Bank™

Your bank, in Claude. Read-only, self-hosted, one user.

Bank™ is not a bank. It is a small open-source server you host yourself (package name bank-mcp). It connects to your banks through Enable Banking, which wraps 2,700+ European banks in one PSD2 API, and exposes them to Claude as an MCP connector. Read-only, no payments, no third party holding your data.

"Has the invoice from Acme been paid?" · "What did we spend on groceries in August?" · "Which subscriptions am I paying for, and what do they cost per year?" · "Tell me when my balance drops below 5,000."

How it works

Claude ──OAuth──▶ your Bank™ server ──JWT──▶ Enable Banking ──PSD2──▶ your bank

• Claude talks to your server as a custom connector. You sign in once with a password; tokens handle the rest.

• Your server holds the Enable Banking application key, the bank consents and your account ids. It never stores balances or transactions and sends no telemetry.

• Enable Banking is the licensed provider. You log in at your bank's own site to approve access; nobody sees your bank credentials.

Related MCP server: Monzo MCP Server

Setup

You need an Enable Banking account (free), a place to run a container with a public https address, and about fifteen minutes.

1. Deploy

Any container host works. The server needs a persistent volume at /data and a public https address; it asks you for everything else in the browser.

Railway: New Project, Deploy from GitHub repo, pick this repo. Add a volume mounted at /data and generate a domain (Settings, Networking, port 8080). The Dockerfile and railway.json are picked up automatically, and the server learns its own address from Railway.

Docker Compose on your own box: docker compose up -d, then put a TLS terminator in front (Caddy needs two lines: YOUR-HOST { reverse_proxy localhost:8080 }) and set BASE_URL to the public address. Fly.io works like Railway: volume at /data, the app name gives the address.

Open the address. A fresh server shows a setup page.

2. Register an Enable Banking application

The setup page lists the exact values Enable Banking's form asks for: the redirect URL, a description for the consent screen, and the privacy and terms URLs, all pointing at your server. At https://enablebanking.com/cp/applications create an application with them:

• Environment: Production for your real accounts, Sandbox for test data (see Going live below for the production rules).

• Keep "generate private key" selected. A .pem file downloads once when you save; that is the key. The application id (a UUID) is shown after saving.

3. Finish setup

Back on the setup page: paste the application id, choose the .pem file, pick a password of twelve characters or more. Everything is stored on the volume, and the page turns into a status page showing the connector URL for Claude.

Prefer configuration by environment? Set these and the setup page never appears:

Optional: NOTIFY_WEBHOOK_URL for watch notifications and sign-in alerts (a Slack incoming webhook works). Full list in .env.example. npm run check verifies a configuration from a terminal.

4. Add the connector in Claude

In claude.ai (or the desktop app): Settings → Connectors → Add custom connector. Name it Bank™, paste https://YOUR-HOST/mcp, save, then click Connect. Your server shows a password page; enter the admin password. That is the only login you will do.

In Claude Code:

claude mcp add --transport http bank https://YOUR-HOST/mcp

then run /mcp inside Claude Code to sign in.

5. Connect your bank

In Claude, say "connect my bank" (or use the connect-bank prompt). Claude looks up your bank, gives you a link, you log in at the bank and approve, and the accounts appear. Consents last up to 180 days; Claude tells you when one is about to expire and the same conversation renews it.

Give accounts labels ("Everyday", "Joint expenses", "Mortgage") when Claude suggests them. Every tool accepts labels instead of ids.

Going live with your own accounts

Enable Banking's production environment normally requires a contract, but it has a restricted mode for accessing your own accounts, explicitly allowed for individual non-commercial use. After registering a Production application:

1. On the (Inactive) application click Activate by linking accounts.

2. Log in at your bank and approve. Repeat for each bank you want.

3. The application becomes active and the API only ever returns accounts you linked this way.

Read the Restriction of Use section of Enable Banking's Terms of Service before you rely on it: restricted mode is for your own accounts, not for offering a service to others. This project does not change those terms.

