Events section

Event Catalog

Learn how payment, risk, identity, card, ledger, provider, ops, and finance events become a reliable contract between services through schemas, retries, replay, and ownership.

4 event flows Replay is controlled recovery Versions protect consumers

Interactive flow lab

Make asynchronous behavior understandable

Switch between event design, delivery lifecycle, event families, and schema change.

High-level sequence

Publish once, fan out to every subscriber

Signed, versioned, idempotent events are the real integration contract between services.

Producer service Event backbone Cards Ledger · Treasury Notifications

1

Producer service→Event backbonerequest

Publish a signed, versioned event with an idempotency key.
2

Event backbone→Cardsevent

Deliver (at-least-once).
3

Event backbone→Ledger · Treasuryevent

Deliver.
4

Event backbone→Notificationsevent

Deliver.
5

Cards⇢Event backboneresponse

Ack — unacked events retry with backoff.
6

Subscriber→Subscriberidempotent

Dedupe by idempotency key so replay stays safe.

Endpoint map

Find the event control point

Filter catalog, schema, subscription, delivery, dead-letter, and replay endpoints.

Concept notes

The event ideas worth remembering

Questions

Check your understanding

Pick an answer and the page will explain the reasoning.