Windmill

Pricing

Two plans — see which one is right for you.

Free

Best for trying it out

$0/ month

  • 34 agent runs a dayTemporarily boosted from 8*
  • Runs on GPT-5.6 Luna or Claude Haiku 5.5
  • Paper trading against the live Kalshi order book
  • Live trading on your own Kalshi account
  • The full transcript of every run
  • Risk limits enforced in code: allocation, order size, stop loss
  • Schedules down to every 10 minutes

Pro

Best for running a fleet

$20/ month

  • Everything in Free and:
  • 200 agent runs a dayMore runs a day, so a rule can cover more of the day or run beside a variant
  • On Kalshi's 15-minute bitcoin market: run your rule and a variant through every window, around the clock
  • Your choice of model for each agent

* While we're in beta, Free accounts get 34 agent runs a day instead of 8.

Features

FreePro

Runs

Agent runs34 / day200 / day
Budget windowRolling 24 hoursRolling 24 hours

Models

GPT-5.6 Luna
DeepSeek V4 Flash
Muse Spark 1.2
Claude Haiku 5.5
Claude Sonnet 5.5
Claude Opus 5.5

Trading

Paper trading against the live Kalshi book
Live trading on your own Kalshi account

FAQ

How does the run budget work?

Every account has one budget of agent runs, counted over a rolling 24 hours. It's shared across all your agents: spend it on one agent that checks the market every 10 minutes, or spread it over twenty quiet ones. Once the budget is used, agents skip their runs until older runs fall out of the window.

What counts as a run?

A run is one wake-up of one agent: it reads the market, decides, and reports. Runs that finish, fail or time out all count. Runs the platform skips (because the budget is spent, for instance) don't. Scheduled runs and the ones you start by hand share the same budget.

What happens when I hit the budget?

Nothing breaks. Agents that come due are skipped, and each skipped run says why. As runs from the last 24 hours age out, the budget frees up and the schedule resumes. The dashboard shows how many runs you have left.

What does Pro add on the 15-minute bitcoin market?

More runs a day, not faster ones: schedules go down to every 10 minutes on both plans. Kalshi opens a new bitcoin market every 15 minutes, and an agent that bets each one spends a run on it. Pro has enough runs to take your rule and a variant through every window around the clock (96 windows a day each), so you can compare them side by side.

Can I trade real money?

Yes. Agents run on paper by default, filled against the live Kalshi order book with real fees, so paper results are what would have happened. When you're ready, connect your own Kalshi account and build a live agent. The same limits apply — allocation, order size, stop loss — and the agent trades only what you gave it.

Which model runs my agent?

Free accounts pick GPT-5.6 Luna or Claude Haiku 5.5. Pro can pick any model, including Claude Sonnet 5.5 and Opus 5.5, with up to $10 of Claude usage a day.

How do I cancel?

From this page: Manage billing opens your billing portal, where you can cancel or change your card.