Quarkus MCP Server

Build MCP servers with Java 21, Quarkus, and HTTP SSE transport.

Stack

Java 21 with Quarkus Framework
MCP Server Extension: mcp-server-sse
CDI for dependency injection
MCP Endpoint: http://localhost:8080/mcp/sse

Quick Start

bash

quarkus create app --no-code -x rest-client-jackson,qute,mcp-server-sse your-domain-mcp-server

Structure

Use standard Java naming conventions (PascalCase classes, camelCase methods)
Organize in packages: model, repository, service, mcp
Use Record types for immutable data models
State management for immutable data must be managed by repository layer
Add Javadoc for public methods

MCP Tools

Must be public methods in @ApplicationScoped CDI beans
Use @Tool(name="tool_name", description="clear description")
Never return null - return error messages instead
Always validate parameters and handle errors gracefully

Architecture

Separate concerns: MCP tools → Service layer → Repository
Use @Inject for dependency injection
Make data operations thread-safe
Use Optional<T> to avoid null pointer exceptions

Common Issues

Don't put business logic in MCP tools (use service layer)
Don't throw exceptions from tools (return error strings)
Don't forget to validate input parameters
Test with edge cases (null, empty inputs)

Quarkus MCP Server

Build MCP servers with Java 21, Quarkus, and HTTP SSE transport.

Stack

Java 21 with Quarkus Framework
MCP Server Extension: mcp-server-sse
CDI for dependency injection
MCP Endpoint: http://localhost:8080/mcp/sse

Quick Start

bash

quarkus create app --no-code -x rest-client-jackson,qute,mcp-server-sse your-domain-mcp-server

Structure

Use standard Java naming conventions (PascalCase classes, camelCase methods)
Organize in packages: model, repository, service, mcp
Use Record types for immutable data models
State management for immutable data must be managed by repository layer
Add Javadoc for public methods

MCP Tools

Must be public methods in @ApplicationScoped CDI beans
Use @Tool(name="tool_name", description="clear description")
Never return null - return error messages instead
Always validate parameters and handle errors gracefully

Architecture

Separate concerns: MCP tools → Service layer → Repository
Use @Inject for dependency injection
Make data operations thread-safe
Use Optional<T> to avoid null pointer exceptions

Common Issues

Don't put business logic in MCP tools (use service layer)
Don't throw exceptions from tools (return error strings)
Don't forget to validate input parameters
Test with edge cases (null, empty inputs)

Quarkus MCP Server

Quarkus MCP Server

Stack

Quick Start

Structure

MCP Tools

Architecture

Common Issues

Tags

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Quarkus MCP Server

Stack

Quick Start

Structure

MCP Tools

Architecture

Common Issues