Fin

A private, self-hosted dashboard for one household's investment accounts.

Fin is a personal, non-commercial application built and operated by a single household for its own use. It brings a family's brokerage and retirement accounts together into one view and offers straightforward, passive-investing rebalancing guidance.

It is not a product, not offered to the public, and has no users other than the household that runs it. There is no sign-up, and no accounts can be created by anyone else.

What it does

• Aggregates investment holdings and balances across several brokerages and retirement providers, for more than one family member.
• Classifies each holding into US stocks, international stocks, bonds, or cash.
• Compares the household's combined allocation against a chosen three-fund target.
• Suggests which funds to buy or sell when the allocation drifts past a threshold.

How account data is accessed

Fin uses Plaid to connect to financial institutions. The household member authenticates directly with their own institution through Plaid; Fin never sees or stores institution credentials.

Fin requests only the investments product, which provides account balances and the list of securities held. It cannot move money, place trades, or initiate transfers of any kind. Its rebalancing output is a suggestion for a human to act on manually.

Where data lives

Fin runs on hardware controlled by the household, and account data is stored in its own self-hosted database. Nothing is sold, shared, or sent to advertisers or data brokers. See the privacy policy for details.

How it is built

Python and FastAPI on the backend, React and TypeScript on the front end, PostgreSQL for storage, Plaid for institution connectivity, and Financial Modeling Prep for classifying securities that Plaid's metadata does not cover.