WHMCS Billing API
Invoice, payment, and transaction management
WHMCS Billing API is one of 7 APIs that WHMCS publishes on the APIs.io network, described by a machine-readable OpenAPI specification.
This API exposes 4 JSON Schema definitions.
Tagged areas include Billing. The published artifact set on APIs.io includes an OpenAPI specification, API documentation, an API reference, a getting-started guide, authentication docs, and 4 JSON Schemas.
This API exposes 3 operations across 3 paths, and defines 5 schemas. It is described by OpenAPI 3.0.3, at version 1.0.0.
Requests are made against a single base URL, https://{your-domain}/includes/api.php.
Metadata
The identity and technical contract details declared by the specification.
Authentication & Security 1
WHMCS Billing API declares
1 security scheme
for authenticating requests.
An API key is passed in the query as identifier (ApiCredentials).
By default, every request must be authenticated.
ApiCredentials— WHMCS API credentials. Provide identifier and secret parameters in the POST request body, along with the action parameter.
Paths & Operations 3
Across 3 paths, the API surfaces 3 operations — 3 POST. Each is listed below with its method, path, parameters, and response codes.
Invoice, payment, and transaction management
Schemas 5
The contract defines 5 schemas that model the data the API accepts and returns. The most detailed are Invoice (17 properties), InvoiceResponse (8 properties), InvoicesListResponse (5 properties), AuthCredentials (3 properties). Each schema is shown below with its type and property counts.
Specification
The full machine-readable OpenAPI contract behind this narrative.
Source
More from WHMCS 6
Other APIs WHMCS publishes across the network.