MinDelegateTakeSet

Event Re-added v149 → v165, v195 → v219, v233 → v247, v252 → v265, v273 → v277, v290 → v315, v320 → v326, v334 → v367, v372 → current #66

Emitted when the minimum allowed delegate take is changed.

View events on chain

Useful for: validatorsdelegatorsanalyticsdevelopers

The Big Picture

The min delegate take sets a floor on commission rates. It prevents a 'race to the bottom' where validators undercut each other to zero, potentially compromising service quality. It also ensures validators have minimum sustainable economics. A non-zero min protects the validator ecosystem from unsustainable pricing competition.

Why This Matters

As a delegator shopping for validators, no one can offer you less than this commission. As a validator, this protects you from competitors driving prices unsustainably low. Understanding the range (min to max take) helps set realistic expectations.

Example Scenario

To ensure validators remain sustainable, governance sets min take to 5%. MinDelegateTakeSet fires. A validator at 3% take must stay there (grandfathered) but new delegates can't go below 5%. If the 3% validator ever increases, they can't drop below 5% again.

Common Questions

Why have a minimum take at all?: Validators provide real services (infrastructure, validation work). A minimum ensures they can sustain operations. Zero-take validators might cut corners or abandon delegators.
What's a typical min take value?: It varies by network policy. Check the current MinDelegateTake constant. Common values are 0-10% depending on how much validator protection governance wants.
Does min take apply to child key take too?: No, child key take has its own MinChildKeyTake parameter. Different relationships, different economics, different limits.

Use Cases

Track minimum commission validators must charge
Understand validator pricing floor
Monitor network-wide validator economic policies
Build delegation planning tools with correct bounds

How to Use This Event

→ Monitor min take to understand best-case delegation terms
→ Track validator economic sustainability policies
→ Build tools showing the valid take range

From Chain Metadata

minimum delegate take is set by sudo/admin transaction

Triggers

Preconditions

Caller has admin/sudo privileges
New min is valid percentage

Effects

Postconditions

MinDelegateTake storage updated

Side Effects

Delegates cannot decrease take below this value

Event Data

#	Name	Type	Description
0	arg0	u16	Event field #0 (u16)

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

Version History

Version:

v149 block 3,014,339 1 args

v195 block 3,791,350 1 args

v233 block 4,920,350 1 args

v252 block 5,163,656 1 args

v273 block 5,659,032 1 args

v290 block 5,947,548 1 args

v320 block 6,523,566 1 args

v334 block 6,811,690 1 args

v372 block 7,430,358 1 args Current

Runtime Info

View Source

Pallet Index: 7
Event Index: 66
First Version: v149
Current Version: v393

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