The Merchant's Window

Night has fallen on a small shop. A customer paid a deposit for a custom order, and the supplier will not release the materials until someone sees the money really landed. His auditor stands at your counter with a written ask, and only your key can show the payment. The rows you will read are real testnet payments, pulled live from the chain.

What it teaches

Your key is a viewing key. It reads only the money arriving at one account: the amount, your address, the payer's message, the time and the block. It never names who paid, it never shows money leaving, and it can never spend a coin. Reading and spending are two separate secrets. One payment can also be proved on its own, without handing over the key that reads the whole account.

What you will see

A counter under one lamp, a record board of real payments, a till with a keyhole, a brass key, the auditor holding a folded letter, and a dark window on the far wall.