---
title: "Update experimentation settings"
method: PUT
path: "/api/v2/projects/{projectKey}/experimentation-settings"
tags: ["Experiments"]
---

# Update experimentation settings

`PUT /api/v2/projects/{projectKey}/experimentation-settings`

Update experimentation settings for the given project

## Path parameters

- `projectKey` string, string, required — The project key

## Request body

- RandomizationSettingsPut
  - `randomizationUnits` RandomizationUnitInput[], required — An array of randomization units allowed for this project.
    - `randomizationUnit` string, required — The unit of randomization. Must match the key of an existing context kind in this project.
    - `default` boolean — If true, any experiment iterations created within this project will default to using this randomization unit. A project can only have one default randomization unit.
    - `standardRandomizationUnit` string — (deprecated) This field is deprecated and will be removed. Use randomizationUnit instead.

## Response `200`

Experimentation settings response

- RandomizationSettingsRep
  - `_projectId` string — The project ID
  - `_projectKey` string — The project key
  - `randomizationUnits` RandomizationUnitRep[] — An array of the randomization units in this project
    - `randomizationUnit` string — The unit of randomization. Defaults to user.
    - `default` boolean — Whether this randomization unit is the default for experiments
    - `_hidden` boolean
    - `_displayName` string — The display name for the randomization unit, displayed in the LaunchDarkly user interface.
  - `_creationDate` integer
  - `_links` object — The location and content type of related resources

## Other responses

- `400` — Invalid request
- `401` — Invalid access token
- `403` — Forbidden
- `404` — Invalid resource identifier
- `405` — Method not allowed
- `429` — Rate limited

## Changes

- **2026-02-28** `69c5c9aafe78` — 6 breaking, 1 warning, 1 info
  - removed the enum value `guest` of the request property `randomizationUnits/items/standardRandomizationUnit`
  - removed the enum value `guestTime` of the request property `randomizationUnits/items/standardRandomizationUnit`
  - removed the enum value `organization` of the request property `randomizationUnits/items/standardRandomizationUnit`
  - removed the enum value `request` of the request property `randomizationUnits/items/standardRandomizationUnit`
  - …4 more

[Change history](https://skmtc.dev/launchdarkly/apis/launchdarkly-rest-api/changes/api/v2/projects/:projectKey/experimentation-settings/put.md)

---

[API](https://skmtc.dev/launchdarkly/apis/launchdarkly-rest-api.md) · [All operations](https://skmtc.dev/launchdarkly/apis/launchdarkly-rest-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/launchdarkly/launchdarkly-rest-api/revisions/69c5c9aafe78/schema)