---
title: Change history
slug: feature-experimentation/docs/history
docTags: 
createdAt: 2026-08-05T20:40:03.000Z
---

Optimizely Feature Experimentation logs actions performed for a project and for a flag, such as creating an event, modifying a rule, and adding and removing audiences. These actions are listed in the change history, which displays the record of user activity for each of your [projects](docId\:eJ1318kIsNBqMt1MqD9eI) and [flags](docId\:eJ1318kIsNBqMt1MqD9eI). These actions are also available through webhooks. See [Create a Webhook](docId\:fxs-QgSDWJiHQc0JQ1Y0C).

If an experiment starts to behave strangely or stops working correctly, you can troubleshoot by checking the change history to see which changes were made, when, and by which [collaborator](docId\:bNAxj4srKHVczBp27i1DH). The detailed change history creates an activity trail that provides additional security to individuals and teams with multiple collaborators.

See [Change history in Feature Experimentation](docId\:CvMxeG8fRRnvPX_fCGIJK) in the user documentation for what project-level and flag-level changes are tracked.

## Project history

Each project's change history is available using the REST API and in the UI.

### Access project history with the REST API

See the [Retrieve changes for a project](docId\:SXDBIrOGqRlaNtlIfxhrS) endpoint documentation for information on how to get a list of changes for a given project. You can use optional filters to refine the list of changes.

### Access project history in the UI

See [Change history in Feature Experimentation](docId\:CvMxeG8fRRnvPX_fCGIJK) in the user documentation for step-by-step instructions.