Lirand API allows you to develop Spigot plugins faster, easier and more Kotlin-like way.

It includes a lot of cool features like:

• Command DSL builders based on the Mojang Brigadier
• Three types of inventory-based menus and their DSL builders
• Easy way to change the NBT of items and entities
• Shared event flow
• Items and inventories serialization/deserialization
• Online player collections
• A bunch of useful extensions for working with chat, events, items, inventories, etc.
• Scoreboard builder (experimental)

And most importantly it is backward compatible via 1.16+ Minecraft versions.

Add the following to your build script:

repositories { 
    // ...
    mavenCentral()
    maven("https://jitpack.io")
    maven("https://repo.codemc.io/repository/maven-snapshots/")
    maven("https://libraries.minecraft.net")
    // ...
}

dependencies {
    // ... 
    implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.6.10")
    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-jdk9:1.6.0")
    implementation("com.github.dyam0:LirandAPI:VERSION")
    compileOnly("com.mojang:brigadier:1.0.18")
    // ...
}

Replace VERSION with the version of Lirand API you need. Also you can build the latest snapshot on the JitPack and use it as a dependency.

I highly recommend you to shade this dependency into your Jar file as well as some dependencies of Lirand API (MCCoroutine and AnvilGUI).