https://www.polygon.com/2018/7/20/17595328/stardew-valley-multiplayer-mode-pc-release-date

The full release of Stardew Valley’s multiplayer update will launch Aug. 1, publisher Chucklefish announced. Previously available only as a public Steam beta, the mode will launch across multiple PC storefronts, including Humble and GOG.

It sounds like the multiplayer mode will remain mostly the same when it’s out of beta. Among its features are the ability to recruit up to three friends as either farmhands, who work for the host player, or fellow farmers, who get their own cabin on the host’s farmland. Either way, Stardew Valley’s co-op encourages people to collaborate, not compete to see who’s the best and richest farmer.