Alpaca Trading Bot in Python

This guide shows how to build a Alpaca trading bot in Python with LumiBot, for both AI agent trading and algorithmic trading. LumiBot connects to Alpaca through CCXT, the open source library that talks to more than 100 crypto exchanges. You will create a Alpaca account and API key, connect it, and run two examples: a simple algorithmic trading bot and an agentic trading bot where an AI agent makes the calls.

Alpaca at a glance

CCXT exchange id

alpaca

Markets

Spot

Testnet (sandbox)

Yes

Credentials

API key, API secret

Live data streams

prices, order book, trades, candles, your orders

CCXT request spacing

about 333 ms between requests

Official site

https://alpaca.markets

API docs

https://alpaca.markets/docs/

Fees

https://docs.alpaca.markets/docs/crypto-fees

What is Alpaca?

Alpaca is a trading platform with an API for stocks and crypto. Its crypto API lets you trade coins such as BTC around the clock against USD, USDT and USDC.

Sign up for Alpaca

  1. Sign up for an Alpaca Trading API account with your email address.

  2. To trade real money, open a live account and finish Alpaca’s account application. Anyone can start with a paper-only account.

  3. Your account comes with a paper trading account. Alpaca starts it with a $100,000 simulated balance.

Open a Alpaca account

Create a Alpaca API key

  1. Log in to the Alpaca dashboard.

  2. Pick the account you want the bot to use: paper or live. Each one has its own keys.

  3. On the Home page, generate your API Key and Secret Key.

  4. Copy the Secret Key right away. Alpaca shows it only once.

  5. If you make a new paper account later, generate new keys for it.

Which permissions to turn on: Alpaca’s docs describe one key ID and one secret key per account, with no separate permission boxes. Anyone with the key can trade the account, so keep it private. If Alpaca ever shows a withdrawal or transfer option for a key, leave it off.

Warning

Never turn on withdrawals for a Alpaca trading bot key. Bind the key to your server’s IP address when Alpaca lets you, keep the secret out of your code and out of Git, and delete the key if it ever leaks.

Connect Alpaca to LumiBot

The simplest way: put these lines in a .env file next to your strategy. LumiBot loads the file, sees TRADING_BROKER=ccxt:alpaca and connects to Alpaca for you, so your strategy needs no broker code.

TRADING_BROKER=ccxt:alpaca
ALPACA_API_KEY=your_apiKey
ALPACA_API_SECRET=your_secret
ALPACA_SANDBOX=true   # testnet; remove this line for your live account

alpaca is also the name of one of LumiBot’s own brokers, so the ccxt: prefix tells LumiBot to use the Alpaca exchange through CCXT.

LumiBot reads exactly the fields CCXT needs for Alpaca (apiKey, secret). If one is missing, LumiBot stops at start-up and names the variable you still need.

You can also build the broker in code. This is handy when one script talks to more than one exchange, or when you need extra CCXT options. The keys in the config are CCXT’s own credential names for Alpaca:

import os

ALPACA_CONFIG = {
    "exchange_id": "alpaca",
    "apiKey": os.environ.get("ALPACA_API_KEY"),
    "secret": os.environ.get("ALPACA_API_SECRET"),
    "sandbox": True,  # testnet first; set False for your live account
}

from lumibot.brokers import Ccxt

broker = Ccxt(ALPACA_CONFIG)
# then: MyStrategy(broker=broker, ...)

Either way, LumiBot turns on CCXT’s built-in rate limiting for you.

Practice on the Alpaca testnet

Alpaca’s sandbox is its paper trading account at https://paper-api.alpaca.markets. It fills orders against real-time quotes but sends nothing to a live market, and it uses separate paper keys. Set ALPACA_SANDBOX=true (or "sandbox": True in a code config) to use it.

CCXT sends sandbox requests to: https://broker-api.sandbox.alpaca.markets, https://paper-api.alpaca.markets. Testnet and live accounts use different keys.

