Decision Engine

Local-first Windows desktop financial simulation engine.

Decision Engine models monthly cashflow, debt payoff strategies, liquidity risk, and scenario comparisons — all running natively on your machine.

No accounts.
No cloud sync.
No data leaving your computer.

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Overview

Decision Engine is not a budgeting app.

It is a deterministic financial simulator built to answer one core question:

If I make this decision, what happens to my financial stability over time?

The system projects forward month-by-month and exposes where risk appears — not just where balances end up.

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Features

Monthly Cashflow Projection

Projects:

• Income
• Expenses
• Minimum debt payments
• Extra debt payments
• Interest accrued
• Net monthly change
• Ending cash
• Remaining total debt

Debt Strategy Modeling

Supports:

• Avalanche (highest APR first)
• Snowball (smallest balance first)
• Custom targeted payoff
• Adjustable extra monthly payments

Liquidity Risk Signals

Automatically identifies:

• First month cash goes negative
• First month cash drops below buffer
• Worst cash position
• Debt-free month (if achieved)

Scenario Management

• Save scenarios locally using SQLite
• Load and modify previous scenarios
• Compare two scenarios side-by-side
• Measure interest differences and outcome deltas

All data is stored locally.

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Tech Stack

• Tauri (native Windows shell)
• React + TypeScript (UI + simulation engine)
• SQLite (local persistence)
• Rust (Tauri backend)
• Recharts (visualization)

No external APIs. No remote storage.

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Installation (Development)

Clone the repository:

git clone https://github.com/GISMO-1/decision-engine.git
cd decision-engine

Install dependencies:

npm install

Run in development mode:

npm run tauri:dev

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Requirements

• Rust toolchain
• Windows C++ Build Tools
• Microsoft Edge WebView2 runtime
• Node.js 18+

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Build Production Installer

npm run tauri:build

This produces a native Windows installer.

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Model Assumptions

• Monthly time buckets
• Interest = APR / 12
• Deterministic cashflow (no stochastic modeling yet)
• No tax modeling (planned)
• No investment return modeling (planned)

This version focuses on liquidity stability and debt payoff dynamics.

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Roadmap

Planned upgrades:

• One-time expense modeling (shock simulation)
• Income disruption modeling
• Monte Carlo risk simulation
• Investment growth module
• Safe spending calculator
• Objective-based optimization engine

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Philosophy

Markets are uncertain.

Liquidity, leverage, and timing are controllable.

Decision Engine focuses on what you can actually manage.

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License

MIT