---
title: Android-SDK - 5.1.0
slug: feature-experimentation/release-notes/android-sdk-5-1-0
docTags: 
createdAt: 2026-07-20T15:44:23.400Z
---

## 5.1.0

[#510](docId:1_CBkrjxz3Ns7lD_DbYBt)

December 19th, 2025

### New Features

[#new-features](docId:1_CBkrjxz3Ns7lD_DbYBt)

This release introduces new primary features: [Contextual Multi-Armed Bandit (CMAB)](docId\:im-eIEuuMKEvpues-LxuK) and [Holdouts](docId\:DogKLoT6bPNNCcoA2ch7a).

**Contextual Multi-Armed Bandit (CMAB)**

- Add support for CMAB experiments with new configuration options and cache control (#514).
- Add new `decideAsync` methods to support asynchronous CMAB decision (#514).
- For configuration details, see the [CMAB configuration documentation](docId\:eOXBfHv-9RrPvr7wuZg4h).

**Holdouts**

- Add Holdouts Feature Experimentation feature (#516).

### Other Changes

[#other-changes](docId:1_CBkrjxz3Ns7lD_DbYBt)

- Upgrade targetSDK to 35

[https://github.com/optimizely/android-sdk/releases/tag/5.1.0](https://github.com/optimizely/android-sdk/releases/tag/5.1.0)