The Churn
Whereas the mesh is the accessible state of the players, their identity and functional relationships as the history of the wealth-acknowledgments between them, the "churn" is the process by which new entities are added to the mesh and by which existing entities become further enmeshed. This "enmeshment" is the result of discrete events. Thus the mesh is the "nouns" of the open money world, whereas the churn is its verbs. There are just a handful of events, and they can be seen as procedure calls with parameters.
Create Namespace: parameters: new namespace name, parent namespace
Create Account: parameters: new account name, parent namespace
Create Currency: parameters: new currency name, currency specification, parent namespace
Join Currency: parameters: account, currency
Acknowledge Flow: parameters: declaring account, accepting account, flow specification