On the Steam page, they offer to evaluate the compatibility of their library with Steam Deck

Valve has opened up an opportunity for everyone to evaluate the performance of their Steam game library on the new Steam Deck console. To do this, users need to visit a separate page , on which the service will show how many optimized entertainment will be available to you at the time of the release of the platform.

Once logged in, Steam will display how many games in the library are already optimized and which ones are expected to be added for future support. The list will be gradually updated with fresh titles, so you can find out in real time whether this or that game will be launched on Steam Deck.

The release of new items will take place tomorrow, in Russia the console will not appear yet.