Qdrant Semantic Search

A Model Context Protocol (MCP) server that gives Claude persistent semantic memory via Qdrant, a high-performance vector database.

🎯 What is this?

This MCP server allows Claude to:

• 💾 Store information with semantic search capabilities
• 🔍 Retrieve content based on meaning, not just keywords
• 🧠 Remember conversations, code, documentation
• 🎯 Intelligently search through a knowledge base

Real-World Use Cases

• Semantic Code Search: "Find me code that handles JWT authentication"
• Team Knowledge Base: Store and retrieve procedures, best practices
• Conversational Memory: Claude remembers preferences and context
• Smart Documentation: Retrieve docs even with different phrasing

✨ Features

7 Available MCP Tools

Tool	Description
store_memory	Store information with semantic indexing
search_memory	Search by semantic similarity
delete_memory	Delete a memory by ID
get_memory	Retrieve a specific memory
list_memories	List all memories with pagination
get_stats	Get collection statistics
clear_all_memories	Delete all memories

🏗️ Architecture

┌─────────────┐         ┌──────────────┐         ┌─────────────┐
│   Claude    │ ◄─MCP──►│  MCP Server  │ ◄─────► │   Qdrant    │
│   Desktop   │         │  (TypeScript)│         │  Vector DB  │
└─────────────┘         └──────────────┘         └─────────────┘
                              │
                              ▼
                        ┌──────────────┐
                        │    OpenAI    │
                        │  Embeddings  │
                        └──────────────┘

🚀 Quick Start

Prerequisites

• Node.js 18+
• Docker
• OpenAI API Key
• Claude Desktop

Installation

# 1. Install dependencies
npm install

# 2. Configure environment
cp .env.example .env
# Edit .env and add your OPENAI_API_KEY

# 3. Start Qdrant
docker-compose up -d

# 4. Build the project
npm run build

# 5. Configure Claude Desktop
# See INSTALL.md for details

For complete installation, see INSTALL.md.

📖 Usage

Examples in Claude Desktop

1. Store Information

Store this information: "Our API uses JWT for authentication.
Tokens expire after 24h and must be renewed via /refresh-token"

Response:

{
  "success": true,
  "message": "Memory stored successfully",
  "id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "content": "Our API uses JWT for authentication..."
}

2. Semantic Search

Search for how to handle user sessions

Claude will use search_memory and find the JWT information even if the exact words don't match!

3. Store Code with Metadata

Store this code with tags "authentication" and "nodejs":

function validateToken(token) {
  try {
    return jwt.verify(token, process.env.JWT_SECRET);
  } catch (error) {
    throw new Error('Invalid token');
  }
}

4. Advanced Search with Filters

Search for authentication code, only JavaScript snippets

Claude can use filters to refine the search.

5. Get Statistics

Show me my semantic memory stats

Response:

{
  "success": true,
  "stats": {
    "name": "semantic_memory",
    "points_count": 42,
    "status": "green"
  },
  "embedding_model": "text-embedding-3-large",
  "embedding_dimensions": 1536
}

🎓 Key Concepts

Embeddings (Vectors)

Embeddings transform text into numerical vectors that capture semantic meaning.

# Conceptual
"JWT authentication" → [0.234, -0.567, 0.891, ..., 0.123]
"Token security"     → [0.219, -0.543, 0.876, ..., 0.134]
# These two vectors are close = similar meaning!

Cosine Similarity

Qdrant uses cosine similarity to measure "semantic proximity" between two vectors.

• Score 1.0: Identical
• Score 0.8-0.9: Very similar
• Score 0.7: Similar (default threshold)
• Score < 0.7: Less similar

Collections

A collection is like a database table, but optimized for vectors.

