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set-mechanism-count

Set the number of mechanisms on a subnet.

Mechanisms are independent incentive sub-markets within one subnet, each running its own weights and consensus; this owner-only call sets how many the subnet runs. The count must be greater than zero, and the chain caps how many mechanisms a subnet may have. Increasing the count opens new mechanisms; decreasing it removes the highest-numbered ones and the miner state in them. Any change to the count clears the emission split back to an even division. Rate-limited and blocked during the end-of-epoch admin freeze window.

Signer	Origin	Pallet	Wraps
`coldkey`	subnet owner	AdminUtils	`AdminUtils.sudo_set_mechanism_count`

Parameters

Parameter	Type	Required	Description
`netuid`	integer	yes	Subnet to configure; the signer must be its owner.
`mechanism_count`	integer	yes	Number of mechanisms the subnet should run.

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 set-mechanism-count \
  --netuid <int> \
  --mechanism-count <int> --dry-run
btcli tx set-mechanism-count \
  --netuid <int> \
  --mechanism-count <int> -w my_coldkey

Python

import bittensor as bt
from bittensor.wallet import Wallet

wallet = Wallet(name="my_coldkey", hotkey="my_hotkey")
intent = bt.SetMechanismCount(netuid=1, mechanism_count=0)

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("set_mechanism_count", {...}, wallet)

On-chain implementation

AdminUtils.sudo_set_mechanism_count — pallets/admin-utils/src/lib.rs#L1873:

#[pallet::call_index(76)]
#[pallet::weight(<T as Config>::WeightInfo::sudo_set_mechanism_count())]
pub fn sudo_set_mechanism_count(
    origin: OriginFor<T>,
    netuid: NetUid,
    mechanism_count: MechId,
) -> DispatchResult {
    let maybe_owner = pallet_subtensor::Pallet::<T>::ensure_sn_owner_or_root_with_limits(
        origin,
        netuid,
        &[TransactionType::MechanismCountUpdate],
    )?;
    pallet_subtensor::Pallet::<T>::ensure_admin_window_open(netuid)?;

    pallet_subtensor::Pallet::<T>::do_set_mechanism_count(netuid, mechanism_count)?;

    pallet_subtensor::Pallet::<T>::record_owner_rl(
        maybe_owner,
        netuid,
        &[TransactionType::MechanismCountUpdate],
    );
    Ok(())
}

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