Polymarket Trading Bot (TypeScript)

Overview

This bot trades on Polymarket’s 15-minute Up/Down prediction markets for BTC, ETH, Solana, and XRP. The strategy has two parts:

1. Dual limit at period start — At the start of each 15-minute period, place limit buy orders for both Up and Down tokens at a fixed price (e.g. $0.45), in a single batch.
2. Limit sell when one side fills — If exactly one side gets filled and the unfilled side’s best bid crosses a trigger (default $0.80), place a limit sell at a target price (default $0.85) on the filled token. No market buys, no stop-loss.

Markets are discovered by slug (e.g. btc-updown-15m-{timestamp}). BTC is always enabled; ETH, Solana, and XRP can be turned on or off in config.

Trading logic summary

Step	When	Action
1. Limit buys	Start of each 15-minute period (or within 2s if bot started mid-period)	Place a batch of limit buys: Up and Down at dual_limit_price (e.g. $0.45), dual_limit_shares per side. One CLOB batch per period.
2. Market refresh	When the period timestamp changes	Re-discover markets for the new period and re-fetch the order book snapshot.
3. Limit sell (SL)	Every poll after 2s elapsed, once per market per period	For each market: if one side has balance and the other has none, and the unfilled side’s best bid ≥ dual_limit_SL_sell_trigger_bid (e.g. $0.80), place a limit sell at dual_limit_SL_sell_at_price (e.g. $0.85) for the filled token (size = filled balance). Track so we only do this once per period per market.

There is no hedge (no market buy on the unfilled side), no stop-loss, and no automatic redemption at market close — only the limit buys at start and the optional limit sell when the trigger is hit.

Watch the bot in action:

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Architecture

┌─────────────────┐
│  Monitor        │  Fetches snapshots, discovers markets by slug
└────────┬────────┘
         │
         ▼
┌─────────────────┐
│  Main loop      │  Period start → batch limit buys; then check balances + trigger → limit sell
└────────┬────────┘
         │
         ▼
┌─────────────────┐
│  Trader         │  executeLimitBuyBatch, executeLimitSell, getBalance
└────────┬────────┘
         │
         ▼
┌─────────────────┐
│  CLOB / Gamma   │  Auth (API key + signature_type + proxy), orders, balance
└─────────────────┘

Requirements

• Node.js >= 18
• config.json with Polymarket private_key and (for production) api_key, api_secret, api_passphrase. Use proxy_wallet_address and signature_type: 2 if you use a proxy/Gnosis Safe wallet.

Setup

npm install
cp config.json.example config.json   # or copy from another project
# Edit config.json: set polymarket.private_key and API credentials

Usage

• Simulation (default) — no real orders, logs what would be placed:

  npm run dev
  # or
  npx tsx src/main-dual-limit-045.ts

• Production (live) — place real limit orders:

  npm run live
  # or
  npx tsx src/main-dual-limit-045.ts --no-simulation

• Config path:

  npx tsx src/main-dual-limit-045.ts -c /path/to/config.json

Configuration

Create or edit config.json in the project root.

Example config.json

{
  "polymarket": {
    "gamma_api_url": "https://gamma-api.polymarket.com",
    "clob_api_url": "https://clob.polymarket.com",
    "api_key": "your_api_key",
    "api_secret": "your_api_secret",
    "api_passphrase": "your_passphrase",
    "private_key": "your_private_key_hex",
    "proxy_wallet_address": "0x...your_proxy_wallet",
    "signature_type": 2
  },
  "trading": {
    "check_interval_ms": 1000,
    "enable_eth_trading": false,
    "enable_solana_trading": false,
    "enable_xrp_trading": false,
    "dual_limit_price": 0.45,
    "dual_limit_shares": 5,
    "dual_limit_SL_sell_trigger_bid": 0.2,
    "dual_limit_SL_sell_at_price": 0.15
  }
}

Polymarket (API) settings

Parameter	Description	Required
api_key	Polymarket API key	Yes (production)
api_secret	Polymarket API secret	Yes (production)
api_passphrase	Polymarket API passphrase	Yes (production)
private_key	Wallet private key (hex, with or without 0x)	Yes
proxy_wallet_address	Polymarket proxy wallet address	For proxy/Gnosis Safe
signature_type	0 = EOA, 1 = Proxy, 2 = Gnosis Safe	Use 2 for proxy wallet

Trading settings

Parameter	Description	Default
check_interval_ms	Poll interval (ms) for market snapshot	1000
dual_limit_price	Limit buy price for Up/Down at period start	0.45
dual_limit_shares	Shares per limit order (each side)	1
dual_limit_SL_sell_trigger_bid	When one side filled: place limit sell on filled token only if unfilled side’s best bid ≥ this	0.8
dual_limit_SL_sell_at_price	Limit sell price for the filled token when trigger is hit	0.85
enable_eth_trading	Enable ETH 15m Up/Down market	false
enable_solana_trading	Enable Solana 15m Up/Down market	false
enable_xrp_trading	Enable XRP 15m Up/Down market	false

Market discovery

Markets are discovered by slug (e.g. btc-updown-15m-{period_timestamp}). When the 15-minute period changes, the bot refreshes markets for the new period. No condition IDs need to be set in config.

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Features

• Automatic market discovery — Finds 15-minute Up/Down markets for BTC, ETH, Solana, XRP; refreshes on period rollover.
• Dual limit at period start — Single batch of limit buys for Up and Down at a configurable price and shares.
• Limit sell on trigger — When exactly one side is filled and the unfilled side’s bid crosses the trigger, place a limit sell at a target price on the filled token (once per market per period).
• Configurable markets — BTC always on; enable/disable ETH, Solana, XRP.
• Simulation mode — Run without sending orders.
• Structured logging — Stderr logging for monitoring and debugging.

Build

npm run build
node dist/main-dual-limit-045.js
# or with flags:
node dist/main-dual-limit-045.js --no-simulation -c config.json

Security

• Do not commit config.json with real keys or secrets.
• Use simulation and small sizes when testing.
• Monitor logs and balances in production.

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Support

There are many free Polymarket trading bots available on GitHub. However, most of them fail to generate consistent profits.

Profitable trading on Polymarket requires more than just automation — it requires strategy, risk management, and disciplined execution.

Many traders are drawn to the challenge. While higher capital can amplify returns, it also significantly increases risk. Position sizing and proper testing are critical.

Our team has developed a bot focused on strategy optimization and controlled risk exposure.

We encourage users to:

• Start with a small amount
• Evaluate real performance
• Scale gradually only if results meet expectations

Trade smart. Scale responsibly.

User Experience

We’ve spoken with many users currently running our bot, and here’s what we consistently hear:

This is automated trading — which means opportunity and risk.

Some users shared their real experiences:

• Started with $50 → earned around $20, but also experienced losses
• Started with $100 → earned around $50, with some drawdowns
• Started with $500 → in some cases doubled capital, though volatility remains
• Larger allocations increase potential upside — but also increase exposure

The key takeaway is simple:

📈 Higher capital can scale returns. ⚠️ Higher capital also scales risk.

There is no “always profit” system. Markets move. Liquidity shifts. Outcomes vary.

Our recommendation:

• Start small

• Observe performance

• Understand the risk

• Scale gradually and responsibly

Serious traders treat this as a strategy — not a guarantee.

If you’re interested in testing or learning more, feel free to reach out.