> For the complete documentation index, see [llms.txt](https://onestore-dev.gitbook.io/dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://onestore-dev.gitbook.io/dev/eng/tools/billing/old-version/v16.md).

# ONE store In-App SDK v16

### **References and downloads for In-App SDK v16** <a href="#onestoreinappsdkv16-referencesanddownloadsforin-appsdkv16" id="onestoreinappsdkv16-referencesanddownloadsforin-appsdkv16"></a>

ONE store developer center IAP provides the payment service in a more convenient and safer way with various forms of payment,\
stronger security and specialized user experience for Korean users.

THIS GUIDES ARE VALID ONLY FOR THE IN-APP SDK V16 VERSION.\
If you are looking for the latest version of In-App SDK(v17), just [click here](https://dev.onestore.co.kr/wiki/en/doc/one-store-in-app-purchase-api-v5-sdk-v17-1081855.html).

### **Introduction** <a href="#onestoreinappsdkv16-introduction" id="onestoreinappsdkv16-introduction"></a>

* [Introduction to ONE store In-App SDK v16](https://github.com/ONE-store/inapp-sdk-eng/wiki)

### **Download SDK**  <a href="#onestoreinappsdkv16-downloadsdk" id="onestoreinappsdkv16-downloadsdk"></a>

* [IAP SDK v16 download (For Android / For Unity3D)](https://github.com/ONE-store/inapp-sdk/wiki/IAP-Download)

### **Developer Guide** <a href="#onestoreinappsdkv16-developerguide" id="onestoreinappsdkv16-developerguide"></a>

* [Developer Guide of IAP SDK v16](https://github.com/ONE-store/inapp-sdk-eng/wiki/IAP-Developer-Guide)
* Download IAP Setting App

  &#x20;Read More

### **IAP v16 Developer Guide for Unity3D** <a href="#onestoreinappsdkv16-iapv16developerguideforunity3d" id="onestoreinappsdkv16-iapv16developerguideforunity3d"></a>

* [Developer Guide for Unity3D](https://github.com/ONE-store/inapp-sdk-eng/wiki/IAP-Game-Unity-Developer-Guide)

### **References** <a href="#onestoreinappsdkv16-references" id="onestoreinappsdkv16-references"></a>

* [References for SDK](https://github.com/ONE-store/inapp-sdk-eng/wiki/IAP-SDK-Reference)&#x20;
* [References for Server-API](https://github.com/ONE-store/inapp-sdk-eng/wiki/IAP-Reference-Server-API)
* [References for Result-Code](https://github.com/ONE-store/inapp-sdk-eng/wiki/IAP-Reference-Result-Code)
* [References for Request and Response](https://github.com/ONE-store/inapp-sdk-eng/wiki/IAP-Sample-Specification)

<br>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## 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, and the optional `goal` query parameter:

```
GET https://onestore-dev.gitbook.io/dev/eng/tools/billing/old-version/v16.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.