There exist two resources accessible via the GET method:

The placeholder {FEN} must be substituted by a valid FEN position, separating its elements with underscores instead of spaces (ignore the halfmove clock and the fullmove number). The intended winner can be specified after the FEN with an underscore followed by the word white or black.
(If not specified, the default intended winner is the player without the turn.)

Response schema application/json

intendedWinner string "w" or "b"
winnable boolean definite result of the analysis
helpmate string helpmate sequence in UCI format (if the possition is winnable)
microseconds integer analysis execution time measured in μs
searchNodes integer number of nodes explored during the analysis
interrupted string guessed result (not necessarily correct)