Overview of Spend

Spend is a comprehensive multi-user personal finance and cash flow management platform, aimed at absolute arithmetic accuracy and high security experience. The core difference of Spend is its operation on a non-floating-point arithmetic architecture (BigInt), completely eliminating errors when calculating balances, transactions, and currency conversions.

Core Features

• Asset Management & Multi-Currency:

  • Track diverse accounts: Banks, E-wallets, Cash, Credit cards, and virtual accounts (Accounts Receivable/Accounts Payable).
  • Supports 12 standard currencies (VND, USD, EUR, USDT...) along with custom currencies; automatically saves historical exchange rates when converting.

• Consolidated Financial Goals:

  • Spending Limit: Budget cap according to monthly categories.
  • Savings Goals: Automatically calculates the amount needed to save each month and forecasts completion time.
  • Earmarking: Links accumulated funds to a specific wallet, accurately counting the actual amount available for spending (Available = Balance − Allocated) and alerts when the earmarked amount exceeds the actual balance.

• Commitment Center (Invoices & Debt Management):

  • Automatically tracks recurring bills, compensates missed cycles via cron jobs, and reminds through Web Push.
  • Manages loaned/borrowed amounts with gradual repayment schedules on dedicated virtual accounts.

• Group Money & Trips:

  • Create a shared expense ledger, split money in real-time, and invite through QR code/link with detailed permissions.
  • Smart settlement algorithm (automatically rounds), records actual payments, supports virtual members, and exports "Trip Story" images in 1080×1920 for sharing.

• AI Data Entry & Natural Language (Spend Agent):

  • Recognizes Vietnamese/English commands (e.g., "Eating beef noodle 45k in Momo wallet") to create instant transactions.
  • Multi-tier architecture (Internal Rules → Gemini NLP/Tool Calling) handles both split transactions, recurring transactions, and balance inquiries.

• Reports & In-Depth Analysis:

  • Visualizes cash flow and spending structure through Recharts (bar, pie, line).
  • Filters flexibly by time frame, each expense ledger, or each separate currency.

• Security & Privacy:

  • SSO authentication via JWKS (stateless JWT) and JIT Provisioning.
  • Protected by a secondary PIN (4/6 digits) encrypted scrypt, proxy fail-closed, along with a one-touch mode that hides sensitive amounts on the screen.

• Data, Notifications & Experience:

  • Web Push notifications via VAPID (deduplication, bilingual support).
  • Exports Excel-compatible CSV, JSON backup/restoration, data recovery trash can, and detailed activity logs.
  • Supports bilingual Vietnamese & English, dark-first interface, shortcut ⌘K, and is ready to run as PWA on all devices.