Build a Polymarket trading bot

How it works

1. 1
   Write or clone a strategy

   Implement the banger.Strategy interface in Python, or clone a public Polymarket strategy and configure it with form fields. A complete strategy is about 30 lines.

2. 2
   Paper-trade against the live book

   Run against real Polymarket market data with simulated fills. Inspect orders, fills, logs, and P&L before a single real order is placed.

3. 3
   Go live with hard limits

   Add your Polymarket key, set a per-trade cap, daily loss stop, and max open positions, then promote the same strategy to live when the evidence is good enough.

A Polymarket strategy in ~25 lines

from decimal import Decimal
from banger import Strategy, signals
from banger.risk import RiskEnvelope
from banger.venues.polymarket import Polymarket


class FadeOverconfidence(Strategy):
    name = "fade_overconfidence"
    venues = [Polymarket()]
    universe = signals.polymarket_markets(
        time_to_resolution_lt="24h", min_volume_usd=25_000
    )
    risk = RiskEnvelope(
        max_position_usd=Decimal("50"), max_daily_loss_usd=Decimal("250")
    )

    async def on_market_tick(self, market, tick, ctx):
        yes = float(tick.yes_price or 0)
        if yes >= 0.97 and ctx.can_open_position():
            await ctx.place(self.venues[0], market, side="no",
                            size=ctx.kelly(edge=yes - 0.5))

Install with pip install bangertrades, then banger run strategy.py --paper.

FAQ

How do I build a Polymarket trading bot?

Install Banger with `pip install bangertrades`, write a strategy that implements the banger.Strategy interface (or clone one from the marketplace), then run `banger run strategy.py --paper` to paper-trade against the live Polymarket book. Promote to live when you are convinced.

Is it legal to run a trading bot on Polymarket?

Automated and API trading is permitted. US persons trade legally via Polymarket US (a CFTC-regulated exchange); the international site does not serve US persons. Always check the current terms for your jurisdiction.

Does Banger hold my funds or keys?

No. Banger never custodies funds. Your venue keys are encrypted at rest and used only to place your own orders.