personal-finance-mcp

Unofficial. This project is not affiliated with, endorsed by, or sponsored by Plaid Inc. "Plaid" is a trademark of Plaid Inc. This is a self-hosted client that talks to Plaid's API using credentials you supply.

A self-hosted, read-only MCP server that connects your banks, credit cards, loans, and brokerage accounts (via Plaid) to an MCP client like Claude Code. Ask questions about your own finances in plain English — no third-party aggregator (Monarch, Mint, etc.) involved.

What you can ask

• "What's my total balance across all accounts?"

• "Show me transactions over $100 in the last 30 days."

• "Which subscriptions am I still paying for?"

• "How much did I spend on groceries last month?"

• "Any bank that needs re-authentication?"

Example session (illustrative):

you    : What did I spend on groceries last month?
claude : [calls get_transactions]
         $487.23 across 14 transactions. Top merchants:
         Whole Foods ($198), Trader Joe's ($156), Safeway ($89).

you    : Any subscriptions I'm still paying for?
claude : [calls get_recurring_transactions]
         7 active recurring outflows totaling $142/mo:
         Netflix ($15.99), Spotify ($11.99), NYT ($4), ...

Tools

All 9 tools are read-only. Each returns {<data>: [...], "warnings": [...]} so one broken bank doesn't break the whole query.

Quickstart

Requires Python 3.11+, a Plaid account (free Trial plan), and an MCP client.

1. Plaid setup

1. Sign up at https://dashboard.plaid.com/signup → choose the Trial plan (free, 10 Items).

2. Team Settings → Products: enable Transactions, Liabilities, Investments.

3. Team Settings → API: copy your client_id and production secret.

2. Install

git clone https://github.com/<you>/personal-finance-mcp.git
cd personal-finance-mcp
python3.11 -m venv .venv && source .venv/bin/activate
pip install -r requirements.txt
cp .env.example .env   # then fill in PLAID_CLIENT_ID and PLAID_SECRET
pytest -v              # sanity check

3. Link each bank

Run once per bank you want to connect:

uvicorn link_helper:app --port 8765

Open http://localhost:8765, click Link a bank, complete Plaid Link. The terminal prints a line like PLAID_TOKEN_CHASE=access-prod-xxx... — paste it into .env and repeat for each bank.

4. Run it

python server.py   # serves on http://localhost:8000/mcp

5. Add to Claude Code

claude mcp add --transport http personal-finance http://localhost:8000/mcp

Try "list my accounts" to confirm.

Deployment

For a deployment you can use from anywhere:

• Docker (included): docker build -t personal-finance-mcp . && docker run --rm -p 8000:8000 --env-file .env personal-finance-mcp

• Any Python host (Fly.io, Railway, Raspberry Pi + Tailscale, a VPS): set the env vars from .env.example, expose /mcp over HTTPS, gate it with auth.

• Prefect Horizon (what the author uses — $0 recurring cost): see docs/DEPLOYMENT.md for the full walkthrough.

Gate the endpoint. An exposed MCP endpoint with your tokens leaks every linked account. Use OAuth 2.1, Cloudflare Access, or bind to a private network only.

Security

• Single-tenant. One deployment per person. Don't share.

• Read-only. No tool mutates state at any institution. Don't add any that do.

• Tokens live in env vars, never on disk. .env is gitignored.

• You own Plaid compliance. You're the Plaid customer under your own account.

Before each deploy:

• .env never committed: git log --all -- .env returns nothing

• No real tokens in history: git log -S'access-prod-' --all returns only placeholders

• Auth gate in front of the MCP endpoint (or localhost-only)

• HORIZON=1 (or similar) set in deployment env, blocking link_helper.py there

• Check get_institutions_status() every few weeks for re-auth needs

Troubleshooting

Tool returns empty despite real data. Plaid products weren't enabled when you linked the bank. Re-link with Transactions + Liabilities + Investments active. The tool surfaces PRODUCTS_NOT_SUPPORTED in warnings when this is the cause.

get_institutions_status() shows re_auth_required. The bank's Plaid session expired. Run link_helper.py in update mode — your existing access token stays the same. See docs/DEPLOYMENT.md.

Plaid Link shows a bank as "unsupported" (common with Amex). Usually an INSTITUTION_REGISTRATION_REQUIRED issue — OAuth banks need per-institution registration in the Plaid dashboard first. See docs/TROUBLESHOOTING.md.

More issues: docs/TROUBLESHOOTING.md.

Architecture

• server.py — FastMCP server, 9 read-only tools.

• plaid_client.py — Plaid SDK wrapper: SecretStr token redaction, 5-minute per-Item health cache, response shaping, structured error mapping.

• link_helper.py — Local-only FastAPI app for Plaid Link. Refuses to run if HORIZON=1 is set.

Deeper dive (including why /transactions/get over /transactions/sync): docs/ARCHITECTURE.md.

Contributing

See CONTRIBUTING.md. Scope is deliberately narrow: read-only, single-tenant, Plaid-backed.