PACT update: first real PayPal Sandbox payment, end to end
PACT is a financial governance runtime for AI agents. It sits between an agent and the payment provider and decides whether a payment may happen, under which limits and with whose approval.
This week it ran its first full governed purchase on the PayPal Sandbox:
- Claude Code asked to buy a $79 mechanical keyboard through MCP.
- PACT's policy engine required human approval, because the amount was above the user threshold.
- I approved the exact order in the admin dashboard.
- PACT issued a single-use grant bound to that order, merchant, amount and currency.
- PayPal Sandbox captured the payment, and PACT recorded the capture id.
- The audit log, a hash chain of 459 events, verified as intact.
What's new since the last update:
- Admin dashboard: overview, approval centre showing every policy finding, policy editor and an audit explorer.
- Merchant Lab storefront: catalogue, a live cart that updates while the agent shops, and an order page that walks through approval, grant and payment as it happens. You can also buy as a human, governed by the same PACT rules.
- Shared budgets: several agents draw from one org budget, so the last request is denied by the global budget even when it is within its own agent's cap.
- Replay and tamper protection: a reused grant or a changed order is rejected and audited.
- Tests and security: 1,256 tests, end-to-end acceptance tests that run the real PayPal adapter against a mock, and a security test matrix with a threat model.
- PayPal fixes: handling for expired orders, capture errors and abandoned checkouts.
No agent tool can approve a payment. The AI proposes, and deterministic code decides.
PACT is a sandbox reference implementation and processes no real money. Code: https://github.com/MohanPrasand/PACT
Next: tightening the remaining security findings, deployment, and more payment providers behind the same adapter interface.