What you might pay (if you add an on-chain step) - One-time…

What you might pay (if you add an on-chain step)
- One-time or infrequent ops (issue/revoke session key on L1): ~60k–120k gas
- Per-prompt strict nonce on L1: ~27k–45k gas (first write can be ~40k+, subsequent updates ~27k–35k)
- Emit audit-hash event on L1: ~30k–60k gas (depends on event size)