# Leger_OS – Personal finance mainframe with paycheck cycle burn modeling

> Source: <https://github.com/tiago-quinha/LEGER_OS>
> Published: 2026-08-27 01:49:22+00:00

Empirical Liquidity Engine & Zero-Credential Financial Intelligence

IMPORTANT:LEGER_OS is architected primarily as a mobile-first operating system(Android Native`.apk`

/ Mobile Progressive Web App).The core automation capabilities—such as

Zero-Credential Android Push IngestionandiOS Apple Wallet Automations—require a mobile device to capture real-time payment events. Desktop browsers are fully functional for deep ledger audits, but mobile is the primary intended form factor.

**Web Application / PWA:**[https://leger-os.vercel.app](https://leger-os.vercel.app)(Install via Safari / Chrome*"Add to Home Screen"*)**Android Native APK:**[Download Direct APK](https://leger-os.vercel.app/downloads/leger-os.apk)

Traditional personal finance applications (YNAB, Monarch, Copilot) charge **$70–$120/year** while relying on third-party Open Banking aggregators (Plaid, Salt Edge, GoCardless). In practice:

**High Sync Failure Rate (~22%):** Bank API connections routinely break, requiring constant re-authentication.**Privacy Vulnerabilities:** Users must hand over banking login credentials to foreign third-party intermediaries.**Rigid Calendar Slicing:** Incumbents force tracking into calendar months (Day 1–31), ignoring real-world bi-weekly, 4-week, or irregular salary deposit cycles.

**LEGER_OS eliminates aggregators entirely** by replacing them with local device-level notification listeners and webhook automations.

- Uses a custom Capacitor Java plugin (
`LegerBankSyncPlugin`

) with a native`NotificationListenerService`

. **Zero Storage:** Payment push notifications are processed in device memory via deterministic regex parsing to extract merchant, amount, and currency. The raw text and any PII/OTPs are discarded immediately.**Agnostic to Any Bank:** Supports any banking application, digital wallet (MB WAY, Apple Pay, Google Wallet), fintech (Revolut, Wise, N26), or broker (XTB, Trade Republic) installed on your device.

- Provides a secure, private webhook endpoint (
`/api/transactions/device-push`

). - Integrates directly with native Apple Shortcuts automations triggered upon Apple Pay transactions with zero cloud credential sharing.

Future liquidity is projected daily using statistical analysis rather than static historical averages:

-
**Recency Decay Weighting (** Spending velocity applies exponential time-decay weighting (~6-day half-life), prioritizing recent spending momentum over older expenses.$\lambda = 0.12$ ): -
**Heavy Current Cycle Alpha (** Forecasts favor the active paycheck cycle over distant historical baselines:$\alpha \ge 0.65$ ):$$\alpha = \min(1.0, 0.65 + 0.35 \cdot (\text{days elapsed} / \text{total days}))$$ -
**Zero Synthetic Interpolation:** Plotted charts only map executed transactions or verified market ticks—never synthetic linear price interpolations.

Integrated neural interface supporting custom API keys and local offline inference:

**Google Gemini**(`gemini-2.5-pro`

)**OpenAI**(`gpt-4o-mini`

)**Groq**(`llama-3.3-70b-versatile`

)**Local Ollama**(100% free local offline inference without external API tokens)

**Frontend:** Next.js 16.2 (Turbopack, App Router), React 19, Tailwind CSS 4, Lucide Icons, Recharts, Framer Motion.**Backend & Database:** Supabase (PostgreSQL with Row Level Security, Storage, Realtime).**Mobile Runtime:** Capacitor 6 with native Android Java bridge.**AI Bridge:** Multi-provider client wrapper with fallback heuristics.**Hosting:** Vercel Edge Runtime & Serverless Functions.

**Zero Bank Logins:** LEGER_OS never asks for, stores, or transmits your banking credentials.**Encrypted Transmission:** All telemetry and database queries are transmitted over 256-bit SSL encryption.**Isolated Multi-Tenant Storage:** Secured by PostgreSQL Row Level Security (RLS) policies isolating user records strictly to authenticated IDs.

Copyright © 2026 LEGER_OS. All Rights Reserved.

LEGER_OS is source-available software provided under a **Strict Proprietary License**.

**Allowed:** Personal, non-commercial educational review, local evaluation, and security auditing.**Prohibited:** Commercial use, public hosted SaaS/cloud deployments, re-licensing, distribution, mobile app store republishing, or creating unauthorized commercial forks/derivatives.

For full terms and conditions, see the [LICENSE](/tiago-quinha/LEGER_OS/blob/master/LICENSE) file.