# Bittensor Subnet Developer Guide

> Source: https://docs.bittensor.com | https://github.com/opentensor/bittensor

## Installation

```bash
pip install --upgrade bittensor
pip install bittensor-cli
btcli --version
```

## Core Concepts

**netuid (Subnet ID):** Each subnet has a unique integer ID
- netuid=1: Text prompting subnet (largest and most mature)
- netuid=18: Cortex.t (multimodal)
- `btcli subnet list` to view all subnets

**Roles:**
- **Miner**: Provides AI compute/services, earns TAO rewards
- **Validator**: Evaluates Miner output quality, requires staking TAO

## Register to Subnet

```bash
btcli subnet register --netuid <netuid> --wallet.name <wallet> --wallet.hotkey <hotkey>
btcli subnet metagraph --netuid <netuid>
btcli wallet overview --wallet.name <wallet>
```

## Python SDK v10

```python
import bittensor as bt

subtensor = bt.Subtensor(network="finney")  # mainnet
metagraph = subtensor.metagraph(netuid=1)
print(f"Subnet size: {metagraph.n} neurons")

wallet = bt.wallet(name="my_wallet", hotkey="my_hotkey")
balance = subtensor.get_balance(wallet.hotkey.ss58_address)
```

## Create Subnet

```bash
# Testnet (free)
btcli subnet create --wallet.name <wallet> --subtensor.network test
# Mainnet (requires TAO payment)
btcli subnet create --wallet.name <wallet> --subtensor.network finney
```

## Grant

- Opentensor Foundation: https://opentensor.foundation
- Discord: discord.gg/bittensor