---
title: PHP-SDK - v4.0.1
slug: feature-experimentation/release-notes/php-sdk-v4-0-1
docTags: 
createdAt: 2026-07-20T15:45:04.725Z
---

## [#whats-changed](docId\:Mikffk_XkUKyZKIXcJzEN)What's Changed

- \[FSSDK-9022] Dev Containers and bug bash by @Mat001 in [https://github.com/optimizely/php-sdk/pull/269](https://github.com/optimizely/php-sdk/pull/269)
- \[FSSDK-9553] Add GitHub Issues templates by @mikechu-optimizely in [https://github.com/optimizely/php-sdk/pull/278](https://github.com/optimizely/php-sdk/pull/278)
- \[FSSDK-9573] Fix: Deprecation warning by @mikechu-optimizely in [https://github.com/optimizely/php-sdk/pull/279](https://github.com/optimizely/php-sdk/pull/279)
- \[FSSDK-9784] Return Latest Experiment When Duplicate Keys in Config by @mikechu-optimizely in [https://github.com/optimizely/php-sdk/pull/280](https://github.com/optimizely/php-sdk/pull/280)
- \[FSSDK-9630] Fix: Code examples by @localheinz in [https://github.com/optimizely/php-sdk/pull/281](https://github.com/optimizely/php-sdk/pull/281)

**Full Changelog**: [https://github.com/optimizely/php-sdk/compare/4.0.0...4.0.1](https://github.com/optimizely/php-sdk/compare/4.0.0...4.0.1)

[https://github.com/optimizely/php-sdk/releases/tag/4.0.1](https://github.com/optimizely/php-sdk/releases/tag/4.0.1)