Mechanism Emission Split
Mechanism emission split is a per-subnet hyperparameter, listed in the documentation as
MechanismEmissionSplit, that sets how emission is divided across the mechanisms on a subnet. The
reference describes it as setting the emission splits of mechanisms in a subnet
(Subnet Hyperparameters).
What It Controls
The hyperparameter allocates shares among mechanisms, not among individual miners or validators. A subnet can run more than one mechanism when mechanism count is above one; mechanism emission split decides what fraction of the subnet’s emission budget each mechanism receives (Subnet Hyperparameters, Emission).
It does not define the subnet task, validator weights, or Yuma Consensus bonding rules inside a mechanism. It only partitions the emission envelope across mechanism slots before each mechanism’s own incentive path runs (Yuma Consensus, Understanding Subnets).
The split is owner-tunable per subnet, so netuid 1 can use one allocation while another netuid divides emission differently across its mechanisms, and the live vector is chain state rather than a network constant (Subnet Hyperparameters, Bittensor Networks).
Documented Type and Setter
The Subnet Hyperparameters
reference lists MechanismEmissionSplit as a vector type and marks the permission required to
change it as subnet owner
(Subnet Hyperparameters).
Because each subnet carries its own hyperparameters, the split vector on one netuid can differ from another subnet’s allocation and should be read for the selected subnet rather than assumed from a reference example (Subnet Hyperparameters).
The rate-limit reference documents a 7,200-block cooldown (about 24 hours) on main net, or 1 block in fastblocks development mode, between successful emission-split updates on a subnet. That limit is separate from the mechanism-count update cooldown, so changing how many mechanisms run and changing how emissions are divided among them are paced independently (Chain Rate Limits: Subnet Mechanism emission split update rate limit).
Reading the Live Value for netuid 1
Mechanism emission split is per-subnet chain state, so any live claim is tied to a specific netuid. For the documented example netuid 1 on Finney mainnet, the split appears in that subnet’s hyperparameter table, which the reference describes under viewing a subnet’s hyperparameters (Subnet Hyperparameters: View hyperparameters). The infobox uses netuid 1 only as an example label; other subnets expose their own values (Bittensor Networks).
Distinction from Mechanism Count
Mechanism count sets how many mechanisms a subnet runs. Mechanism emission split sets how emission is divided among those mechanisms once the count is above one (Subnet Hyperparameters).
- Mechanism count — number of mechanisms on the subnet.
- Mechanism emission split — emission share allocated to each mechanism.