Valve just released the source code for Team Fortress 2 — on purpose

By Patrick Hearn Published February 19, 2025

Valve just released the entirety of the Team Fortress 2 client and server source code, and it wasn’t even an accident. In a post on the Team Fortress website titled “The TF2 SDK has arrived!” Valve addresses mod creators directly.

“We’ve just released a massive update to the Source SDK, adding all the Team Fortress 2 client and server game code. This update will allow content creators to build entirely new games based on TF2,” the post says. Valve adds that it is also updating all of its multiplayer back-catalogue Source engine titles, adding in a load of improvements to make them more playable.

However, there’s a caveat: any games created with this source code must be free: “The SDK is licensed to users on a non-commercial basis, meaning that any mod created using the SDK must be free, and any content in those mods must be free.” Valve goes on to ask that mod makers not create mods that would profit off the efforts of all the Steam Workshop contributors over the years, and that they hope players will continue to be able to access their TF2 inventory if it makes sense for the mod.

Team Fortress 2 is 18 years old now, long past the point most player counts have dwindled to nothing, yet its fan base continues to be as loyal as ever. Part of that is due to Valve’s continued support of the game, fixing bugs 17 years after the game launched.

Valve acknowledges the community’s part in keeping the game alive. “The majority of items in the game now are thanks to the hard work of the TF2 community,” its post says. Releasing the source code feels like Valve is officially passing the torch to the fans, a final tribute to the community — especially since Valve is bound by fate to never release a trilogy.

With the full source code in hand, the community can keep the Team Fortress 2 going for years to come and potentially create an entire extended universe of Scout-based shenanigans.