Idempotency

Idempotency keys prevent duplicate side effects when agents or clients retry write operations.

result = client.invoke(
    "refund_user",
    {"user_id": "u_1", "amount": 100, "reason": "duplicate"},
    idempotency_key="refund-u_1-001",
)

REST callers can send:

• Idempotency-Key
• X-Idempotency-Key
• idempotency_key in the JSON body

The key is scoped by:

• tool name
• actor
• key

If the same actor/tool/key/arguments are used again, ToolRampart replays the stored result with replayed: true.

If the same key is reused with different arguments, ToolRampart returns idempotency_conflict.