Projects

Finlity Is Now Open Source

Tyler Merritt · October 7, 2026

Finlity is open source.

It started as a private tool. I wanted one place to see my family's investments, and I didn't want to hand a spreadsheet of my financial life to a service I couldn't inspect. So I built a portfolio tracker that runs on my own machine and keeps everything there. On September 28 I scrubbed the history, flipped the repo to public, and put an MIT license on it.

I decided to publish Finlity because financial freedom is a dream nearly all of us share, and if I can make one part of that process free to you by sharing my knowledge and skills, then that's time well spent in my opinion.

What it does

Finlity is a self-hosted investment portfolio tracker with a FastAPI backend. You can:

  • Import CSV and Excel exports from Schwab, Fidelity, and Vanguard, or use the smart import wizard to parse statements and spot recurring bills.
  • See allocation and risk analysis: Sharpe, Sortino, max drawdown, and VaR, plus allocation triggers that alert you when a slice of the portfolio drifts past a threshold you set.
  • Run Monte Carlo retirement projections and a FIRE calculator.
  • Track liabilities and debts next to your assets, so the dashboard shows net worth instead of half the picture.
  • Connect bank accounts through SimpleFIN and Akahu.
  • Extend it with plugins for new importers, analyses, and dashboard widgets.

Local-first, on purpose

Privacy was the whole reason this exists, so it shaped the architecture. Self-hosted, your data stays on your machine. In the hosted demo, your data lives in SQLite inside your own browser, not on my server. The demo itself runs on synthetic data, so you can poke at every screen without putting anything real into it.

What changed since it went public

The first week after going public was busy. The dashboard got a full redesign, with an overview-first layout and proper phone navigation. Liabilities and net worth landed, then the smart import wizard, then bank connections. Most of that shipped in a few days of pull requests.

I built a lot of it with Claude Code as a collaborator. I'm not going to pretend otherwise, and I don't think it's a footnote. It is a big part of why a personal side project could grow this fast.

I very much enjoy the process of building with AI. Chiseling code from the lightning rock. It's been an incredible process just in the last 10 months. I started this project over a one-week holiday break, challenging myself to build the most complicated thing I could, back when we were using Opus 4.6 I believe, maybe even earlier. Things have improved dramatically (with Claude; I'm still mostly the same), and I'm fortunate to have enough agency in my life to dedicate some time to the pursuit of sharing with others.

Try it, break it, improve it

If you find a bug, a brokerage format it chokes on, or a feature you wish it had, open an issue. If you'd rather fix it yourself, pull requests are welcome. It's MIT licensed, so take it and make it yours.