io.modelcontext/clojure-sdk

What is io.modelcontext/clojure-sdk?

A Clojure SDK for building servers that implement the Model Context Protocol (MCP). It provides core components including server implementation, STDIO transport, error handling, and protocol specifications. It is aimed at Clojure developers who want to create MCP servers that expose tools, resources, and prompts to AI clients like Claude Desktop.

How to use io.modelcontext/clojure-sdk?

Add the dependency via git coordinates in deps.edn or use the provided deps-new template or GitHub template to quickly scaffold a new project. Build the examples jar with make clean && make examples-jar, then run any example server (e.g., calculator_server, vegalite_server, code_analysis_server) using java with the required JVM properties and classpath.

Key features of io.modelcontext/clojure-sdk

• Core server implementation handling MCP request/response cycles
• STDIO transport layer using core.async channels
• Custom error handling and protocol specification validation
• Example servers: calculator, Vega-lite charting, and code analysis
• Templates for quick project scaffolding (deps-new, GitHub)

Use cases of io.modelcontext/clojure-sdk

• Expose arithmetic tools (add, subtract, multiply, etc.) to an MCP client
• Generate Vega-lite charts from data via a dedicated tool server
• Provide analysis prompts for code review or poetry generation
• Build custom MCP servers in Clojure with minimal boilerplate

FAQ from io.modelcontext/clojure-sdk

What is the MCP protocol and how does this SDK relate to it?

The Model Context Protocol (MCP) is a client-server protocol for AI assistants to interact with tools, resources, and prompts. This SDK implements that protocol in Clojure, handling initialization, discovery, and interaction phases.

What dependencies or runtime requirements does this SDK have?

It requires a Java runtime and Clojure build tools (deps.edn). The Vega-lite example additionally needs the vl-convert CLI installed.

How can I create a new MCP server using this SDK?

Use the deps-new template mcp-clojure-server-deps-new or the GitHub template example-cool-mcp-server to quickly start a new project.

How do I run the example servers?

Build the examples jar with make clean && make examples-jar, then invoke each server via java with the specified JVM properties and classpath. Examples are configured for Claude Desktop or MCP Inspector.

What transport does this SDK support?

The SDK implements STDIO transport for communication between client and server.