Box Developer Documentation
Log in
Latest version

Preflight check before upload

options
https://api.box.com/2.0
/files/content

This endpoint is in the version 2024.0. No changes are required to continue using it. For more details, see Box API versioning.

Performs a check to verify that a file will be accepted by Box before you upload the entire file.

Related Guides

Request

bearer [ACCESS_TOKEN]
application/json

Request Body

stringin bodyoptional
"File.mp4"

The name for the file

objectin body

The parent folder to upload the file to

stringin bodyoptional
"123"

The ID of parent item

integer (int32)in bodyoptional
1024

The size of the file in bytes

Response

application/jsonUpload URL

If the check passed, the response will include a session URL that can be used to upload the file to.

application/jsonConflict error

If the check did not pass, the response will include some details on why it did not pass.

application/jsonClient error

An unexpected client error.

options
Preflight check before upload
You can now try out some of our APIs live, right here in the documentation.
Log in

Request Example

cURL
curl -i -X OPTIONS "https://api.box.com/2.0/files/content" \
     -H "authorization: Bearer <ACCESS_TOKEN>" \
     -H "content-type: application/json" \
     -d '{"name":"Contract.pdf", "parent":{"id":"11446498"}}'
TypeScript Gen
await client.uploads.preflightFileUploadCheck({
  name: newFileName,
  size: 1024 * 1024,
  parent: { id: '0' } satisfies PreflightFileUploadCheckRequestBodyParentField,
} satisfies PreflightFileUploadCheckRequestBody);
Python Gen
client.uploads.preflight_file_upload_check(
    name=new_file_name, size=1024 * 1024, parent=PreflightFileUploadCheckParent(id="0")
)
Java
String fileName = "My Doc.pdf";
BoxFolder rootFolder = BoxFolder.getRootFolder(api);
try {
    folder.canUpload(fileName, 98734576);

    // If the file upload would not have succeeded, it will not be attempted
    folder.uploadFile(fileContents, fileName);
} catch (BoxAPIException ex) (

)
Node
// Verify that uploading a 200MB file named "Preso.ppt" to folder 12345 would succeed
client.files.preflightUploadFile(
		'12345',
		{
			name: 'Preso.ppt',
			size: 200000000
		},
		null,
		callback
	);

Response Example

{
  "upload_token": "Pc3FIOG9vSGV4VHo4QzAyg5T1JvNnJoZ3ExaVNyQWw6WjRsanRKZG5lQk9qUE1BVQP",
  "upload_url": "https://upload-las.app.box.com/api/2.0/files/content?upload_session_id=1234"
}