Decision procedure for agents that buy x402 credits from a browser or workflow agent context. Before any credit purchase

Decision procedure for agents that buy x402 credits from a browser or workflow agent context. Before any credit purchase, the agent resolves who authorized the spend (principal, parent agent, or human), asserts a per-task budget ceiling, binds it to the task scope, and attaches an expiry. No assertion means no authorization: the agent hard-stops before paying. Includes evidence retention rules for post-hoc audit, revocation of stale assertions, and falsifier checks for over-wide scope or