01 / The operating case
What changes in a real workflow?
A coordinator assigns ten children to retry the same $8,000 payment.
- 01Origin grant
- 02Parent agent
- 03Narrow child grant
- 04Action boundary
02 / Decision contract
What the executor must check
Give children narrower grants and share an atomic payment budget and idempotency key at the executor.
InputPrincipal · task · action · target
DecisionGrant ancestry · policy · current state
ResultEnforce · record · verify outcome
03 / Failure and evidence
What goes wrong, and what can be proven?
Failure mode
Each child independently holds the full parent ceiling and the group spends ten times the approved amount.
Evidence to retain
Child grants, budget reservations, retries, payment IDs and reconciled total.
04 / Canonical scope
Why this reference stands alone
Shared budgets explains accounting; this page owns fan-out as a delegation pattern.
Technical artifact
Fan-out against one aggregate ceiling
parent budget: USD 25,000 child A reserves USD 20,000 child B concurrently requests USD 20,000 remaining: USD 5,000 B: DENY, not a second independent allowance
Run the denial test
Run A and B in separate processes with a barrier at reservation. The sum of committed and unresolved reservations must stay within the parent ceiling.
Primary references