---
title: "Update a dataset row"
method: PATCH
path: "/v1/projects/{projectSlug}/datasets/{datasetSlug}/rows/{rowId}"
tags: ["Datasets"]
---

# Update a dataset row

`PATCH /v1/projects/{projectSlug}/datasets/{datasetSlug}/rows/{rowId}`

Partially updates a single row. Only the cells you send are changed; omitted cells keep their current value. Use this to fill in an `expectedOutput` (or any other cell) after rows were imported. Bumps the dataset version.

## Path parameters

- `projectSlug` string, required — Project slug (human-readable identifier)
- `datasetSlug` string, required — Dataset slug (human-readable identifier within the project).
- `rowId` string, required — Stable row identifier (from `listDatasetRows`).

## Request body

- UpdateDatasetRowBody
  - `input` union — New input cell. Omit to leave it unchanged.
    - string
    - number
    - boolean
    - unknown[]
      - unknown
    - object
  - `output` union — New output cell. Omit to leave it unchanged.
    - string
    - number
    - boolean
    - unknown[]
      - unknown
    - object
  - `expectedOutput` union — New correct answer for this row. Filled in by curators; usually distinct from `output`. Omit to leave it unchanged.
    - string
    - number
    - boolean
    - unknown[]
      - unknown
    - object
  - `metadata` union — New metadata cell. Omit to leave it unchanged.
    - string
    - number
    - boolean
    - unknown[]
      - unknown
    - object
  - `custom` object — Custom column values to set, keyed by column identifier. Merged onto the row's existing custom values — columns you omit are left unchanged. Unknown or removed columns are rejected.

## Response `200`

Row updated

- UpdateDatasetRowResponse
  - `versionId` string, required — New dataset version id.
  - `version` integer, required — New dataset version number.

## Other responses

- `400` — Validation error
- `401` — Unauthorized
- `404` — Not found

## Changes

- **2026-06-29** `5d232d9bc8a7` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/latitude-dev/apis/latitude/changes/v1/projects/:projectSlug/datasets/:datasetSlug/rows/:rowId/patch.md)

---

[API](https://skmtc.dev/latitude-dev/apis/latitude.md) · [All operations](https://skmtc.dev/latitude-dev/apis/latitude/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/latitude-dev/latitude/revisions/a0bf72a85607/schema)