steam_api.dll is part of Steamworks – it’s automatically placed in a game’s folder by Steam.
This is the most reliable way to recover a missing or corrupted steam_api.dll Steam_api.dll errors and how to fix it - ThinkMobiles
Steam-api.dll is a dynamic link library developed by Valve Corporation. It acts as a bridge between a game or application and the Steam client. When you launch a game purchased on Steam (or a non-Steam game that uses Steamworks features), the game calls upon this DLL to: