---
title: "Start a normally billed preset comparison [write]"
method: POST
path: "/arena/personal"
tags: ["Arena"]
---

# Start a normally billed preset comparison \[write\]

`POST /arena/personal`

## Request

- Base URL: `https://api.agentsky.dev/v1`
- URL: `https://api.agentsky.dev/v1/arena/personal`
- Auth: HTTP bearer

Uses the Mac's existing runnable-preset owner. Set billing normal to acknowledge normal usage pricing; no free credit, waiver or quota bypass is created. Reuse requestId when retrying. Missing/formerly sponsored presets remain retired (410). A rejected admitted start can carry playgroundId: inspect it before starting another.

## Request body

- object
  - `task` string, required
  - `preset` string, required
  - `requestId` string, required
  - `billing` 'normal', required
  - `timezone` string

## Response `201`

OK; private, no-store

- object
  - `playgroundId` string
  - `columns` object[]

## Other responses

- `400`: Error — { error: { code, message } }
- `401`: Error — { error: { code, message } }
- `403`: Error — { error: { code, message } }
- `404`: Error — { error: { code, message } }
- `409`: Error — { error: { code, message } }
- `410`: Error — { error: { code, message } }
- `422`: Error — { error: { code, message } }

## Changes

- **2026-11-02** `e5e8f0229a99`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/agentsky/apis/agentsky-developer-api/changes/arena/personal/post.md)

---

[API](https://skmtc.dev/agentsky/apis/agentsky-developer-api.md) - [All operations](https://skmtc.dev/agentsky/apis/agentsky-developer-api/llms.txt) - [OpenAPI document](https://skmtc.dev/agentsky/apis/agentsky-developer-api/revisions/8280a065ef6a?raw)