WHMCS website screenshot

WHMCS

WHMCS (Web Host Manager Complete Solution) is a leading web hosting automation platform that provides billing, client management, support, domain management, and provisioning automation for web hosting businesses. It offers a comprehensive API with 150+ commands covering clients, orders, invoicing, domains, support tickets, and system administration.

WHMCS publishes 7 APIs on the APIs.io network, including Authentication API, Billing API, Clients API, and 4 more. Tagged areas include Web Hosting, Billing Automation, Client Management, Domain Management, and Support Tickets.

The WHMCS catalog on APIs.io includes 1 JSON-LD context and 2 Spectral governance rulesets.

WHMCS’s developer surface includes authentication, documentation, API reference, engineering blog, and 9 more developer resources.

🌐 Visit website 📡 Source on GitHub
52.4/100 developing ▬ flat Agent 31/100 agent aware Full breakdown ↓
scored 2026-08-05 · rubric v0.9.1
AccessFreemiumSelf serve⚡ Free to try
7 APIs
Web HostingBilling AutomationClient ManagementDomain ManagementSupport TicketsProvisioning

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-05 · rubric v0.9.1
Composite quality — 52.4/100 · developing
Contract Quality 17.6 / 25
Developer Ergonomics 5.7 / 20
Commercial Clarity 7.9 / 20
Operational Transparency 6.8 / 13
Governance 7.0 / 12
Discoverability 7.4 / 10
Agent readiness — 31/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/whmcs: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 7

Individual APIs this provider publishes, each with its own machine-readable definition.

WHMCS Authentication API

OAuth and SSO authentication operations

WHMCS Billing API

Invoice, payment, and transaction management

WHMCS Clients API

Client account management operations

WHMCS Domains API

Domain registration and management

WHMCS Orders API

Order and quote management operations

WHMCS Support API

Ticket and announcement management

WHMCS System API

System administration and configuration

Scroll for all 7

Open Collections 1

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

WHMCS API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Whmcs Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Whmcs Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Whmcs Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Whmcs Context

12 classes · 23 properties

JSON-LD

Spectral Rules 2

Spectral governance rulesets for linting and validating these APIs.

WHMCS API Rules

5 rules · 4 warnings 1 info

SPECTRAL

WHMCS API Rules

10 rules · 5 errors 5 warnings

SPECTRAL

JSON Schema 3

Standalone JSON Schema definitions for this provider's data models.

WHMCS Client

19 properties

JSON SCHEMA

WHMCS Invoice

15 properties

JSON SCHEMA

WHMCS Support Ticket

16 properties

JSON SCHEMA

JSON Structure 1

JSON Structure definitions describing this provider's data shapes.

Whmcs Api Structure

0 properties

JSON STRUCTURE

Examples 4

Example request and response payloads for these APIs.

Whmcs Create Invoice Example

4 fields

EXAMPLE

Whmcs Get Clients Example

4 fields

EXAMPLE

Whmcs Open Ticket Example

4 fields

EXAMPLE

Whmcs Validate Login Example

4 fields

EXAMPLE

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Whmcs Authentication

apiKey · 1 scheme

SECURITY

Whmcs Domain Security

TLSv1.3 · DMARC

SECURITY

Whmcs Vulnerability Disclosure

Hackerone · security.txt · contact published

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Whmcs Agentic Access

19 operations · 19 acting

19 operations · 19 acting

AGENTIC

Resources

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 3

Authentication, authorization, and security posture

VulnerabilityDisclosure
VulnerabilityDisclosure
 DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 2

Status, limits, changes, and where to get help

Forums
Forums
 StatusPage
StatusPage

Company 3

The organization behind the API

LinkedIn
LinkedIn
 Website
Website
 Blog
Blog

Other 1

Properties that don't map to a standard resource type

Marketplace
Marketplace

Source (apis.yml)

