Is it possible to get user\'s steamID by his nickname? I didn\'t find solution in steam API documentation. The only one thing that I found is an old post on http://dev.dota2.com
Have you read over this from the Steam Web API?
https://developer.valvesoftware.com/wiki/Steam_Web_API#GetPlayerSummaries_.28v0002.29
It has an example of using a steam profile url to return the users Steam ID, also some other arguments to gather other information.
If you read down a bit from there it states that "Returns the friend list of any Steam user
Example URL: http://api.steampowered.com/ISteamUser/GetFriendList/v0001/?key=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX&steamid=76561197960435530&relationship=friend"