Composing domain-specific harness on Python in 10 mins

A domain-specific agent needs its business rules implemented around the model. The Cayu walkthrough illustrates this with a fictional university dining purchase: whole potatoes cost less but take longer to prepare, so with reduced kitchen staffing the peeled option is the one that fits. Python tools calculate quantities, cost and preparation time; the model compares the options and explains the tradeoffs. Submitting an order requires approval of the exact proposal, after which the application rechecks the plan, policy, product facts and stock before writing a receipt, and the agent reads that receipt to verify the purchase. The walkthrough calls the harness the domain-specific system of instructions, tools, knowledge, policies and approval rules assembled around the model, turning a purchasing conversation into a controlled sequence of actions.