Configuration Reference

All configuration is stored in src/server-config.json. This file is read at startup and updated at runtime via POST /api/config.

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src/server-config.json

{
  "host": "0.0.0.0",
  "frontendPort": 3000,
  "address": "",
  "inputThrottleMs": 8,
  "sensitivity": 1.0,
  "invertScroll": false
}

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Fields

host

• Type: string
• Default: "0.0.0.0"
• Description: The bind address for the HTTP server. "0.0.0.0" listens on all interfaces (required for LAN access). Set to "127.0.0.1" to restrict to localhost only.

frontendPort

• Type: integer
• Default: 3000
• Range: 1–65535
• Description: The TCP port for the HTTP server. All clients must connect to this port. Changing this via the Settings UI triggers a browser redirect to the new URL.

address

• Type: string
• Default: ""
• Description: Optional manual override for the LAN IP address shown in the QR code. Leave empty to use automatic detection via UDP socket.

inputThrottleMs

• Type: integer
• Default: 8
• Range: 1–1000
• Description: Minimum time in milliseconds between move and scroll events. Lower values increase responsiveness but use more bandwidth. The default of 8ms corresponds to ~125 Hz.

sensitivity

• Type: float
• Default: 1.0
• Range: 0.1–10.0
• Description: Mouse pointer speed multiplier applied at the server-side motion calculation. Combined with the acceleration curve (ACCEL_FACTOR, ACCEL_EXPONENT).

invertScroll

• Type: boolean
• Default: false
• Description: When false (natural scrolling), swiping up scrolls content up. When true (traditional scrolling), swiping up scrolls content down.

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Runtime vs. Restart

Setting	Applied Immediately	Requires Restart
sensitivity	✅ (propagated to WebRTCManager → active InputHandler instances)	❌
invertScroll	✅ (propagated to WebRTCManager → active InputHandler instances)	❌
frontendPort	❌	✅
host	❌	✅
inputThrottleMs	❌ (affects new connections)	✅ for active
address	✅ (next IP fetch)	❌

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Write Behavior

Config changes submitted via POST /api/config immediately call WebRTCManager.updateConfig(), propagating input sensitivity and scroll inversion in real time to all connected client input handlers.

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Client-Side Settings (LocalStorage)

These settings are stored on the client device (phone/tablet) only — never sent to or stored on the server:

Key	Type	Default	Description
rein_sensitivity	string (float)	"1.0"	Mouse sensitivity (mirrors server config)
rein_invert	string (bool)	"false"	Scroll inversion (mirrors server config)
rein_theme	"dark" | "light"	"dark"	Application theme
rein_auth_token	string	—	Cached auth token (from QR scan)

Note: rein_sensitivity and rein_invert are mirrored to the server on change. The server value is authoritative for active connections; the local value is used as the initial value when loading the settings page.