API and webhooks | ADP Car Market Hub

External API access

External API access provides the vehicle data that is imported and synchronized inside WordPress.

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Credential management

Credentials authorize API requests and should only be stored in protected plugin settings.

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REST and AJAX endpoints

Technical endpoints support plugin operations, frontend workflows and controlled WordPress admin interactions.

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Webhook workflows

Webhook documentation explains how integration events or external signals can be handled where supported.

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Diagnostics and support

Connection tests, logs and troubleshooting documents help identify failed requests, blocked endpoints or configuration errors.

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External vehicle data source Provides structured vehicle inventory data through configured API access.
HTTPS API request The WordPress server must be able to reach external endpoints over secure HTTPS.
Authentication and credentials API credentials validate access and determine which inventory can be retrieved.
ADP Car Market Hub WordPress Plugin Handles configuration, connection tests, imports and internal processing.
Import processing Transforms external data into WordPress vehicle records, metadata and media.
WordPress database and media library Stores imported vehicle content, images, settings, logs and related operational data.
REST, AJAX and frontend workflows Support controlled admin actions, frontend interactions and integration behavior.
Logs, diagnostics and support Help diagnose connection failures, endpoint issues and integration errors.

Required values

API Base URL
Token URL
Client ID
Client Secret
Seller ID or account identifier
API environment
Connection test endpoint where configured

Credential handling rules

Do not publish credentials in documentation
Do not commit credentials to repositories
Store credentials only in protected plugin settings
Limit access to trusted administrators
Confirm account permissions before importing
Rotate credentials when access changes
Use staging credentials for staging tests where possible

Open API Credentials Setup Open External API Credentials Open AutoScout24 API Setup

Valid HTTPS website

Valid external API URL

Outbound HTTPS requests allowed

No hosting firewall blocking API calls

DNS resolution works from the server

SSL certificate chain is valid

Token endpoint reachable

API base URL reachable

Credentials entered correctly

Seller or account access confirmed

Connection test completed

Relevant logs reviewed

Open API Network and SSL Requirements Open API Connection Errors

REST API endpoints Technical

REST API documentation describes the plugin endpoint surface, expected behavior and technical usage boundaries.

Endpoint namespace
Request purpose
Authentication context
Expected responses
Error handling
Security checks

REST API Endpoints REST API for Developers

AJAX actions Technical

AJAX documentation describes controlled admin or frontend interactions that rely on WordPress AJAX behavior.

Action purpose
Nonce checks
Capability checks
Input validation
Response format
Error handling

AJAX Actions AJAX Actions for Developers

Use cases

Webhook use cases

Use webhooks to understand how event driven integration patterns can complement scheduled imports and manual actions.

Webhook Integration

Handling

Webhook handling

Webhook handling should validate the request source, sanitize input, log failures and avoid exposing private data.

Webhooks Technical Documentation

Troubleshooting

Webhook troubleshooting

Failed webhook calls should be diagnosed through logs, endpoint reachability, authentication checks and payload validation.

Troubleshooting

Webhook availability and behavior depend on the installed plugin version and configured integration scenario.

Safe integration practices

Use HTTPS for all external communication
Restrict credential access to authorized administrators
Validate API URLs before importing
Use staging credentials for tests where available
Monitor failed API requests
Review logs without exposing personal data
Document public behavior only

Do not publish

Client secrets
API tokens
Private API URLs
Customer data
Personal data
Raw webhook payloads with private data
Internal server paths
Security sensitive implementation details

Issue	Likely cause	Recommended check	Documentation
Connection test fails	Wrong URL, blocked outbound request or SSL issue	Check API URL, DNS, hosting firewall and SSL chain	API Network and SSL API Connection Errors
Authentication fails	Invalid client ID, client secret, token endpoint or account permissions	Check credentials and seller account access	API Credentials Setup External API Credentials
Imports return no vehicles	Seller ID, account mapping or API permissions do not match expected inventory	Check account access and import configuration	AutoScout24 API Setup
Webhook not received	Endpoint not reachable or external sender not configured	Check webhook URL, authentication and logs	Webhook Integration
AJAX request fails	Nonce, permission or malformed request issue	Check browser console, admin permissions and logs	AJAX Actions
REST request fails	Authentication, capability or endpoint issue	Check endpoint namespace, request method and response	REST API Endpoints