Kotlin Fundamentals

Name: Kotlin Fundamentals
Author: pluginagentmarketplace

pluginagentmarketplace/custom-plugin-kotlin

22 installs
7 repo stars
Updated January 5, 2026
pluginagentmarketplace/custom-plugin-kotlin

kotlin-fundamentals is a Claude Code skill for ai & agent building.

About

kotlin-fundamentals is a Claude Code skill for ai & agent building. It helps solo builders move faster with AI-assisted development.

kotlin-fundamentals
AI & Agent Building
AI-coding skill

Kotlin Fundamentals by the numbers

22 all-time installs (skills.sh)
Ranked #10,169 of 16,546 AI & Agent Building skills by installs in the Skillselion catalog
Data as of Aug 4, 2026 (Skillselion catalog sync)

npx skills add https://github.com/pluginagentmarketplace/custom-plugin-kotlin --skill kotlin-fundamentals

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Installs	22
repo stars	★ 7
Last updated	January 5, 2026
Repository	pluginagentmarketplace/custom-plugin-kotlin ↗

How do I helps with ai & agent building tasks.?

Helps with ai & agent building tasks.

Who is it for?

Best when you're working on ai & agent building and need structured help with kotlin fundamentals.

Skip if: Teams with no ai & agent building needs, or anyone wanting a generic chat assistant without this specific workflow.

When should I use this skill?

When you need to helps with ai & agent building tasks., or when kotlin-fundamentals is a claude code skill for ai & agent building.

What you get

Structured output aligned to kotlin-fundamentals: kotlin-fundamentals, AI & Agent Building.

Files

SKILL.mdMarkdownGitHub ↗

Kotlin Fundamentals Skill

Master Kotlin programming fundamentals with production-ready patterns.

Topics Covered

Null Safety

// Safe call + Elvis
val name = user?.name ?: "Anonymous"

// requireNotNull for validation
requireNotNull(user) { "User required" }

Data Classes

data class User(val id: Long, val name: String) {
    init { require(name.isNotBlank()) }
}

Scope Functions

Function	Context	Returns	Use Case
`let`	it	Lambda result	Null-safe transforms
`apply`	this	Same object	Object configuration
`run`	this	Lambda result	Object scope + result
`also`	it	Same object	Side effects

Troubleshooting

Issue	Resolution
NPE despite null check	Check platform types from Java
Smart cast fails	Use local variable or let

Usage

Skill("kotlin-fundamentals")

plugins {
    kotlin("jvm") version "{{KOTLIN_VERSION}}"
}

group = "{{GROUP_ID}}"
version = "{{VERSION}}"

repositories {
    mavenCentral()
}

dependencies {
    implementation(kotlin("stdlib"))
    testImplementation(kotlin("test"))
}

kotlin {
    jvmToolchain(17)
}

# Kotlin Fundamentals Configuration
kotlin_version: "1.9.22"
jvm_target: "17"

code_style:
  indent_size: 4
  continuation_indent: 4
  
null_safety:
  strict: true
  platform_types: warning
  
coroutines:
  default_dispatcher: Dispatchers.Default

Kotlin Fundamentals Guide

Null Safety

// Nullable types
var name: String? = null

// Safe call
val length = name?.length

// Elvis operator
val len = name?.length ?: 0

// Not-null assertion (avoid!)
val len = name!!.length

Data Classes

data class User(
    val id: Long,
    val name: String,
    val email: String
)

// Auto-generated: equals(), hashCode(), toString(), copy()
val user = User(1, "John", "john@example.com")
val copy = user.copy(name = "Jane")

Extension Functions

fun String.addExclamation(): String = "$this!"

val message = "Hello".addExclamation() // "Hello!"

#!/bin/bash
# Kotlin Lint Script
if ! command -v ktlint &> /dev/null; then
    echo "ktlint not found. Install with: brew install ktlint"
    exit 1
fi
ktlint --format "src/**/*.kt"
echo "✅ Kotlin linting complete"