Mem0 Custom MCP Server

A custom Model Context Protocol (MCP) server that connects to self-hosted Mem0 API instances. Enables Claude Code to use your own Mem0 deployment for memory management.

Why This Exists

The official @mem0/mcp-server and community @pinkpixel/mem0-mcp packages only support:

• Mem0's cloud platform (requires MEM0_API_KEY)
• Supabase backend
• Local storage

Neither supports connecting to custom self-hosted Mem0 API endpoints.

This custom MCP server bridges that gap by providing a wrapper around your self-hosted Mem0 API.

Features

• ✅ Connects to self-hosted Mem0 API at custom endpoints
• ✅ Implements MCP stdio protocol for Claude Code integration
• ✅ Supports all core Mem0 operations:
  • add_memory - Store new memories
  • search_memories - Semantic search through memories
  • get_memories - Retrieve all memories for a user
  • delete_memory - Delete specific memories
• ✅ Environment variable configuration
• ✅ Full TypeScript implementation with type safety
• ✅ 120-second timeout for slow Mem0 API responses (handles LLM processing delays)

Installation

From GitHub (Recommended for now)

# Clone the repository
git clone https://github.com/emasoudy/mem0-custom-mcp.git
cd mem0-custom-mcp

# Install dependencies
npm install

# Build the project
npm run build

From npm (Future - when published)

# This will be available after npm publish
npm install -g mem0-custom-mcp

Configuration

The server is configured via environment variables:

• MEM0_API_URL - Your Mem0 API endpoint (default: http://localhost:8888)
• DEFAULT_USER_ID - Default user ID for memory operations (default: default)

Example configurations:

• Local: http://localhost:8888
• Docker: http://host.docker.internal:8888
• Remote/VPN: http://your-server-ip:8888

Claude Code Configuration

You can configure this MCP server at either user level (available in all projects) or project level (specific project only).

Option 1: Using CLI (Recommended)

User-level (available everywhere):

claude mcp add mem0 \
  --scope user \
  --command node \
  --arg "/absolute/path/to/mem0-custom-mcp/dist/index.js" \
  --env MEM0_API_URL=http://localhost:8888 \
  --env DEFAULT_USER_ID=default

Project-level (specific project only):

cd /path/to/your/project
claude mcp add mem0 \
  --scope project \
  --command node \
  --arg "/absolute/path/to/mem0-custom-mcp/dist/index.js" \
  --env MEM0_API_URL=http://localhost:8888 \
  --env DEFAULT_USER_ID=default

Option 2: Manual Configuration

User-level - Edit ~/.claude.json:

{
  "mcpServers": {
    "mem0": {
      "type": "stdio",
      "command": "node",
      "args": [
        "/absolute/path/to/mem0-custom-mcp/dist/index.js"
      ],
      "env": {
        "MEM0_API_URL": "http://localhost:8888",
        "DEFAULT_USER_ID": "default"
      }
    }
  }
}

Project-level - Edit .claude.json in your project root:

{
  "projects": {
    "your-project-path": {
      "mcpServers": {
        "mem0": {
          "type": "stdio",
          "command": "node",
          "args": [
            "/absolute/path/to/mem0-custom-mcp/dist/index.js"
          ],
          "env": {
            "MEM0_API_URL": "http://localhost:8888",
            "DEFAULT_USER_ID": "default"
          }
        }
      }
    }
  }
}

Verify installation:

claude mcp list
# Should show "mem0" in the list

Development

• npm run build - Compile TypeScript to JavaScript
• npm run dev - Build and run the server
• npm start - Run the compiled server

Available Tools

add_memory

Store a new memory in Mem0.

Parameters:

• content (required) - The content to store
• user_id (optional) - User ID (defaults to env DEFAULT_USER_ID)
• metadata (optional) - Additional metadata object

search_memories

Search memories using semantic search.

Parameters:

• query (required) - Search query string
• user_id (optional) - User ID (defaults to env DEFAULT_USER_ID)
• limit (optional) - Maximum results (default: 10)

get_memories

Retrieve all memories for a user.

