curl -X POST 'https://api.va.landing.ai/v1/ade/extract/build-schema' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -F 'markdowns=@markdown.md' \
  -F 'model=extract-latest' \
  -F 'prompt=Extract invoice fields including vendor, date, and total amount'

{
  "extraction_schema": "<string>",
  "metadata": {
    "filename": "<string>",
    "org_id": "<string>",
    "duration_ms": 0,
    "credit_usage": 0,
    "job_id": "",
    "version": "<string>",
    "warnings": [
      {
        "code": "nonconformant_schema",
        "msg": "<string>"
      }
    ]
  }
}