---
title: "Change experiment rollout"
method: PATCH
path: "/application/{applicationId}/v2/experiments/{experimentId}/rollout"
tags: ["Experiments (V2)"]
---

# Change experiment rollout

`PATCH /application/{applicationId}/v2/experiments/{experimentId}/rollout`

## Request

- Base URL: `https://api.gamebeast.gg`
- URL: `https://api.gamebeast.gg/application/{applicationId}/v2/experiments/{experimentId}/rollout`
- Auth: HTTP bearer

Change a scheduled or active experiment's staged rollout: `set` a percentage, `advance` to the next scheduled step, `pause` or `resume` the schedule, or `replaceSteps` with a new one. Takes effect on the next SDK request. Only changes who may newly enroll — already-enrolled units keep their group, so lowering or pausing stops new enrollment and evicts no one. Group weights are unchanged.

## Path parameters

- `applicationId` integer, required
- `experimentId` integer, required

## Headers

- `environment_id` number, required

## Request body

- union
  - object
    - `action` 'set', required
    - `rolloutBps` integer, required
    - `reason` string, required
  - object
    - `action` 'advance', required
    - `reason` string, required
  - object
    - `action` 'pause', required
    - `reason` string, required
  - object
    - `action` 'resume', required
    - `reason` string, required
  - object
    - `action` 'replaceSteps', required
    - `steps` object[], required
      - `targetBps` integer, required
      - `startsAt` string, date-time, required
    - `reason` string, required

## Response `200`

Default Response

- object
  - `rollout` object, required
    - `initialBps` integer, required
    - `rolloutBps` integer, required
    - `rolloutSetAt` string, date-time, required
    - `pausedAt` string, date-time, nullable, required
    - `steps` object[], required
      - `targetBps` integer, required
      - `startsAt` string, date-time, required
    - `effectiveBps` integer, required
  - `events` object[], required
    - `kind` 'created' | 'set' | 'advance' | 'pause' | 'resume' | 'replaceSteps' | 'step', required
    - `fromBps` integer, required
    - `toBps` integer, required
    - `reason` string, nullable, required
    - `actorId` string, uuid, nullable, required
    - `occurredAt` string, date-time, required

## Changes

- **2026-10-03** `e6cbc297dcb1`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/gamebeast/apis/gamebeast-api/changes/application/:applicationId/v2/experiments/:experimentId/rollout/patch.md)

---

[API](https://skmtc.dev/gamebeast/apis/gamebeast-api.md) - [All operations](https://skmtc.dev/gamebeast/apis/gamebeast-api/llms.txt) - [OpenAPI document](https://skmtc.dev/gamebeast/apis/gamebeast-api/revisions/24605f243ed0?raw)