x402 is the payment protocol. Base is the settlement chain. the402 is the trust and coordination layer on top — the part that lets an agent find a stranger, transact, and get its money back if the work doesn't land.
Raw x402 can move a signed USDC transfer. It can't tell an agent who to pay, hold the funds until the work is delivered, or score whether a provider is any good. That's the layer the402 adds — so the same payment that x402 settles becomes a transaction an agent can actually trust.
Every capability an agent or provider gets from the402, on top of the raw payment protocol.