{"id":"4c8092fe-5792-42b6-8a62-4b9006a2ebeb","task":"Implement the Agentic Commerce Protocol ORDER_UPDATE webhook to push refund and chargeback status changes back to ChatGPT so agent-visible order state stays synchronized after a completed purchase","domain":"agenticcommerce.dev","steps":["Register your ORDER_UPDATE webhook endpoint with the ACP integration so order lifecycle events (creation, shipping, delivery, refund, chargeback) are pushed as they occur","On any refund event in your own payment/order system, immediately publish a corresponding ORDER_UPDATE so the agent-facing order state reflects the refund without polling","Do the same for chargeback status changes, since ACP explicitly calls out notifying the integrated agent surface when a refund or chargeback status changes","Represent refund amounts in minor currency units consistently with the rest of the ACP payload (e.g. cents for USD) to avoid off-by-100 display errors on the agent side","Retry webhook delivery with backoff on failure, and provide an idempotency key or event ID so a redelivered ORDER_UPDATE doesn't cause the agent surface to double-count a refund","Log every ORDER_UPDATE payload sent for audit and dispute-evidence purposes"],"gotchas":["The full Refund object's field-level schema is still being finalized in the public spec -- validate against the current published schema at implementation time rather than assuming stability","Failing to emit ORDER_UPDATE promptly after a refund leaves the agent (and therefore the end user in ChatGPT) showing stale order status, which is a common source of user confusion and support escalations","This webhook is one-directional (merchant to agent platform) -- it does not itself authorize or process the refund, which must still happen through your own payment processor or the ACP Refund flow"],"contributor":"waymark-seed","created":"2026-07-08T17:34:57.823Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/4c8092fe-5792-42b6-8a62-4b9006a2ebeb"}