Monzo MCP Server

What is Monzo MCP Server about?

Monzo MCP Server enables a Claude desktop tool to interact with your Monzo account. It implements Model Context Protocol (MCP) functions that retrieve balances, list pots, deposit/withdraw from pots, fetch and annotate transactions, and more, all backed by the official Monzo API.

How to use Monzo MCP Server?

1. Clone the repository and navigate to the project folder.
2. Install dependencies with uv install (or use pip if preferred).
3. Create a .env file containing your Monzo access token, user ID, default account ID, and optional specific account IDs.
4. Run the server via the MCP CLI: uv run mcp install main.py (automatic) or manually add a server entry to claude_desktop_config.json pointing to the uv command and the main.py script.
5. Restart Claude Desktop. You can now ask Claude questions about your Monzo data.

Key Features of Monzo MCP Server

• Balance retrieval for default, personal, prepaid, flex, rewards, and joint accounts.
• Pots management: list pots, deposit into pots, withdraw from pots with deduplication support.
• Transaction handling: list recent transactions, retrieve specific transaction details, annotate or delete notes.
• Configurable account IDs to minimise API calls and improve response speed.
• Integration with Claude Desktop using MCP CLI for seamless tool usage.

Use Cases of Monzo MCP Server

• Quickly check current balances across multiple Monzo accounts via natural language.
• Manage savings pots (deposit/withdraw) without opening the Monzo app.
• Review recent transactions or search by date range directly in a conversation.
• Add or remove notes on transactions for personal budgeting or record‑keeping.
• Automate personal finance queries in scripts or AI assistants.

FAQ from Monzo MCP Server

• Claude Desktop does not detect the server: Verify the path to uv in claude_desktop_config.json, ensure requests is included in the --with argument, and restart the app.
• Claude answers but does not call the MCP tool: Rephrase the query to explicitly request Monzo data, e.g., “Check my Monzo balance using the Monzo tool.” Check logs at ~/Library/Logs/Claude/mcp-server-Monzo.log for errors.
• How do pot deposits/withdrawals avoid duplicates?: The server generates a unique dedupe_id containing a triggered_by field (default “mcp”). This identifier prevents accidental duplicate transfers.
• What is uv?: uv is a fast Python package manager and installer that creates isolated environments and resolves dependencies efficiently.

🏦 Monzo MCP Server

A Model Context Protocol (MCP) server that provides access to your Monzo banking data through a Claude tool.

🪧 Demo

https://github.com/user-attachments/assets/ca3f9558-bc4b-460f-8658-99674f9c16b7

🖼️ Result

🚀 Installation

# Clone the repository
git clone https://github.com/BfdCampos/monzo-mcp-bfdcampos.git
cd monzo-mcp-bfdcampos/monzo-mcp-bfdcampos

# Install dependencies using uv (Python package manager)
uv install

🔑 API Setup

Create a .env file in the project directory with your Monzo credentials:

[!NOTE] To get your credentials, follow the instructions in the official Monzo Dev API Docs

MONZO_ACCESS_TOKEN='your_access_token'
MONZO_USER_ID='your_user_id'
MONZO_ACCOUNT_ID='your_default_account_id'

# Add specific account IDs for different account types
MONZO_UK_PREPAID_PERSONAL_ACCOUNT_ID='your_prepaid_account_id'
MONZO_UK_RETAIL_PERSONAL_ACCOUNT_ID='your_personal_account_id'
MONZO_UK_MONZO_FLEX_PERSONAL_ACCOUNT_ID='your_flex_account_id'
MONZO_UK_REWARDS_PERSONAL_ACCOUNT_ID='your_rewards_account_id'
MONZO_UK_RETAIL_JOINT_JOINT_ACCOUNT_ID='your_joint_account_id'

[!NOTE] I recommend getting the account IDs and adding them to your dotenv file to have a smoother experience with the server and reduce the number of API calls. This can also be found in the official Monzo Dev API Docs.

🔧 Setup with Claude Desktop

Method 1: Automatic Installation

Use the MCP CLI tool to install the server automatically:

uv run mcp install main.py

Method 2: Manual Configuration

Add the server to your Claude Desktop configuration file located at ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "Monzo": {
      "command": "/Users/[Your Home Directory]/.local/bin/uv",
      "args": [
        "run",
        "--with",
        "mcp[cli],requests",
        "mcp",
        "run",
        "/path/to/your/monzo-mcp-bfdcampos/monzo-mcp-bfdcampos/main.py"
      ]
    }
  }
}

Note: Replace /path/to/your/ with your actual paths. Important: Make sure to include requests in the --with argument as shown above.

