Momento/mcp-server

Memento MCP Server

Model Context Protocol (MCP) server for integrating Memento note-taking app with N8N, Claude Desktop, Cursor, and other MCP clients.

Version 3.2.0 - Enhanced with error handling, observability, rate limiting, and input validation.

Features

• ✅ 22 Tools for notes, notebooks, labels, and reminders
• 🔒 API Key Authentication with secure storage
• 🚀 Performance Optimized with connection pooling and caching
• 📊 Observability with Prometheus metrics export
• 🛡️ Input Validation using Zod schemas
• ⏱️ Rate Limiting per-user and global
• 🚨 Structured Error Handling with detailed messages
• 📝 Audit Logging for compliance

Quick Start

cd mcp-server
npm install

stdio Mode (Claude Desktop, Cline)

npm start
# or
node index.js

Claude Desktop configuration:

{
  "mcpServers": {
    "memento": {
      "command": "docker",
      "args": ["exec", "-i", "memento-mcp", "node", "index.js"]
    }
  }
}

HTTP Streamable Mode (N8N, remote)

npm run start:http
# or
node index-sse.js

Authentication

When MCP_REQUIRE_AUTH=true (default in Docker), all requests require an x-api-key header.

Generate API keys from the Memento web UI: Settings > MCP.

# Example: health check with API key
curl -H "x-api-key: mcp_sk_xxx" http://localhost:3001/health

Available Tools (22)

Notes (13)

Tool	Description
create_note	Create a new note
get_notes	List notes (filterable)
get_note	Get a specific note by ID
update_note	Update an existing note
delete_note	Delete a note permanently
search_notes	Search notes by keyword
move_note	Move a note to a notebook
toggle_pin	Pin/unpin a note
toggle_archive	Archive/unarchive a note
append_to_note	Append content to a note
find_and_update_note	Find and update a note
batch_move_notes	Move multiple notes at once
batch_delete_notes	Delete multiple notes at once

Notebooks (6)

Tool	Description
create_notebook	Create a notebook
get_notebooks	List all notebooks
get_notebook	Get notebook details
update_notebook	Update a notebook
delete_notebook	Delete a notebook
reorder_notebooks	Reorder notebooks
get_notebook_hierarchy	Get tree structure of notebooks

Labels (4)

Tool	Description
create_label	Create a label
get_labels	List labels
update_label	Update a label
delete_label	Delete a label

Reminders (1)

Tool	Description
get_due_reminders	Get due reminders

Utilities (2)

Tool	Description
export_notes	Export notes as JSON
import_notes	Import notes from JSON

HTTP Endpoints

Endpoint	Method	Description	Auth Required
/	GET	Server info	No
/health	GET	Health check	No
/metrics	GET	Prometheus metrics	No*
/sessions	GET	Active sessions	Yes
/mcp	GET/POST	Main MCP endpoint	Yes
/sse	GET/POST	Legacy redirect to /mcp	Yes

*Metrics can be disabled with MCP_ENABLE_METRICS=false

Configuration

Variable	Default	Description
PORT	3001	Server port
DATABASE_URL	required	PostgreSQL connection string
MCP_REQUIRE_AUTH	false	Require x-api-key header
MCP_API_KEY	-	Static fallback API key
MCP_LOG_LEVEL	info	Log level (debug, info, warn, error, silent)
MCP_REQUEST_TIMEOUT	30000	Request timeout in ms
MCP_RATE_LIMIT	100	Requests per window per user
MCP_RATE_LIMIT_WINDOW	60000	Rate limit window in ms
MCP_MAX_SESSIONS	500	Maximum concurrent sessions
MCP_SESSION_TTL	3600000	Session TTL in ms
MCP_ENABLE_METRICS	true	Enable metrics endpoint
MCP_ENABLE_AUDIT_LOG	true	Enable audit logging
MCP_MAX_REQUEST_SIZE	10485760	Max request size in bytes (10MB)
APP_BASE_URL	http://localhost:3000	Memento app URL
USER_ID	-	Optional user ID filter
DB_CONNECTION_LIMIT	10	Prisma connection pool limit
DB_POOL_TIMEOUT	10	Prisma pool timeout in seconds

