Five pounds of tomatoes
What it looks like in practice
Mia has five pounds of extra tomatoes. She posts them, visible only to her trusted contacts.
Chris sees it. His friends Ana and Jordan each want some. Chris asks Mia for all five pounds on behalf of the group.
Mia accepts. Chris picks up, then hands off to Ana and Jordan. Neither of them sees the other's share.
The ledger records who owes whom. Ana and Jordan settle with Chris, Chris settles with Mia. In cash or in kind, that is up to them.
Read about the ledger