🤖 Using with Claude Desktop

1. Restart Claude Desktop after installation.
2. Open the app and start a new conversation.
3. You can now ask Claude about your Monzo accounts:
   • "What's my current balance?"
   • "How much money do I have in my joint account?"
   • "Show me all my Monzo accounts"
   • "Move £50 from my personal account to my Savings pot"
   • "Show me my transactions from today"

📊 Available Functions

💷 balance: link to official docs

Returns the balance, spending today, and currency for a specified account type.

Parameters:

• account_type (optional): Type of account to check balance for. Options: "default", "personal", "prepaid", "flex", "rewards", "joint"
• total_balance (optional): If set to true, returns the total balance for the account. Default is false

Example requests:

What's my current balance?
How much money do I have in my joint account?
What's the balance of my flex account?

🍯 pots: link to official docs

Returns the list of pots for a specified account type.

Parameters:

• account_type (optional): Type of account to check pots for. Options: "default", "personal", "prepaid", "flex", "rewards", "joint"

Example requests:

Show me my pots
How many pots do I have?
How much money do I have in my "Savings" pot?

🪙 pot_deposit: link to official docs

Deposit money from an account into a pot.

Parameters:

• pot_id (required): The ID of the pot to deposit money into
• amount (required): The amount to deposit in pence (e.g., 1000 for £10.00)
• account_type (optional): The account to withdraw from. Default is "personal"

Example requests:

Add £25 to my Savings pot
Move £10 from my personal account to my Holiday pot

🏧 pot_withdraw: link to official docs

Withdraw money from a pot back to an account.

Parameters:

• pot_id (required): The ID of the pot to withdraw money from
• amount (required): The amount to withdraw in pence (e.g., 1000 for £10.00)
• account_type (optional): The account to deposit into. Default is "personal"

Example requests:

Take £25 from my Savings pot
Withdraw £10 from my Holiday pot to my personal account

🧾 list_transactions: link to official docs

Lists transactions for a specified account.

Parameters:

• account_type (optional): Type of account to list transactions for. Default is "personal"
• since (optional): Start date for transactions in ISO 8601 format (e.g., "2025-05-20T00:00:00Z")
• before (optional): End date for transactions in ISO 8601 format
• limit (optional): Maximum number of transactions to return. Default is 1000

Example requests:

Show me my recent transactions
What transactions do I have from today?
List all transactions from my joint account this month

📖 retrieve_transaction: link to official docs

Retrieves details of a specific transaction.

Parameters:

• transaction_id (required): The ID of the transaction to retrieve
• expand (optional): Additional data to include in the response. Default is "merchant"

Example requests:

Show me the details of my last transaction
What was the last transaction I made?

📝 annotate_transaction: link to official docs

Edits the metadata of a transaction.

Parameters:

• transaction_id (required): The ID of the transaction to annotate
• metadata_key (required): The key of the metadata to edit. Default is 'notes'
• metadata_value (required): The new value for the metadata key. Empty values will remove the key
• delete_note (optional): If set to true, the note will be deleted. Default is false

Example requests:

Add a note to my last transaction saying "Dinner with friends"
Remove the note from my last transaction

📦 Missing Functions from the Monzo MCP present in the Monzo API

• Create feed item
• Upload Attachment
• Register Attachment
• Deregister Attachement
• Create Receipt
• Retrieve Receipt
• Delete Receipt
• Registering a Webhook
• List Webhooks
• Deleting a Webhook
• Transaction Created
• General Payment Initiation for outside your own Monzo Account transfers

❓ FAQ

• Ensure you have the latest version of Claude Desktop.
• Restart Claude Desktop by force quitting the app and reopening it.
• Make sure your path is correct in the configuration file.
• Use the absolute path to your uv installation, e.g., /Users/[Your Home Directory]/.local/bin/uv in the command section of the configuration file.
• Verify that the requests library is included in the --with argument list in your configuration, as this is a common cause of connection issues.

• LLMs like Claude may not always use the MCP server for every request. Try rephrasing your question, specifically asking Claude to check your Monzo balance using the Monzo MCP tool.
• You can check if there were any errors by looking at the logs in ~/Library/Logs/Claude/mcp-server-Monzo.log.

• When you deposit money into a pot or withdraw from a pot, the MCP creates a unique dedupe_id that includes the "triggered_by" parameter.
• This helps identify transactions and prevents accidental duplicate transactions.
• The default "triggered_by" value is "mcp", but you can customise this to track different sources of pot transfers.

• uv is a Python package manager and installer that's designed to be much faster than pip.
• It maintains isolated environments for your projects and resolves dependencies efficiently.
• Learn more at github.com/astral-sh/uv.