Transactions

update-symbol

Update a subnet's symbol (from the chain's fixed catalog).

Cosmetic call for the subnet owner (or root): changes the short ticker shown for the subnet's alpha token in wallets, explorers, and CLIs. Symbols are not arbitrary strings — the chain keeps a fixed catalog of roughly 439 predefined symbols, and anything outside it is rejected with SymbolDoesNotExist. A symbol already taken by another subnet is rejected with SymbolAlreadyInUse. No economic effect — balances, stake, and emissions are untouched.

Signer	Origin	Pallet	Wraps
`coldkey`	subnet owner	SubtensorModule	`SubtensorModule.update_symbol`

Parameters

Parameter	Type	Required	Description
`netuid`	integer	yes	Subnet whose symbol to change; the signer must be its owner.
`symbol`	string	yes	New token symbol; must be one of the chain's predefined symbols and not in use by another subnet.

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 update-symbol \
  --netuid <int> \
  --symbol <value> --dry-run
btcli tx update-symbol \
  --netuid <int> \
  --symbol <value> -w my_coldkey

Python

import bittensor as bt
from bittensor.wallet import Wallet

wallet = Wallet(name="my_coldkey", hotkey="my_hotkey")
intent = bt.UpdateSymbol(netuid=1, symbol="...")

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

On-chain implementation

SubtensorModule.update_symbol — pallets/subtensor/src/macros/dispatches.rs#L1721:

#[pallet::call_index(112)]
#[pallet::weight(<T as crate::pallet::Config>::WeightInfo::update_symbol())]
pub fn update_symbol(
    origin: OriginFor<T>,
    netuid: NetUid,
    symbol: Vec<u8>,
) -> DispatchResult {
    Self::ensure_subnet_owner_or_root(origin, netuid)?;
    ensure!(Self::if_subnet_exist(netuid), Error::<T>::SubnetNotExists);

    Self::ensure_symbol_exists(&symbol)?;
    Self::ensure_symbol_available(&symbol)?;

    TokenSymbol::<T>::insert(netuid, symbol.clone());

    Self::deposit_event(Event::SymbolUpdated { netuid, symbol });
    Ok(())
}

Delegates to ensure_subnet_owner_or_root, if_subnet_exist, ensure_symbol_exists.

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