Signature is formed from request body parameters and API secret like follows: request json fields are recursively sorted by keys. Then values are concatenated using '|' with '|'+secret at the end and hashed using sha512 algorithm into a hex string. Note that json values are used, with '"' used for string values and none for booleans, numbers, etc. {"a":"a","b":"b","c":"c","obj":{"obj-a":"obj-a","obj-b":"obj-b"},"true":true,"z":"z","number":0.055555} and secret being "secret" for example, with no quotation marks used for signature string. Example: "a"|"b"|"c"|0.055555|"obj-a"|"obj-b"|true|"z"|secret -> 882a390e003d362049bef504cf85d1c7fc5f376b182ccd1a94c4be05ceb0d250403 731dcf603f07e92c64a92a823b85334929d099df93d9ae5da025deb03316e