Current Value
0.10 TAO (100000000 raw)
Conversion: ÷ 10^9 (RAO → TAO)
Relevant for: subnet ownersdevelopersdevelopers
The Big Picture
Subnet owners can set MaxBurn to cap registration costs, but this constant sets a floor on MaxBurn. It prevents subnet owners from setting MaxBurn so low that burn registration becomes trivially cheap even at maximum, potentially enabling spam or Sybil attacks.
Why This Matters
When configuring subnet burn parameters, you cannot set MaxBurn below this floor. It ensures burn registration always has meaningful cost at peak demand.
Example
With MaxBurnLowerBound of 1 TAO, a subnet owner cannot set MaxBurn to 0.1 TAO. Even at maximum demand, burn registration will cost at least 1 TAO, maintaining economic stakers against spam.
Common Questions
- What if a subnet wants truly cheap registration?
- Use POW registration instead. Burn is meant to have economic cost. The floor ensures burn serves its anti-spam purpose.
- How does this interact with MinBurn?
- MaxBurn must be >= MinBurn, and both have bounds. MaxBurn >= MaxBurnLowerBound, MinBurn <= MinBurnUpperBound. The parameters must stay within valid ranges.
From Chain Metadata
Max burn lower bound.
Use Cases
- Burn limits
- Parameter 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 MaxBurnLowerBound constant
const value = api.consts[stringCamelCase("SubtensorModule")][stringCamelCase("MaxBurnLowerBound")];
console.log("MaxBurnLowerBound:", value.toHuman());
// Convert RAO to TAO if this is a balance value
const taoValue = value.toBigInt() / BigInt(1e9);
console.log("TAO:", taoValue.toString());Type Information
- Type
- u64
- Byte Size
- 8 bytes
- Encoding
- fixed
- Raw Hex
- 0x00e1f50500000000
Runtime Info
- Pallet
- SubtensorModule
- First Version
- v315
- Latest Version
- v315
- Current Runtime
- v393