Diagrams that move.

---
title: Checkout request
---
flowchart LR
  client([Browser]) --> gw[API Gateway]
  gw -->|verify| auth[Auth]
  gw --> orders[Orders]
  orders --> db[(Postgres)]
  orders -.-> queue{{Queue}}
  queue --> mail[Email worker]
  subgraph backend [Backend]
    auth
    orders
    db
  end

scenario Happy path
  client -> gw : POST /checkout
  gw -> auth : token
  auth is done
  gw -> orders
  orders is active
  orders -> db : insert
  db is done
  orders -> queue, orders -> gw
  note orders : Order #42 created
  queue -> mail : receipt
  mail is done
  gw -> client : 201 Created
  orders is done

scenario Token expired
  client -> gw : POST /checkout
  gw -> auth
  auth is error
  note auth : JWT expired
  gw -> client : 401
  client is warn