> ## Documentation Index
> Fetch the complete documentation index at: https://docs.oxen.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Post apirepos workspaces data framescolumnsschemametadata

> Set the metadata on a single column of a data frame, the HTTP equivalent of `oxen schemas add <path> -c <column> -m '{...}'`. Staged into the workspace, so no commit is required. Replaces that column's existing metadata wholesale.



## OpenAPI

````yaml https://hub.oxen.ai/api/_spec/oxen_server_openapi.json post /api/repos/{namespace}/{repo_name}/workspaces/{workspace_id}/data_frames/columns/schema/metadata/{path}
openapi: 3.1.0
info:
  description: >-
    Oxen is a fast, unstructured data version control, to help version large
    machine learning datasets written in Rust.
  license:
    name: ''
  title: oxen-server
  version: 0.52.9
servers:
  - description: Production API
    url: https://hub.oxen.ai
  - description: Local Development
    url: http://localhost:3000
security:
  - api_key: []
tags:
  - description: Namespace management endpoints
    name: Namespaces
  - description: Repository management endpoints.
    name: Repositories
  - description: >-
      Editing a data frame inside a workspace, including its schema and column
      metadata.
    name: Workspace Data Frames
paths:
  /api/repos/{namespace}/{repo_name}/workspaces/{workspace_id}/data_frames/columns/schema/metadata/{path}:
    post:
      tags:
        - Workspace Data Frames
      description: >-
        Set the metadata on a single column of a data frame, the HTTP equivalent
        of `oxen schemas add <path> -c <column> -m '{...}'`. Staged into the
        workspace, so no commit is required. Replaces that column's existing
        metadata wholesale.
      operationId: add_column_metadata
      parameters:
        - description: Namespace of the repository
          example: ox
          in: path
          name: namespace
          required: true
          schema:
            type: string
        - description: Name of the repository
          example: ImageNet-1k
          in: path
          name: repo_name
          required: true
          schema:
            type: string
        - description: ID or name of the workspace
          example: b3f27f05-0955-4076-805f-39575853b27b
          in: path
          name: workspace_id
          required: true
          schema:
            type: string
        - description: Path to the data frame within the repository
          example: annotations/train.csv
          in: path
          name: path
          required: true
          schema:
            type: string
      requestBody:
        content:
          text/plain:
            example:
              column_name: file
              metadata:
                _oxen:
                  render:
                    func: image
            schema:
              type: string
        description: >-
          The column to annotate and the metadata to store on it.
          `_oxen.render.func` controls how oxen renders the column's values.
        required: true
      responses:
        '200':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/StatusMessage'
          description: Column metadata updated
        '400':
          description: >-
            Invalid request body, missing `column_name`, the path is not a
            tabular data frame, or the column does not exist in the schema
        '404':
          description: Repository, workspace, or data frame not found
        '409':
          description: The data frame is staged for removal in this workspace
components:
  schemas:
    StatusMessage:
      properties:
        oxen_version:
          type:
            - string
            - 'null'
        status:
          type: string
        status_message:
          type: string
      required:
        - status
        - status_message
      type: object
  securitySchemes:
    api_key:
      bearerFormat: JWT
      scheme: bearer
      type: http

````