Parameters:

• user_id (optional) - User ID (defaults to env DEFAULT_USER_ID)
• limit (optional) - Maximum results (default: 100)

delete_memory

Delete a specific memory by ID.

Parameters:

• memory_id (required) - ID of the memory to delete

Architecture

This MCP server acts as a bridge between Claude Code and your self-hosted Mem0 API instance:

┌─────────────────────────┐
│     Claude Code         │
└────────────┬────────────┘
             │ MCP stdio protocol
             │
┌────────────▼────────────┐
│   mem0-custom-mcp       │  ← This MCP server (Node.js)
│   (MCP wrapper)         │
└────────────┬────────────┘
             │ HTTP REST API (localhost:8888 or custom URL)
             │
┌────────────▼────────────┐
│  Self-Hosted Mem0 API   │  ← Mem0 API server (Python/FastAPI)
│  (your-server:8888)     │    Handles memory operations
└────────────┬────────────┘
             │
        ┌────┴─────┐
        │          │
   ┌────▼───┐  ┌──▼──────┐
   │PGVector│  │  Neo4j  │  ← Databases managed by Mem0 API
   │(Vector)│  │ (Graph) │
   └────────┘  └─────────┘

Flow:

1. Claude Code calls MCP tools (add_memory, search_memories, etc.)
2. mem0-custom-mcp receives requests via MCP stdio protocol
3. mem0-custom-mcp forwards to Mem0 API via HTTP
4. Mem0 API processes requests and manages PostgreSQL/Neo4j databases
5. Results flow back through the chain to Claude Code

Note: This server does NOT directly access PostgreSQL or Neo4j. It communicates only with the Mem0 API endpoint, which handles all database operations.

Mem0 API Endpoints Used

This MCP server uses the following Mem0 API endpoints:

• POST /v1/memories - Add new memory
  • Body: {"messages": [{"role": "user", "content": "..."}], "user_id": "...", "metadata": {}}
• GET /v1/memories/{user_id} - Get all memories for a user
  • Path parameter: user_id
• POST /v1/memories/search - Search memories with semantic search
  • Body: {"query": "...", "user_id": "...", "limit": 10}
• DELETE /v1/memories/{memory_id} - Delete a specific memory
  • Path parameter: memory_id

Troubleshooting

Server won't start

Check debug logs in ~/.claude/debug/ for error messages.

Common issues:

• Mem0 API not accessible (check VPN connection)
• Invalid endpoint URL
• Port conflicts

Connection timeout

The MCP server has a built-in 120-second timeout for Mem0 API requests. This accommodates the time needed for:

• OpenAI API calls to generate embeddings
• LLM processing to extract entities and relationships
• Database operations (PostgreSQL + Neo4j)

Typical memory creation takes 30-60 seconds when using GPT-5-mini.

If you need to adjust the timeout, modify src/index.ts line 59:

const timeoutId = setTimeout(() => controller.abort(), 120000); // 2 minutes

Tool errors

Verify your Mem0 API is running:

# For local deployment
curl http://localhost:8888/health

# For remote/VPN deployment
curl http://your-server-ip:8888/health

Expected response:

{"status":"ok","db_connected":true,"stores":{"vector":"postgresql","graph":"neo4j"}}

Contributing

Contributions are welcome! Please see CONTRIBUTING.md for guidelines.

Development

# Clone and setup
git clone https://github.com/emasoudy/mem0-custom-mcp.git
cd mem0-custom-mcp
npm install

# Make changes to src/index.ts
# Build and test
npm run build
npm run dev  # Build and run

Changelog

See CHANGELOG.md for version history.

License

MIT License - see LICENSE for details.

Acknowledgments

• Built for the Model Context Protocol
• Works with Mem0 self-hosted instances
• Designed for Claude Code

Support

• 🐛 Report bugs
• 💡 Request features
• 📖 Read the docs