API overview

High-level vs low-level APIs

The SDK exposes two main ways of interacting with the EFL Leasing Online API:

• High-level client: EflClient
  • Orchestrates typical ecommerce flows.
  • Hides most HTTP and model details behind convenient methods.
• Low-level API clients in the Api namespace:
  • CalculationApiClient
  • CustomerApiClient
  • ProcessApiClient
  • ProductsApiClient
  • LeadApiClient
  • RestorationApiClient
  • TestingApiClient
  • DemoApiClient

EflClient uses these low-level clients internally. You can typically stay on the high-level API and only drop to low-level clients when you need more control or advanced scenarios.

Models

Request and response payloads are represented by immutable value objects in the Model namespace. They are grouped by domain:

• Model\Calculation – calculation requests and results.
• Model\Customer – customer data, addresses, emails, phones and statements.
• Model\Lead – leads and contact data.
• Model\Process – process and authentication responses.
• Model\Products – product catalogue trees.
• Model\Verification – identity verification inputs and outputs.
• Model\Restoration – session restoration results.
• Model\Error – ProblemDetails for structured API error responses.

Most request models provide a ::builder() method that returns a fluent builder for easier construction.

Error handling

All SDK-specific errors extend EflLeasingException. The most important subclasses are:

• ApiException – API-level errors (HTTP 4xx/5xx) with access to ProblemDetails.
• HttpException – transport-level failures (network errors, timeouts, invalid responses).

You should catch these exceptions at your application boundaries and translate them into appropriate HTTP responses, logs or user-facing messages.

Where to go next

• Clients – see the EflClient overview and low-level clients in the clients section for details and reference of all available clients.
• Models – see the models overview page and individual model files for details and builders.
• Errors – see the errors reference for a deeper explanation of the exception hierarchy and error payloads.
• HTTP – see the HTTP reference for details on the HTTP abstraction layer, adapters and integration.