Transactions

trim-subnet

Trim a subnet to at most `max_n` UIDs (subnet owner).

Lowers the subnet's UID capacity and immediately deregisters the lowest-emission neurons above the new limit — those miners lose their slots and would have to re-register (paying the burn cost) to return. max_n must be between the chain's minimum allowed UIDs (64) and the subnet's current max_allowed_uids. Owner-immune and temporally immune UIDs are skipped, and the call fails if immune UIDs would exceed 80% of max_n. Surviving UIDs are renumbered consecutively from zero, so UID values change. Rate-limited to once per 216,000 blocks (30 days) and blocked during the end-of-epoch admin freeze window. Owner-only and disruptive to affected participants, so announce it before shrinking a live subnet. To simply cap future growth without evicting anyone, set the max_allowed_uids hyperparameter to a value at or above the current UID count instead.

Signer	Pallet	Wraps
`coldkey`	AdminUtils	`AdminUtils.sudo_trim_to_max_allowed_uids`

Parameters

Parameter	Type	Required	Description
`netuid`	integer	yes	Subnet to trim; the signer must be its owner.
`max_n`	integer	yes	New maximum number of UIDs; lowest-emission neurons above this are removed.

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 trim-subnet \
  --netuid <int> \
  --max-n <int> --dry-run
btcli tx trim-subnet \
  --netuid <int> \
  --max-n <int> -w my_coldkey

Python

import bittensor as sub
from bittensor.wallet import Wallet

wallet = Wallet(name="my_coldkey", hotkey="my_hotkey")
intent = sub.TrimSubnet(netuid=1, max_n=0)

async with sub.Client("finney") as client:
    plan = await client.plan(intent, wallet)   # fee, effects, policy — no submission
    result = await client.execute(intent, wallet)
    if not result.success:
        print(result.error.code, result.error.remediation)

Or build it by op name, as an agent would:

await client.execute_tool("trim_subnet", {...}, wallet)