The notebook

Sam keeps the co-op’s records in one notebook. Members have already delivered supplies, the treasurer is away, and the fuel seller needs to be paid. A smudged page is now stopping a real service.

This lesson looks at ways to keep a record that more than one person can inspect. A shared ledger is a record held or checked by several parties under agreed rules. A cryptocurrency is a digital token recorded by software; it is one possible tool, not a requirement for a shared ledger.

Harbor Co-op does not need to create a new token. It needs a reliable record of deliveries, amounts owed, and a way to authorize payment to the fuel seller.

The problem is not the handwriting. The problem is that one person and one notebook are the only source of the record.

A common mistake is to start by designing a token. Start with the payment and the record that must support it.

Next, consider what changes when the co-op can share the record.