HotkeySwappedOnSubnet

Event Re-added v276 → v277, v290 → v315, v320 → v326, v334 → v367, v372 → v377, v385 → current #100

Emitted for each subnet when a hotkey swap occurs.

Useful for: minersvalidatorssubnet ownersanalytics

The Big Picture

When a hotkey is swapped, the registration needs to update on each subnet where that hotkey was registered. This event fires once per subnet, confirming the subnet-level records are updated. Your UID stays the same, but the hotkey address associated with it changes. This is the granular view of what HotkeySwapped accomplished.

Why This Matters

If you're swapping a hotkey that's on multiple subnets, you want confirmation for each subnet. This event provides that - one event per subnet showing the hotkey swap was recorded there. If you see HotkeySwapped but not HotkeySwappedOnSubnet for a subnet, something may be wrong.

Example Scenario

You're swapping a hotkey registered on subnets 1, 3, and 7. During the swap, you see three HotkeySwappedOnSubnet events: one for netuid 1, one for netuid 3, one for netuid 7. Each confirms your UID on that subnet now points to your new hotkey address.

Common Questions

Do I get one event per subnet automatically?: Yes, the runtime emits one HotkeySwappedOnSubnet for each subnet where the old hotkey was registered. You don't need to do anything special.
What if I'm missing an event for a subnet?: Check if the hotkey was actually registered there. If it wasn't, no event would fire. If it was and there's no event, investigate - the migration may have partially failed.
Does this mean my miner/validator is still running?: This updates the chain's records. Your actual miner/validator software needs to be updated with the new hotkey independently. The chain knows the new identity; your software needs to use it.

Use Cases

Track hotkey migration across specific subnets
Verify registrations transferred correctly per subnet
Monitor subnet-level identity changes
Build per-subnet hotkey tracking tools

How to Use This Event

→ Monitor for each subnet you operate on during hotkey swap
→ Track per-subnet migration for verification
→ Build detailed migration audit trails

From Chain Metadata

the hotkey is swapped

Triggers

Emitted by

swap_hotkey

Preconditions

Hotkey swap is in progress
Hotkey was registered on this subnet

Effects

Storage Modified

Alpha Axons ChildKeys ChildkeyTake Delegates IsNetworkMember Keys LastHotkeySwapOnNetuid NeuronCertificates OwnedHotkeys Owner ParentKeys Prometheus StakingHotkeys TotalHotkeyAlpha TotalHotkeyShares Uids

Postconditions

Subnet-specific registrations updated

Side Effects

UIDs preserved across swap

Event Data

#	Name	Type	Description
0	coldkey	AccountId	Cold wallet address (offline storage) (hex -> SS58)
1	old_hotkey	AccountId	old_hotkey (AccountId) (hex -> SS58)
2	new_hotkey	AccountId	new_hotkey (AccountId) (hex -> SS58)
3	netuid	u16	Subnet/network identifier (0-65535)

Code Examples

import { ApiPromise, WsProvider } from "@polkadot/api";
import { stringCamelCase } from "@polkadot/util";

const provider = new WsProvider("wss://entrypoint-finney.opentensor.ai:443");
const api = await ApiPromise.create({ provider });

// Subscribe to HotkeySwappedOnSubnet events
api.query.system.events((events) => {
  events
    .filter(({ event }) =>
      event.section === stringCamelCase("SubtensorModule") &&
      event.method === "HotkeySwappedOnSubnet"
    )
    .forEach(({ event }) => {
      console.log("HotkeySwappedOnSubnet:", event.data.toHuman());
    });
});

Version History

Version:

v276 block 5,781,672 4 args

v290 block 5,947,548 4 args

v320 block 6,523,566 4 args

v334 block 6,811,690 4 args

v372 block 7,430,358 4 args

v385 block 7,782,670 4 args Current

Runtime Info

View Source

Pallet Index: 7
Event Index: 100
First Version: v276
Current Version: v393

Back to SubtensorModule Events