get
https://api.sintalk.com.br/v3/files/constraints
Return the limits every upload is checked against: for each file kind the content types it accepts and its maximum size, plus the kinds each usage allows.
Read it before requesting an upload URL: pick a content_type listed for a kind the intended usage permits, and keep size_bytes at or below that kind's max_size_bytes. Anything else is rejected by POST /files/upload-url with 415 or 413.