Setting up the tools · Workshop docs

There's no separate SDK to download. Everything you need to build and publish content comes with the game, in its bin folder:

steamapps/common/Black Mesa/bin/

To find it, right-click Black Mesa in your Steam library, choose Manage → Browse local files, then open bin.

What's in the bin folder

Tool	What it's for
`hammer.exe`	The level editor. You build your maps here.
`vbsp.exe`, `vvis.exe`, `vrad.exe`	The map compilers. Hammer runs them for you when you press F9.
`vpk.exe`	Packs a folder of content into a single `.vpk` file for the Workshop.
`blackmesa_publish.exe`	The Black Mesa Content Publishing Tool. Uploads and updates your Workshop items.
`hlmv.exe`	The model viewer, for checking models and their skins.
`studiomdl.exe`, `vtex.exe`	Compile models and textures from source files.
`bspzip.exe`	Packs extra files straight into a compiled `.bsp`.
`bms.fgd`, `base.fgd`, `halflife2.fgd`	Entity definitions, which tell Hammer what entities exist and what settings they have.

Point Hammer at the Black Mesa entities

Hammer should open ready to go, but it needs the Black Mesa entity definitions (FGD) or you'll be missing everything specific to the game.

Open hammer.exe.
Go to Tools → Options → Game Configurations.
Next to Game Data files, click Add and choose bin/bms.fgd.
Click OK.

While you're in Game Configurations, check that Game Directory points at the bms folder inside your Black Mesa install, e.g. C:\Program Files (x86)\Steam\steamapps\common\Black Mesa\bms. Hammer uses it to find textures and models, and the compilers use it to know which game they're building for.

If Hammer complains about VPROJECT

Most people never see this. If you've set up tools for another Source game before, Hammer may show a VPROJECT error or load the wrong game's content. VPROJECT is a Windows environment variable that tells Source tools which game folder to use.

Press Start, type environment variables, and open Edit environment variables for your account.
Under User variables, find VProject. If it isn't there, click New.
Set Variable name to VProject and Variable value to your bms folder, e.g. C:\Program Files (x86)\Steam\steamapps\common\Black Mesa\bms.
Click OK, then restart Hammer.

Optional extras

None of these are required, but most mappers end up using at least one.

Official Black Mesa map sources. The VMFs for the game's own maps. The best way to learn how a lift, a scripted sequence or a level transition is really put together is to open the original and look.
VPKEdit. Opens the game's .vpk files so you can browse or extract models, materials and scripts. You'll want it for standalone mods.
Hammer++. A community build of Hammer with real-time lighting preview and many fixes. This Steam guide covers installing it for Black Mesa. It's unofficial, so if something misbehaves, check whether it happens in the stock Hammer too.
HTCT. A standalone compiler front-end with a Black Mesa preset. It's simpler than setting up Hammer's expert compile by hand.

Useful launch options for testing

In Steam, right-click Black Mesa, choose Properties, and add these under Launch options while you're working:

-dev -console

-console opens the developer console at startup (you'll use it constantly to load maps and run commands), and -dev prints extra diagnostic messages that help you spot missing files. Remove them when you want to see the game as players will.