{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://raw.githubusercontent.com/api-evangelist/university-of-cape-town/main/json-schema/university-of-cape-town-variable-schema.json",
  "title": "DataFirst Study Variable",
  "description": "A single measured variable inside a DataFirst study data file, as returned by GET /catalog/variables/{idno}. Field set observed live on 2026-08-30.",
  "type": "object",
  "required": ["uid", "sid", "fid", "vid", "name"],
  "properties": {
    "uid": { "type": "integer", "description": "Globally unique variable identifier.", "examples": [1736429] },
    "sid": { "type": "integer", "description": "Internal id of the owning study.", "examples": [890] },
    "fid": { "type": "string", "description": "File id the variable belongs to.", "examples": ["F3"] },
    "vid": { "type": "string", "description": "Variable id within the file.", "examples": ["V21"] },
    "name": { "type": "string", "description": "Variable name as stored in the data file.", "examples": ["sex"] },
    "labl": { "type": ["string", "null"], "description": "Human-readable variable label.", "examples": ["Sex"] }
  },
  "additionalProperties": true
}