VYNN AI
A personal financial analyst for every investor
founder & sole engineer · 2025–present · 5,000+ registered users
Why it exists
I started VYNN because the research that moves markets is sold by the seat, and the AI tools built to replace it make up their numbers. Individual investors deserve what an analyst gets: the number, the arithmetic, and where every input came from.
What I built
So I built every investor a personal financial analyst. Name a company, a fund, a coin or a prediction market, in any language. VYNN reads the filings and the news, builds the valuation model and writes the report in about two minutes, for about three cents. Code computes every number, and every claim carries its source. I built every part of it and run it myself.
Where it’s going
Next, VYNN stops waiting to be asked. It will watch every portfolio around the clock and tell investors the moment news, earnings or a price move changes the case for what they own.
Open the product (opens in new tab)Company & demo (opens in new tab)Build retrospectiveSource repositories (opens in new tab)
Impact
- 5,000+ investors signed up, from a 500-person pilot.
- Six to twelve hours of an analyst’s research in about two minutes, for about three cents.
- Every release is checked against a set of reference valuations before it ships.
Scroll across to follow the full system
Explore the individual layers
Explore the stack
Research, calculate, then check the claim
A tool-use agent selects financial, market-data, and analysis tools, with specialists for deeper research. Financial statements feed a symbolic valuation engine; model and news work can run in parallel before the report is assembled.
- Calculation
- Code computes valuation and recommendation fields. Sourced market inputs ground the cost of capital; the exported ten-sheet workbook retains its formulas.
- Publication
- Evidence and citation checks gate the narrative. A value the analysts do not back is still published, at low confidence, with an alert that states both positions.
Decisions behind the product
The model never writes a number
A deterministic DCF engine computes the valuation, and a formula evaluator reads the workbook back. The model writes the explanation. A validator rejects any figure that doesn’t match the calculator, and any write-up that cites fewer than 95% of its claims.
It stands by its value
When well-covered analysts disagree, VYNN still publishes its fair value and rating, at low confidence. An alert shows both numbers on the report’s first page, in the workbook and in the chat.
Discount rates from real market data
The cost of capital is built from published rates in the cash flows’ own currency (about 20 currencies), with Damodaran’s risk premiums and a beta measured against the company’s home index. A Tokyo listing is valued in yen, against Japanese rates.
Four repositories, one system
stock-analyst
Research engine · PythonThe research engine. One agent chooses its tools for each question. Four specialist agents do the heavy research, with the model and the news work running in parallel. A deterministic engine owns every number.
Tools chosen per question
A valuation computed in code
Publishing with confidence
Currencies and units
Python · LangGraph · Tool-use agents · Symbolic DCF · MongoDB
api-runner
Control plane · FastAPIThe control plane. Each analysis runs in its own locked-down container from a pinned image. Jobs survive restarts, progress streams live, and every record belongs to one user.
Jobs that survive restarts
Data and caching
Live progress without extra load
Versioned research and synced portfolios
Per-user isolation
Python · FastAPI · Docker · MongoDB · SSE · WebSocket · OAuth · Redis
Private repository
vynnai-web
Product interface · React + TypeScriptThe app: research chat next to a dashboard for companies, funds, crypto and prediction markets. Every number keeps its source, date, currency and confidence on screen.
The alert stays with the number
Prices in the right units
Data fetching and live streams
Missing data shown as missing
React · TypeScript · Vite · TanStack Query · WebSocket · Recharts
Private repository
vynn-core
Shared persistence · PythonShared storage for the API and the research workers. One implementation of article identity, timestamps and connections, so the two services can’t disagree about a record.
One identity per article
Timestamps in UTC
Shared connections
Python · MongoDB · Redis · Canonical URLs · UTC / BSON