---
title: Swift-SDK - 5.1.1
slug: feature-experimentation/release-notes/swift-sdk-5-1-1
docTags: 
createdAt: 2026-07-20T15:45:43.525Z
---

## 5.1.1

[#511](docId\:Gd0xd8SekS-KCQPWzH1_M)

Jun 2th, 2025

### Functionality Enhancement

[#functionality-enhancement](docId\:Gd0xd8SekS-KCQPWzH1_M)

- Add experiment id and variation id added into decision notification payload ([#589](https://github.com/optimizely/swift-sdk/pull/589)).

[https://github.com/optimizely/swift-sdk/releases/tag/v5.1.1](https://github.com/optimizely/swift-sdk/releases/tag/v5.1.1)