Cache

Personal wealth ledger. Track net worth across asset and liability categories with AES-256-GCM encryption and local-only data storage.

Single HTML file. No build system, no dependencies, no server. Open it in a browser.

Features

• 13 asset & liability categories: real estate, stocks, Bitcoin, retirement, cash, mortgages, auto loans, credit, student loans, BTC-backed loans, and more
• AES-256-GCM encryption with PBKDF2-derived keys; data encrypted at rest in localStorage
• Auto-lock: 15-minute idle timeout clears the session key and wipes data from memory
• Live BTC price from CoinGecko (fallback: Coinbase); Bitcoin values stored in satoshis
• BTC-backed loan tracking with LTV alerts, collateral aggregation, and auto-calculated outstanding balances
• Real estate valuations via RentCast AVM integration
• Multi-currency support: USD, EUR, GBP, CAD, AUD, CHF, JPY with live exchange rates
• Net worth chart via Chart.js (assets vs. liabilities)
• Bookmarklet to auto-scrape account balances from financial institution websites
• PWA install for standalone app experience on desktop and mobile
• Dark and light themes
• Mobile-friendly responsive layout
• Guided onboarding tour for first-time users
• JSON export and import for backup and restore

Getting started

# Clone and open
git clone https://github.com/peerloomllc/cache.git
cd cache
xdg-open cache.html    # Linux
open cache.html         # macOS
start cache.html        # Windows

Or just double-click cache.html. No install required.

On first launch, set a password. This derives your encryption key. You can change your password later in Settings, but there is no reset or recovery if you forget it.

How it works

All data stays on your device. The only network requests are:

Request	Purpose
CoinGecko / Coinbase API	BTC/USD price
frankfurter.app	Currency exchange rates
RentCast API	Property valuations (requires your own API key)

Data storage

• cache-v1-enc in localStorage: AES-256-GCM ciphertext of your data
• cache-v1-meta in localStorage: PBKDF2 salt (not secret)

The password is never stored. The derived CryptoKey is held in memory only and cleared on lock or idle timeout.

Architecture

Everything lives in one file (cache.html, ~3000 lines):

Section	Purpose
CSS	Dark/light themes, grid layout, animations
HTML	All UI markup
JS: Encryption	AES-256-GCM, PBKDF2, session management
JS: Categories	Metadata and account type options per category
JS: BTC price	CoinGecko / Coinbase API calls
JS: Row CRUD	Entry management and DOM rendering
JS: Calculations	Totals, interest, Chart.js integration
JS: Persistence	Save, load, export, import

Security model

• AES-256-GCM with PBKDF2-derived keys (310,000 iterations, SHA-256)
• No plaintext ever hits disk; data is encrypted before writing to localStorage
• 15-minute idle auto-lock destroys the in-memory key
• No server, no cookies, no analytics, no telemetry

License

Copyright PeerLoom LLC. All rights reserved.