VaultRadar architecture

Two diagrams: the system view and the flow of one paid request on the Hedera rail. Rendered PNGs live next to this file (architecture.png, payment-flow.png).

Both diagrams show the designed system. Pieces still in flight at the time of writing are called out in the README's scope notes; the Hedera Harness PR was cut from scope and is not drawn here.

System view

One paid request, Hedera rail

The five phases read as horizontal bands; the numbered steps within each run left to right, the same seventeen messages as before. The dashed boxes are the checks each side performs between messages, on this rail they are the product, not garnish.