🔧 Canary Agent Tool Calls With Duplicate Deliveries and an Idempotency Gate

The counterexample first


Here is an event order that a surprising number of agent runtimes produce under a perfectly ordinary network hiccup:



t1: agent -> toolservice: charge_customer(order=91, amount=40)
t2: toolservice: executes charge, txn=TXN-441
t3: toolservice -> agent: ACK lost (gateway timeout at the proxy)
t4: agent runtime:...