Privacy and support information for the browser extension by 301.st.
View the Project on GitHub investblog/agent-readiness-inspector
Last updated: August 2, 2026
Agent Readiness Inspector is a browser extension for Microsoft Edge, Google Chrome, and Mozilla Firefox. It audits websites against open standards used by AI agents.
The developer, 301.st, does not collect, receive, sell, or use your browsing data. The extension processes audit data in your browser and transfers none of it to 301.st. Two narrow exceptions are described under Network requests: a DNS lookup that one check needs, and the blog feed, if you switch it on.
To perform its user-facing audit, the extension handles:
The extension does not include analytics, advertising, telemetry, crash reporting, tracking identifiers, or remotely hosted code.
Data is stored only in the browser profile:
| Data | Purpose | Retention |
|---|---|---|
| Saved site origins | Dashboard, batch scans, and monitoring | Until you remove the site |
| Scan history for saved sites | Trends and regression detection | Latest 50 scans per site |
| Monitoring alerts | Local alert inbox | Latest 50 alerts |
| Settings | Your selected checks and preferences | Until changed or the extension is removed |
| Session score cache | Avoid repeated scans while browsing | Up to 100 origins; entries expire after 10 minutes and the cache ends with the browser session |
A manual scan of an unsaved site does not create persistent scan history. Removing a saved site removes its history and related alerts. Uninstalling the extension removes its local data.
The audit consists of HTTP requests to the site you selected. Public machine
files such as robots.txt, sitemaps, and /.well-known/ resources are fetched
without cookies. The site’s root page and its markdown variants may be fetched
with the current browser session so the audit can reflect authenticated pages.
Response data is evaluated locally and is not sent to 301.st.
Requests may also occur later when you explicitly put a saved site on watch, or while browsing if you enable the off-by-default auto-scan setting. A site receives normal network information such as your IP address and request headers. If the site redirects a request, the browser follows that redirect. The destination site’s own privacy policy applies.
One check, DNS-AID, asks whether a site publishes _index._agents SVCB records
and whether that answer is DNSSEC-validated. Browsers expose no DNS API, so the
extension performs this as a DNS-over-HTTPS request to Cloudflare’s public
resolver at cloudflare-dns.com. The resolver receives the queried name — the
audited hostname prefixed with _index._agents — and ordinary request metadata
such as your IP address. It receives no page content, no cookies, and nothing
about what you were reading. Cloudflare’s privacy policy governs its processing.
Off by default. Nothing is requested until you enable it in Dashboard settings.
Once enabled, the extension reads a public JSON feed of published posts at
301.sh/posts.json every six hours. The request carries no identifier and no
information about you or the sites you audit; 301.st sees an ordinary read of a
public file, the same as a browser visiting the blog. New posts are filed in
your local inbox. Disabling it stops the schedule.
Earlier versions offered an optional comparison that sent an API token, Account
ID and target URL to api.cloudflare.com. That feature was removed in v0.1.1,
along with Firefox’s authenticationInfo and browsingActivity data
permissions, which existed only to serve it. Any credentials a previous version
stored are deleted when this version first runs.
The extension contains links to standards documentation, GitHub, and 301.st. They open only when you select them. The destination’s privacy policy applies.
The extension sends no analytics and makes no install or update tracking request
to 301.st. When you uninstall the extension, the browser opens the visible
301.st/contact feedback page with campaign parameters identifying the extension
and the uninstall action. No scan results, saved sites, settings, or unique user
identifier are included in that URL. The destination receives the ordinary
request information described above under “Links and third-party destinations.”
<all_urls>): required to audit whichever HTTP or
HTTPS site you choose, read its response headers, and fetch its machine files.
The extension does not inject promotional content into pages.301.st has no server receiving extension audit data and cannot access data in your browser profile. We do not sell user data or use it for advertising, creditworthiness, or any purpose unrelated to the extension’s single purpose. No person at 301.st can read your scan data.
The extension’s use of information received from browser APIs complies with the Chrome Web Store User Data Policy, including its Limited Use requirements.
You can remove a saved site and its history, clear monitoring alerts, disable watch or auto-scan, revoke optional permissions in the browser, or uninstall the extension to remove all extension data.
The extension is a developer and webmaster tool and is not directed at children.
Material changes will appear on this page with a new date. Changes that affect data leaving the browser will also be disclosed in the extension UI or release notes as required.
Questions: 301.st/contact Issues: github.com/investblog/agent-readiness-inspector/issues