There are quite a few mods available in Minecraft, and they are usually restricted to the Java Edition. While behavior pack add-ons can change the way Bedrock Edition runs, mods can do so much more.
These source files were generated via MCP, for your usage. I've set up this old MCP940 for 1.12 to work with 1.12.2. I zipped and committed the decompiled source files if you want to view them.
If you don't want to setup Port Forwarding, you can use TCP tunnelling instead: Make sure you have "server-ip=localhost" in your server.properties file Run install_node.bat to install NodeJS and ...