DMCP - Dynamic Model Context Protocol

Semantic tool discovery for MCP - Solves the "too many tools" problem by making tool discovery query-driven with vector search.

🎯 The Problem

When you aggregate 20+ MCP servers (~300+ tools):

• Token explosion: 100,000+ tokens just listing tools
• LLM confusion: Too many choices = poor tool selection
• No filtering: Standard MCP returns ALL tools upfront

✨ The Solution

DMCP uses semantic vector search to discover tools on-demand:

User: "Create a GitHub issue for this bug"

LLM calls: search_tools(query="create GitHub issue")
    → Returns top-15 relevant tools (via semantic vector search)
    → Tools become available for use

LLM calls: github_create_issue(...)
    → Issue created!

Key insight: The LLM discovers tools by asking, not by loading everything upfront.

✨ Features

• 🔍 Semantic Search: ToolRet-trained E5 model for accurate tool retrieval
• ⚡ Fast: ~50ms search latency, 98% token reduction
• 🔄 Connection Resilience: Auto-retry, health checks, reconnection
• 🐳 Docker Ready: Full stack with Redis VSS + Embedding service
• 📊 Observable: Health endpoints, session logging, connection status
• ✅ Tested: 56 unit tests with vitest

🏗️ Architecture

┌─────────────────────────────────────────────────────────────────────────────┐
│                           VS Code / GitHub Copilot                          │
│                                                                             │
│  User: "search for kubernetes tools"                                        │
│        → search_tools("kubernetes")                                         │
│        ← Returns: 15 k8s tools (get_pods, list_deployments, ...)           │
└─────────────────────────────────┬───────────────────────────────────────────┘
                                  │ HTTP (Streamable HTTP Transport)
                                  ▼
┌─────────────────────────────────────────────────────────────────────────────┐
│                         DMCP Server (port 3001)                             │
│                                                                             │
│  • Exposes 1 meta-tool: search_tools                                        │
│  • Pure vector search (COSINE similarity, HNSW index)                       │
│  • Sends listChanged notifications when tools discovered                    │
│  • Connection keep-alive with health checks (30s interval)                  │
│  • Auto-retry on connection failures (3 attempts, exponential backoff)      │
└────────────┬──────────────────────────────────────────────────┬─────────────┘
             │                                                  │
             │ Query embeddings                                 │ Tool calls (SSE)
             ▼                                                  ▼
┌────────────────────────────────┐                ┌────────────────────────────┐
│   Redis Stack (port 6380)      │                │     Backend MCP Servers    │
│                                │                │     (via Agent Gateway)    │
│  • Vector Index (HNSW)         │                │                            │
│  • COSINE similarity           │                │  • GitHub, Jira, Confluence│
│  • 400+ tools indexed          │                │  • Google Workspace, Notion│
└────────────────────────────────┘                │  • Kubernetes, AWS, Azure  │
             ▲                                    │  • And more...             │
             │                                    └────────────────────────────┘
┌────────────────────────────────┐
│  Infinity Embedding Service    │
│  (port 5000)                   │
│                                │
│  • ToolRet e5-large-v2 model   │
│  • 1024 dimensions             │
│  • OpenAI-compatible API       │
└────────────────────────────────┘

🚀 Quick Start

Prerequisites

• Docker & Docker Compose
• An MCP server gateway exposing your tools (e.g., Agent Gateway)

1. Clone and Start

git clone https://github.com/yourusername/dmcp.git
cd dmcp

# Start everything: Redis, Embedding Service, and DMCP Server
docker compose up -d

# Wait for services to be healthy (~2-3 minutes for embedding model to load)
docker compose ps

2. Index Your Tools

# Run the indexer to populate Redis with tools from your MCP gateway
docker compose run --rm indexer

# Verify tools are indexed
curl http://localhost:3001/health
# → {"status":"healthy","toolCount":420,...}

3. Configure VS Code

Add to your .vscode/mcp.json:

{
  "servers": {
    "dmcp": {
      "type": "http",
      "url": "http://localhost:3001/mcp"
    }
  }
}

That's it! The search_tools meta-tool is now available in VS Code / GitHub Copilot.

