Grokzo

Monzo → MCP → Grok

Your bank account, as an MCP.

Connect Monzo to Grok, then ask about your own money in plain English. Grokzo is a small open-source server you run yourself. It can read; it cannot move a penny.

Read-onlyOpen sourceSelf-hostedBuilt because I wanted it
Get the codeHow it works

Ask your money questions

Ask the way you would ask a person.

  • What did I spend yesterday?get_transactions · yesterday
  • How much did I spend at Amazon last month?search_transactions · last_month
  • Which subscriptions am I still paying for?recurring_payments
  • How much is actually available after my regular bills?get_balance + recurring_payments
  • Find my last payment to JLCPCB.search_transactions
  • Compare spending this month with last month.monthly_cashflow · months=2

How it works

Four boxes. One of them is yours.

  1. MonzoYour account, via the Monzo Developer API. You approve access in the Monzo app.
  2. GrokzoYour server. Syncs transactions into SQLite and keeps the history.
  3. MCPEleven read-only tools over Streamable HTTP, behind OAuth that only you can approve.
  4. GrokAdded as a custom connector. Calls the tools and answers from the results.

Grok gets structured answers to specific questions (totals, matching transactions, balances), not a dump of your account. Amounts are exact integers in pence, so totals add up.

Security

Read-only by construction.

Grokzo can

  • Read balances, pots and transactions
  • Search and total your spending
  • Spot recurring payments

Grokzo cannot

  • Pay anyone or move money
  • Withdraw from or deposit to pots
  • Change anything in Monzo

How that is enforced

  • The Monzo client's network layer only allows six read endpoints
  • Only you can approve a connection; tokens are hashed at rest
  • No amounts, merchants or tokens in the logs

Source

Run your own.

One container, one SQLite file, one Debian box. MIT licensed. The public repository goes live at launch.

git clone <repository> grokzo && cd grokzo
cp .env.example .env    # Monzo client, secrets, your domain
GROKZO_DOMAIN=mcp.example.com docker compose up -d --build

The Monzo Developer API is for personal use: your own account, or a few people you explicitly allow. Grokzo is a single-user tool, not a hosted service.