apis.yml Raw ↑ 
aid: whmcs
name: WHMCS
description: WHMCS (Web Host Manager Complete Solution) is a leading web hosting automation platform that provides billing,
  client management, support, domain management, and provisioning automation for web hosting businesses. It offers a comprehensive
  API with 150+ commands covering clients, orders, invoicing, domains, support tickets, and system administration.
type: Index
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
position: Consumer
access: 3rd-Party
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/whmcs.png
tags:
- Web Hosting
- Billing Automation
- Client Management
- Domain Management
- Support Tickets
- Provisioning
url: https://raw.githubusercontent.com/api-evangelist/whmcs/refs/heads/main/apis.yml
created: '2025-02-09'
modified: '2026-05-19'
specificationVersion: '0.19'
apis:
- aid: whmcs:whmcs-authentication-api
  name: WHMCS Authentication API
  description: OAuth and SSO authentication operations
  humanURL: https://developers.whmcs.com/
  baseURL: https://{your-domain}/includes/api.php
  tags:
  - Authentication
  properties:
  - type: OpenAPI
    url: openapi/whmcs-authentication-api-openapi.yml
  - type: Documentation
    url: https://developers.whmcs.com/api/
  - type: APIReference
    url: https://developers.whmcs.com/api-reference/
  - type: APIIndex
    url: https://developers.whmcs.com/api/api-index/
  - type: GettingStarted
    url: https://developers.whmcs.com/api/getting-started/
  - type: Authentication
    url: https://developers.whmcs.com/api/authentication/
  - type: SampleCode
    url: https://developers.whmcs.com/api/sample-code/
  - type: GitHub
    url: https://github.com/WHMCS
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-client-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-invoice-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-ticket-schema.json
  - type: JSONStructure
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-structure/whmcs-api-structure.json
  - type: JSONLDContext
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-ld/whmcs-context.jsonld
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/rules/whmcs-rules.yml
  - type: Vocabulary
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/vocabulary/whmcs-vocabulary.yml
- aid: whmcs:whmcs-billing-api
  name: WHMCS Billing API
  description: Invoice, payment, and transaction management
  humanURL: https://developers.whmcs.com/
  baseURL: https://{your-domain}/includes/api.php
  tags:
  - Billing
  properties:
  - type: OpenAPI
    url: openapi/whmcs-billing-api-openapi.yml
  - type: Documentation
    url: https://developers.whmcs.com/api/
  - type: APIReference
    url: https://developers.whmcs.com/api-reference/
  - type: APIIndex
    url: https://developers.whmcs.com/api/api-index/
  - type: GettingStarted
    url: https://developers.whmcs.com/api/getting-started/
  - type: Authentication
    url: https://developers.whmcs.com/api/authentication/
  - type: SampleCode
    url: https://developers.whmcs.com/api/sample-code/
  - type: GitHub
    url: https://github.com/WHMCS
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-client-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-invoice-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-ticket-schema.json
  - type: JSONStructure
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-structure/whmcs-api-structure.json
  - type: JSONLDContext
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-ld/whmcs-context.jsonld
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/rules/whmcs-rules.yml
  - type: Vocabulary
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/vocabulary/whmcs-vocabulary.yml
- aid: whmcs:whmcs-clients-api
  name: WHMCS Clients API
  description: Client account management operations
  humanURL: https://developers.whmcs.com/
  baseURL: https://{your-domain}/includes/api.php
  tags:
  - Clients
  properties:
  - type: OpenAPI
    url: openapi/whmcs-clients-api-openapi.yml
  - type: Documentation
    url: https://developers.whmcs.com/api/
  - type: APIReference
    url: https://developers.whmcs.com/api-reference/
  - type: APIIndex
    url: https://developers.whmcs.com/api/api-index/
  - type: GettingStarted
    url: https://developers.whmcs.com/api/getting-started/
  - type: Authentication
    url: https://developers.whmcs.com/api/authentication/
  - type: SampleCode
    url: https://developers.whmcs.com/api/sample-code/
  - type: GitHub
    url: https://github.com/WHMCS
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-client-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-invoice-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-ticket-schema.json
  - type: JSONStructure
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-structure/whmcs-api-structure.json
  - type: JSONLDContext
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-ld/whmcs-context.jsonld
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/rules/whmcs-rules.yml
  - type: Vocabulary
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/vocabulary/whmcs-vocabulary.yml
- aid: whmcs:whmcs-domains-api
  name: WHMCS Domains API
  description: Domain registration and management
  humanURL: https://developers.whmcs.com/
  baseURL: https://{your-domain}/includes/api.php
  tags:
  - Domains
  properties:
  - type: OpenAPI
    url: openapi/whmcs-domains-api-openapi.yml
  - type: Documentation
    url: https://developers.whmcs.com/api/
  - type: APIReference
    url: https://developers.whmcs.com/api-reference/
  - type: APIIndex
    url: https://developers.whmcs.com/api/api-index/
  - type: GettingStarted
    url: https://developers.whmcs.com/api/getting-started/
  - type: Authentication
    url: https://developers.whmcs.com/api/authentication/
