Subnet Management

Subnet

Creation, configuration, and dissolution of subnets with locked TAO and owner-controlled hyperparameters.

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The Big Picture

Subnets are independent competition arenas within Bittensor. Each subnet defines what task miners perform and how validators evaluate them. Creating one requires locking TAO as collateral. Subnet owners configure hyperparameters (tempo, max UIDs, immunity period) and earn an owner cut of emissions.

Why This Matters

Subnets are where the actual work of Bittensor happens. Understanding subnet economics — lock cost, emission share, owner cut — is essential for subnet operators and stakers choosing where to allocate capital.

Example Scenario

Creating a new subnet when 50 exist costs ~100 TAO locked. The owner configures it with Tempo=360, MaxAllowedUids=256, and 10% owner cut. As validators and miners register, and stakers allocate to the subnet, it begins earning emission via TAO Flow.

Common Questions

Do I get my locked TAO back?
Yes, when you dissolve the subnet. The lock is returned in full — it is collateral, not a fee.

Use Cases

  • Planning subnet launch economics
  • Configuring subnet hyperparameters
  • Monitoring subnet health and registration
  • Comparing subnet economics for investment

Subnets are independent networks within Bittensor. Creating a subnet requires locking TAO (the cost decreases over time as more subnets exist). Subnet owners configure hyperparameters like tempo, max UIDs, immunity period, and earn an owner cut of emissions.

Owners can set subnet identity metadata, adjust parameters, and dissolve subnets to reclaim locked TAO.

Triggers

  • User submits register_network call
  • Owner adjusts hyperparameters

Inputs (2)

ItemTypeRole
register_network SubtensorModulecallCreate a new subnet
SubnetLimit SubtensorModulestorageMaximum number of subnets allowed

Outputs (5)

ItemTypeRole
NetworkAdded SubtensorModuleeventEmitted when subnet is created
NetworkRemoved SubtensorModuleeventEmitted when subnet is dissolved
NetworksAdded SubtensorModulestorageRegistry of active subnets
SubnetOwner SubtensorModulestorageOwner account for each subnet
SubnetLocked SubtensorModulestorageTAO locked per subnet

Source Files

pallets/subtensor/src/subnets/subnet.rs
do_register_network()
pallets/subtensor/src/coinbase/root.rs
get_network_lock_cost()
Lines: 508-584

Formulas

Subnet Lock Cost

The TAO cost to create a subnet resets to 2x the last lock cost on each registration, then linearly decays over time. The decay rate is lock_reduction_interval blocks (default ~14 days). Additionally, the lock cost is modulated by network emission rate — subnets with higher emission cost more to create, creating a market signal.

mult = 2 if last_lock_block != 0 else 1
lock_cost = last_lock * mult - (last_lock / lock_reduction_interval) * blocks_elapsed
lock_cost = max(lock_cost, min_lock)
// Linear decay: full cost at t=0, reaches min_lock after lock_reduction_interval blocks
// Emission modulation: lock_cost *= subnet_emission_rate / avg_emission_rate
// Ensures high-emission subnets cost proportionally more to register

Related Workflows

register-subnet

Version History

v101 Initial subnet registration
v200 Subnet limit increased from 32 to 64
v250 Subnet hyperparameter governance by owner
v290 Subnet identity metadata and owner cut support
v340 Dynamic subnet limit based on network capacity