📁 Project Structure

dmcp/
├── docker-compose.yml          # Full stack configuration
├── server/                     # DMCP Server (TypeScript)
│   ├── src/
│   │   ├── dmcp-server.ts      # Main server with connection management
│   │   ├── redis-vss.ts        # Redis vector similarity search
│   │   ├── custom-embedding-provider.ts
│   │   ├── dmcp-server.test.ts # Unit tests (28 tests)
│   │   └── redis-vss.test.ts   # Unit tests (28 tests)
│   ├── vitest.config.ts
│   └── package.json
├── indexer/                    # Tool Indexer (TypeScript)
│   └── src/
│       └── index.ts            # CLI indexer with parallel discovery
└── README.md

🐳 Docker Commands

# Start full stack
docker compose up -d

# View logs
docker compose logs -f dmcp-server

# Run one-shot indexing
docker compose run --rm indexer

# Start continuous sync worker
docker compose --profile worker up -d

# Rebuild after code changes
docker compose build dmcp-server && docker compose up -d dmcp-server

# Stop everything
docker compose down

# Stop and delete indexed data
docker compose down -v

⚙️ Configuration

Environment Variables

Connection Resilience

Docker Compose Services

🔍 How Search Works

DMCP uses pure vector search with the ToolRet embedding model:

1. Query is embedded using ToolRet-trained E5-large-v2
2. Redis performs HNSW nearest neighbor search
3. Top-K results are returned sorted by COSINE similarity
4. Tools become available via notifications/tools/list_changed

Example queries:

🏥 Health & Monitoring

Health Endpoint

curl http://localhost:3001/health

Response:

{
  "status": "healthy",
  "toolCount": 440,
  "activeSessions": 2,
  "backendConnections": {
    "total": 5,
    "healthy": 5,
    "details": [
      {"serverId": "github", "healthy": true, "lastCheck": 1704700000000},
      {"serverId": "serena", "healthy": true, "lastCheck": 1704700000000}
    ]
  },
  "config": {
    "retryAttempts": 3,
    "retryDelayMs": 1000,
    "healthIntervalMs": 30000,
    "connectionTimeoutMs": 10000
  },
  "uptime": 3600
}

Server Logs

docker compose logs -f dmcp-server

# Example output:
# 16:38:36 [DMCP] 🚀 Server listening on http://0.0.0.0:3000
# 16:38:36 [DMCP] ✓ Found 440 indexed tools
# 16:38:52 [DMCP] POST /mcp [initialize]
# 16:38:52 [DMCP] 📡 New connection request (session #1)
# 16:39:01 [DMCP] 🔍 Search: "kubernetes pods" (limit: 15)
# 16:39:01 [DMCP] ✓ Found 12 tools in 45ms

🧪 Testing

cd server

# Run tests
npm test

# Run with watch mode
npm run test:watch

# Run with coverage
npm run test:coverage

Test Coverage: 56 tests covering:

• Tool name sanitization and parsing
• Connection retry and health check logic
• Redis vector search operations
• Embedding operations

🔧 Local Development

# Start only infrastructure
docker compose up -d redis-vss embedding-service

# Run server locally
cd server
npm install
REDIS_PORT=6380 EMBEDDING_URL=http://localhost:5000 npm run start

# Run tests
npm test

➕ Adding MCP Servers

DMCP works with any MCP server. Example configurations are in gateway/config_parts/.

Notion MCP Server

Notion MCP provides tools for searching, reading, and creating Notion pages/databases.

1. Create a Notion integration at notion.so/my-integrations
2. Add to your gateway config (gateway/config_parts/70-notion.yaml):

targets:
  - name: notion
    type: mcp
    target_config:
      command: npx
      args:
        - -y
        - "@notionhq/notion-mcp-server"
      env:
        OPENAPI_MCP_HEADERS: '{"Authorization": "Bearer ${NOTION_API_KEY}", "Notion-Version": "2022-06-28"}'

3. Set your API key: export NOTION_API_KEY=ntn_...
4. Restart gateway and re-index: docker compose run --rm indexer

Other Popular MCP Servers

📊 Performance

📐 MCP Spec Compliance

Implements MCP Specification with Streamable HTTP Transport:

• ✅ listChanged: true capability
• ✅ notifications/tools/list_changed notifications
• ✅ Dynamic tool availability based on search
• ✅ Streamable HTTP transport (POST/GET/DELETE)
• ✅ Session management with UUID session IDs
• ✅ SSE for async notifications

🔬 Research Foundation

Implementation based on "Retrieval Models Aren't Tool-Savvy" (ACL 2025):

• 📄 Paper
• 🤗 Model: mangopy/ToolRet-trained-e5-large-v2
• 🏠 GitHub

Key Insight: General IR models perform poorly on tool retrieval; tool-specific training is essential.

🎬 Inspiration

• 📺 MCP Tool Overload Problem - YouTube
• 📝 Redis Blog: From Reasoning to Retrieval

📄 License

MIT