What can you do with this server?

The Design Patterns MCP Server provides intelligent design pattern recommendations through semantic search and natural language queries, accessing a comprehensive catalog of 555+ patterns across 20+ categories. Core Capabilities: * Natural language pattern discovery: Find relevant patterns using problem descriptions with confidence-scored recommendations * Advanced search options: Perform keyword, semantic, or hybrid searches with filtering by categories (GoF, Architectural, Microservices, React, AI/ML, Security, etc.) and programming languages * Detailed pattern information: Access comprehensive details including multi-language code examples, relationships, and use cases for any specific pattern * Catalog statistics: Query total pattern counts with optional category breakdowns * High-performance operations: Fast vector search using sqlite-vec with LRU caching and object pooling, delivering 30-40% faster repeated queries * AI assistant integration: Compatible with MCP clients like Claude Code and Cursor for seamless workflow integration

Which integrations are available for this server?

Uses SQLite with vector extensions for efficient semantic search and storage of design pattern embeddings and metadata

How do I use Design Patterns MCP Server?

1. Click on "Install Server". 2. Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state. 3. In the chat, type @ followed by the MCP server name and your instructions, e.g., "@Design Patterns MCP Server I need a pattern for handling user authentication with multiple providers" That's it! The server will respond to your query, and you can continue using it as needed. Here is a step-by-step guide with screenshots.

Design Patterns MCP Server

Version License: MIT Test Status Patterns TypeScript

An intelligent MCP (Model Context Protocol) server that provides design pattern recommendations using hybrid search (semantic + keyword + graph augmentation). Access 685+ design patterns across 90+ categories through a natural language interface with advanced blended RAG architecture.

Quick Start

# Clone and setup git clone https://github.com/apolosan/design_patterns_mcp.git cd design_patterns_mcp # Install dependencies bun install # Build and setup database bun run db:setup # Start the server bun run dev

Configure in your MCP client (Claude Desktop, Cursor, etc.) and start discovering patterns through natural language queries.

Features

Feature	Description
Hybrid Search Engine	Blended RAG combining semantic, keyword (TF-IDF), and graph-augmented retrieval
685+ Patterns	Comprehensive catalog across 12 major categories
MCP Integration	Seamless integration with Claude, Cursor, and other MCP clients
Multi-Level Caching	L1 in-memory + L3 SQLite cache with 95%+ hit rate
Event Bus System	Decoupled service communication via pub/sub
Telemetry & Health	Real-time performance metrics and system monitoring
SOLID Architecture	Clean, maintainable codebase following best practices
Production Ready	464 test cases with 100% pass rate

Available Pattern Categories

Category	Count	Examples
Classic GoF Patterns	34	Factory, Builder, Observer, Strategy, Command
Architectural Patterns	56	MVC, Clean Architecture, Hexagonal, DDD
Microservices & Cloud	39	Circuit Breaker, Saga, Service Mesh
Data Engineering	54	Repository, CQRS, Event Sourcing
AI/ML & MLOps	46	RAG, Fine-Tuning, Model Compression
React Patterns	27	Hooks, Server Components, Performance
Blockchain & Web3	115	DeFi, NFTs, Smart Contracts, MEV
Concurrency & Reactive	45	Producer-Consumer, Actor Model
Security	21	OAuth, RBAC, Zero Trust
Functional Programming	26	Monads, Functors, Higher-Order Functions

Architecture

src/ ├── adapters/ # External service adapters (LLM, embeddings) ├── cli/ # CLI commands (migrate, seed, embeddings, setup-relationships) ├── core/ # DI Container, configuration builder ├── db/ # Database migrations ├── events/ # Event bus system ├── handlers/ # MCP request handlers (hybrid search, recommendations) ├── health/ # Health check services ├── repositories/ # Data access layer ├── search/ # Hybrid search engine ├── services/ # Business services (cache, telemetry, pattern service) ├── strategies/ # Strategy pattern implementations ├── types/ # TypeScript type definitions └── mcp-server.ts # MCP server entry point data/ ├── patterns/ # 750+ JSON pattern definitions └── design-patterns.db # SQLite database with embeddings

Usage

Finding Patterns

Ask natural language questions through your MCP client:

"I need to create complex objects with many optional configurations" → Builder, Abstract Factory, Factory Method "How to handle service failures gracefully in distributed systems?" → Circuit Breaker, Bulkhead, Retry, Fallback "What pattern helps with state-dependent behavior in React?" → State Machine, Observer, useReducer "How to implement secure authentication and authorization?" → OAuth 2.0, RBAC, JWT, Zero Trust

MCP Tools

Tool	Description
`find_patterns`	Hybrid search for patterns using problem descriptions
`search_patterns`	Keyword or semantic search with filtering
`get_pattern_details`	Comprehensive pattern information with code examples
`count_patterns`	Statistics about available patterns
`get_health_status`	System health and service status

Installation

Prerequisites

Node.js >= 18.0.0
Bun >= 1.0.0 (recommended) or npm >= 8.0.0

Setup

# Install dependencies bun install # Build project bun run build # Complete database setup (migrate + seed + embeddings + relationships) bun run db:setup # Or run steps individually bun run migrate bun run seed bun run generate-embeddings bun run setup-relationships

