MaxChildkeyTake

Storage Plain v195 → current

Maximum allowed child key take rate.

Explore chain
Queried by: validatorsdeveloperssubnet owners

The Big Picture

The protocol limits how much children can charge. MaxChildkeyTake prevents children from keeping unreasonably large portions, ensuring parents maintain incentive to delegate.

Why This Matters

Setting child take rate? You can't go above this maximum. It protects the delegation system from breakdown due to excessive child fees.

Example Scenario

Query MaxChildkeyTake() returns 8000 (80%). No child can charge more than 80% take. Attempting to set higher will fail.

Common Questions

Why is there a maximum?
Without caps, children could charge 99% making delegation pointless. The cap ensures reasonable economics for both parties.

Use Cases

  • Check maximum allowed take when setting child take
  • Build UI sliders with correct max bounds
  • Verify protocol limits for child economics
  • Research child key incentive design

Purpose & Usage

Purpose

Cap on child key commission - protects parents from excessive child fees.

Common Query Patterns

  • Single value query
  • Verify take rate is within bounds
  • Build take rate pickers with correct limits

Stored Value

value (u16)

Relationships

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 MaxChildkeyTake storage (no keys - plain value)
const result = await api.query
  [stringCamelCase("SubtensorModule")]
  [stringCamelCase("MaxChildkeyTake")]();
console.log("MaxChildkeyTake:", result.toHuman());

Runtime Info

View Source
Pallet
SubtensorModule
Storage Kind
Plain
First Version
v195
Current Version
v393