VDF Build Config Files: App and Depot Field Reference

Valve Data Format (VDF) files are the build manifests that SteamCMD reads when uploading your game to Steam. Onyx generates these files automatically when you run the setup wizard, but understanding their structure helps you customize builds, add depots, and troubleshoot upload failures.

File naming and location

VDF files live inside your ContentBuilder scripts/ directory. Onyx expects exactly this naming convention:

File	Pattern	Example
App manifest	`app_<APPID>.vdf`	`app_1234560.vdf`
Depot manifest	`depot_<DEPOTID>.vdf`	`depot_1234561.vdf`

App files that do not match the app_<integer>.vdf pattern are silently ignored. If no apps appear on the Onyx main screen, verify the filenames in your scripts/ folder.

Your ContentBuilder directory should look like this:

ContentBuilder

builder

content

output

scripts

app_1234560.vdf

depot_1234561.vdf

depot_1234562.vdf

App VDF structure

The app VDF tells SteamCMD which depots to include, where to write build output, and metadata about the build. Onyx generates this file from a template during setup.

app_1234560.vdf

"appbuild"
{
    "appid"       "1234560"
    "desc"        "Generated with SteamBuildUploader by Silver Demon Studios"
    "buildoutput" "D:\SteamSDK\tools\ContentBuilder\output"
    "contentroot" ""
    "setlive"     ""
    "preview"     "0"
    "local"       ""
    "depots"
    {
        "1234561" "depot_1234561.vdf"
    }
}

Field reference

Field	Description	Managed by
`appid`	Your Steam App ID. Must match the filename.	Onyx (setup wizard)
`desc`	Human-readable label for this build. Shown in the Steamworks partner dashboard.	Onyx (editable in UI, written before each upload)
`buildoutput`	Absolute path where SteamCMD writes build logs and manifests.	Template (edit manually to match your SDK path)
`contentroot`	Root path prepended to all depot content roots. Leave empty if depot VDFs use absolute paths.	Template
`setlive`	Branch name to set live after upload (e.g. `beta`). Leave empty to upload without going live.	Manual
`preview`	Set to `"1"` to do a dry-run upload that does not publish to Steam.	Manual
`local`	Path to a local content server. Leave empty for standard Steam distribution.	Manual
`depots`	Maps Depot IDs to their corresponding depot VDF filenames.	Onyx (setup wizard)

The desc field is the only app VDF value Onyx modifies after initial setup. Whatever you type in the build description field in the UI is written to desc immediately before SteamCMD runs.

To add a depot after initial setup, add a new entry to the depots block and create the corresponding depot_<DEPOTID>.vdf file. Onyx will detect the new depot on the next launch.

Depot VDF structure

Each depot VDF describes what files to include for one depot, and where those files live on disk.

depot_1234561.vdf

"DepotBuildConfig"
{
    "DepotID"     "1234561"
    "contentroot" "C:\MyGame\build\win64"
    "FileMapping"
    {
        "LocalPath" "*"
        "DepotPath" "."
        "recursive" "1"
    }
    "FileExclusion" "*.pdb"
}

Field reference

Field	Description	Managed by
`DepotID`	The Steam Depot ID this file configures.	Onyx (setup wizard)
`contentroot`	Absolute path to the directory containing files to upload. Onyx reads this to display the content root in the UI.	Onyx (setup wizard) / manual edits
`FileMapping.LocalPath`	Glob pattern of files to include relative to `contentroot`. `*` means all files.	Template
`FileMapping.DepotPath`	Destination path inside the depot. `.` means the depot root.	Template
`FileMapping.recursive`	`"1"` includes subdirectories recursively. `"0"` uploads only the top level.	Template
`FileExclusion`	Glob pattern of files to skip. The default excludes `.pdb` debug symbol files.	Manual

Changing `FileExclusion`

The default exclusion rule (*.pdb) drops Windows debug symbols, which are large and unnecessary for players. You may want to adjust this if:

You ship a Linux build where .pdb files don’t exist (the rule is harmless but you can remove it for clarity).
You want to exclude additional file types, such as editor metadata or source assets.
You intentionally ship debug symbols for a developer branch.

Multiple exclusion rules require multiple FileExclusion lines:

"FileExclusion" "*.pdb"
"FileExclusion" "*.map"
"FileExclusion" "editor_data/*"

Fields Onyx reads vs. fields you manage manually

Managed by Onyx

appid — read to identify the build
desc — written before every upload
depots block — parsed to list and count depots
DepotID — read per depot
contentroot (depot) — displayed in the depot list

Edit manually in the VDF

buildoutput — must point to your actual SDK output folder
setlive — set the branch name when you want auto-promotion
preview — set to "1" for dry-run testing
contentroot (app) — set if depots use relative paths
FileMapping rules — customize inclusions per depot
FileExclusion rules — add or remove file filters

Get Started

Using the App

Reference

VDF Build Config Files: App and Depot Field Reference

File naming and location

App VDF structure

Field reference

Depot VDF structure

Field reference

Changing `FileExclusion`

Fields Onyx reads vs. fields you manage manually

Managed by Onyx

Edit manually in the VDF

​File naming and location

​App VDF structure

​Field reference

​Depot VDF structure

​Field reference

​Changing FileExclusion

​Fields Onyx reads vs. fields you manage manually

Managed by Onyx

Edit manually in the VDF

File naming and location

App VDF structure

Field reference

Depot VDF structure

Field reference

Changing `FileExclusion`

Fields Onyx reads vs. fields you manage manually