agent wallet

On the card side the wallet keeps the credential and issues a scoped grant instead of it. Stripe's documentation describes shared payment tokens as scoped grants that let an agent use a customer's payment method, each carrying usage and expiration limits, issued from a wallet built for agents. That wallet's own description is that payment credentials are never exposed, and that each purchase is confirmed by the person in the wallet's app. Finer-grained spending controls are listed as not yet available.

On the stablecoin side the wallet is a signing key. Under x402's exact scheme the agent signs an authorization for a stated amount to a stated address, and the signature is what travels. The funds move when a facilitator submits that authorization. The limit is the authorization itself — an amount, a recipient and a validity window — rather than an approval step at the moment of spending.

The two models put the control in different places, which is worth knowing before either is handed a budget. A wallet that confirms each purchase can decline one. An authorization that has already been signed is a signature somebody else can submit, and what arrives at the endpoint either satisfies the quoted terms or does not.