What you get

Tools (all read-only):

Prompts: connect-bank, monthly-summary, subscription-audit, unusual-transactions.

Watches run on the server. Rules: balance below or above an amount, a single debit over an amount, an incoming or outgoing payment matching a name, and "tell me if this payment has not arrived by this date". Accounts are checked at most four times a day, the PSD2 limit for unattended access. Notifications go to NOTIFY_WEBHOOK_URL as a Slack message or a JSON POST.

Enable Banking's own webhooks cover payment initiation only, so account data is polled. There is no way around that under PSD2.

Claude Code plugin

The repository is also a Claude Code plugin marketplace. The bank plugin bundles the connector entry and a skill that encodes how to work with the data: an account map, categorisation rules, the monthly review format and when to create watches.

Point it at your server, then install:

export OPENBANK_URL=https://YOUR-HOST/mcp   # put this in your shell profile

/plugin marketplace add noskillish/bank
/plugin install bank@bank

Then /mcp, select bank, Authenticate, and enter your password. No organisation admin is involved; plugins are per user.

The skill lives at plugin/skills/bank/SKILL.md. Copy it into your own skills to fill in the account map and your merchant rules. The server stays generic; your rules stay yours.

Running it on your own machine

The server can also run locally over stdio, with no OAuth, for Claude Code in this directory. The repository ships a .mcp.json for that:

npm install
cp .env.example .env    # EB_APP_ID, EB_PRIVATE_KEY_PATH, ADMIN_PASSWORD
npm run dev             # http server, for the bank redirect

Production applications require an https redirect URL even locally. Create a certificate with mkcert, set TLS_CERT_PATH, TLS_KEY_PATH and BASE_URL=https://localhost:8080, and register https://localhost:8080/callback as a redirect URL.

Security notes

• The server is a complete OAuth 2.1 authorization server with one user. Discovery, dynamic client registration and PKCE come from the MCP SDK; tokens are stored hashed; five wrong passwords lock an address out for fifteen minutes.

• State is one JSON file in DATA_DIR: consents, account ids, watches and OAuth tokens. Back it up if you care about not re-consenting; delete it to forget everything.

• Only clients that redirect back to claude.ai, claude.com or localhost can register (ALLOWED_REDIRECT_HOSTS), so a phishing link cannot route your sign-in to another site. The sign-in page also names the host you will be sent back to.

• Anyone with the admin password can read your accounts. Use a long one. Every successful sign-in is logged and, if NOTIFY_WEBHOOK_URL is set, sent to you as a message. A sign-in you did not make is your alarm.

• Changing ADMIN_PASSWORD_HASH (or ADMIN_PASSWORD) and restarting logs every client out. That is the kill switch. Revoking the consents at your bank, or deleting the state file, is the step beyond it.

• There are no payment tools and none will be added. Payments need a licensed PISP and a very different security model.

Commands

npm start              # http server (reads env from the environment)
npm run dev            # same, with reload and .env
npm run check          # verify config and the Enable Banking application
npm run hash-password  # produce ADMIN_PASSWORD_HASH
npm run watch -- --force   # run all watches once, print what fired
npm test               # unit tests (node:test)
npm run typecheck

Requires Node 24 or newer (runs TypeScript directly, no build step).

Layout

src/server.ts         Express: /mcp behind OAuth, OAuth endpoints, /callback, status page
src/auth.ts           single-user OAuth provider, password login page
src/mcp.ts            McpServer factory (tools + prompts + instructions)
src/tools.ts          the MCP tools
src/prompts.ts        the MCP prompts
src/watcher.ts        background rule checks and notifications
src/enablebanking.ts  JWT signing and a thin typed API client
src/store.ts          the JSON state file
src/data.ts           shaping balances and transactions for an assistant
src/stdio.ts          local stdio entry point
src/cli.ts            check, hash-password, watch
plugin/               Claude Code plugin with the bank skill

License

MIT