Gamma Utils

This is a fully configurable and client side Gamma / Brightness utility mod, making it much easier to see in the dark.
It's a really basic mod that allows you to change the gamma value in game way higher than the in game brightness setting allows.
Nights will look like day and caves will look like they're fully lit up. Basically Fullbright / Gammabright but for Fabric and NeoForge.

Press G to toggle between 100% and 1500% Gamma

Press H to toggle client side Night Vision on or off
This works better in combination with shaders than gamma

Fully adjustable to your liking

To see everything that can be done and adjusted open the function and configuration spoilers below. 
Here are some examples of what's possible though:

Mod overview video from BlackNinja745:

Toggle Night Vision
High gamma won't work in combination with shaders, however, night vision will work with at least some shaders:

Smooth Transition
Enable smooth transition (off by default) for a less intense transition when toggling gamma: 

Status Effects
Enable fully client side status effects (off by default) to keep you reminded that you've enabled gamma outside normal values:

Keybindings
All keybindings can be changed in the default minecraft keybinding settings

All Functions & Commands

Toggle Gamma
Usage: Keybind (default: G )   or   /gamma toggle
Toggle between the default gamma percentage and the configured toggled percentage.

Increase Gamma
Usage: Keybind (default: arrow up)   or   /gamma increase <value> (value is optional)
Increase the gamma percentage by the configured step percentage or the given value.

Decrease Gamma
Usage: Keybind (default: arrow down)   or   /gamma decrease <value> (value is optional)
Decrease the gamma percentage by the configured step percentage or the given value.

Set Gamma
Usage: /gamma set <value>
Set the gamma to a specific percentage.

Max Gamma
Usage: Keybind   or   /gamma max
Sets the gamma to the configured maximum limit. 

Min Gamma
Usage: Keybind   or   /gamma min
Sets the gamma to the configured minimum limit. 

Toggle Night Vision
Usage: Keybind (default: H )   or   /gamma nightvision
Toggle night vision on or off.

All Configuration Options (File / Mod Menu)

Default Gamma Percentage
Default: 100%
Gamma percentage for when the mod is toggled off.

Toggled Gamma Percentage
Default: 1500%
Gamma percentage for when the mod is toggled on.

Update Toggle Value
Default: false
Enabling this will make the toggle value remember the last non default value you've used.

Smooth Transition
Default: false
Make the transition when toggling gamma smoother.

Transition Speed
Default: 4500
Speed in gamma percentage per second.

Show Status Effect
Default: false
Show a client side status effect when the gamma percentage is outside normal range.
("Low Gamma" below 0% and "High Gamma" above 100%)

Limit Check
Default: true
Should the mod enforce the minimum and maximum gamma limits.

Minimum Gamma Limit
Default: -750%
Minimum gamma percentage the mod will allow if the Limit Check is enabled.

Maximum Gamma Limit
Default: 1500%
Maximum gamma percentage the mod will allow if the Limit Check is enabled.

Gamma Percentage Step
Default: 10%
Gamma percentage change for every increase or decrease.

Show Gamma Message
Default: true
Show a message with the new gamma value.

Reset on Close
Default: false
Reset the gamma value to default when Minecraft closes.

Dependencies

From 1.19 onwards this mod no longer includes Cloth Config

Required:

• Fabric API
• Cloth Config API (Is needed to make the config work)

Optional:

• Mod Menu (This mod allows you to edit the configs in game)

Older Versions:

1.16 - 1.18

Required:

• Fabric API (0.31.0 or later)

Optional:

• Mod Menu

Already included/embedded:

• Cloth Config API

1.14 - 1.15

Required:

• Fabric API (0.14.0 or later)

Optional:

• Mod Menu

Already included/embedded:

• Auto Config Updated API
• Cloth Config API 

Please let me know if you experience any issues or have any suggestions