MinBurnSet

Event Re-added v101 → v127, v133 → v219, v233 → v247, v252 → v265, v273 → v277, v290 → current #38

Emitted when minimum burn for registration is changed.

Useful for: minersvalidatorssubnet ownersanalyticsdevelopers

The Big Picture

Burn registration cost fluctuates with demand, but there's a floor - it can't go below MinBurn. This ensures there's always some cost to register, preventing completely free entry even during low-demand periods. Subnet owners set this based on their spam prevention needs.

Why This Matters

MinBurn is the best possible burn registration cost. Even if demand drops to zero, you'll pay at least this much. Understanding the floor helps you budget and decide when to register. If current burn equals MinBurn, it can't go lower - that's the optimal time.

Example Scenario

Subnet 6 had MinBurn of 0.1 TAO. To increase the barrier to spam, they raise it to 0.5 TAO. MinBurnSet fires. Even during quiet periods, burn registration now costs at least 0.5 TAO. The floor is higher - budget accordingly.

Common Questions

What if MinBurn is raised above current burn?: Current burn would increase to meet the new minimum. Burn can't be below MinBurn.
Is MinBurn the same as actual burn cost?: MinBurn is the floor. Actual burn depends on demand and can be much higher. MinBurn is what you pay when demand is lowest.
Can MinBurn be zero?: Technically possible but rare. Zero MinBurn would allow free registration during low demand, which most subnets want to prevent.

Use Cases

Track minimum registration costs on subnets
Plan registration budget with known floor
Monitor subnet registration economics
Build registration cost tracking tools

How to Use This Event

→ Track minimum burn as your best-case registration cost
→ Monitor floor changes affecting entry costs
→ Build registration planning tools with bound awareness

From Chain Metadata

setting min burn on a network.

Triggers

Preconditions

Caller has admin/sudo privileges

Effects

Postconditions

MinBurn updated for subnet

Side Effects

Sets floor for burn registration cost

Event Data

#	Name	Type	Description
0	arg0	u16	Event field #0 (u16)
1	arg1	u64	Event field #1 (u64)

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

Version History

Version:

v101 block 1 2 args

v133 block 1,404,224 2 args

v233 block 4,920,350 2 args

v252 block 5,163,656 2 args

v273 block 5,659,032 2 args

v290 block 5,947,548 2 args Current

Runtime Info

View Source

Pallet Index: 7
Event Index: 38
First Version: v101
Current Version: v393

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