MathTree

Real-estate underwriting and property operations for an owner-investor. Underwrite a deal, track it through the pipeline, run it once it is owned, and compare it with what was expected. Every number on screen is either a fact the owner stated or an assumption the owner can explain to a lender; the app never invents an input.

Live app: mathtree-app.web.app

What it does

• Dashboard. Owned holdings and the acquisition pipeline, with portfolio totals for what is owned.
• Deal studio. One page per property. Prospects show the underwriting (overview, pro-forma, property, debt, diligence, sensitivity); owned properties open on performance and add an Operate tab (rent roll, payments, recoveries, CAM).
• Engine. One shared calculator: projections, debt, taxes and depreciation, IRR and NPV, sensitivity, Monte Carlo, remodel plans, refinance. The database stores facts only; results are computed on demand.
• Investor profile. Your underwriting standards (vacancy, expenses, reserves, utilities, property tax rate, appreciation, exit cap, selling costs, closing time) by asset class. They are starting points for screening, copied into a deal only where it is silent. Nothing is fixed: a new profile starts with common conventions (a six-week closing, for example), you can change any of them globally in your profile, or individually on any single property. A property's own figure always wins; the rest keep following your profile.
• Inputs needed. When a deal lacks something the engine requires, the app lists exactly what, instead of guessing.
• Compare. Side-by-side boards of deals and scenarios, with charts and saved views.
• Operations. Rent roll, payments, escalations, NNN recoveries and daily reminders across owned properties.
• Briefs. Printable deal and portfolio PDFs computed from the same engine.

Asset classes: single-family, multi-unit, commercial (gross and NNN), and storage.

Stack

React 18, Vite, TypeScript, Tailwind, Chart.js. Supabase (Postgres with row-level security, Deno edge functions). Firebase Hosting; GitHub Actions build every pull request and deploy on merge to main.

Working on it

npm install
npm run dev        # local app
npx tsc --noEmit   # type-check
npx vitest run <file> --reporter=dot   # one test file at a time

The printed briefs have their own layout check. It prints the investor brief and the lender summary to real PDFs in headless Chromium (on the public sample deal, read-only) and fails if any page spills past a sheet or a sheet is nearly empty. It needs a Chromium once per machine:

npx playwright install chromium   # one time
npm run test:brief                # prints the PDFs to a temp folder (the path is shown) and checks them

Read ARCHITECTURE.md for how it fits together and AGENTS.md for how changes are made (branches and pull requests only, no full-suite test runs, no plan documents in the repo).