---
title: "Preview Dataset Version"
method: POST
path: "/public/v2/datasets/{dataset_id}/versions/{version_index}/preview"
tags: ["datasets"]
---

# Preview Dataset Version

`POST /public/v2/datasets/{dataset_id}/versions/{version_index}/preview`

## Request

- Base URL: `https://api.galileo.ai`
- URL: `https://api.galileo.ai/public/v2/datasets/{dataset_id}/versions/{version_index}/preview`
- Auth: one of:
  - API key in header `Splunk-AO-API-Key`
  - API key in header `Galileo-API-Key`
  - OAuth 2
    - Password
    - Token URL: `https://api.galileo.ai/login`
  - HTTP basic
- TypeScript: <https://skmtc.dev/galileo/apis/galileo-api-server/docs/public/v2/datasets/:dataset_id/versions/:version_index/preview/post.ts> (a function with typed inputs; its response is checked against the schema)

## Path parameters

- `dataset_id` string, uuid4, required
- `version_index` integer, required

## Query parameters

- `limit` integer
- `cursor` string, nullable

## Request body

- LunaDatasetPreviewRequest
  - `mappings` union, required
    - LunaDatasetMappings: Semantic mappings shared by preview, validation, and dataset finalization.
      - `input` LunaMappingConfig
        - `columns` string[], required
        - `flatten` boolean
      - `output` LunaMappingConfig
        - `columns` string[], required
        - `flatten` boolean
      - `label` LunaMappingConfig
        - `columns` string[], required
        - `flatten` boolean
      - `evaluator_ground_truth` LunaMappingConfig
        - `columns` string[], required
        - `flatten` boolean
      - `metadata` LunaMappingConfig
        - `columns` string[], required
        - `flatten` boolean
      - `tools` LunaMappingConfig
        - `columns` string[], required
        - `flatten` boolean
      - `documents` LunaMappingConfig
        - `columns` string[], required
        - `flatten` boolean
      - `mgt` object
    - LunaSemanticMapping[]
      - `source_column` string, required
      - `target_field` 'input' | 'output' | 'label' | 'evaluator_ground_truth' | 'metadata' | 'tools' | 'documents' | 'generated_output' | 'ground_truth', required

## Response `200`

Successful Response

- LunaDatasetPreview
  - `dataset` union, required
    - LunaPreviewDraftRef
      - `kind` 'draft'
      - `dataset_id` string, uuid4, required
      - `draft_revision` string, required
    - LunaPreviewVersionRef
      - `kind` 'version'
      - `dataset_id` string, uuid4, required
      - `version_index` integer, required
  - `columns` LunaDatasetPreviewColumn[], required
    - `key` string, required
    - `label` string, required
    - `source_columns` string[], required
    - `source_column` string, nullable
    - `samples` PydanticTypesJsonValue[]
      - unknown
    - `group` string, nullable
    - `scorer_id` string, uuid4, nullable
  - `rows` LunaDatasetPreviewRow[], required
    - `row_ref` string, required
    - `values` object, required
    - `truncated_columns` string[]
  - `total_row_count` integer, required
  - `column_count` integer, required
  - `next_cursor` string, nullable

## Other responses

- `404`: Dataset or immutable version unavailable
- `412`: Draft revision conflict or unavailable revision
- `422`: Invalid preview request, mapping or pagination
- `428`: If-Match is required for draft preview
- `503`: Preview storage is temporarily unavailable

## Changes

> 41 revisions in range; 2 not diffed.

- **2026-11-09** `2ad8ff2a1c36`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/galileo/apis/galileo-api-server/changes/public/v2/datasets/:dataset_id/versions/:version_index/preview/post.md)

---

[API](https://skmtc.dev/galileo/apis/galileo-api-server.md) - [All operations](https://skmtc.dev/galileo/apis/galileo-api-server/llms.txt) - [OpenAPI document](https://skmtc.dev/galileo/apis/galileo-api-server/revisions/7a6f6a3451a5?raw)