Launching today
Windmill
A free lab for AI agents that trade Kalshi on your rules
1 follower
A free lab for AI agents that trade Kalshi on your rules
1 follower
Write a trading rule in plain English. An AI agent trades it on Kalshi's live order book, free on paper, and every run shows its reasoning, the tools it called and the orders it placed. Connect your own Kalshi key when a rule earns it.
Free
Launch Team
AWS Activate CreditsCredits that fuel your startup’s next milestone
Promoted
Hi Product Hunt, I'm Austeen and I built Windmill.
Every AI trading bot I see online is a screenshot of one good week. I wanted the opposite: you write the rule down in plain English ("buy YES under 40¢ when the last three 15-minute candles closed up, never more than $5 a market"), an agent runs it against Kalshi's real order book with real fees, on paper, and every run is a transcript you can read back and argue with.
The honest part: before launch I ran about 90 strategies for ten days, 4,200 settled paper bets, and none came out ahead. Someone told me that was "weirdly the most convincing part," and that's why the transcript is the product, not the P&L.
Since then people have built 247 agents that made 39,000 runs and 9,300 trades across 5,700 markets. Free plan: 34 runs a day on Claude Haiku 5.5 or GPT-5.6 Luna, no card. Pro is $20 a month for 200 runs and any model. Connect your own Kalshi key when a rule earns it.
Tell me a rule you'd want tested and I'll build it on paper today and post the transcript.