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Carlos Guzman

Fibrant

A multi-currency investment tracker with a multi-model AI analyst, built as a DeepSpace project.

Fibrant dashboard for the demo portfolio US Growth: total value, gains, returns and a chart of portfolio value over time.
Fig. 1 — The Fibrant dashboard, shown with a demo account and made-up data.

Problem

A portfolio held in US dollars and Mexican pesos is easy to measure wrong: deposits and withdrawals distort simple percentages, and every figure moves with the exchange rate. Fibrant tracks investments in both currencies with returns calculated properly, and adds an analyst you can ask about your own holdings.

My role

I'm the main developer of Fibrant, a DeepSpace project. My work spans the database and its access rules, the AI analyst and the interface.

Approach

  • AI analyst. You choose the model: Claude, ChatGPT or Gemini. The analyst reads the portfolio through tool use instead of guessing, keeps a memory per portfolio, and runs on a static system prompt designed to stay cache-friendly. Usage is metered in credits by tier.
  • Returns. Time-weighted returns and XIRR are calculated with decimal.js, so money math doesn't pick up floating-point error, and values convert between USD and MXN.
  • Access. Supabase row-level security decides who sees what, including portfolios shared with other users.
The AI analyst's tool useA question goes to the model you choose: Claude, ChatGPT or Gemini, with usage metered in credits by tier. The model runs on a static, cache-friendly system prompt and the portfolio's own memory, and reads the portfolio through tool use, from Supabase behind row-level security, before it answers.Your questioncredits by tierModel selectorClaude · ChatGPT · GeminiSystem promptstatic, cache-friendlyMemoryone per portfolioTool usereads the portfolioSupabaserow-level securityAnswer
Fig. 2 — How the analyst answers: the model you choose reads the portfolio through tool use.
A Fibrant AI analyst conversation: a request for a health check of the US Growth portfolio, answered with a table of market value, cash, invested capital, gains, dividends and open positions.
Fig. 3 — The analyst answering a health-check question about the demo portfolio.

Outcome

Fibrant is launched at fibrant.app.

Code walkthrough available on request.