diff --git a/addons/auto_flashlight/addon.json b/addons/auto_flashlight/addon.json
new file mode 100644
index 0000000..9c8c077
--- /dev/null
+++ b/addons/auto_flashlight/addon.json
@@ -0,0 +1,6 @@
+{
+    "title": "Auto-Flashlight",
+    "type": "effects",
+    "tags": ["scenic", "roleplay"],
+    "ignore": []
+}
diff --git a/addons/auto_flashlight/lua/autorun/client/cl_autoflashlight.lua b/addons/auto_flashlight/lua/autorun/client/cl_autoflashlight.lua
new file mode 100644
index 0000000..29fff64
--- /dev/null
+++ b/addons/auto_flashlight/lua/autorun/client/cl_autoflashlight.lua
@@ -0,0 +1,140 @@
+--
+-- Localization stuff
+--
+language.Add("spawnmenu.options.autoflashlight", "Auto-Flashlight")
+
+language.Add("spawnmenu.options.autoflashlight.cvar.enabled", "Enabled")
+language.Add(
+    "spawnmenu.options.autoflashlight.cvartooltip.enabled",
+    "Whether or not auto-flashlight is enabled."
+)
+
+language.Add("spawnmenu.options.autoflashlight.cvar.threshold", "Light Threshold")
+language.Add(
+    "spawnmenu.options.autoflashlight.cvartooltip.threshold",
+    "The threshold for the automatic flashlight to trigger. Higher values mean the flashlight will activate in brighter areas. Default: 0.0055"
+)
+
+--
+-- ConVars, variables & functions
+--
+local CVAR_AUTO_FLASHLIGHT_ENABLED = CreateClientConVar(
+    "cl_flashlight_auto",
+    "1",
+    true,
+    false,
+    language.GetPhrase("#spawnmenu.options.autoflashlight.cvartooltip.enabled")
+)
+
+local CVAR_AUTO_FLASHLIGHT_THRESHOLD = CreateClientConVar(
+    "cl_flashlight_auto_threshold",
+    "0.0055",
+    true,
+    false,
+    language.GetPhrase("#spawnmenu.options.autoflashlight.cvartooltip.threshold"),
+    0,
+    0.5
+)
+
+local wasInDarkness = false
+
+autoflashlight = autoflashlight or {}
+
+--
+-- This function is designed to be overwritten by other developers who
+-- might want their custom flashlight implementation to support Auto-Flashlight.
+--
+-- I'm assuming that not all flashlight implementations make use of "impulse 100",
+-- but who knows
+--
+function autoflashlight.SetFlashlightEnabled(isEnabled)
+    -- If isEnabled is not provided, just assume the flashlight is being enabled
+    isEnabled = Either(isEnabled ~= nil, isEnabled, true)
+
+    local ply = LocalPlayer()
+    if not IsValid(ply) then return end
+
+    if (isEnabled and not ply:FlashlightIsOn()) or (not isEnabled and ply:FlashlightIsOn()) then
+        RunConsoleCommand("impulse", "100")
+    end
+end
+
+-- Returns whether or not we were in darkness the last time we checked it
+function autoflashlight.GetWasInDarkness()
+    return wasInDarkness
+end
+
+function autoflashlight.GetEnabled()
+    return CVAR_AUTO_FLASHLIGHT_ENABLED:GetBool()
+end
+
+function autoflashlight.GetThreshold()
+    return CVAR_AUTO_FLASHLIGHT_THRESHOLD:GetFloat()
+end
+
+--
+-- Main calculation/execution script
+--
+timer.Create("AutoFlashlight.DoToggle", 0.2, 0, function()
+    if not CVAR_AUTO_FLASHLIGHT_ENABLED:GetBool() then return end
+
+    local ply = LocalPlayer()
+    -- If player isn't valid for any reason
+    if not IsValid(ply) then return end
+
+    local col = render.GetLightColor(ply:EyePos())
+    -- Determine luminance from the R, G, B values of the light
+    local luminance = (col.x * 0.299) + (col.y * 0.587) + (col.z * 0.114)
+
+    local darknessThreshold = CVAR_AUTO_FLASHLIGHT_THRESHOLD:GetFloat()
+
+    -- Allow controlling the auto-flashlight through hooks
+    -- If the hook returns false, the auto-flashlight will be disabled
+    if hook.Run("AutoFlashlight.ShouldAllow", luminance, darknessThreshold, wasInDarkness) == false then return end
+
+    local isInDarkness = luminance < darknessThreshold
+
+    -- If we're in a dark area, and weren't previously in a dark area
+    if isInDarkness and not wasInDarkness then
+        -- Allow developers to control if auto-flashlight can turn on
+        -- Returning false will stop it from turning on
+        local flashlightAllowedToTurnOn = hook.Run("AutoFlashlight.CanFlashlightTurnOn", luminance, darknessThreshold, wasInDarkness)
+
+        -- ...and the flashlight isn't on yet, and can be turned on
+        if not ply:FlashlightIsOn() and flashlightAllowedToTurnOn ~= false then
+            -- ...then turn it on
+            autoflashlight.SetFlashlightEnabled(true)
+        end
+    -- If we're not in a dark area, but we were previously
+    elseif not isInDarkness and wasInDarkness then
+        -- Allow developers to control if auto-flashlight can turn off
+        -- Returning false will stop it from turning off
+        local flashlightAllowedToTurnOff = hook.Run("AutoFlashlight.CanFlashlightTurnOff", luminance, darknessThreshold, wasInDarkness)
+
+        -- ...and the flashlight is on, and can be turned off
+        if ply:FlashlightIsOn() and flashlightAllowedToTurnOff ~= false then
+            -- ...then turn it of
+            autoflashlight.SetFlashlightEnabled(false)
+        end
+    end
+
+    wasInDarkness = isInDarkness
+end)
+
+--
+-- Add Sandbox options menu
+--
+hook.Add("AddToolMenuCategories", "AutoFlashlight.AddSpawnmenuCategory", function()
+    spawnmenu.AddToolCategory("Options", "AutoFlashlight", "#spawnmenu.options.autoflashlight")
+end)
+
+hook.Add("PopulateToolMenu", "AutoFlashlight.PopulateSpawnmenuCategory", function()
+    spawnmenu.AddToolMenuOption("Options", "AutoFlashlight", "AutoFlashlightSettingsMain", "Settings", "", "", function(pnl)
+        pnl:Help("Main Settings")
+
+        pnl:CheckBox("#spawnmenu.options.autoflashlight.cvar.enabled", "cl_flashlight_auto")
+
+        pnl:NumSlider("#spawnmenu.options.autoflashlight.cvar.threshold", "cl_flashlight_auto_threshold", 0, 0.5, 4)
+        pnl:ControlHelp("#spawnmenu.options.autoflashlight.cvartooltip.threshold")
+    end)
+end)
diff --git a/images/icon_auto_flashlight.png b/images/icon_auto_flashlight.png
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diff --git a/images/icon_auto_flashlight.xcf b/images/icon_auto_flashlight.xcf
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