Server loop

Repeated server.lua logic runs through Scheduler:OnTick(), once per simulation tick.

Minimal loop

local function Tick()
    local agent = Agents:GetLocalAgent()

    if agent == nil or agent.Health == nil then
        return
    end

    -- Server logic
end

Scheduler:OnTick(Tick)

Retrieve live objects again. An agent or item cached across rounds may become unavailable.

Work less often than every tick

Keep a target tick for infrequent checks:

local TickDuration = Time:TickToSeconds(1)
local IntervalTicks = math.ceil(0.25 / TickDuration)
local NextUpdateTick = 0

local function Tick()
    if Time.Tick < NextUpdateTick then
        return
    end

    NextUpdateTick = Time.Tick + IntervalTicks

    -- At most four times per second
end

Scheduler:OnTick(Tick)

math.ceil(seconds / tickDuration) avoids shortening a positive interval by one tick due to conversion precision.

CPU budget

Reflex server execution has a limited budget. Inspect the remainder through CpuLimit:

if CpuLimit.RemainingCpuTime < 0.2 then
    return
end

This is an emergency guard, not a substitute for optimization. Reduce expensive scan frequency, return early, avoid identical messages, and do not traverse the same array repeatedly.

Subscription control

OnTick() returns an EventSubscription:

local subscription

subscription = Scheduler:OnTick(function()
    if DefusalGame.IsGameEnded then
        subscription:Cancel()
        return
    end
end)

Keep the reference when the loop must stop before reload.

Context errors stop execution

server.lua has no OnFrame, UI, cameras, or client input. Missing-member access can terminate current Lua logic. Do not probe unavailable APIs inside the main loop.

Reference: Scheduler, Time, CpuLimit, and Agent.