FractalMesh / IronVision Nexus · son, real engineering, no buzzword theater
Every payment integration — AI agent or otherwise — has one feature buyers
actually verify before trusting it with money: can it charge me twice?
Not "will it behave." Can it physically fail in the way that hurts people.
The cloud-favorite answer is "webhooks are at-least-once delivery, so make
your handler idempotent." That's a recommendation. This is the enforced version:
Our order ledger stores every event against UNIQUE(event_id)
. The webhook
signature is verified on the raw body; the event_id is the natural key for
that exact charge. If the same event arrives twice — retries, at-least-once
redelivery, a replay, a bug — the second insert hits the UNIQUE constraint and
is rejected, not debited.
Two things happen on a duplicate:
No double bill. Ever. The database enforces it, not a promise in the handler.
An AI agent that moves money does not handle "maybe the SDK throttled, maybe
I retried" gracefully the way a booked-in-advance human flow does. Agents
retry. Agents parallelize. Agents are exactly the clients that hit your
endpoint more than once and need the same answer, once.
Bank-grade idempotency keys are table stakes for agent-to-agent payments: the reader should get idempotent, deterministic settlement without being
asked to "just be careful not to double-submit."
None of this is magic. Our live balance is real — currently -A$462.00
, zero
customers, funnel not yet public. We are not pretending otherwise. The reason
this proof is worth stating is that it's auditable: point a second request
at the same event_id and watch the ledger hold the line.
Sovereign automation. Verified by charge. Zero fabrication.
Built by Sam Hiotis · IronVision Nexus Pty Ltd · ABN 56 628 117 363