Is SimpleFIN safe to use?
Yes, for most people. SimpleFIN is read-only, so an app using it can see your accounts but cannot move money. SimpleFIN says your bank login goes to its connection partner, MX, and never touches its own servers. You can turn off any app's access at any time. Its one disclosed incident, in May 2026, came from a bug at MX and briefly showed up to 39 users each other's data.
The part you protect is the access URL an app receives when you connect it. It works like a password to your transaction feed, so connect only apps you trust, and turn off access for any app you stop using.
What is SimpleFIN?
SimpleFIN is two things: an open protocol for read-only financial data, which its site calls RSS for financial information, and SimpleFIN Bridge, a paid service that connects your banks and serves that data to the apps you choose. The Bridge is run by One Part Rain, LLC, doing business as SimpleFIN.
It costs $1.50 a month or $15 a year, plus tax, for up to 25 institutions and 25 apps. You pay SimpleFIN directly, unlike Plaid, where the app pays.
Self-hosted and independent budgeting tools use it, including Actual Budget and Firefly III. SimpleFIN keeps a longer list of apps, and notes that being listed is not an endorsement.
How does SimpleFIN connect to your bank?
You create a SimpleFIN Bridge account, link your banks there, and get a setup token. You paste the token into your budgeting app, which trades it for an access URL and uses that URL to fetch your data. SimpleFIN uses MX to sign in to your banks, and says no bank credentials ever touch its servers.
SimpleFIN Bridge has no password of its own. You sign in with a passkey or a code sent to your email. It notifies you every time your transaction data is accessed from a new IP address. It supports U.S. and Canadian institutions.
What can SimpleFIN see, and how often does it update?
Account names, balances, and transactions from the institutions you link. SimpleFIN is meant for daily updates. An app may make 24 requests a day or fewer, and each request covers at most 90 days. How much history you get varies by bank.
Actual Budget's documentation says SimpleFIN data updates once a day, depending on the bank and MX. Expect new transactions a day or so after they post.
What does SimpleFIN do with your data?
SimpleFIN's privacy policy, effective October 27, 2026, says its app keeps no banking data. MX, its connection partner, keeps your accounts and transactions until you delete the connection, then removes them within two weeks. The policy does not say SimpleFIN never sells data; it says data may transfer if the business is sold.
Each app you connect gets its own copy of what it fetches and has its own privacy policy, so read that one too.
Has SimpleFIN had a data breach?
SimpleFIN disclosed one incident. On May 28, 2026, a bug deployed at MX meant that during a four-hour window up to 39 users may have seen each other's transactions, balances, and account names. SimpleFIN says no bank credentials were exposed. We found no other disclosed incident.
Users have also reported sync problems on GitHub and in forums, such as pending transactions that stayed after they posted and showed as duplicates. Those are reliability reports, not security incidents.
SimpleFIN vs Plaid: what is the difference?
SimpleFIN is a service you pay for and control. You link your banks once and hand a token to each app. Plaid is free to you because apps pay it, and you link your bank inside each app on Plaid's screen. SimpleFIN connects through MX; Plaid connects to banks itself, often through your bank's own sign-in page. Both give budgeting apps read access to your accounts.
The bigger practical difference is which apps support each. Most mainstream apps and AI assistants, including ChatGPT Finances, Personal Finance in Claude, Monarch, and Candor, use Plaid. SimpleFIN is mostly used by self-hosted and independent budgeting tools.