MCP Configuration

Add to your .mcp.json or Claude Desktop configuration:

{ "mcpServers": { "design-patterns": { "command": "node", "args": ["dist/src/mcp-server.js"], "cwd": "/path/to/design-patterns-mcp", "env": { "LOG_LEVEL": "info", "DATABASE_PATH": "./data/design-patterns.db", "ENABLE_HYBRID_SEARCH": "true", "ENABLE_GRAPH_AUGMENTATION": "true", "EMBEDDING_COMPRESSION": "true", "ENABLE_FUZZY_LOGIC": "true", "ENABLE_TELEMETRY": "true", "ENABLE_MULTI_LEVEL_CACHE": "true" } } } }

Environment Variables

Variable	Default	Description
`LOG_LEVEL`	`info`	Logging level (debug, info, warn, error)
`DATABASE_PATH`	`./data/design-patterns.db`	SQLite database path
`ENABLE_HYBRID_SEARCH`	`true`	Enable blended RAG search
`ENABLE_GRAPH_AUGMENTATION`	`true`	Enable pattern relationship traversal
`EMBEDDING_COMPRESSION`	`true`	Dimensionality reduction
`ENABLE_FUZZY_LOGIC`	`true`	Fuzzy logic result refinement
`ENABLE_TELEMETRY`	`true`	Performance metrics
`ENABLE_MULTI_LEVEL_CACHE`	`true`	L1 + L3 caching
`MAX_CONCURRENT_REQUESTS`	`10`	Request concurrency limit
`CACHE_MAX_SIZE`	`1000`	Cache size limit
`CACHE_TTL`	`3600000`	Cache TTL in milliseconds
`TRANSPORT_MODE`	`stdio`	Transport mode (stdio/http)
`HTTP_PORT`	`3000`	HTTP port (http mode)
`MCP_ENDPOINT`	`/mcp`	MCP endpoint path
`HEALTH_CHECK_PATH`	`/health`	Health check path
`SKIP_DB_SETUP`	`false`	Skip database setup

Docker Deployment

Quick Start

# Build docker build -t design-patterns-mcp . # Run HTTP mode docker run -p 3000:3000 -e TRANSPORT_MODE=http design-patterns-mcp # Run stdio mode (default) docker run design-patterns-mcp

Docker Compose

docker compose up --build -d

Environment Variables

Variable	Default	Description
`TRANSPORT_MODE`	`stdio`	Transport mode (stdio/http)
`HTTP_PORT`	`3000`	HTTP port (http mode)
`MCP_ENDPOINT`	`/mcp`	MCP endpoint path
`HEALTH_CHECK_PATH`	`/health`	Health check path
`DATABASE_PATH`	`/app/data/design-patterns.db`	SQLite database path
`LOG_LEVEL`	`info`	Logging level
`SKIP_DB_SETUP`	`false`	Skip database setup

Endpoints (HTTP mode)

GET /health - Health check
POST /mcp - MCP JSON-RPC endpoint

Commands

# Development bun run build # Compile TypeScript bun run dev # Development with hot reload bun run start # Build and start production server # Database bun run db:setup # Complete database setup bun run migrate # Run migrations bun run seed # Seed pattern data bun run generate-embeddings # Generate semantic embeddings bun run setup-relationships # Setup pattern relationships # Quality bun run test # Run all tests bun run lint # Check code quality bun run lint:fix # Auto-fix linting issues bun run typecheck # TypeScript type checking

Testing

The project includes 464 test cases across 41 test files with 100% pass rate:

Contract Tests: MCP protocol compliance validation
Integration Tests: Component interaction tests
Performance Tests: Search and vectorization benchmarks
Unit Tests: Individual component tests

# Run all tests bun run test # Run specific test suites bun run test:unit -- --grep "PatternService" bun run test:integration -- --grep "database" bun run test:performance -- --timeout 30000

Architecture Patterns

This project implements the patterns it documents:

Pattern	Implementation
Repository	`repositories/pattern-repository.ts`
Service Layer	`services/pattern-service.ts`
Object Pool	`services/statement-pool.ts`
Dependency Injection	`core/container.ts`
Strategy	`strategies/search-strategy.ts`
Event Bus	`events/event-bus.ts`
Multi-Level Cache	`services/multi-level-cache.ts`
Builder	`core/config-builder.ts`

Contributing

Contributions are welcome! Please read our contributing guidelines before submitting PRs.

Fork the repository
Create a feature branch
Make changes following SOLID principles
Run tests and linting
Submit a pull request

License

MIT License - see LICENSE for details.

Resources

Version: 0.4.4
Last Updated: February 2026
Patterns: 685+ (750+ JSON files)
Tests: 464 test cases | 100% pass rate

Design Patterns MCP Server

Design Patterns MCP Server

Quick Start

Features

Available Pattern Categories

Architecture

Usage

Finding Patterns

MCP Tools

Installation

Prerequisites

Setup

MCP Configuration

Environment Variables

Docker Deployment

Quick Start

Docker Compose

Environment Variables

Endpoints (HTTP mode)

Commands

Testing

Architecture Patterns

Contributing

License

Resources

Resources

Tools

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