AutoFish for Forge
This mod is probably the most accurate among all automatic fishing mods for Minecraft Forge.
It is fully client-sided and works on vanilla servers (and should also work on other servers, but I didn't test it.)
If you want a Fabric version, check this out (note that it is not made by me and this mod is created by me completed from scratch)
1. Go to control and set the keybind
2. Use the keybinds to toggle on/off the mod and its features
3. Open the GUI to set the recast/reel in delay* (in ticks) and item filter**
4. Throw your bobber into the water and it will do its thing.
*Optional and only works with version 1.1.0+
**Does not work in multiplayer
About public servers, it is not recommended to use this as the mod provides unfair advantages. Use this at your own risk. If you get banned, it is NOT my fault.
You should only use this in singleplayer or private servers.
The Reason Behind
Because of the 1.16 update. Mojang nerfed AFK fish farms by removing the chance of getting treasures in old designs.
There were some new designs, but they are not as good as the old ones.
To solve this problem, I made this mod.
With this mod, you will be able to AFK fish in 1.16, while still getting the treasures.
The Mechanic Behind
It is a very simple solution.
As everyone knows, casting your fishing rod will spawn a bobber. This mod tracks the motion of the bobber.
When the vertical motion of the bobber is low enough, we know it catches a fish, so we retract it and BAM! You got your reward.
A GUI for whatever reason. (Potentially item filtering and a better way to configure the mod) Porting the GUI to older versions.
Will be ported to older version (I don't know if I will do it since I have already brought it down to 1.8.9)
An alternate of this mod, which add enchantments for fishing rod and this will be one of them.
Reels in fake line.
You Can Help
The license of this mod is GNUv3, so you can fork it and do your own thing with it.
This link is the GitHub repository of this project.
1.17.x (Tested with 1.17.1)
1.16.x (Tested with 1.16.1, 1.16.4, 1.16.5)
Unsupported, but there are files for these versions