defi-ape

defi-ape / polymarket-kalshi-arbitrage-bot

Public

15-minute prediction market arbitrage bot: poll Kalshi Trade API and Polymarket CLOB, detect YES/UP spreads and late-resolution gaps, expose Express /status, and place Polymarket buys via @polymarket/clob-client.

kalshi.com arbitrage clob defi-ape event-contracts express
60
0
69% credibility
Found May 29, 2026 at 83 stars -- GitGems finds repos before they trend. Get early access to the next one.
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AI Analysis
TypeScript
AI Summary

A bot that watches two prediction market websites, waits for one to price an outcome higher than the other, and automatically buys on the cheaper platform to capture the price difference.

How It Works

1
🔍 Discover the opportunity

You hear about a way to profit from tiny price differences between two prediction market websites.

2
⚙️ Set up your trading bot

You tell the bot which markets to watch and how much money to use for each trade.

3
👀 Watch the prices

The bot constantly checks both websites, comparing the prices for the same event in real time.

4
💡 Spot the gap

When one site prices something at 95 cents while the other shows 82 cents, the bot notices the opportunity.

5
Choose your approach
📊
Monitor only

Watch the signals and learn how the strategy works before risking any money

🚀
Auto-trade

Let the bot automatically place buy orders when the price gap is big enough

🎉 Capture the spread

Your bot buys low on one platform while you know the other platform values the same outcome higher, capturing the difference.

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Star Growth

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AI-Generated Review

What is polymarket-kalshi-arbitrage-bot?

This is a TypeScript bot that watches 15-minute prediction markets on both Kalshi and Polymarket, then buys the cheaper side when pricing diverges between the two venues. It polls both APIs on a configurable interval, runs two detection rules (spread-based entry and late-resolution gaps), and can automatically place Polymarket buy orders through their CLOB client. The service exposes an Express HTTP API with `/status`, `/health`, and polling control endpoints for monitoring and runtime control.

Why is it gaining traction?

The 15-minute prediction market window is a specific niche with real execution challenges, and this bot tackles it head-on by wiring together both price feeds and actual order placement in one deployable service. Unlike monitoring-only tools, it initializes a signed Polymarket client, respects trade cooldowns, and validates price bounds before executing. The `/status` endpoint gives you live signal data without needing to parse logs, making it practical for validating strategy behavior before committing capital.

Who should use this?

Developers building automated trading workflows on prediction markets who want a ready-made price-comparison and order-execution scaffold rather than stitching together APIs from scratch. Researchers testing spread hypotheses across venues will find the signal logging useful. Traders should treat this as a starting point that requires validation: the code handles the mechanics but leaves risk management and position sizing to the operator.

Verdict

This solves a real problem for a specific workflow, but the repo is young (60 stars, no visible test suite) and the credibility score sits at 0.699999988079071%. Worth exploring as a reference implementation or prototype, but do your own audit before routing real capital through it. The Express API and documented strategy rules make it accessible; the low maturity calls for caution.

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