Overview

What Fortuna is

Fortuna is a personal finance system. It tracks a person’s whole financial life (bank accounts, credit cards, investments, expenses and earnings) in one place, and turns that history into tabular views, drillable charts and forward projections.

The problem it addresses is scattered data: one bank’s app, another bank’s statement PDF, a broker’s portal, a credit card invoice, and a hand-made spreadsheet to make sense of the rest. Fortuna is built to answer two questions without an afternoon of manual work: where did the money go, and where will I be in six months? It is self-hostable, so the data stays on a machine or server you control.

It is made of two repositories.

• Fortuna API is the back end: an HTTP API, built with ASP.NET Core on .NET 10, that owns the domain, the data and the integrations. It also contains a native core written in Rust, which exposes the same operations through a C interface so that a desktop app can work with no server at all.
• Fortuna UI is the front end: a single Flutter application for the web, Windows, Linux and Android that reads and writes everything through the API. The API owns the domain, the money and the integrations; the UI owns the experience.

What it does

The list below is what the two READMEs describe. Where the interface does not cover a feature yet, the Status section says so.

• Tracks holdings. Bank accounts, credit cards (with billing cycles and statements) and investments, each with its own currency and history.
• Records money movement. Expenses, earnings and transfers, plus installment purchases and recurring commitments.
• Brings data in from several sources. Manual entry, the Pluggy open-banking service, Excel workbooks and supported PDF statement layouts, all behind one pluggable source contract. Today the supported PDF layout is the Nubank credit card invoice.
• Handles multiple currencies. Exact decimal arithmetic, and dated, attributable exchange rates from the Banco Central do Brasil’s PTAX service.
• Presents data as a table and as charts. A spreadsheet-shaped table, and chart aggregations that drill down to the individual transactions behind a figure.
• Projects the future. From recurring commitments, unbilled installments and statements due.
• Exports and attaches. CSV, Excel and PDF exports, and attachments filed against transactions.
• Honors data rights. Consent before any third-party processing, a complete export of your personal data, and erasure of your account.
• Runs in more than one shape. Multi-user on a shared instance, or offline on a Windows or Linux desktop through the native core.

What it does not do

These are deliberate exclusions, not features that are still to come.

• It does not move money. No payments, no transfers executed at a bank, no trading. Fortuna reads and records; it never writes to a financial institution.
• It does not give financial advice. A projection is arithmetic over your own data.
• It does not do tax filing or accounting compliance.
• It does not store bank credentials. Open-banking access lives with Pluggy and is referenced by token.
• It does not manage users. Identity belongs to Heimdall. The one exception is the desktop offline account, which Fortuna owns because there is no network to reach Heimdall over.
• The API does not render a user interface. It serves the numbers and the Flutter client draws them.

The UI adds exclusions of its own.

• It does not compute money. Every balance, total, aggregation and projection is asked of the API. The client formats figures; it never derives them.
• It does not own data. There is no client-side database, and nothing is authoritative until the API has accepted it.
• It does not parse or render files. An import is uploaded whole, and an export is produced by the API and only saved by the client.
• It does not talk to external services. Everything is reached through the API. The one exception is Google, which issues a sign-in token that the API exchanges.
• It does not run on iOS or macOS.
• It does not work offline outside desktop offline mode. A lost connection is reported, never disguised by a cache.

Who it is for

Fortuna is for individuals and households who want a single, trustworthy ledger of their own money and are not willing to hand that data to a service they do not control. The Project Overview documents of both repositories name these roles.

The business rules behind the first two rows are API-BR-01 and API-BR-02 for the API and UI-BR-21 for the interface.

Three ways to run it

The UI runs in three shapes, and the interface is meant to be the same in all three.

• Connected. Signed in through the Fortuna API against the shared identity provider, talking to a remote instance. This is the normal path. Connected or self-hosted are the only modes on the web and Android.
• Self-hosted. The same experience, pointed at an instance you run yourself.
• Desktop offline. Windows and Linux only, and only where the installation provides the Fortuna core library. The app calls the core in process, with no network and no server. In this version the app starts but cannot be signed into yet.

The API supports two deployment shapes: a single self-hosted owner, or a shared instance with several registered users, each strictly isolated from the others.

Status

This page was checked on 2026-10-13. The released versions below come from GitHub; the READMEs’ own status lines and backlog counts are not repeated here because they go stale.

None of these releases has downloadable files attached, so there is nothing to download from a release page yet. The project boards are the live view of the work: Fortuna API and Fortuna UI.

The API README still names version 1.0.0 as the released version, which GitHub no longer matches. This site follows GitHub.

What the interface does not cover yet

The UI README describes its own state as specification complete with implementation under way, and names UC-04, UC-23 and UC-35 as the use cases that remain. GitHub agrees: those three issues are open. Here is what that means in practice.

• UC-04, completing a two-factor challenge at sign-in, is unfinished. The route exists, but it shows a placeholder screen. See issue #5.
• UC-23, managing recurring commitments, has no screen. No route for it exists yet. See issue #24.
• UC-35, managing a transaction’s attachments, is open. The UI has no attachment screen yet. See issue #36.
• The home screen is a placeholder. The route / shows a screen titled Overview that is marked as implemented by UC-38; it is not a dashboard.
• There is no navigation menu in the code yet. Most screens have no link from any other screen, so on the web they are opened by typing their address, and the code has no control that opens them on Windows, Linux or Android. See There is no menu in the User guide.
• The desktop local-account screens and two-factor management have no route. The screens for creating a local account, signing in to it and recovering it (UC-06, UC-07 and UC-08), and for managing two-factor authentication (UC-10), are written and tested, but no route opens them and no screen links to them. See Offline mode and Settings in the User guide.
• The file-import screen sends only the file. The API also requires a target and, for a workbook, a column mapping. See Imports and connections (UC-32) in the User guide.
• Sign-up (UC-47) is on the develop branch but not in a release. The UI changelog lists it under Unreleased.

Desktop offline mode is partial

The native core does not yet implement everything the API does. In offline mode the UI shows these as “Not available offline”, with the core’s reason, instead of offering them and then refusing: file imports and import retry, data-set export, charts, net position and projections, transfers, installment purchases, card statements and closing or settling them, budget consumption, goal progress, and reconciliation. The exact list of operations, including the personal-data archive the core does provide, is in the native core README, and the API’s open issues #200 and #201 track the native core’s remaining work.

Sources

This page is written from the READMEs, the Project Overview documents and the Vision Documents of fortuna-api and fortuna-ui, checked against the code and the GitHub releases and issues where they differ.