A substantial cache of internal Valve data, reportedly dating between 2003 and 2013, has allegedly been leaked online. The leaked files are said to encompass beta builds of several classic Valve titles and potential assets from the never-released Half-Life 2: Episode 3.

The leak, which began circulating over the weekend from an unspecified source, comprises approximately 12 terabytes of data that data miners are currently examining. Initial reports suggest that data from Counter-Strike: Global Offensive, Left 4 Dead, and Portal 2 are included.

Among the most significant alleged inclusions is the complete Portal 2 beta from 2009. This version of the game reportedly features a different narrative progression compared to the final release. In this beta build, players are guided through Aperture Science's test chambers by pre-recorded messages from GLaDOS, rather than the character Wheatley, and other personality cores are more prominent. This discovery follows a recent four-year fan project that recreated the 2009 Portal 2 beta build with high fidelity.

Furthermore, information surfaced by Valve enthusiast Gabe Follower indicates the presence of the "Weaponizer," an unfinished weapon previously associated with Half-Life 2: Episode 3. Details about this weapon first emerged in a 2011 leak within a directory labeled "ep3," and a similar-looking firearm was showcased in footage from Episode 3 featured in Valve's 20th-anniversary documentary on Half-Life 2.

The leak also reportedly contains files for F-STOP, a canceled puzzle game that served as a precursor to Portal 2. In development for about a year, F-STOP, also known as 'Aperture Camera,' featured a core mechanic similar to that of the 2023 game Viewfinder, where player-taken photographs could be integrated as 3D objects within the game environment. However, the leaked files are not believed to include a playable build of F-STOP.

While the origin of the leak remains unclear, it has been tentatively linked to Valve's older Steam2 content-server infrastructure, which was superseded by SteamPipe in March 2013. This transition would explain the apparent cutoff date of the archived files.

Valve has been contacted for comment on the reported data leak.