Open source arbitrage scripts vs Arbitrage Agent: comparing build-it-yourself approaches against a managed platform for prediction market arbitrage on Polymarket and Kalshi.
| Feature | Arbitrage Agent | Open Source Scripts |
|---|---|---|
| Setup time | 30 minutes | Days to weeks |
| Maintenance | Managed (zero) | Ongoing (API changes, bugs) |
| Event matching | AI semantic (99.2%) | Rule-based / keyword (varies) |
| Execution speed | Under 400ms | Varies by implementation |
| Circuit breaker | Built-in | Must build yourself |
| Dashboard | Web UI included | None (logs only) |
| Cost | From $19/mo | $0 (but significant dev time) |
| API updates handled | Yes, automatic | You fix it when it breaks |
Open source prediction market arbitrage scripts exist on GitHub — typically Python bots that connect to Polymarket and Kalshi APIs, scan for price gaps, and execute trades. Some are well-maintained; many are abandoned or broken by API changes.
The appeal is obvious: free, full control, no monthly fee. The hidden cost is development time. Connecting to both APIs, handling authentication, building event matching logic, implementing risk controls, and keeping up with API changes is a significant engineering project.
Most open source scripts use simple keyword or embedding-based matching with no fine-tuning for resolution criteria. False match rates are often 5–15% — meaning you can unknowingly be holding directional risk disguised as arbitrage.
Source: https://github.com
Arbitrage Agent monitors 4,812 binary event markets across Polymarket and Kalshi in real time via WebSocket. AI-powered semantic matching (99.2% precision) links identical events across platforms — even when titles differ completely.
When a price gap creates an arbitrage opportunity, both legs execute in parallel under 400ms. A circuit breaker auto-unwinds if one leg fails, ensuring zero directional exposure. The agent is fully non-custodial — your capital stays on Kalshi and Polymarket at all times.
Difference 1
The difference between 99.2% and 90% matching precision sounds small. At 4,812 market pairs, 90% precision means ~480 false matches — pairs that appear to be the same event but aren't. Every false match is an unhedged directional trade. Arbitrage Agent's matching combines embeddings, resolution-criteria diffing, and date validation to reach 99.2%.
Difference 2
Polymarket and Kalshi update their APIs frequently. Every breaking change requires debugging, patching, and redeploying your script — often at 2am when you discover trades stopped executing. Arbitrage Agent maintains API compatibility automatically.
Difference 3
A local Python script running on your laptop isn't production-grade. Arbitrage Agent runs on cloud infrastructure with 99.98% uptime, automatic restarts, and monitoring. A script that crashes while you're asleep and misses an 8% spread opportunity has a hidden cost.
Difference 4
Building and maintaining a production-quality arbitrage system from scratch realistically takes 200–500 hours of engineering time. At any reasonable hourly value, that's $10,000–$50,000 in opportunity cost. A managed platform at $19/month is a different proposition entirely.
When to choose Open Source Scripts
When to choose Arbitrage Agent
Open source scripts are a great starting point for developers who want to understand the mechanics. For production use — where reliability, matching accuracy, and maintenance overhead actually matter — a managed platform is almost always the better economic choice once you factor in real engineering time.
Are there good open source prediction market arbitrage bots?
Some exist, but quality varies enormously. The main risks are stale API integrations (Polymarket and Kalshi APIs change frequently), poor event matching logic (keyword-based matching produces many false pairs), and no production infrastructure (scripts running on laptops aren't reliable).
Can I use an open source script as a starting point and improve it?
Yes — and this is actually a good way to learn the mechanics. Just be aware that the hardest parts (robust event matching, circuit breaker logic, reliable execution) are the parts most open source scripts don't handle well.
What's the real cost of building my own?
Plan for 2–4 weeks of engineering time to build something production-ready, plus ongoing maintenance as APIs change. Arbitrage Agent at $19/month pays back in saved engineering time almost immediately for most developers.
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