Upload up to 20 documents in one request to be converted and added to the Knowledge Base. Repeat the files part once per document. All files in the request form ONE batch — one batch_id to poll, and the Admin the token was issued for gets ONE email when the whole batch is done. Validation is all-or-nothing: if any file is invalid (bad extension, empty, over 10 MB, or the request exceeds 40 MB total), nothing is imported and the error lists every problem file. The legacy single file field remains supported.