# Invoicing

{% hint style="info" %}
Implementation is **OPTIONAL** (*Recommended*)
{% endhint %}

Smarts will store detailed confirmation invoice only for two months. So it is important to save detailed invoice copy.

### Implementation

You only need to create a new class, implement **`InvoiceReceiverAdapter`** interface and fill all required methods.  API endpoints for invoicing are created automatically and secured with token. 

It is important to add `@Component` annotation on top of the class. There is no restriction for class name or location in your project. Our SDK will find your implementation based on the interface (DI).

```java
import ee.smarts.common.v1.Entities.invoice.Invoice;
import ee.smarts.starter.adapter.InvoiceReceiverAdapter;
import org.springframework.stereotype.Component;

@Component
public class InvoiceReceiverImpl implements InvoiceReceiverAdapter {
    @Override
    public void receive(Invoice invoice) {
        // implement this method
    } 
}
```

{% hint style="warning" %}
Default invoicing **is not used** when merchant side invoicing is enabled. Merchant side invoicing is using receipt listener method in [ReceiptAdapter](/integration/spring-boot-starter/merchant-side-invoicing.md).
{% endhint %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://developer.smarts.ee/integration/spring-boot-starter/invoicing.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.