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WHMCS Clients API

Client account management operations

WHMCS Clients 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 Clients. 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 5 operations across 5 paths, and defines 8 schemas. It is described by OpenAPI 3.2.0, at version 1.0.0.

Requests are made against a single base URL, https://{your-domain}/includes/api.php.

5 operations 5 paths 8 schemas 5 POST

Metadata

The identity and technical contract details declared by the specification.

Specification
OpenAPI 3.2.0
API Version
1.0.0
Base URL
https://{your-domain}/includes/api.php
Authentication
API Key
Resource Areas
1

Authentication & Security 1

WHMCS Clients 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 5

Across 5 paths, the API surfaces 5 operations — 5 POST. Each is listed below with its method, path, parameters, and response codes.

Clients 5

Client account management operations

POST
/?action=GetClients
Get Clients
getClients body → 200
POST
/?action=GetClientsDetails
Get Client Details
getClientsDetails body → 200
POST
/?action=AddClient
Add Client
addClient body → 200
POST
/?action=UpdateClient
Update Client
updateClient body → 200
POST
/?action=DeleteClient
Delete Client
deleteClient body → 200

Schemas 8

The contract defines 8 schemas that model the data the API accepts and returns. The most detailed are ClientInput (16 properties), Client (9 properties), ClientsListResponse (5 properties), AuthCredentials (3 properties). Each schema is shown below with its type and property counts.

ClientInput
object
16 properties
AuthCredentials
object
3 properties 3 required
ClientsListResponse
object
5 properties
Client
object
9 properties
AddClientResponse
object
2 properties
SuccessResponse
object
2 properties
ClientDetailsResponse
object
2 properties
ClientDetail

Specification

The full machine-readable OpenAPI contract behind this narrative.

Source

whmcs-clients-api-openapi.yml Raw ↑

Other APIs WHMCS publishes across the network.

WHMCS Authentication API
WHMCS Billing API
WHMCS Domains API
WHMCS Orders API
WHMCS Support API
WHMCS System API
Where this information came from

This is an independent, third-party profile of WHMCS Clients API, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.

The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.

Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.

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