---
title: "set_default_variant"
description: "Promote one variant to the group's default and demote every other variant in one atomic update."
sidebarTitle: "set_default_variant"
lastUpdated: "2026-09-23"
---

> **For AI agents:** the complete documentation index is at [llms.txt](/llms.txt). Append `.md` to any page URL for its markdown version.

{/* GENERATED FILE: do not edit by hand. Regenerate with: node scripts/generate.mjs */}

Promote one variant to the group's default and demote every other variant in one atomic update.

<Info>
  **Writes data · Idempotent · Calls external systems.**
</Info>

## Parameters

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `acknowledge` | boolean | No | Reset edit budget after user approval |
| `group_id` | number | Yes | Variable group id |
| `variant_id` | number | Yes | Variant id to make default |

## Example arguments

Illustrative arguments an agent supplies when calling this tool:

```json
{
  "group_id": 0,
  "variant_id": 0
}
```

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