InventoryAPI by Erply is a powerful backend for web shops, and more.
This is a list of all company related API functions. Click on function name and you'll find all required and optional input parameters and response fields.
verifyUser. Successful log-in will give you a session key; include it with every subsequent API call. (Send it as input parameter "sessionKey").
verifyUseragain to receive a fresh session key.
verifyUserreturns error 1050, 1051 or 1052.