What is idempotency?
An operation is idempotent when performing it repeatedly produces the same result as performing it once. In APIs this is usually achieved with a client-supplied key that the server uses to recognise and collapse duplicates.
It matters wherever a network can fail after the server acted but before the client heard back. Without it, the safe behaviour — retrying — becomes the dangerous one.
For agents the stakes are higher, because retries can be automatic and the actions can be consequential. Charging a card twice because a stream dropped is a failure of plumbing, not of intelligence.
Run creation requires an idempotency key, and assertion identifiers are single-use so a replayed exchange is rejected rather than honoured twice.
Related terms
- Audit trail — A durable record of what a system did, who caused it, and what it touched — sufficient to reconstruct events afterwards.
- Tool calling — The mechanism by which a language model requests that a specific function be run with specific arguments.
See it working rather than described.
The product demo runs one agent across three systems and stops at the approval gate.