The File Extensions Database

.AIN File Extension

  • Developer by: Valve
  • Category: Game Files

What is an .AIN file?

.AIN is Source Engine Compiled AI Nodegraph File

Game data file used by games developed with Source, a first-person shooter (FPS) game engine developed by Valve; stores a navigation mesh, which consists of points and connected lines that make up potential traversal paths for artificial intelligence (AI) non-player characters (NPCs), or "bots;" used for real-time navigation and movement for AI computer players.

The original nodegraph is created using the Level Designer component of the Source engine SDK, which is called the Valve Hammer Editor. Once complete, an AIN file is automatically compiled by the Source engine when the game is loaded. The compiled AIN file is saved to the \maps\graphs\ directory within the game installation directory.

NOTE: The Valve Source engine is used for games such as Half-Life 2 and Team Fortress 2.

Programs that open Source Engine Compiled AI Nodegraph File
Valve Source
Valve Hammer Editor
File Type 2 AIN Compressed File Archive
Category: Compressed Files

File or group of file compressed with AIN compression software; AIN was a shareware archiving program available for MS-DOS in the 1990s.

How to solve problems with AIN files

  • Associate the AIN file extension with the correct application. On :
    Windows: Right click on any AIN file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *.AIN files". Mac: Right click (or Ctrl-click) the AIN file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
  • Update your software that should actually open .AIN is Source Engine Compiled AI Nodegraph File. Because only the current version supports the latest AIN file format. Search, therefore, e.g. on the Valve manufacturer website after an available .AIN is Source Engine Compiled AI Nodegraph File update.
  • To make sure that your AIN file is not corrupted or virus-infected, get the file again and scan it with antivirus software.