Please note that this post is tagged as a rumor .
Free-to-play project may involve custom witchers

MP1st reports that an unannounced The Witcher game is in development as a free-to-play co-op action RPG for PC and mobile devices . The report does not mention PlayStation, Xbox or Nintendo Switch versions.
According to the report, the game is set in 1230, during a period when Geralt is still a young witcher. Players reportedly create their own witcher, with gender and appearance options.
Custom witchers, contracts and co-op
The gameplay loop is said to be based on monster contracts across forests, villages and haunted ruins. Combat reportedly uses abilities linked to Witcher schools, Signs and potion crafting. The system is also said to include timing-based blocks, dodges, parries and executions.

Source: CD Projekt Red
The studio behind the project has not been confirmed. MP1st suggests the game may be related to CD Projekt’s partnership with Scopely, which was announced for a game based on one of CD Projekt’s franchises.
This should not be confused with Project Sirius , at least until CD Projekt confirms otherwise. Sirius was announced in 2022 as a Witcher project with single-player and multiplayer gameplay. CD Projekt later listed Sirius among its active development projects, alongside The Witcher 4, Cyberpunk 2 and several unannounced games.
Source: MP1st