SetChildrenScheduled

Event Re-added v216 → v219, v233 → v247, v252 → v265, v273 → v277, v290 → v315, v320 → v326, v334 → v367, v372 → v377, v385 → current #73

Emitted when a child hotkey change is scheduled for future execution.

View events on chain

Useful for: validatorsdelegatorssubnet ownersanalytics

The Big Picture

Child key changes aren't instant - they're scheduled in advance to protect delegators. If a validator could instantly redirect rewards to new addresses, delegators might be caught off guard. The schedule delay (typically days) gives everyone time to review the change and adjust their delegation if they don't like it. This event is the 'heads up'.

Why This Matters

As a delegator, you deserve to know when your validator plans to change their reward structure. This event tells you: 'In X blocks, the children will change to Y.' If you don't like the new arrangement, you have time to move your delegation.

Example Scenario

You're delegated to Validator Z. SetChildrenScheduled fires showing: Validator Z will add a new 40% child in 3 days. Currently Z keeps 100%, but soon 40% goes to the new partner. You can decide: Is this partner legit? Do I trust this change? You have 3 days to unstake if you want out before the change.

Common Questions

Can the schedule be cancelled?: Typically yes, before execution. Check the specific implementation. The parent can cancel their own scheduled change during the delay period.
What happens if I don't react to a scheduled change?: The change executes automatically after the delay. Your stake stays with the validator, but rewards will be split according to the new child key arrangement.
How long is the delay?: Check the SetChildKeyScheduleDuration constant. It's designed to give meaningful notice - typically hours to days, not minutes.

Use Cases

Schedule changes to reward distribution with advance notice
Detect when validators plan to change their child key structure
Give delegators time to react before changes take effect
Track pending organizational changes to validators

How to Use This Event

→ Monitor validators you're delegated to for scheduled changes
→ Build notification systems for upcoming child key changes
→ Track pending changes network-wide

From Chain Metadata

Setting of children of a hotkey have been scheduled

Triggers

Emitted by

set_children

Preconditions

Caller owns the parent hotkey
Valid schedule parameters provided
No conflicting pending schedule exists

Effects

Storage Modified

ChildKeys LastTxBlock ParentKeys PendingChildKeys

Postconditions

PendingChildKeys updated with scheduled change
Change will execute after delay period

Side Effects

Allows time for delegators to react to changes
Existing children continue receiving rewards until execution

Event Data

#	Name	Type	Description
0	arg0	AccountId	Event field #0 (AccountId) (hex -> SS58)
1	arg1	u16	Event field #1 (u16)
2	arg2	u64	Event field #2 (u64)
3	arg3	Vec<(u64, AccountId)> Vec	Event field #3 (Vec<(u64, AccountId)>)

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

On-Chain Activity

Emission Frequency

●●●○○○ Active 100K–1M emissions

Regular feature-level activity

#39 most emitted event

As of block 7,429,232

Version History

Version:

v216 block 4,510,996 4 args

v233 block 4,920,350 4 args

v252 block 5,163,656 4 args

v273 block 5,659,032 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: 73
First Version: v216
Current Version: v393

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