file_name must carry a supported extension (.pdf .doc .docx .png .jpg .jpeg; .csv and .xlsx only when enabled for the account), the binary must match it, and the file must be 100 MB or smaller.

Known product gap: the passthrough currently rejects multipart uploads with 400 JSON Schema Validation Error — Failed to parse the request body parameters, and rejects JSON with 400 Unsupported content type: application/json. No upload succeeds through the wrapper today.

{
  "file_name": "pricing.pdf"
}

{
  "id": "pfbid0GNkExampleExampleExample"
}