ColdStarter

ColdStarter automatically wakes your server when players connect, then puts it to sleep when idle. You only pay for active time.

How It Works

1. Idle: No players → server sleeps (minimal cost)
2. Connect: Player tries to join → ColdStarter intercepts
3. Wake: Server starts in background (10-30 seconds)
4. Play: Player connects to running server

Your server still shows as "online" in server browsers while sleeping.

Cost Savings

Typical hobby server:

• Without ColdStarter: 720 hours/month (24/7)
• With ColdStarter: 100 hours/month (actual playtime)

Result: ~85% cost reduction

Configuration

Configured per-scroll via scroll.yaml:

ports:
  - name: game
    port: 25565
    protocol: tcp
    sleep_handler: packet_handler/minecraft.lua
    start_delay: 10
    check_activity: true

Port Options

• sleep_handler - Path to Lua packet handler (required for ColdStarter)
• start_delay - Seconds to wait before port is ready
• check_activity - Enable idle detection
• finish_after_command - Wait for command to finish before opening port

Packet Handlers

Lua handlers respond to game protocols while server is asleep.

Example: minecraft.lua

Lua API

-- Send data to client
sendData(string)

-- Trigger server wake
finish()

-- Get snapshot/queue status
get_queue()
get_snapshot_percentage()
get_finish_sec()

Supported Games

All 95 published scrolls support ColdStarter:

• Minecraft (all variants)
• Rust (Vanilla, Oxide)
• Hytale
• 10 LGSM games (Palworld, ARK, CS2, etc.)

Custom Handlers

Create packet_handler/game.lua in your scroll:

function handle(ctx, data)
    -- Parse packet
    if isStatusRequest(data) then
        sendData("Server starting...")
    end
    
    -- Wake on connect
    if isConnectionAttempt(data) then
        finish()
    end
end