---
title: "Preview Experiment Participants"
method: POST
path: "/admin/experiments/preview-participants"
tags: ["admin", "experiments"]
---

# Preview Experiment Participants

`POST /admin/experiments/preview-participants`

## Request

- Base URL: `https://api-docs.upsmith.com` (the document declares no server; this is the origin it was published from)
- URL: `https://api-docs.upsmith.com/admin/experiments/preview-participants`
- Auth: one of:
  - API key in header `x-api-key`
  - HTTP bearer

## Headers

- `organization-id` string, nullable
- `timezone` string
- `x-user-id` string, nullable
- `x-actor-email` string, nullable
- `x-request-source` string, nullable
- `x-operation-id` string, nullable
- `x-commit-message` string, nullable
- `x-confirmation-id` string, nullable
- `x-chat-id` string, nullable

## Request body

- ParticipantPreviewRequest
  - `scope` ExperimentTypedReference, required
    - `type` string, required
    - `id` string, required
  - `arms` ExperimentArmInput[]
    - `key` string, required
    - `name` string, required
    - `role` 'control' | 'candidate', required
    - `allocation_percentage` union, required
      - number
      - string
    - `target` ExperimentTypedReference
      - `type` string, required
      - `id` string, required
    - `change_spec` ExperimentChangeSpec: The delta a multi-participant candidate arm applies per participant — either an objective/hook link repoint to a global version, or a model override (the all-agents fleet scope). An arm carries link repoints or a model, never both.
      - `objective_links` ChangeSpecObjectiveLink[]
        - `group_id` string, required
        - `objective_id` string, required
      - `hook_links` ChangeSpecHookLink[]
        - `group_id` string, required
        - `hook_id` string, required
      - `model` string, nullable
      - `system_prompt_components` SystemPromptComponentReference[], nullable
        - `prompt_name` string, required
        - `prompt_version` string, required
        - `parameters` object

## Response `200`

Successful Response

- ExperimentAudiencePreview
  - `participants` ExperimentParticipantPreview[]
    - `organization_id` string, required
    - `agent_v2_id` string, required
    - `organization_name` string, nullable
    - `agent_name` string, nullable
    - `current_id` string, nullable
    - `no_op` boolean
    - `linked_objective_group_ids` string[]

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/upsmith/apis/upsmith-api.md) - [All operations](https://skmtc.dev/upsmith/apis/upsmith-api/llms.txt) - [OpenAPI document](https://skmtc.dev/upsmith/apis/upsmith-api/revisions/cce8b07a5787?raw)