register-subnet

Registers a brand-new subnet with the signing coldkey as its owner and the wallet's hotkey as the subnet-owner hotkey. The network registration cost — potentially thousands of TAO — is taken from the coldkey; it doubles after each new subnet registration and decays linearly back over the lock reduction interval, and is only known at execution time, so a configured spend cap blocks this call until raised. The full cost becomes the new subnet's initial TAO pool reserve — a sunk cost, not a refundable deposit. Network registrations are rate-limited per coldkey. If capacity is available, the subnet is created in the registration block. If the chain is at its subnet limit, registration first queues while the non-immune subnet with the lowest EMA price is dissolved across idle block time; SDK execution waits for the matching NetworkAdded event before returning by default. The result's registration_mode distinguishes the two paths and netuid is the subnet actually assigned. The new subnet starts inactive: call start_call once the chain's activation delay has passed to activate it; the subnet's share of TAO emission additionally stays off until root enables the subnet's emission-enabled flag. This is a major, expensive commitment — check the current cost before sending.

Parameters

Address parameters (--hotkey, --coldkey, --dest, ...) accept a raw ss58 address, an address-book or proxy-book name, or a local wallet/hotkey name.

CLI

Preview with --dry-run (shows fee, effects, and policy result without submitting), then submit:

btcli tx register-subnet --dry-run
btcli tx register-subnet -w my_coldkey

Python

import bittensor as bt
from bittensor.wallet import Wallet

wallet = Wallet(name="my_coldkey", hotkey="my_hotkey")
intent = bt.RegisterSubnet()

sub = bt.Subtensor()
plan = sub.plan(intent, wallet)   # fee, effects, policy — no submission
result = sub.execute(intent, wallet)
if not result.success:
    print(result.error.code, result.error.remediation)

(bt.Subtensor is also the async client — async with bt.Subtensor() as client: — see The client.) Or build the intent by op name, as an agent would:

result = sub.execute_tool("register_subnet", {...}, wallet)

On-chain implementation

SubtensorModule.register_network — pallets/subtensor/src/macros/dispatches.rs#L1004:

#[pallet::call_index(59)]
#[pallet::weight(<T as crate::pallet::Config>::WeightInfo::register_network())]
pub fn register_network(origin: OriginFor<T>, hotkey: T::AccountId) -> DispatchResult {
    Self::do_register_network(origin, &hotkey, 1, None)
}

Delegates to do_register_network.

Every file is browsable under /code exactly as built into the runtime, or as plain text under /code/raw/<path> (index: /code/index.json).