Files

File fields do not store bytes in Mongo. The client:

1. Starts an upload session (declared filename, contentType, size).
2. PUTs the bytes to the returned presigned URL (S3/MinIO).
3. Completes the session so the file is attached to the record.

The SDKs wrap this in uploadFile.

The record must already exist. Create the document first, then upload.

JavaScript

uploadFile accepts a Blob, ArrayBuffer, or Uint8Array.

const bytes = new Uint8Array(await file.arrayBuffer());
const meta = await posts.uploadFile(recordId, 'attachment', {
  data: bytes,
  size: bytes.byteLength,
  filename: 'photo.jpg',
  contentType: 'image/jpeg',
});

const download = await posts.getDownloadUrl(recordId, 'attachment', meta.id);
console.log(download.url);

await posts.deleteFile(recordId, 'attachment', meta.id);

Dart

final bytes = await File('photo.jpg').readAsBytes();
final meta = await posts.uploadFile(
  recordId,
  'attachment',
  data: Stream.value(bytes),
  length: bytes.length,
  filename: 'photo.jpg',
  contentType: 'image/jpeg',
);

final download = await posts.getDownloadUrl(recordId, 'attachment', meta.id);
print(download.url);

await posts.deleteFile(recordId, 'attachment', meta.id);

REST

Step	Method	Path
Start	POST	/api/p/:projectId/:table/:recordId/files/:field/upload-sessions
Complete	POST	/api/p/:projectId/:table/:recordId/files/:field/:fileId/complete
Download URL	GET	/api/p/:projectId/:table/:recordId/files/:field/:fileId
Delete	DELETE	same as download

Enable the upload, download, and fileDelete endpoints. Add file rules (fileSizeLimit, fileMimeType, fileExtensionAllow) on upload.

The platform also enforces a global FILE_MAX_BYTES cap.