  - type: SampleCode
    url: https://developers.whmcs.com/api/sample-code/
  - type: GitHub
    url: https://github.com/WHMCS
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-client-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-invoice-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-ticket-schema.json
  - type: JSONStructure
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-structure/whmcs-api-structure.json
  - type: JSONLDContext
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-ld/whmcs-context.jsonld
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/rules/whmcs-rules.yml
  - type: Vocabulary
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/vocabulary/whmcs-vocabulary.yml
- aid: whmcs:whmcs-orders-api
  name: WHMCS Orders API
  description: Order and quote management operations
  humanURL: https://developers.whmcs.com/
  baseURL: https://{your-domain}/includes/api.php
  tags:
  - Orders
  properties:
  - type: OpenAPI
    url: openapi/whmcs-orders-api-openapi.yml
  - type: Documentation
    url: https://developers.whmcs.com/api/
  - type: APIReference
    url: https://developers.whmcs.com/api-reference/
  - type: APIIndex
    url: https://developers.whmcs.com/api/api-index/
  - type: GettingStarted
    url: https://developers.whmcs.com/api/getting-started/
  - type: Authentication
    url: https://developers.whmcs.com/api/authentication/
  - type: SampleCode
    url: https://developers.whmcs.com/api/sample-code/
  - type: GitHub
    url: https://github.com/WHMCS
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-client-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-invoice-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-ticket-schema.json
  - type: JSONStructure
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-structure/whmcs-api-structure.json
  - type: JSONLDContext
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-ld/whmcs-context.jsonld
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/rules/whmcs-rules.yml
  - type: Vocabulary
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/vocabulary/whmcs-vocabulary.yml
- aid: whmcs:whmcs-support-api
  name: WHMCS Support API
  description: Ticket and announcement management
  humanURL: https://developers.whmcs.com/
  baseURL: https://{your-domain}/includes/api.php
  tags:
  - Support
  properties:
  - type: OpenAPI
    url: openapi/whmcs-support-api-openapi.yml
  - type: Documentation
    url: https://developers.whmcs.com/api/
  - type: APIReference
    url: https://developers.whmcs.com/api-reference/
  - type: APIIndex
    url: https://developers.whmcs.com/api/api-index/
  - type: GettingStarted
    url: https://developers.whmcs.com/api/getting-started/
  - type: Authentication
    url: https://developers.whmcs.com/api/authentication/
  - type: SampleCode
    url: https://developers.whmcs.com/api/sample-code/
  - type: GitHub
    url: https://github.com/WHMCS
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-client-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-invoice-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-ticket-schema.json
  - type: JSONStructure
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-structure/whmcs-api-structure.json
  - type: JSONLDContext
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-ld/whmcs-context.jsonld
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/rules/whmcs-rules.yml
  - type: Vocabulary
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/vocabulary/whmcs-vocabulary.yml
- aid: whmcs:whmcs-system-api
  name: WHMCS System API
  description: System administration and configuration
  humanURL: https://developers.whmcs.com/
  baseURL: https://{your-domain}/includes/api.php
  tags:
  - System
  properties:
  - type: OpenAPI
    url: openapi/whmcs-system-api-openapi.yml
  - type: Documentation
    url: https://developers.whmcs.com/api/
  - type: APIReference
    url: https://developers.whmcs.com/api-reference/
  - type: APIIndex
    url: https://developers.whmcs.com/api/api-index/
  - type: GettingStarted
    url: https://developers.whmcs.com/api/getting-started/
  - type: Authentication
    url: https://developers.whmcs.com/api/authentication/
  - type: SampleCode
    url: https://developers.whmcs.com/api/sample-code/
  - type: GitHub
    url: https://github.com/WHMCS
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-client-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-invoice-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-schema/whmcs-ticket-schema.json
  - type: JSONStructure
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-structure/whmcs-api-structure.json
  - type: JSONLDContext
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/json-ld/whmcs-context.jsonld
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/rules/whmcs-rules.yml
  - type: Vocabulary
    url: https://raw.githubusercontent.com/api-evangelist/whmcs/main/vocabulary/whmcs-vocabulary.yml
common:
- type: AgenticAccess
  url: agentic-access/whmcs-agentic-access.yml
- type: VulnerabilityDisclosure
  url: security/whmcs-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/whmcs-domain-security.yml
- type: Authentication
  url: authentication/whmcs-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/whmcs-ltd
- type: Website
  url: https://www.whmcs.com/
- type: Documentation
  url: https://developers.whmcs.com/
- type: APIReference
  url: https://developers.whmcs.com/api-reference/
- type: Blog
  url: https://blog.whmcs.com/
- type: GitHubOrganization
  url: https://github.com/WHMCS
- type: Marketplace
  url: https://marketplace.whmcs.com/
- type: Forums
  url: https://whmcs.community/
- type: StatusPage
  url: https://whmcsstatus.com/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com