# Developer Tools

### Sample App Download <a href="#sampledownload-sampleappdownload" id="sampledownload-sampleappdownload"></a>

You can download sample apps required to use the ONE store IAP API V7 (SDK V21) from github.

| branch | Description                                                                                                                                                                                                                                                                           |
| ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| master | <p><a href="https://github.com/ONE-store/onestore_iap_release/tree/master/onestore_iap_sample/sample_luckyone">sample\_luckyone </a><br><a href="https://github.com/ONE-store/onestore_iap_release/tree/master/onestore_iap_sample/sample_subscription">sample\_subscription</a> </p> |

### Download ONE Billing Lab <a href="#id-10.-downloadonebillinglab" id="id-10.-downloadonebillinglab"></a>

The ONE Billing Lab app for ONE store in-app payment development can be downloaded from the ONE store app or GitHub.

* [Install from the ONE store app](https://onesto.re/0001002700)
* [Install from GitHub](https://github.com/ONE-store/one_billing_lab)

Note: [ONE Billing Lab Guide](https://onestore-dev.gitbook.io/dev/tools/one-billing-lab)


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# 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://onestore-dev.gitbook.io/dev/eng/tools/billing/v21/sample.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.