---
title: Agent - 4.4.0
slug: feature-experimentation/release-notes/agent-4-4-0
docTags: 
createdAt: 2026-07-20T15:45:31.198Z
---

## \[4.4.0] - December 18, 2025

[#440---december-18-2025](docId\:VdPvM_Y9y52pyG4fAXaN5)

This release adds support for Holdouts, allowing you to measure the incremental impact of feature flags and experiments by holding back a percentage of users from seeing any changes.

### New Features

[#new-features](docId\:VdPvM_Y9y52pyG4fAXaN5)

- **Holdouts Support** ([#452](https://github.com/optimizely/agent/pull/452)): Agent now fully supports Optimizely's Holdouts feature for measuring incremental impact of flags and experiments. Features include:
  - Full holdouts evaluation through go-sdk v2.3.0
  - Support for global (project-level) holdouts
  - Holdouts evaluated before experiments and rollouts in decision flow
  - Holdout decisions return `enabled: false`, `variationKey: "off"`, and `ruleKey` containing the holdout identifier
  - Forced decisions correctly override holdout bucketing
  - Zero Agent code changes required - all holdout logic handled by go-sdk
  - Comprehensive acceptance test coverage with real project datafile

:::Paragraph{indent="1"}
This enables accurate measurement of feature impact by comparing users held out from experiments against those receiving variations.
:::

- **CMAB Acceptance Tests** ([#451](https://github.com/optimizely/agent/pull/451)): Added comprehensive acceptance tests for Contextual Multi-Armed Bandit (CMAB) functionality to ensure reliable AI-powered experimentation

### Changed

[#changed](docId\:VdPvM_Y9y52pyG4fAXaN5)

- Updated to go-sdk v2.3.0 with holdouts support and CMAB improvements
- Updated CMAB API migration to use `CmabConfig.PredictionEndpointTemplate` field

### Fixed

[#fixed](docId\:VdPvM_Y9y52pyG4fAXaN5)

- Fixed Prisma security scanning issues ([#450](https://github.com/optimizely/agent/pull/450))

[https://github.com/optimizely/agent/releases/tag/v4.4.0](https://github.com/optimizely/agent/releases/tag/v4.4.0)