Connect SimpleFIN to Open Net Worth for US Bank Sync

SimpleFIN is the shortest route from a US or Canadian bank to your books in Open Net Worth. You sign up at SimpleFIN Bridge, paste one Setup Token into the app, and Lucius, the AI agent inside this open-source personal wealth agent, can fetch your balances and transactions and book them. The connection is read-only and the bank connectors are in beta.

Short answer: Connect your banks at SimpleFIN Bridge ($15 a year), copy a Setup Token, and paste it under Connectors → Browse & add → SimpleFIN. Then link each account. Ask Lucius to fetch, or switch on the Sync SimpleFIN Automation, which runs every 6 hours and looks back 14 days.

Note: Open Net Worth is software, not a financial advisor. This guide shows how a connector works; it is not financial, investment, tax or legal advice.

What the SimpleFIN connection does

It reads three things from the banks and cards you connected at the Bridge: accounts, balances and transactions. Nothing goes the other way. The connector can’t move money, and no bank password is stored in Open Net Worth. You sign in to your bank at the Bridge, and the app only ever holds the access key the Bridge hands back.

Fetching isn’t a background daemon. It happens inside a conversation with Lucius, either when you ask or when an Automation runs him on a schedule. The same pattern applies to every connector in the bank and brokerage docs.

What you need

Three things:

The Bridge account. Sign up at SimpleFIN Bridge, pay $15 a year plus tax (the Bridge also sells a $1.50 a month plan), and connect your banks and cards there. The Bridge has a Supported institutions list; check it for your bank before you pay.

The model. Fetching and booking happen in a Lucius conversation, so a model has to be connected first. An API key, an existing Claude Code or Codex sign-in, or a free local model through Ollama all work; see connecting an AI provider. If the model later goes away, your ledger keeps working, but nothing new is fetched.

The token. A Setup Token is single-use. The Bridge exchanges it once for a permanent access key, and the token is dead after that, so don’t paste it anywhere else first.

Set up SimpleFIN step by step

1. Connect your banks at the Bridge. Sign up at bridge.simplefin.org and link your banks and cards there.
2. Create a Setup Token. In the Bridge, create a new app connection and copy the Setup Token it shows, a long string of letters and numbers.
3. Add the connector. In Open Net Worth, open Connectors in the sidebar, click Browse & add, choose Data sources, click the SimpleFIN card, then Add connector.
4. Paste the token. Put it in Setup token and click Save. The app exchanges it for the permanent access key straight away, and the field goes blank again.
5. Link your accounts. At the bottom of the form is an Accounts list, one row per account the Bridge can see. Add creates a new account with name, type, currency and today’s balance filled in. Link… ties the row to an account you already have.

Links save immediately; there is no second save. A linked row reads Linked to “account name”, and Unlink undoes it. Lucius only books into linked accounts. For an unlinked one he asks you instead of guessing.

The saved access key is write-only: the form never shows it. To re-link later, for example after you revoke access at the Bridge, create a new Setup Token and paste it into the same field. Leaving the field blank keeps the access you already have.

Check that it works with a first fetch

Before you automate anything, ask Lucius for a small fetch:

Fetch my SimpleFIN transactions from the last 7 days and show me what’s new.

If he lists transactions, you’re connected. The connector’s form also shows Last fetched, with how the last request went, for example “up to date” or “credentials need attention”.

A few things are worth checking in that first list:

• Balances. Compare each linked account’s balance with your bank’s own screen. A new account starts from today’s balance as its starting balance.
• Missing accounts. For an account you didn’t link, Lucius asks you instead of booking.
• Pending charges. A fetch skips pending transactions by default and takes them once they post, so a card swipe from this morning can show up a sync later.
• Categories. Lucius picks the category of yours that fits the merchant. When none fits, he creates a plain, general one and tells you which. A transaction stays Uncategorized only when he can’t tell what it is.

Treat the first fetch as the moment to compare against a real statement. If the numbers disagree and you can’t see why, importing a statement file is the fallback; our guide to importing bank statements covers the formats.

Turn on automatic syncing

Nothing syncs on a schedule until you switch it on. Open the SimpleFIN connector and click Automate. That opens Sync SimpleFIN as a draft you can read and edit; click Create automation to start it. The same draft sits under Automations → Sync a connector.

The template runs every 6 hours. The schedule and the wording are yours to change in Automations. Sync templates start in Automatically approve, so the run books without asking you each time. That is why the first manual fetch above matters.

How a sync behaves

Each run follows the same rules:

• A 14-day lookback from the newest booked transaction. A transaction your bank posts late is still caught, and after a pause the next run picks up where the book stops.
• Idempotent. A transaction already booked is skipped, so overlapping windows never double up.
• A changed transaction is brought in line, but never over something you edited by hand. Lucius keeps your version and tells you.
• A withdrawn transaction is flagged, never deleted. If a booked row disappears from the feed, he marks it for your review. Deleting is your call.
• Hand-typed entries are matched. If you logged a purchase yourself and the bank reports it later, he links the two. Unlink source on the transaction separates them if he got it wrong.
• Quiet by default. He messages you only when something was booked or something went wrong.

Because a model does the reading and booking, a local model keeps those prompts on your machine; where your financial data goes lists every call the app makes.

Common problems

“Could not save. The setup token may be invalid or already used.” A Setup Token works once. Create a new one at the Bridge and paste that.

Last fetched says “credentials need attention”. The access key was revoked or expired. Open ⋯ → Edit configuration and paste a fresh Setup Token.

Lucius says he can’t fetch. Check that an AI model is connected and that the connector isn’t paused.

No accounts in the list. You haven’t connected a bank at the Bridge yet, or the connector is paused.

To stop syncing, use Pause on the connector (Resume turns it back on) or ⋯ → Remove connector. Revoke the access at the Bridge too if you no longer want it.

When Plaid or Enable Banking fits better

SimpleFIN is the easiest US and Canada option, but it isn’t the only one.

Plaid runs on your own Plaid developer account: you copy a client ID and secret, and Production needs Plaid’s approval before it reaches a real bank. One Plaid connector holds several banks, each with its own Reconnect and Remove. Pick it when you want direct developer keys rather than a Bridge subscription. Our Plaid setup guide covers the keys, Plaid’s plans and the four-step form.

Enable Banking covers EU and UK banks through open-banking consent. You register an application, paste its private key, and approve access at your bank. Consent lasts about 90 days and is renewed by hand. The docs call it the newest connector and the least tested.

Every option follows the same four steps in the connector docs: get the credential, add the connector, link accounts, then check and automate. If you’d rather not link a bank at all, self-hosted personal finance works from statement files too, and the Monarch and Actual Budget comparisons show how bank sync differs there. Coming from YNAB? Its own connector moves the whole plan across. For what Lucius can do once the transactions are in, see AI agent for personal finance.