Radius Alpha – Privacy Policy

2 November 2026

This Privacy Policy explains how Earendil Works Co. ("Earendil," "we," "us" or "our") collects, uses and discloses personal data when you use Radius. "Personal data" means any information that relates to an identified or identifiable person. Radius is an early, pre-release service, and this policy describes how it works today.

1. Information we collect

• Account information. Your email address, sign-in details, the organizations you belong to and your role in them, and the API keys you create.
• Billing information. Our payment provider, Stripe, processes card payments. We receive limited billing details from Stripe.
• Usage data. Information about how you use Radius, such as the models you use, the number of tokens, cost, response times and whether requests succeed. Usage data powers the analytics you see in Radius and never includes the content of your prompts or responses.
• Content you choose to provide and store. Artifacts you publish, sessions you attach to a bug report, provider keys you add for BYOK, and the connections you configure.
• Communications. What you send us through support, feedback or research conversations.
• Technical information. Information such as your approximate location and network or device details, which we use to secure Radius and prevent abuse.

2. How we use information

• Service operation: to provide Radius, route your requests and run the features you use.
• Analytics and improvement: to show you your usage, and to improve and tailor Radius, including by creating aggregated statistics that do not identify you or your organization.
• Account administration and billing: to manage your account and organization and process payments.
• Support and communication: to respond to you and tell you about Radius, including changes to it.
• Security and abuse prevention: to protect Radius, our users and our partners.
• Legal and compliance: to meet our legal obligations and enforce our Terms of Service.

3. Your prompts and responses

Radius processes your prompts, files and responses only to handle your requests, and does not store them afterwards or use them to train models. We may keep short-lived descriptions of images in memory, so the same image is not processed twice, and limited error information for security and debugging; our error monitoring excludes prompts and responses. If you ask us to debug a session, you choose what to send us.

We use our technology partner OpenRouter, Inc. ("OpenRouter") to route your requests to the companies that provide each model ("model providers"). Whether a model provider keeps your prompts and responses, or uses them for training, depends on the model, as shown in our Model catalog. Our agreement with OpenRouter includes data protection commitments. OpenRouter may also classify prompts, without storing them, to produce anonymous statistics about how its service is used, and may use anonymized usage data, such as the model and token counts, to provide and improve its service. When you use your own provider keys (BYOK), your requests go directly to that provider, not through OpenRouter, and your agreement with that provider governs how it handles your content.

If your organization turns on web search, your search queries go to our search provider. Whether the provider keeps them depends on the search option your organization chooses, as described in our web search documentation.

4. How we disclose information

In the normal course of providing Radius, your account information and other personal data stay with us and the service providers that help us run Radius. We disclose information only in the cases below.

• Corporate affiliates. Other companies in the Earendil group that help us run and support Radius, under the same protections as this Privacy Policy.
• Your organization. Its administrators can manage your account and see your usage.
• Service providers. Your prompts and responses go to OpenRouter and the model provider that serves the model you choose only to process your request, as described in Section 3, together with a pseudonymous identifier that helps them prevent abuse. Other providers help us with payments, web search (if your organization turns it on), hosting and error monitoring, and receive only what they need for that purpose.
• At your direction. When you share an artifact or connect a third-party service, we share the information you choose to share.
• Partners and the public. Only aggregated statistics that do not identify you or your organization.
• Misuse and legal requirements. If OpenRouter or a model provider reasonably suspects that an account has broken its terms or the law, we may share limited account information with it, only to investigate. Recipients must delete it within 12 months, with limited exceptions, such as where the law requires them to keep it. We may also disclose information to legal or public authorities when the law requires it, or to protect Radius, our users or the public.
• Corporate transactions. If Earendil is involved in a merger, acquisition or sale of assets, your information may be transferred as part of that transaction.

We do not sell your personal data or use it for targeted advertising.

5. Retention and international transfers

We keep account, billing and usage data while your account is active. When we delete your account at your request, we delete your account information and anonymize your usage data. We keep billing records as tax law requires. We may keep anonymized or aggregated usage data that cannot be linked to you, and we will not try to re-identify it.

Artifacts are kept until you delete them or they expire under your organization's settings, which by default is 90 days. Bug reports expire automatically.

We store your personal data in the United States. Some of our service providers may process it in other countries. Where data protection law requires it, we use appropriate safeguards for these transfers.

6. Your rights

You can ask us to access, correct or delete your personal data, or exercise any other right described below, by contacting feedback@earendil.com. We aim to respond within two weeks.

Where EU or UK law applies, we process personal data to perform our agreement with you; for our legitimate interests in operating, securing and improving Radius, preventing misuse and producing aggregated statistics; to comply with the law; and with your consent where required. Depending on where you live, you may have the right to access, correct, delete, restrict or port your data, to object to processing, to withdraw consent, and to complain to a data protection authority where you live.

If you belong to an organization, its administrators control parts of your account. This Privacy Policy is not a data processing agreement.

7. Changes and contact

Radius is not intended for anyone under 18. We may update this Privacy Policy and will tell you about material changes. Radius is provided by Earendil Works Co., 251 Little Falls Drive, Wilmington, DE 19808, United States.

For questions or requests, contact feedback@earendil.com and tell us which Radius account or organization your request is about.