Session-Scoped Payment Authorization

Problem

Per-transaction human approval does not scale to an agent making hundreds of micropayments a minute, but handing the agent an open-ended wallet exposes the user to runaway or adversarial spend. The system needs a unit of authorization larger than one transaction yet bounded enough that a compromised or looping agent cannot drain funds.

Solution

Introduce a session as the authorization boundary for spend. When the agent begins a paid workflow, it opens a session and the wallet (or a governance layer) pre-authorizes a maximum amount and possibly a time-to-live. Inside the session the agent streams micropayments to services without further approval, each debited against the remaining cap; when the cap is reached the session blocks or escalates. On completion the session closes and settles once, reconciling the streamed payments. The cap, TTL, and per-recipient limits are the safety envelope; the agent's freedom exists only inside it. This is the session model emerging in machine-payment protocols layered over x402, AP2, and ACP.

When to use

• An agent makes frequent micropayments that cannot each be human-approved.
• You need a hard ceiling on autonomous spend per workflow.
• Settlement is cheaper or cleaner done once per session than per payment.
• The payment rails support pre-authorization and held caps (x402, AP2, ACP).