Lab 4 · Under the hood: accounts & your first transaction

MilesVault is an operating system for your points and miles — and like any OS, it runs on something underneath. That something is a plain-text beancount ledger: the source of truth for every point, mile, and rupee you track. The AI writes it for you, but it's always yours — you can read and edit every line.

This lab makes you fluent in the basics by having you write them yourself:

• The one rule behind double-entry bookkeeping
• The five kinds of accounts
• How to open your own accounts by hand
• How to record a transaction as text — and what makes it valid
• How the AI produces the exact same beancount, so you can trust and check its drafts

By the end you'll have a real account and a real transaction in your ledger — typed by you.