one-time-service — one delivery for one payment: hired once, delivered once, accepted or disputed, paid once (ext agentic-product-commerce)
subscription-product — a product paid by the period: each period is one sale through the same hops; the hold covers the period (ext agentic-product-commerce)
bid-job — a job posted by the buyer and bid on by sellers: the accepted bid is the price, the delivery is the job (ext agentic-product-commerce)
listed-agent — an agent listed at its own price on a market: the buyer hires it by the job; the listing keeps its price (ext agentic-product-commerce)