Kotlin MCP Server Generator

An MCP server generator for Kotlin that scaffolds production-ready Model Context Protocol servers with tool definitions and resource handlers for AI integrations using Ktor or Spring Boot.

What Is This?

Overview

This skill generates complete MCP server implementations in Kotlin with server initialization, tool registration, resource management, and JSON-RPC communication. It produces idiomatic Kotlin code leveraging coroutines and null safety for robust AI tool integrations.

Who Should Use This

Perfect for Kotlin developers building AI tool integrations, backend teams creating MCP-compatible services, and organizations standardizing AI interfaces across Kotlin microservices.

Why Use It?

Problems It Solves

Building MCP servers manually requires understanding protocol specifications, implementing JSON-RPC correctly, and managing tool schemas. Generated scaffolding leverages Kotlin coroutines and sealed classes for type-safe, maintainable protocol handling without boilerplate.

Core Highlights

• Complete Scaffolding - Generates server structure with initialization and routing
• Coroutine Support - Async tool handlers using Kotlin suspend functions
• Type Safety - Sealed classes for protocol messages and tool parameters
• Framework Choice - Supports both Ktor and Spring Boot backends
• Schema Generation - Automatic JSON Schema from Kotlin data classes

How to Use It?

Basic Usage

Ask Claude to generate a Kotlin MCP server, and this skill will create complete implementations.

Scenario 1: Basic MCP Server

Ask Claude: "Generate a Kotlin MCP server with a file search tool"

Claude will create:

import io.modelcontextprotocol.kotlin.sdk.*

class FileSearchServer : MCPServer("file-search", "1.0.0") {
    init {
        addTool(
            Tool(
                name = "search_files",
                description = "Search files by name pattern",
                inputSchema = jsonSchema {
                    property("pattern", StringSchema("Glob pattern"))
                    property("directory", StringSchema("Search directory"))
                    required("pattern")
                }
            ),
            handler = ::handleSearch
        )
    }

    private suspend fun handleSearch(params: Map<String, Any>): ToolResult {
        val pattern = params["pattern"] as String
        val dir = params.getOrDefault("directory", ".") as String
        val matches = findFiles(dir, pattern)
        return ToolResult.text(matches.joinToString("\n"))
    }
}

fun main() {
    val server = FileSearchServer()
    server.startStdio()
}

Scenario 2: Adding Resource Handlers

Tell Claude: "Add a database resource handler to my MCP server"

Claude will generate:

fun MCPServer.addDatabaseResource() {
    addResource(
        Resource(
            uri = "db:///{table}",
            name = "Database Reader",
            description = "Read rows from database table"
        )
    ) { uri ->
        val table = uri.substringAfterLast("/")
        val rows = db.query("SELECT * FROM $table LIMIT 100")
        ResourceResult.text(rows.toJson())
    }
}

Real-World Examples

DevOps Automation Server

A platform team built a Kotlin MCP server exposing Kubernetes operations to Claude. Coroutine-based handlers enabled concurrent pod queries without blocking, handling 100+ simultaneous tool calls efficiently.

Data Analytics Integration

A fintech company created an MCP server connecting Claude to their analytics pipeline. Sealed classes ensured type-safe handling of query results across different data sources.

Advanced Tips

Sealed Class Error Handling

Use Kotlin sealed classes for MCP response types, ensuring exhaustive handling of success, error, and partial result states at compile time.

Coroutine Scoping

Use structured concurrency with coroutineScope in tool handlers to manage cancellation properly when Claude terminates a request.

When to Use It?

Use Cases

• Custom Tool Servers - Build Kotlin tools for Claude to access internal APIs
• Database Integration - Connect AI models to data sources via MCP
• DevOps Automation - Expose infrastructure operations as MCP tools
• Microservice Bridge - Wrap existing Kotlin services as MCP endpoints

Related Topics

When you ask Claude these questions, this skill will activate:

• "Create an MCP server in Kotlin"
• "Generate Kotlin tool handler for Claude"
• "Build Ktor MCP server"
• "Kotlin MCP resource handler"

Important Notes

Requirements

• Kotlin 1.9+ for latest language features
• JVM 17+ runtime
• Ktor 2.3+ or Spring Boot 3.1+ depending on framework
• MCP SDK for Kotlin dependency
• Gradle 8.0+ or Maven 3.8+ for builds

Usage Recommendations

Do:

• Define clear tool schemas - Provide detailed parameter descriptions and types
• Use suspend functions - Leverage coroutines for async tool handlers
• Validate inputs - Check parameter types and constraints before processing
• Return structured errors - Provide descriptive error messages in responses

Don't:

• Don't block coroutines - Avoid blocking calls inside suspend functions
• Don't expose internal state - Sanitize responses to prevent data leaks
• Don't skip error handling - Handle all failure cases explicitly

Limitations

• Generated code requires MCP SDK dependency
• Stdio transport by default, HTTP needs additional setup
• Schema validation is runtime-only
• Limited tooling for MCP protocol debugging