Monzo MCP Server
   
Give Claude AI read-only access to your Monzo bank account through the Model Context Protocol.
<p align="center"> <img src="https://upload.wikimedia.org/wikipedia/en/thumb/9/95/Monzo_logo.svg/1200px-Monzo_logo.svg.png" alt="Monzo Logo" width="200"/> </p>
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Overview
This MCP server enables Claude to securely interact with your Monzo bank account, providing insights into your spending habits, account balances, and transaction history—all through natural conversation.
Key Features
| Feature | Description | |---------|-------------| | Account Overview | View all Monzo accounts (current, joint, Flex) | | Balance Tracking | Real-time balance and daily spending | | Transaction History | Browse up to 90 days of transactions | | Smart Analysis | Detect subscriptions and frequent merchants | | Savings Pots | Monitor your savings goals | | Push Notifications | Send custom alerts to your Monzo app |
Security First
- Read-only access — Cannot move money or modify account settings
- OAuth 2.0 — Industry-standard authentication
- Local tokens — Credentials never leave your machine
- Open source — Full transparency, audit the code yourself
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Architecture
┌─────────────────────────────────────────────────────────────────┐
│ Claude AI │
└─────────────────────────────────────────────────────────────────┘
│
│ MCP Protocol (stdio)
▼
┌─────────────────────────────────────────────────────────────────┐
│ Monzo MCP Server │
│ ┌───────────────────────────────────────────────────────────┐ │
│ │ FastMCP │ │
│ │ ┌─────────┐ ┌──────────────┐ ┌──────────┐ ┌───────────┐ │ │
│ │ │Accounts │ │ Transactions │ │ Analysis │ │ Pots │ │ │
│ │ │ Tools │ │ Tools │ │ Tools │ │ Tools │ │ │
│ │ └────┬────┘ └──────┬───────┘ └────┬─────┘ └─────┬─────┘ │ │
│ └───────┼─────────────┼──────────────┼─────────────┼────────┘ │
│ └─────────────┴──────────────┴─────────────┘ │
│ │ │
│ ┌────────▼────────┐ │
│ │ Monzo Client │ │
│ │ (async httpx) │ │
│ └────────┬────────┘ │
└──────────────────────────────┼──────────────────────────────────┘
│
│ HTTPS + Bearer Token
▼
┌─────────────────────┐
│ Monzo API │
│ api.monzo.com │
└─────────────────────┘---
Quick Start
Prerequisites
- Python 3.11+
- A Monzo account
- Claude Code CLI
1. Create a Monzo Developer App
- Visit developers.monzo.com
- Sign in and click "New OAuth Client"
- Configure your app:
| Field | Value | |-------|-------| | Name | Claude MCP (or anything you like) | | Redirect URL | http://localhost:8080/callback | | Confidentiality | Confidential |
- Save your Client ID and Client Secret
2. Install the Server
# Clone the repository
git clone https://github.com/yourusername/monzo-mcp.git
cd monzo-mcp
# Create virtual environment
python -m venv venv
source venv/bin/activate # Windows: venv\Scripts\activate
# Install in development mode
pip install -e .3. Configure Credentials
# Copy example configuration
cp .env.example .env
# Add your credentials to .env
MONZO_CLIENT_ID=oauth2client_xxxxx
MONZO_CLIENT_SECRET=mnzconf.xxxxx4. Authenticate with Monzo
python scripts/auth.pyThis opens your browser for Monzo login. After approving:
Important: Open your Monzo app within 5 minutes to approve the login request, otherwise you'll be limited to 90 days of transaction history.
5. Connect to Claude Code
Add to your Claude Code configuration (~/.claude.json or project .mcp.json):
{
"mcpServers": {
"monzo": {
"command": "/path/to/monzo-mcp/venv/bin/python",
"args": ["-m", "monzo_mcp.server"],
"cwd": "/path/to/monzo-mcp"
}
}
}---
Available Tools
Account Tools
| Tool | Parameters | Description | |------|------------|-------------| | get_accounts | — | List all Monzo accounts with IDs | | get_balance | account_id | Current balance, total balance, today's spending |
Transaction Tools
| Tool | Parameters | Description | |------|------------|-------------| | list_transactions | account_id, limit? | Recent transactions (default: 20, max: 100) | | get_transaction | transaction_id | Detailed info including merchant address |
Analysis Tools
| Tool | Parameters | Description | |------|------------|-------------| | list_subscriptions | account_id | Detect recurring payments (Netflix, Spotify, etc.) | | list_frequent_merchants | account_id, min_transactions? | Find merchants you visit often |
Savings Tools
| Tool | Parameters | Description | |------|------------|-------------| | list_pots | account_id | All savings pots with balances and goals |
Notification Tools
| Tool | Parameters | Description | |------|------------|-------------| | create_feed_item | account_id, title, body | Push notification to Monzo app |
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Example Conversations
You: "What's my current balance?"
Claude: Uses get_accounts then get_balance > Your current account balance is £1,234.56. You've spent £45.20 today.
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You: "Show me my subscriptions"
Claude: Uses list_subscriptions > I found 4 recurring payments: > - Netflix: £15.99/month > - Spotify: £10.99/month > - iCloud: £2.99/month > > Estimated monthly total: £29.97
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You: "Where do I spend the most money?"
Claude: Uses list_frequent_merchants > Your top merchants this month: > 1. Tesco (12 transactions) - £156.78 > 2. TfL (8 transactions) - £42.50 > 3. Pret A Manger (6 transactions) - £31.20
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Project Structure
monzo-mcp/
├── src/monzo_mcp/
│ ├── __init__.py # Package metadata
│ ├── server.py # MCP server entry point
│ ├── monzo_client.py # Async Monzo API client
│ ├── models.py # Data classes & exceptions
│ ├── constants.py # Configuration constants
│ ├── utils.py # Shared utilities
│ ├── analysis.py # Subscription detection logic
│ └── tools/
│ ├── __init__.py # Tool registration
│ ├── accounts.py # Account tools
│ ├── transactions.py # Transaction tools
│ ├── analysis.py # Analysis tools
│ ├── pots.py # Pot tools
│ └── feed.py # Feed/notification tools
├── scripts/
│ └── auth.py # OAuth authentication flow
├── pyproject.toml # Package configuration
├── .env.example # Environment template
└── README.md---
Limitations
| Limitation | Reason | |------------|--------| | 90-day history | Monzo's Strong Customer Authentication (SCA) requirement | | Personal use only | Monzo API terms prohibit public applications | | Rate limits | API calls are throttled; avoid rapid requests | | No money movement | Intentional design choice for security |
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Troubleshooting
"Access token expired"
python scripts/auth.pyRe-authenticate and approve in the Monzo app.
"Rate limited"
Wait 5-10 minutes before making more requests.
"No transactions found"
Ensure you approved the login in your Monzo app within 5 minutes of authenticating.
Server won't start
Check that your virtual environment is activated and credentials are in .env.
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Development
# Install dev dependencies
pip install -e ".[dev]"
# Run linting
ruff check src/
# Run type checking
mypy src/
# Run tests
pytest---
Contributing
Contributions are welcome! Please:
- Fork the repository
- Create a feature branch (
git checkout -b feature/amazing-feature) - Commit your changes (
git commit -m 'Add amazing feature') - Push to the branch (
git push origin feature/amazing-feature) - Open a Pull Request
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License
This project is licensed under the MIT License - see the LICENSE file for details.
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Acknowledgments
- Monzo for their excellent API
- Anthropic for Claude and the MCP protocol
- FastMCP for the MCP server framework
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<p align="center"> Made with ❤️ for the Claude + Monzo community </p>
