Introduction

Building a custom integration for AddressValidation means implementing a set of well-defined, single-responsibility contracts. The framework handles orchestration — the validation pipeline, HTTP resilience, and token caching — so you only need to supply provider-specific logic.

Steps

Follow these steps in order to build a custom integration:

1. Data Models — define the public-facing request type and the provider's JSON DTO classes
2. Mappers — translate between the request model and the provider DTO, and map the provider response to IAddressValidationResponse
3. Authentication — request, cache, and refresh an access token from the provider (OAuth 2.0 only)
4. Validation Client — call the provider's address validation endpoint and bridge the public request to the client
5. Validators — validate the request before sending and the response after receiving
6. Registering Services — wire the pipeline components together and register all components with the DI container

Note

Step 3 is only required when the provider uses OAuth 2.0 bearer tokens. Providers that authenticate via static API keys, query string parameters, or other schemes can skip that step and omit the BearerTokenDelegatingHandler<TClient> from the HTTP client pipeline during service registration.