🔧 Configuration

Environment Variables

Variable	Description	Default
OPENAI_API_KEY	OpenAI API Key (required)	-
QDRANT_URL	Qdrant server URL	http://localhost:6333
QDRANT_API_KEY	Qdrant Cloud API Key (optional)	-
QDRANT_COLLECTION	Collection name	semantic_memory
EMBEDDING_MODEL	OpenAI model	text-embedding-3-large
EMBEDDING_DIMENSIONS	Vector dimensions	1536

Available Embedding Models

Model	Dimensions	Cost	Accuracy
text-embedding-3-small	1536	$	⭐⭐⭐
text-embedding-3-large	3072	$$$	⭐⭐⭐⭐⭐

📊 MCP API

store_memory

{
  content: string,      // Content to store
  metadata?: {          // Optional metadata
    tags?: string[],
    category?: string,
    source?: string,
    // ... other fields
  }
}

search_memory

{
  query: string,        // Natural language query
  limit?: number,       // Number of results (default: 5)
  threshold?: number,   // Min score 0-1 (default: 0.7)
  filter?: object       // Metadata filters
}

delete_memory

{
  id: string           // Memory ID
}

get_memory

{
  id: string           // Memory ID
}

list_memories

{
  limit?: number,      // Number of results (default: 10)
  offset?: string      // Starting ID for pagination
}

get_stats

No parameters. Returns collection statistics.

clear_all_memories

{
  confirm: boolean     // Must be true to confirm
}

🧪 Advanced Examples

1. Team Knowledge Base

Store these:

1. "Staging server accessible via staging.example.com,
    port 3000, credentials in 1Password"

2. "To deploy to production, use 'npm run deploy:prod'
    after tests pass and PR approval"

3. "Rate limiting is 1000 req/min per API key,
    10000/min for enterprise clients"

Then search:

How do I deploy to production?
What are the API limits?

2. Semantic Code Search

Store this code:

// Metadata: language=javascript, topic=authentication
async function authenticateUser(email, password) {
  const user = await db.users.findByEmail(email);
  if (!user) throw new Error('User not found');

  const valid = await bcrypt.compare(password, user.passwordHash);
  if (!valid) throw new Error('Invalid credentials');

  return generateJWT(user);
}

Search:

How to verify user credentials?
Show me login code

3. Conversational Memory

Store my preferences:
- I prefer TypeScript over JavaScript
- I use React 18 with hooks
- My code style follows Airbnb ESLint
- I want JSDoc comments on public functions

Claude will remember this in future conversations!

🔍 Advanced Features

Hybrid Search (Vector + Filters)

// In Claude
Search for authentication code,
only Python snippets created after 2024-01-01

The server can combine semantic search with metadata filters.

Chunking for Large Documents

For storing large documents, split into chunks:

const chunkSize = 500; // words
const chunks = splitIntoChunks(document, chunkSize);

for (const chunk of chunks) {
  await storeMemory({
    content: chunk,
    metadata: {
      document_id: "doc-123",
      chunk_index: i,
      total_chunks: chunks.length
    }
  });
}

🐛 Troubleshooting

Error: "OPENAI_API_KEY is required"

Check that the API key is defined in the Claude Desktop config file.

Qdrant Connection Error

# Check if Qdrant is running
docker ps | grep qdrant

# Restart if needed
docker-compose restart

Empty Search Results

• Lower the threshold (e.g., 0.5 instead of 0.7)
• Check if there's data: get_stats
• Rephrase the query

High OpenAI Costs

• Use text-embedding-3-small (5x cheaper)
• Reduce dimensions to 512 or 1024
• Cache frequent embeddings

🚀 Future Improvements

• Support for Ollama (free local embeddings)
• Web interface for visualizing memories
• Collection export/import
• Multi-modal support (images + text)
• History-based recommendations
• Automatic memory clustering
• Analytics and search insights

📚 Resources

• Model Context Protocol
• Qdrant Documentation
• OpenAI Embeddings Guide
• INSTALL.md - Detailed installation guide

🤝 Contributing

Contributions are welcome! Feel free to:

• Open issues for bugs or suggestions
• Submit Pull Requests
• Improve documentation

📄 License

MIT License - See LICENSE for details.

🙏 Acknowledgments

• Anthropic for the Model Context Protocol
• Qdrant for the vector database
• OpenAI for embedding models

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Note: This project is for educational and demonstration purposes. For production use, consider security, scalability, and costs.

Made with ❤️ to learn MCP and semantic search