Investment Copilot
A personal finance system that tracks investment allocation against targets and market benchmarks, and syncs expenses automatically via Brazil's Open Banking APIs.
Sole developer — end-to-end product and implementation, from data model to UI to the AI reporting layer.
TypeScript · Next.js 16 (App Router) · MySQL · React Query · ECharts · Vercel
$0/mo
§ 01Context
Managing personal investments and expenses meant juggling several bank and brokerage apps plus manual spreadsheets. No single place showed whether the portfolio matched its target allocation, how it was performing against CDI, Ibovespa, IPCA and the S&P 500, or where money was actually going month to month. Re-entering transactions and recalculating allocation drift by hand didn't scale, and it was easy to miss when an asset class had drifted far enough to need rebalancing.
§ 02What I built
A dashboard covering two connected areas: an investment tracker that compares live portfolio allocation against target weights, flags deviations, and benchmarks monthly performance against CDI, Ibovespa, IPCA and the S&P 500; and an expense tracker that pulls transactions automatically from bank accounts and credit cards through Brazil's Open Banking (Open Finance) APIs and auto-categorizes them with rule-based classification. On top of both, a monthly report is generated by an LLM agent that reads the underlying data and writes a structured summary, with no separate paid API integration behind it. A shareable view also lets me show the dashboard to others without exposing real balances.
§ 03Outcome
The dashboard has been in continuous monthly use since late 2025, replacing manual tracking with automatic expense sync and computed allocation alerts. It currently surfaces a persistent ~21pp gap in inflation-linked bonds versus target, the kind of drift that's easy to miss without a computed alert. The AI reporting pipeline runs at zero recurring cost, and the shareable view means the project can be shown and discussed without exposing real financial data.