you can build

Capability	Description
Credit card payments	Charge, refund, void, capture, and bulk-charge cards
ACH bank transfers	Initiate and manage bank-to-bank payments
Customer vault	Store payment profiles and tokenized cards/accounts
Subscriptions & plans	Create and manage recurring billing cycles
Invoicing	Generate, send, and track invoices with line items and taxes
Payment links	Share payment URLs without building a checkout UI
Terminal payments	Integrate BridgePay and Strictly physical terminals
Reporting	Access transaction and deposit reports
Webhooks	Receive real-time event notifications

Base URL

All API requests are sent to:

Code
https://api.paywithzero.net/v1

Every request must include your merchant credentials. See Authentication for details.

Request format

The API accepts JSON-encoded request bodies. Include the Content-Type: application/json header on all requests that send a body.

Response format

All responses return JSON. Successful responses wrap their payload in a data field:

Code
{
  "data": { ... }
}

Error responses follow a consistent shape:

Code
{
  "statusCode": 400,
  "timestamp": "2022-04-11T22:54:13.822Z",
  "path": "/v1/public/payment/charge",
  "response": {
    "code": "300",
    "text": "Transaction was rejected by gateway."
  },
  "message": "Http Exception"
}

See Error Handling for the full list of error codes.

Versioning

The API is currently at v1. Breaking changes will be communicated in advance, and deprecated endpoints are flagged in this documentation.

Next steps

• Quick Start — make your first API call in under 5 minutes
• Authentication — learn how to authenticate requests
• Sandbox & Testing — test your integration risk-free