API usage and authentication
Authenticate server-side production API requests and interpret common responses.
The PayNowPro REST API uses API keys. Make requests from your server or trusted backend only; never expose an API key in browser, mobile, or other publicly distributed client code.
Production base URL
All public API requests use this base URL:
https://api.paynowpro.com/api/v1Endpoint paths in the API reference are relative to this URL.
Authentication and tenant alias
Include the API key in the api-key HTTP header on every request.
curl "https://api.paynowpro.com/api/v1/customers?tenantAlias=YOUR_TENANT_ALIAS" \
-H "api-key: YOUR_API_KEY"Your tenant alias identifies the PayNowPro tenant that owns the request. Depending on the endpoint, provide it in the query string or request body. The generated API reference identifies the required location for every operation.
Get API credentials from your organization's self-hosted PayNowPro dashboard. Contact your dashboard administrator if you need access.
Treat API keys like passwords. Store them in server-side environment variables, restrict access to them, and rotate a key if you believe it was exposed.
Response codes
| Code | Meaning | What to do |
|---|---|---|
200 | The request succeeded. | Process the response. |
201 | A resource or payment intent was created. | Save returned IDs for later operations. |
400 | The request is invalid or breaks a validation rule. | Correct the request using the error details. |
401 | Authentication failed. | Check the API key and tenant alias. |
404 | The requested resource was not found. | Confirm the ID, tenant alias, and resource lifecycle. |
5xx | A server-side failure occurred. | Retry only when your integration can do so safely, then contact support if it persists. |
Error responses contain a code and may include a reason and request or response context.
{
"body": {
"code": 400,
"reason": "A customer with the provided associatedId already exists."
}
}Do not log API keys, full payment details, or other secrets when recording errors. For list endpoints, read Pagination.