Error Handling

All errors follow a structured format:

{
  "_error": true,
  "code": -32602,
  "httpCode": 400,
  "message": "Invalid params",
  "description": "Invalid method parameter(s)",
  "detail": "Input validation failed",
  "field": "content",
  "category": "validation",
  "timestamp": "2026-05-24T12:00:00.000Z"
}

Error Codes

Code	HTTP	Name
-32700	400	Parse error
-32600	400	Invalid request
-32601	404	Tool not found
-32602	400	Invalid params
-32603	500	Internal error
-32000	500	Database error
401	401	Authentication failed
403	403	Forbidden
429	429	Rate limit exceeded
408	408	Request timeout
409	409	Conflict
422	422	Unprocessable entity
503	503	Service unavailable

Metrics

Prometheus-compatible metrics are available at /metrics:

# HELP mcp_requests_total Total number of requests
mcp_requests_total 1234

# HELP mcp_latency_ms Request latency in milliseconds
mcp_latency_ms{quantile="0.5"} 45
mcp_latency_ms{quantile="0.95"} 120
mcp_latency_ms{quantile="0.99"} 250

# HELP mcp_errors_total Total number of errors
mcp_errors_total{category="validation"} 5
mcp_errors_total{category="database"} 2

# HELP mcp_auth_total Authentication attempts
mcp_auth_total{result="success"} 500
mcp_auth_total{result="failure"} 10

# HELP mcp_sessions_active Active sessions
mcp_sessions_active 15

N8N Integration

MCP Client Node Configuration

1. Add a MCP Client node in N8N
2. Select Streamable HTTP as transport
3. Endpoint: http://memento-mcp:3001/mcp (Docker) or http://YOUR_IP:3001/mcp
4. Add Header Auth: x-api-key = your MCP API key

Example Workflow: Create a note from email

{
  "tool": "create_note",
  "arguments": {
    "title": "{{ $json.subject }}",
    "content": "{{ $json.body }}",
    "labels": ["email", "inbox"],
    "notebookId": "inbox-notebook-id"
  }
}

Docker Deployment

services:
  memento-mcp:
    build: ./mcp-server
    environment:
      DATABASE_URL: ${DATABASE_URL}
      MCP_REQUIRE_AUTH: "true"
      MCP_LOG_LEVEL: "info"
    ports:
      - "3001:3001"
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:3001/health"]
      interval: 30s
      timeout: 10s
      retries: 3

Testing

# Run all tests
npm test

# Run performance tests
npm run test:perf

# Run connection tests
npm run test:connection

# Validate configuration
npm run validate

Security Considerations

1. Always use authentication in production (MCP_REQUIRE_AUTH=true)
2. Use HTTPS when exposing the server over the internet
3. Set appropriate rate limits for your use case
4. Monitor metrics for unusual activity
5. Keep dependencies updated with npm audit
6. Use environment variables for sensitive configuration

Troubleshooting

Database connection failed

FATAL: Database connection failed

• Verify DATABASE_URL is correct and reachable
• Check database credentials and permissions
• Ensure database is running and accessible

Rate limit exceeded

429 Too Many Requests

• Wait for the rate limit window to expire (check Retry-After header)
• Increase MCP_RATE_LIMIT if needed
• Use multiple API keys for different applications

Authentication failed

401 Unauthorized

• Verify API key is correct and active
• Check that MCP_REQUIRE_AUTH=true if using API keys
• Ensure API key hasn't been revoked

Development

# Run with debug logging
MCP_LOG_LEVEL=debug npm run dev

# Check configuration
npm run validate

# Run tests
npm test

License

MIT