Preflight check

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

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

Request

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 / int32in 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.

You can now try out some of our APIs live, right here in the documentation.
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Request Example

cURL
curl -X OPTIONS https://upload.box.com/api/2.0/files/content \
     -H "Authorization: Bearer <ACCESS_TOKEN>" \
     -H "Content-Type: multipart/form-data" \
     -F attributes='{"name":"Photo.jpg", "parent":{"id":"11446498"}}'
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_url": "https://upload-las.app.box.com/api/2.0/files/content?upload_session_id=1234",
  "upload_token": "Pc3FIOG9vSGV4VHo4QzAyg5T1JvNnJoZ3ExaVNyQWw6WjRsanRKZG5lQk9qUE1BVQP"
}