Min Burn
Min burn is a per-subnet hyperparameter that sets the lower bound on the dynamic TAO burn required to register a neuron on a subnet. Official documentation describes it as the lower bound for that registration burn, gives a default of 0.0005 TAO, and marks it owner-settable.
References: Subnet Hyperparameters
How the Floor Works
Registering a neuron burns TAO, and that cost is dynamic: it rises as registrations occur and eases back during quieter periods, moving between a lower and an upper bound. Min burn fixes the bottom of that range, so the registration cost can settle toward it but not below it, keeping a baseline cost even when demand is low. Read together with max burn, it defines the floor side of the documented registration-burn band rather than a fixed registration price (Subnet Hyperparameters).
Reference: Subnet Hyperparameters
Per-Subnet Setting
Min burn is one of the subnet hyperparameters that configure a single subnet, for example netuid 1, and a subnet owner can adjust it. The value in force is per-subnet chain state and can differ from the documented default, so the real floor should be read for the subnet in question.
References: Subnet Hyperparameters, Register
Development Stage Context
The Introduction to Bittensor describes subnet development as moving from localnet to testnet and then mainnet. For min burn, that sequence changes how readers should interpret registration-cost floor examples.
In localnet, min-burn hyperparameters can be tested in an isolated environment. Localnet burn floors do not represent production registration costs.
On testnet, registration burn rules can be exercised in a shared non-production network. Testnet min burn values are separate from mainnet subnet state.
On mainnet, min burn is a live per-subnet hyperparameter on production subnets. Observed floors depend on the selected subnet’s on-chain hyperparameter state (Subnet Hyperparameters).
The Bittensor Networks reference separates mainnet, testnet, and localnet. A min-burn example from one environment should not be read as representing production registration costs in another environment.
Relationship to Yuma Consensus
Min Burn and Yuma Consensus describe related parts of Bittensor’s incentive system. Yuma Consensus is the on-chain process that aggregates validator weight signals within a subnet into miner incentives and validator dividends, applying consensus clipping, bonding, and emission calculation (Yuma Consensus).
For readers, min burn names a specific part of that incentive picture, while Yuma Consensus names the consensus process that turns validator weights into the resulting incentives and dividends.
Reader Boundary
This page defines the concept. It does not report the min burn value or the current registration cost on any particular subnet; those are live chain state to check for the relevant netuid.
Max Burn Caps the Same Dynamic Band
The Glossary: Register describes the
neuron registration burn as dynamic with explicit bounds. The burn price is bounded by MinBurn and
MaxBurn, so min burn fixes the floor while max burn fixes the ceiling for the same registration
cost on a subnet
(Subnet Hyperparameters).
Readers comparing burn parameters should treat the pair as one range. Min burn names the lowest allowed registration price; max burn names the highest allowed price under the same dynamic system.
Registration Fees Recycle Alpha From the Subnet Pool
Official register documentation states that alpha tokens worth the current swap value of the registration fee are taken from the subnet’s alpha liquidity pool and recycled when a hotkey registers. The TAO burn is the fee a registrant pays; the recycling step moves equivalent alpha value out of the subnet pool context described in subnet liquidity documentation (Glossary: Register, Understanding Subnets).
That keeps economic bounds separate from pool accounting. Min burn limits how low the TAO fee can fall; the recycling rule explains what happens to subnet alpha when a registration succeeds at any price inside the band.
Registration Allowed Can Close Entry Separately
The registration allowed hyperparameter controls whether new neurons can register on a subnet at all. When it is off, the subnet does not accept new registrations even if the dynamic burn sits near min burn (Subnet Hyperparameters).
Min burn therefore answers how low registration cost can fall, not whether registration is open. Readers should keep the burn floor separate from the root-level switch that gates subnet entry (Register).
BurnHalfLife Pulls the Live Burn Back Toward the Floor
The Glossary: Register describes the
dynamic registration burn as decaying over time according to BurnHalfLife while staying inside the
documented MinBurn and MaxBurn band. When registration demand quiets, that decay drifts the live
burn downward, and min burn is the value it settles toward but cannot fall below
(Subnet Hyperparameters).
That keeps min burn distinct from the decay mechanism. Half-life names how quickly the live burn eases during slow periods; min burn names the floor that decay approaches rather than passes.
References: Glossary: Register, Subnet Hyperparameters
BurnIncreaseMult Steps the Burn Up From the Floor
Official registration vocabulary also states that each successful registration can raise the dynamic
burn through BurnIncreaseMult. That multiplier responds to demand inside the same min/max band:
more registrations push the live burn upward from the floor, while half-life decay pulls it back
down toward min burn when activity slows
(Glossary: Register).
Min burn therefore sets where that upward stepping begins, not how far it can climb. A subnet owner can adjust the floor for their subnet, for example netuid 1, but the multiplier still operates only inside the documented hyperparameter bounds for that subnet (Subnet Hyperparameters).
References: Glossary: Register, Subnet Hyperparameters