---
title: Javascript-SDK - 6.5.0
slug: feature-experimentation/release-notes/javascript-sdk-6-5-0
docTags: 
createdAt: 2026-07-20T15:45:27.013Z
---

## \[6.5.0] - July 8, 2026

### New Features

- **Local Holdouts**: Added support for Local Holdouts, enabling holdout experiments to be scoped to specific feature flag rules rather than applied globally. Local Holdouts let you measure the true incremental impact of individual features by holding out a subset of users from specific rollouts while still serving them other experiences. See [Holdouts docs](docId\:DogKLoT6bPNNCcoA2ch7a) for more information.

### Changed

- Refactor project config creation ([#1164](https://github.com/optimizely/javascript-sdk/pull/1164))
- Replace deprecated url.parse() with the WHATWG URL in NodeRequestHandler ([#1161](https://github.com/optimizely/javascript-sdk/pull/1161))
- Upgrade to uuid v13 ([#1159](https://github.com/optimizely/javascript-sdk/pull/1159))
- Don't send ODP identify event for single identifier ([#1152](https://github.com/optimizely/javascript-sdk/pull/1152))

### Bug Fixes

- Use attribute id instead of key for CMAB prediction requests ([#1160](https://github.com/optimizely/javascript-sdk/pull/1160))
- Normalize decision event campaign\_id, variation\_id, and entity\_id ([#1158](https://github.com/optimizely/javascript-sdk/pull/1158))
- Fix content-length header in NodeRequestHandler ([#1156](https://github.com/optimizely/javascript-sdk/pull/1156))

[https://github.com/optimizely/javascript-sdk/releases/tag/v6.5.0](https://github.com/optimizely/javascript-sdk/releases/tag/v6.5.0)