Modern Treasury has added support for retrieving and creating Documents on associated records. This new API is helpful for when you want to provide more context on a given subject, e.g. adding a PDF invoice to a payment order.
Because of this API we've also now added support for receiving scanned images of checks received through your lockbox. When paper items are created they will now contain attached documents that represent the front and back of the checks as well as any additional documents that were received.
For more, head over to our complete API documentation.