Who pays
- SimpleFIN Bridge
- You: $1.50/mo or $15/yr plus tax
- Plaid
- The app; free to you
How you connect an app
- SimpleFIN Bridge
- Link banks in SimpleFIN once, then paste a setup token into each app
- Plaid
- Link your bank on Plaid's screen inside each app
Bank sign-in
- SimpleFIN Bridge
- Handled by MX; SimpleFIN says credentials never touch its servers
- Plaid
- Your bank's own sign-in page at many large banks, otherwise Plaid's window
Updates
- SimpleFIN Bridge
- About once a day; 90 days per request
- Plaid
- Set by each app
Turning off access
- SimpleFIN Bridge
- Disable an app's access in SimpleFIN Bridge
- Plaid
- Disconnect an app in Plaid Portal at my.plaid.com
Disclosed incidents
- SimpleFIN Bridge
- May 2026: an MX bug showed up to 39 users each other's data
- Plaid
- 2021 privacy settlement; April 2026 phone-number issue affecting 294 people
Used by
- SimpleFIN Bridge
- Actual Budget, Firefly III, and other independent budgeting tools
- Plaid
- More than 9,000 apps, including ChatGPT, Claude, Monarch, and Candor
Which should you use?
Usually the app decides for you. If you self-host Actual Budget or Firefly III, SimpleFIN is the common way to bring in bank data, and $15 a year covers all your apps. If you use a mainstream budgeting app or an AI assistant, it most likely uses Plaid, and you link your bank on Plaid's screen inside that app.
Either way, the choices that matter most come after the connection: what the app can do with your data, what it keeps, and whether it trains AI models on it.
Can you use SimpleFIN with Claude or ChatGPT?
Not officially. SimpleFIN publishes no MCP server or AI integration. Several small community projects on GitHub wrap SimpleFIN as an MCP server you host yourself, which means giving that code your access URL. SimpleFIN's limit of 24 requests a day applies to agents too.
A self-hosted server gives your agent raw transactions. It does not keep a budget, goals, or the reasons behind your decisions between chats unless you build that too.
How does Candor connect your accounts?
Through Plaid. Candor does not support SimpleFIN. Plaid handles the bank sign-in, and Candor gives the AI agent you already use your balances, transactions, investments, and debts, so it can plan from your real accounts. Candor is read-only and has no tool to move money.
Tell your agent what you want with your money, and it sets up goals and a budget that pays for them. Every week Candor reviews your finances and tells your agent what's worth talking through and why. Candor does not sell your financial information or train AI models on it, and it records every read and change your agent makes, with the reason.
If a bank won't connect, you can bring in statements instead. You can disconnect a bank or revoke an agent at any time, and delete your Candor data from your account.
How was this page researched?
SimpleFIN facts come from SimpleFIN's own site, developer guide, security page, and privacy policy, and from Actual Budget's documentation. Plaid facts come from Plaid's own site, privacy policy, and its April 2026 breach notice. All were checked November 6, 2026. We publish Candor, which uses Plaid.
Sync problems users describe on GitHub and in forums are treated as reports, not verified findings.
Common questions
- Does SimpleFIN use Plaid?
- No. SimpleFIN Bridge connects to banks through MX. Plaid is a separate company that most mainstream apps use.
- How much does SimpleFIN cost?
- $1.50 a month or $15 a year, plus tax, for up to 25 institutions and 25 apps. You pay SimpleFIN directly.
- Does SimpleFIN work in Canada?
- Yes. SimpleFIN Bridge supports U.S. and Canadian institutions, including the U.S. and Canadian versions of international banks.
- How do I stop an app from reading my SimpleFIN data?
- Disable that app's access in your SimpleFIN Bridge account. The app can no longer fetch new data, though it may keep what it already downloaded. Deleting a bank connection in SimpleFIN removes its data from MX within two weeks.
- Does Candor support SimpleFIN?
- No. Candor connects accounts through Plaid, and you can bring in statements for a bank that won't connect.
Sources
- SimpleFIN SimpleFIN
- SimpleFIN Bridge developer guide SimpleFIN
- SimpleFIN Bridge security SimpleFIN
- SimpleFIN Bridge privacy policy SimpleFIN, October 27, 2026
- Apps that use SimpleFIN SimpleFIN
- SimpleFIN bank sync Actual Budget
- How Plaid works for consumers Plaid
- End User Privacy Policy Plaid, December 8, 2025
- Plaid to pay $58 million to settle data privacy class action Bloomberg Law, July 21, 2022