Cookies — FerrLens

FerrLens runs entirely on one surface: the site at ferrlens.com, which serves both the marketing pages and the tools.

  <h2>Anonymous tool use</h2>
  <p>
    Running a tool without signing in sets <strong>no cookie</strong>. Tool inputs you share are
    encoded in the URL fragment, never uploaded. The only client-side storage is an optional
    <code>lang-pref</code> entry in <code>localStorage</code> remembering your language choice.
  </p>

  <h2>Signed-in sessions</h2>
  <p>The shared FerrLabs identity provider sets a session cookie when you sign in:</p>
  <ul>
    <li>
      <code>__Secure-fl_session</code> (or <code>fl_session</code> in development) — the session
      JWT, scoped to <code>.ferrlens.com</code>, <code>HttpOnly</code> and <code>Secure</code>.
    </li>
  </ul>
  <p>
    It is read server-side by the FerrLabs API to authenticate your tool history and API quota.
    See the
    <a href="https://ferrlabs.com/cookies">canonical FerrLabs cookie policy</a> for the IdP
    details.
  </p>