Terms of Service

The agreement

By using Windmill, you agree to these terms. If you don't agree, don't use the site. We may update these terms as the product evolves; continuing to use Windmill after a change means you accept the new version.

What Windmill does

Windmill lets you build AI agents that trade prediction markets. In live mode, your agents place orders on your own Kalshi account using the API credentials you connect. Your money never leaves your Kalshi account — Windmill doesn't hold, transfer, or take custody of your funds. We just place trades on your behalf, within the limits you set.

Paper mode is simulated and involves no real money.

Risk and responsibility

Trading prediction markets can lose money, and AI agents can make mistakes — including trades you wouldn't have made yourself. You are responsible for the bots you create, the strategies you give them, and the limits you set. Windmill is provided "as is", and we are not responsible for trading losses or for damages arising from your use of the service.

Nothing on Windmill is financial advice. Only trade with money you can afford to lose.

Your account

Keep your login and Kalshi API credentials secure — you're responsible for activity on your account. Don't use Windmill to break the law, violate Kalshi's terms, or abuse the service. We may suspend accounts that do.

Subscriptions and billing

Plans. Windmill has a free plan and Pro, which costs $20 a month. What each plan includes, such as run limits and model choice, is listed on the pricing page and may change.

Billing. Pro is billed monthly through Stripe from the day you subscribe, and renews automatically until you cancel. Prices don't include any sales tax that may apply.

Price changes. If you're on a paid plan, we'll tell you about a price change at least 30 days before it takes effect.

Cancelling. You can cancel anytime from your account. You keep Pro through the end of the billing period you've paid for, then your account moves to the free plan.

Failed payments. If a payment fails, we retry it for a few days and you keep Pro in the meantime. If it still fails, your account moves to the free plan.

Refunds. Payments aren't refunded, including for partial months or unused runs, with one exception: Windmill is in public beta, and if we shut the service down permanently during a month you've paid for, we'll refund that month's payment in full.

Costs outside Windmill. Your subscription covers Windmill only. Kalshi's trading fees, and any money your bots lose, are not part of it and aren't refunded by Windmill.

Chargebacks. If you dispute a charge with your bank or card issuer, we may suspend your account until the dispute is resolved.

Contact

Questions about these terms? Email windmill-markets@googlegroups.com and we'll help.