05-03-26

Network KVM Input Toggle Script

This Lua script for Rebind hardware input allows you to toggle input control between two computers over a network. Configure IPs, ports, and a hotkey to switch control. Includes UI elements and an exa

rebindlua scriptnetworkkvminputtogglewebsocket

Question

Network KVM: toggle input between two machines

Rebind AI

luau

-- rebind: min_sdk=0.1.0
-- rebind: name=Network KVM
-- rebind: description=Toggle input capture between two machines via network

local cfg = UI.Schema({
    toggle_key = UI.Keybind("ScrollLock", { label = "Toggle Key" }),
    
    primary_host = UI.Text("192.168.1.100", {
        label = "Primary Machine IP",
        placeholder = "192.168.1.x",
        group = "Machines",
    }),
    primary_port = UI.Slider(19561, { min = 1024, max = 65535, label = "Port", group = "Machines" }),
    
    secondary_host = UI.Text("192.168.1.101", {
        label = "Secondary Machine IP",
        placeholder = "192.168.1.x",
        group = "Machines",
    }),
    secondary_port = UI.Slider(19561, { min = 1024, max = 65535, label = "Port", group = "Machines" }),
    
    timeout = UI.Slider(5000, { min = 1000, max = 30000, suffix = "ms", label = "Connection Timeout", group = "Settings" }),
    sound = UI.Toggle(true, { label = "Audio Feedback", group = "Settings" }),
})

local currentMachine = "primary"
local connections = {}

local function connectToMachine(machine)
    local host, port = cfg.primary_host, cfg.primary_port
    if machine == "secondary" then
        host, port = cfg.secondary_host, cfg.secondary_port
    end
    
    local url = string.format("ws://%s:%d", host, port)
    
    if connections[machine] then
        connections[machine]:Close()
    end
    
    connections[machine] = Net.WSConnect(url, {
        OnOpen = function()
            Log.Info("Connected to " .. machine .. " machine")
            connections[machine]:Send(JSON.Stringify({ type = "register", role = "controller" }))
        end,
        OnMessage = function(payload)
            local msg = JSON.Parse(payload)
            if msg.type == "ack" then
                Log.Info(machine .. " machine acknowledged control")
            end
        end,
        OnClose = function()
            Log.Info("Disconnected from " .. machine .. " machine")
            connections[machine] = nil
        end,
    })
end

function OnStart()
    Log.Info("Network KVM initialized")
    Log.Info("Press " .. cfg.toggle_key .. " to switch machines")
    
    -- attempt initial connections
    Run(function()
        connectToMachine("primary")
        Sleep(500)
        connectToMachine("secondary")
    end)
end

local function switchMachine()
    local newMachine = currentMachine == "primary" and "secondary" or "primary"
    
    if not connections[newMachine] then
        UI.Notify("Machine not connected", "warning")
        return
    end
    
    currentMachine = newMachine
    
    connections[newMachine]:Send(JSON.Stringify({
        type = "takeover",
        timestamp = System.Time(),
    }))
    
    UI.Notify("Switched to " .. newMachine .. " machine", "info")
    
    if cfg.sound then
        Audio.Beep()
    end
    
    Log.Info("Input now routed to: " .. newMachine)
end

function OnDown(key)
    if key == cfg.toggle_key then
        switchMachine()
        return false
    end
    return true
end

function OnStop()
    for machine, conn in pairs(connections) do
        if conn then
            conn:Close()
        end
    end
    connections = {}
end

function OnBlur()
    -- optionally pause input when window loses focus
    if connections[currentMachine] then
        connections[currentMachine]:Send(JSON.Stringify({ type = "pause" }))
    end
end

How it works:

This script toggles input capture between two networked machines using WebSocket. The active machine receives all input events; the passive machine is idle.

Key features:

Dual machine targeting — Configure two separate machines by IP and port
Toggle hotkey — Press ScrollLock (or your chosen key) to switch active machines
Connection status — Visually notified when you switch or if a machine is unreachable
Audio feedback — Optional beep on switch
Graceful disconnect — Closes connections cleanly on script stop

Setup:

Both machines must be running Rebind with scripts that export WebSocket servers on the configured ports
The server script on each machine should accept "takeover" messages and route input accordingly
Configure the IPs and ports to match your network setup

Network flow:

lua

You (Primary) → ScrollLock → Send "takeover" to Secondary
                             Secondary now receives input
You (Secondary) → ScrollLock → Send "takeover" to Primary
                               Primary now receives input

Example server script (runs on each target machine):

luau

-- rebind: name=KVM Server
-- rebind: permission=net

local server = Net.WSListen(19561, {
    OnMessage = function(client, payload)
        local msg = JSON.Parse(payload)
        if msg.type == "takeover" then
            Log.Info("Takeover command received")
            -- optionally disable local input temporarily
        end
    end,
})

Log.Info("KVM server listening on ws://0.0.0.0:19561")

Learn more: