---
title: "Override the experiment variant for one user"
method: PUT
path: "/admin/users/{id}/experiments/{key}"
tags: ["Admin Users"]
---

# Override the experiment variant for one user

`PUT /admin/users/{id}/experiments/{key}`

Pins this user to the given variant. Beats weights, experiment status and the global forced variant — only this user is affected. Returns the refreshed experiments overview.

## Path parameters

- `id` string, required
- `key` string, required

## Request body

- SetUserExperimentVariantDto
  - `variantId` string, required — Must be one of the variant ids declared on the experiment. Wins over weights, status and the global forced variant for this user only.

## Response `200`

Variant overridden successfully

- UserExperimentsResponseDto
  - `firebaseUserId` string, nullable, required — Experiment subject id; null when the user has no Firebase UID
  - `experiments` UserExperimentItemDto[], required
    - `key` string, required
    - `name` string, required
    - `status` 'draft' | 'running' | 'paused' | 'completed', required
    - `enrollmentMode` 'auto' | 'manual', required
    - `variants` string[], required — Variant ids declared on the experiment
    - `defaultVariantId` string, nullable, required
    - `forcedVariantId` string, nullable, required
    - `winnerVariantId` string, nullable, required
    - `effectiveVariantId` string, nullable, required — Variant the experiments service resolves for this user now
    - `effectiveSource` 'override' | 'forced' | 'sticky' | 'default', required
    - `enrolledVariantId` string, nullable, required
    - `enrollSource` 'auto_read' | 'manual_event' | 'forced' | 'admin_override', nullable, required
    - `assignedAt` string, date-time, nullable, required
    - `overrideVariantId` string, nullable, required — Variant pinned to this user by an admin, if any

## Other responses

- `400` — Unknown variant id, or user has no Firebase UID
- `404` — User or experiment not found

---

[API](https://skmtc.dev/miaai/apis/backend-template-api.md) · [All operations](https://skmtc.dev/miaai/apis/backend-template-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/miaai/backend-template-api/revisions/2a8d88a5124f/schema)