# start-call (/docs/tx/start-call)

Flips a freshly registered subnet from inactive to active: the subnet
token becomes tradable and alpha emission into the subnet's epochs
begins. It does not enable the subnet's share of TAO emission — that
additionally requires the root-gated emission-enabled flag, which only
root can set. Owner-only, callable once per subnet, and only after the
chain's minimum delay since the subnet was registered — calling too
early fails. Until this is called the subnet earns nothing, so run it
as soon as the delay allows.

| Signer    | Origin       | Pallet          | Wraps                                                                                        |
| --------- | ------------ | --------------- | -------------------------------------------------------------------------------------------- |
| `coldkey` | subnet owner | SubtensorModule | [`SubtensorModule.start_call`](/code/pallets/subtensor/src/macros/dispatches.rs#L1537-L1542) |

## Parameters [#parameters]

| Parameter | Type    | Required | Description                                       |
| --------- | ------- | -------- | ------------------------------------------------- |
| `netuid`  | integer | yes      | Subnet to activate; the signer must be its owner. |

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

## CLI [#cli]

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

```bash
btcli tx start-call \
  --netuid <int> --dry-run
btcli tx start-call \
  --netuid <int> -w my_coldkey
```

## Python [#python]

```python
import bittensor as bt
from bittensor.wallet import Wallet

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

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](/docs/concepts/client).) Or build the intent by op name, as
an agent would:

```python
result = sub.execute_tool("start_call", {...}, wallet)
```

## On-chain implementation [#on-chain-implementation]

`SubtensorModule.start_call` — [`pallets/subtensor/src/macros/dispatches.rs#L1539`](/code/pallets/subtensor/src/macros/dispatches.rs#L1537-L1542):

```rust
#[pallet::call_index(92)]
#[pallet::weight(<T as crate::pallet::Config>::WeightInfo::start_call())]
pub fn start_call(origin: OriginFor<T>, netuid: NetUid) -> DispatchResult {
    Self::do_start_call(origin, netuid)?;
    Ok(())
}
```

Delegates to [`do_start_call`](/code/pallets/subtensor/src/subnets/subnet.rs#L531).

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