Terms of Service

Last updated: March 2026

These Terms of Service ("Terms") govern your use of Kirn ("we", "us", "our"), a product of Varper LLC. By creating an account or using the service, you agree to these Terms.

The service

Kirn connects to your Stripe account via a restricted API key you provide, reads your subscription and billing history, computes churn risk scores, and delivers a weekly digest of your highest-risk accounts. We do not write to your Stripe account or initiate any charges on your behalf.

Your account

You are responsible for keeping your login credentials secure and for all activity under your account. You must provide accurate information when signing up and keep it current. You must be at least 18 years old and authorized to accept these Terms on behalf of any organization you represent.

Stripe API key

You provide Kirn with a Stripe restricted API key with read-only access to customers, subscriptions, and invoices. You are responsible for creating a key with only the permissions listed in our onboarding guide, and for revoking it if you disconnect from Kirn or close your account. We store your key encrypted at rest and use it solely to provide the service.

Subscription and billing

Kirn offers a 30-day free trial. After the trial period, continued access requires a paid subscription at the rates listed on getkirn.com. Subscriptions renew automatically unless cancelled. You can cancel at any time from your account settings; access continues until the end of the current billing period.

We use Stripe to process payments. We do not store your payment card details.

60-day outcome guarantee

If Kirn does not identify at least one at-risk subscriber in your first 60 days of a paid subscription, we will refund your first month's payment. To claim a refund, email [email protected] within 75 days of your first charge with your account email. This guarantee applies once per customer.

How we use your data to generate predictions

Kirn uses your Stripe billing data to compute churn risk scores for your subscribers. This includes statistical models trained on your account's own historical data. These per-account models are used solely to generate predictions for your account — your raw data is never shared with other customers.

We may also use anonymized, aggregated patterns derived from data across accounts to improve prediction accuracy for all users. This cross-account learning uses only statistical signals — not raw subscriber data — and no information that could identify your business or your subscribers is shared with other customers. We may use these patterns to train, validate, or improve our churn prediction models, including more advanced hierarchical models that share a common prior across accounts while keeping individual data private.

You may opt out of contributing to cross-account model improvement at any time by emailing [email protected]. Opting out does not affect your access to churn predictions.

Acceptable use

You agree not to:

• Use Kirn for any unlawful purpose or in violation of Stripe's terms of service
• Attempt to reverse engineer, scrape, or extract Kirn's scoring models or data
• Share your account credentials or resell access to the service
• Interfere with or disrupt the service or its infrastructure

Availability and changes

We aim to keep Kirn available but do not guarantee uninterrupted access. We may update, modify, or discontinue features at any time. We will give reasonable notice of material changes to the service or these Terms by email or in-app notification.

Termination

You may cancel your account at any time. We may suspend or terminate your account if you violate these Terms or if your payment fails and is not resolved within a reasonable period. On termination, we will delete your data within 30 days unless required by law to retain it.

Limitation of liability

Kirn is provided "as is." We make no guarantees that churn predictions will prevent actual churn or that scores will be accurate for every account type. Churn risk scores are informational — business decisions remain yours.

To the fullest extent permitted by law, Kirn's liability to you for any claim arising from the service is limited to the amount you paid us in the three months preceding the claim.

Governing law

These Terms are governed by the laws of the State of Delaware, United States, without regard to conflict of law principles.

Contact

Questions about these Terms? Email [email protected].