Hotkey Swap On Subnet Interval
Hotkey swap on subnet interval is the per-subnet rate limit a hotkey swap must satisfy, named in the
documentation as HotkeySwapOnSubnetInterval. The rate-limits reference lists it as the per-subnet
portion of the hotkey swap rate limit, at roughly 36,000 blocks or about five days
(Rate Limits).
What It Controls
A hotkey swap replaces the hotkey tied to an account’s stake and registrations. The documentation states a swap must satisfy two separate rate limits: a short network-wide transaction limit and this longer per-subnet interval. This interval sets how long must pass on a subnet before a hotkey can be swapped there again (Rate Limits).
Beyond the interval, a per-subnet hotkey swap also carries a fixed cost. The constants reference
lists keySwapOnSubnetCost as 1,000,000 RAO, which is 0.001 TAO, and describes it as the cost of
swapping a hotkey in a subnet, so a per-subnet swap is gated by both that documented cost and this
interval cooldown
(Subtensor Constants).
When It Matters
The common misconception is that clearing the fast network-wide tx rate limit, which lifts after about a block, is enough to swap again. On a subnet it is not: this per-subnet interval still blocks a repeat swap for roughly five days (Rate Limits).
Concretely, an operator who swaps a validator’s hotkey on netuid 1, then realizes the new hotkey is also wrong, cannot immediately swap it again on netuid 1. The network-wide limit clears within a block, but netuid 1’s swap interval must elapse first, so the corrected swap waits out the roughly five-day window. That waiting cost is the point: it makes rapid hotkey rotation on a subnet expensive enough to discourage churning hotkeys to game participation (Rate Limits).
Documented Nature
The Rate Limits reference describes
HotkeySwapOnSubnetInterval as a global interval constant rather than a per-subnet owner setting,
and notes it is not queryable from chain state the way mutable hyperparameters are. The same fixed
interval governs the per-subnet swap cooldown across subnets, evaluated against whichever netuid a
swap touches (Rate Limits,
Bittensor Networks).
Distinction from Tx Rate Limit
Tx rate limit is the short network-wide transaction limit that also applies to hotkey swaps. Hotkey swap on subnet interval is the longer per-subnet cooldown, and a swap must clear both (Rate Limits).
- Tx rate limit — short network-wide transaction cooldown.
- Hotkey swap on subnet interval — longer per-subnet hotkey-swap cooldown.