# register-subnet (/docs/tx/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 the chain is at
its subnet limit, registering dissolves the non-immune subnet with the
lowest EMA price to free the slot (the new subnet reuses its netuid).
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.

| Signer    | Pallet          | Wraps                              |
| --------- | --------------- | ---------------------------------- |
| `coldkey` | SubtensorModule | `SubtensorModule.register_network` |

## Parameters [#parameters]

| Parameter     | Type   | Required | Description                                                              |
| ------------- | ------ | -------- | ------------------------------------------------------------------------ |
| `hotkey_ss58` | string | no       | Subnet-owner hotkey for the new subnet; defaults to the wallet's hotkey. |

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

## Python [#python]

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

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

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:

```python
await client.execute_tool("register_subnet", {...}, wallet)
```