---
title: "Create a dataset split"
method: POST
path: "/v1/datasets/{dataset_identifier}/splits"
tags: ["datasets"]
---

# Create a dataset split

`POST /v1/datasets/{dataset_identifier}/splits`

## Path parameters

- `dataset_identifier` string, required — The dataset identifier: either dataset ID or dataset name.

## Request body

- CreateDatasetSplitRequestBody
  - `name` string, required — A unique name for the split.
  - `description` string, nullable — An optional description of the split.
  - `color` string, nullable — An optional hex color for the split (e.g. #33c5e8). Omit for a default.
  - `metadata` object — Arbitrary JSON metadata for the split.
  - `example_ids` string[] — Optional dataset example IDs (GlobalIDs) to seed the split with. Each example must belong to this dataset. Omit to create an empty split.

## Response `201`

Successful Response

- CreateDatasetSplitResponseBody
  - `data` DatasetSplit, required
    - `id` string, required
    - `name` string, required
    - `description` string, nullable, required
    - `color` string, required
    - `metadata` object, required
    - `example_count` integer, required
    - `created_at` string, date-time, required
    - `updated_at` string, date-time, required

## Other responses

- `403` — Forbidden
- `404` — Dataset or example not found
- `409` — A dataset split with the given name already exists
- `422` — Invalid request

## Changes

- **2026-08-08** `a14d8ad6f708` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/arize-ai/apis/arize-phoenix-rest-api/changes/v1/datasets/:dataset_identifier/splits/post.md)

---

[API](https://skmtc.dev/arize-ai/apis/arize-phoenix-rest-api.md) · [All operations](https://skmtc.dev/arize-ai/apis/arize-phoenix-rest-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/arize-ai/arize-phoenix-rest-api/revisions/b43e9d4f06e0/schema)