Cap on child key commission.
Current Value
11796Relevant for: validatorsdevelopers
The Big Picture
This caps how much a parent can take from child key earnings. Without a ceiling, parents could extract almost all value, making child key operation uneconomical. The cap ensures child keys retain meaningful earnings, making the arrangement attractive to operators.
Why This Matters
If you're considering operating as a child key, this is the worst-case parent take. Parents cannot exceed this, so you're guaranteed to keep at least (100% - max) of earnings.
Example
With MaxChildKeyTake of 2000 (20%), parents cannot take more than 20% from child earnings. A child key is guaranteed at least 80% of their generated emissions.
Common Questions
- Why limit parent take?
- Child key operators need incentive. If parents could take 99%, no one would run child keys. The cap makes the economics viable for both parties.
- Can I negotiate outside these bounds?
- No, the chain enforces bounds. Any take above max is rejected. Off-chain arrangements are possible but not enforceable.
From Chain Metadata
Initial maximum childkey take.
Use Cases
- Child key validation
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 });
// Query InitialMaxChildKeyTake constant
const value = api.consts[stringCamelCase("SubtensorModule")][stringCamelCase("InitialMaxChildKeyTake")];
console.log("InitialMaxChildKeyTake:", value.toHuman());Type Information
- Type
- u16
- Byte Size
- 2 bytes
- Encoding
- fixed
- Raw Hex
- 0x142e
Runtime Info
- Pallet
- SubtensorModule
- First Version
- v195
- Latest Version
- v195
- Current Runtime
- v393