Privacy Policy
Osprey: Browser Protection is committed to protecting your privacy. This Privacy Policy explains what data is processed when you use the Osprey browser extension and its supporting proxy service, and how it is handled.
Osprey consists of two components:
- The browser extension, which runs locally on your device
- The proxy server, hosted in New York, NY at api.osprey.ac
How URL checking works
When you navigate to a website, the browser extension sends the URL to the proxy server, which checks it against threat intelligence providers, DNS filtering services, and local threat intelligence lists.
Providers never see which specific websites you visit. All checks are routed through the proxy server, so providers only ever see requests originating from the proxy's IP address, not yours. Thousands of users' checks are mixed together from a single IP, making it practically impossible for any provider to associate a URL lookup with you specifically.
Most URLs are never sent to providers at all. The proxy server maintains a cache of previously checked URLs. If a URL has already been recently evaluated, the result is returned from cache without contacting any provider.
When a URL does reach a provider, the data sent depends on the provider type:
- DNS-based providers receive only the hostname, never the full URL or path
- API-based providers receive the full URL with query parameters stripped
- Local threat intelligence lists are checked entirely in-memory on the proxy server, with no external calls per request
Your IP address
The proxy server uses your IP address solely for abuse protections such as rate limiting. For this purpose, your IP is immediately hashed and stored in-memory. Raw IP addresses are not written to disk as part of normal proxy operation.
Third-party integrations
If you configure a provider using your own API key (for example, MetaDefender), that provider receives requests directly from your device rather than through the proxy server. The privacy protections described above, meaning IP shielding and caching, do not apply to those integrations. You are subject to that provider's own data handling practices when using a personal API key.
Browser permissions
The extension requires the following permissions, used strictly for its security features:
- tabs: Detects tab navigation events.
- webNavigation: Observes navigation events so that destination URLs can be checked.
- storage: Caches results locally and persists your settings.
- https://api.osprey.ac/*: Allows the extension to send URLs to the Osprey proxy server for checking.
- https://api.metadefender.com/*: Allows the extension to contact the MetaDefender API directly, only when you configure your own MetaDefender API key.
The extension does not request host access to the websites you browse. It cannot read page content, inject scripts, or access cookies or form data on the sites you visit. The URLs you navigate to are observed only through the browser's navigation events, which expose the destination URL but not the contents of the page.
Data stored locally
The extension stores the following data in your browser's storage:
- Allowed cache: URLs checked and found safe, stored per provider with an expiration time.
- Blocked cache: URLs that were flagged, stored per provider with an expiration time and threat type.
- Processing cache: URLs currently being checked to prevent duplicate requests. Stored in-memory only.
- Your settings: Enabled providers, cache expiration preferences, and other protection settings.
All local storage data is cleared when you uninstall the extension, or when you clear the list of excluded websites using the settings page. None of it is transmitted to the proxy server or any third party.
Operational monitoring
The proxy server uses standard operational tooling (Micrometer, Prometheus, Grafana) to monitor service health, stability, and capacity. Metrics include aggregated counts such as requests per provider, cache hit/miss rates, and system performance indicators. This data is used solely for service reliability and abuse prevention, not for advertising or user profiling.
False-positive monitoring
To catch cases where a legitimate website is mistakenly flagged as dangerous, the proxy server keeps a transient log entry whenever a provider returns a malicious or phishing verdict. Each entry records only the provider name, the verdict, and the same value that was checked against that provider: a hostname for DNS-based providers, or the URL with query parameters stripped for URL-based providers. It never includes the query string, your IP address, or any other identifier that could tie the lookup back to you.
Results that come back safe are never logged. These entries exist only in memory, are not written to disk, and are not sent to any external system. They are lost when the proxy restarts.
Data retention
On the proxy server, rate-limit states, local list snapshots, and transient runtime logs (including the false-positive monitoring entries described above) exist only in memory and may be lost on restart. Aggregated operational metrics may be retained longer in Prometheus and Grafana, subject to those systems' retention settings.
Changes to this policy
We may update this Privacy Policy from time to time. The effective date at the top reflects the most recent revision.
Contact
For privacy-related questions, contact us at support@osprey.ac.