Full key list for advanced users: docs_tech/docs_parameters/README_CONFIG_PARAMETERS.md.

Boolean values (in the file and on the command line, case-insensitive): true|1|yes|y|on and false|0|no|n|off. Anything else falls back to the built-in default.

Chapter 1: Files And Priority

Missing effective file → template copied there on first run. Rule: CLI flags always override config.json; missing in both → built-in default. Edit the effective file — the template is only re-seed.

Edit config.json safely

1. Close DjMirror Pulse (several keys are read once at startup).
2. Copy the effective file (for example to config.json.bak) so you can roll back.
3. Edit the effective file in your user-data folder, not the copy next to the executable.
4. Keep the file valid JSON: double quotes, commas between entries, no trailing comma.
5. Start the app. If it misbehaves, put the backup back — see Backup & Restore.

A minimal example that sets a media folder, a fixed port and an API key (all other keys keep their defaults):

{
  "documentsPath": "D:/ShowFiles",
  "port": 8080,
  "apiKey": "change-me",
  "language": "en"
}

Chapter 2: Keys By Task

Server and client

Paths and language (config-only, read once at startup)

Windows, GPU and integrations

What is not in config.json

• Audio devices and sample rates are runtime settings of the audio analyzer.
• Live visual state is stored in the operating-system settings (Windows registry HKCU\Software\DjMirror\DjMirrorPulse, macOS preferences).
• Ableton Link settings are stored there too, so they survive a config.json reset.

Chapter 3: CLI Flags

Launch examples (Windows PowerShell)

# Show a console window with the log (useful when something does not start)
.\DjMirrorPulse.exe --console

# Run as the server for a second screen, on port 9000, and require a key
$env:DJMIRROR_API_TOKEN = "choose-a-long-key"
.\DjMirrorPulse.exe --server --port 9000

# Run as a client that follows that server (no server of its own)
.\DjMirrorPulse.exe --no-server --client http://192.168.1.50:9000 --client-key choose-a-long-key

# List the graphics adapters, then force one
.\DjMirrorPulse.exe --gpu-info
.\DjMirrorPulse.exe --gpu 1 --d3d11

--help lists every flag. A flag is applied only for that run; to make it permanent, set the matching key in the effective config.json (see §1 and §2).

DJMIRROR_API_TOKEN env beats apiKey in file. Prefer config.json over --client-key on shared machines (process lists leak arguments).

Chapter 4: Layouts And Other State

• Visuals/ under documentsPath: Videos|Images|Avatars|Logos|Styles (seeded from Visuals.zip next to the exe when empty). Styles: Visuals/Styles/*.json; playlists: *.txt beside media.
• DMX fixture profiles file: dmx_fixtures_profiles/dmx_fixture_profiles.json (CWD/appDir-resolved).
• NDI saved path: OS-settings group DMX / savedNdiConfigPath.
• Paired phones: <AppDataLocation>/mobile_devices.json. License key: OS-settings License/ActivationKey.
• MCP proxy config: %AppData%/DjMirror/DjMirrorPulse/config_mcp.json (see MCP guide).

Chapter 5: Quick Recipe Card

• Edit the effective config.json (AppData, not exe dir). CLI wins over file over default.
• Server: --server --port 8080; client: --client URL [--client-key]; debug: --console.
• documentsPath = media root; audio/visual live state = OS settings, not the file.
• Secrets via env (DJMIRROR_API_TOKEN), never on shared command lines.

Chapter 6: Troubleshooting

More: Troubleshooting.