Algorithmic trading example: a simple Alpaca bot

This bot buys about 50 USD of BTC on Alpaca once and then holds it. It is a starting point to check that your keys, balances and orders work. If the exchange’s minimum order is larger, raise the amount.

from lumibot.entities import Asset
from lumibot.strategies import Strategy


class AlpacaBuyOnce(Strategy):
    """Buy a small amount of BTC once, then hold it."""

    def initialize(self):
        self.sleeptime = "1H"
        self.set_market("24/7")  # crypto trades all day, every day

    def on_trading_iteration(self):
        coin = Asset("BTC", asset_type=Asset.AssetType.CRYPTO)
        if self.get_position(coin) is not None:
            return  # already holding BTC
        price = self.get_last_price(coin, quote=self.quote_asset)
        if price:
            quantity = round(50 / price, 6)  # about 50 USD worth
            order = self.create_order(coin, quantity, "buy", quote=self.quote_asset)
            self.submit_order(order)


if __name__ == "__main__":
    # LumiBot reads TRADING_BROKER and the keys from your .env file.
    strategy = AlpacaBuyOnce(quote_asset=Asset("USD", asset_type=Asset.AssetType.CRYPTO))
    strategy.run_live()

Agentic trading example: an AI agent that trades on Alpaca

Agentic trading means an AI agent reads the market and decides what to do. In this example one LumiBot agent looks at prices and your Alpaca account, then places the orders itself. There is no Python logic in between: you set the rules in plain English in the prompt, such as what it may trade and how big each order can be. This follows the same pattern as LumiBot’s AI trading team examples.

from lumibot.entities import Asset
from lumibot.strategies import Strategy


class AlpacaAITrader(Strategy):
    """One AI agent researches the market and places the trades itself."""

    def initialize(self):
        self.sleeptime = "4H"
        self.set_market("24/7")
        self.agents.create(
            name="trader",
            model="openai/gpt-6-luna",
            reasoning_effort="high",
            allow_trading=True,
            system_prompt=(
                "You manage a small crypto account on Alpaca. "
                "You may trade BTC and ETH against USD (asset_type 'crypto', quote_symbol 'USD'), or hold cash. "
                "Before every order, call account_portfolio, account_positions and "
                "market_last_price for that exact symbol in the same run. "
                "Keep each order under 10% of the account value. "
                "Explain each decision in one short paragraph."
            ),
        )

    def on_trading_iteration(self):
        self.agents["trader"].run(
            task_prompt="Review recent BTC/USD and ETH/USD prices and your current holdings, then decide whether to buy, sell or hold.",
            context={"exchange": "Alpaca", "quote": "USD", "date": self.get_datetime().isoformat()},
        )


if __name__ == "__main__":
    # LumiBot reads TRADING_BROKER and the keys from your .env file.
    strategy = AlpacaAITrader(quote_asset=Asset("USD", asset_type=Asset.AssetType.CRYPTO))
    strategy.run_live()

The agent needs a model key such as OPENAI_API_KEY in your environment. See the AI agents quickstart for models, tools and memory.

What you can trade on Alpaca through CCXT

Market

Listed by CCXT

Spot

Yes

Margin

No

Perpetual swaps

No

Dated futures

No

Options

No

CCXT lists these order features for Alpaca: market orders, limit orders, stop orders, editing open orders, canceling orders.

Alpaca tips

  • alpaca is also the name of LumiBot’s own Alpaca broker, which keeps priority. To reach Alpaca’s crypto API through CCXT, set TRADING_BROKER=ccxt:alpaca.

  • Paper keys and live keys are different. Alpaca says live keys do not work with the paper API, and paper keys do not work with the live API.

  • Alpaca crypto pairs use a slash, for example BTC/USD. Alpaca supports market, limit and stop limit orders for crypto, with gtc and ioc time in force.

Frequently asked questions

Can I build a Alpaca trading bot in Python?

Yes. Install LumiBot (pip install lumibot), set your Alpaca keys and use the alpaca CCXT exchange id as shown above.

Does Alpaca have a testnet?

Yes. Set ALPACA_SANDBOX=true and use keys from the Alpaca testnet.

Which API permissions does a Alpaca bot need?

Alpaca’s docs describe one key ID and one secret key per account, with no separate permission boxes. Anyone with the key can trade the account, so keep it private. If Alpaca ever shows a withdrawal or transfer option for a key, leave it off.

Can an AI agent trade on Alpaca by itself?

Yes. The agentic example above gives one agent permission to trade. You control what it may trade and how much through its prompt.

Can I trade Alpaca perpetual futures with LumiBot?

CCXT does not list perpetual swaps for Alpaca, so use spot markets.

Is LumiBot free?

Yes. LumiBot is open source on GitHub at https://github.com/Lumiwealth/lumibot. You pay only your exchange’s trading fees and, for AI agents, your model provider.

Run it in the cloud with BotSpot

Do not want to keep a computer running for your Alpaca bot? BotSpot is the hosted home for LumiBot strategies and AI trading agents: build with AI, backtest, connect a broker, and watch every trade with logs and alerts.

Try BotSpot

Sources