Add PostHog and GA4 for logged-out visitors outside the EEA/UK

docs.json

@@ -54,6 +54,19 @@
       "domain": "docs.fly.io"
     }
   },
+  "footer": {
+    "links": [
+      {
+        "header": "Legal",
+        "items": [
+          {
+            "label": "Privacy Policy",
+            "href": "https://fly.io/legal/privacy-policy/"
+          }
+        ]
+      }
+    ]
+  },
   "navigation": {
     "tabs": [
       {

fly-analytics.js

@@ -0,0 +1,116 @@
+// PostHog and Google (GA4) for docs.fly.io, for logged-out visitors outside the EEA/UK.
+//
+// There is no consent banner here. EEA/UK visitors get nothing beyond Plausible (docs.json
+// `integrations.plausible`, which sets nothing on the device). The banner lives on fly.io only.
+//
+// One self-contained file on purpose: Mintlify runs every .js in the content directory
+// in no guaranteed order, so this loads its own PostHog bundle (the vendored
+// no-external-code build that landing serves from fly.io) instead of relying on another file.
+//
+// docs.fly.io has no server, so it asks ui-ex's /api/consent-scope on fly.io (cross-origin,
+// session cookie included; ui-ex allows exactly https://docs.fly.io) for:
+//   * eu_scope      — did the visitor arrive via an EEA/UK edge?
+//   * authenticated — is the visitor logged in?
+// Anything other than a clear "not EEA/UK, logged out" (including preview hosts, local
+// `mint dev` and network errors) loads nothing.
+(function () {
+  if (window.__flyAnalytics) return;
+  window.__flyAnalytics = true;
+
+  var POSTHOG_KEY = "phc_nuaUijb3iLWut9Kbr56bSHSP4MYdeb8CFd9BgPm3LAVY";
+  var POSTHOG_HOST = "https://posthog.fly.io";
+  var POSTHOG_SRC = "https://fly.io/static/javascripts/posthog.js";
+  var CONSENT_SCOPE_URL = "https://fly.io/api/consent-scope";
+  var GA_ID = "G-EX6DMZ1DZV";
+  var ANALYTICS_BASE = "https://analytics.fly.io";
+
+  fetch(CONSENT_SCOPE_URL, { credentials: "include", headers: { Accept: "application/json" } })
+    .then(function (r) {
+      return r.ok ? r.json() : null;
+    })
+    .catch(function () {
+      return null;
+    })
+    .then(function (data) {
+      if (!data || data.authenticated || data.eu_scope !== false) return;
+      loadPosthog();
+      initGoogle();
+    });
+
+  // Hosts we treat as "us" for referrer attribution: fly.io and any *.fly.io subdomain.
+  function isInternalHost(host, currentHost) {
+    return host === currentHost || host === "fly.io" || host.endsWith(".fly.io");
+  }
+
+  // Rewrite internal referrers to PostHog's "$direct" so moving between fly.io and the
+  // docs doesn't overwrite the real traffic source. Mirrors landing and ui-ex.
+  function scrubInternalReferrer(props, currentHost) {
+    if (!props) return;
+    var pairs = [
+      ["$referring_domain", "$referrer"],
+      ["$initial_referring_domain", "$initial_referrer"],
+    ];
+    for (var i = 0; i < pairs.length; i++) {
+      var domain = props[pairs[i][0]];
+      if (typeof domain === "string" && domain !== "$direct" && isInternalHost(domain, currentHost)) {
+        props[pairs[i][0]] = "$direct";
+        props[pairs[i][1]] = "$direct";
+      }
+    }
+  }
+
+  function beforeSend(event) {
+    if (!event || !event.properties) return event;
+    var currentHost = window.location.hostname;
+    scrubInternalReferrer(event.properties, currentHost);
+    scrubInternalReferrer(event.properties.$set_once, currentHost);
+    return event;
+  }
+
+  function loadPosthog() {
+    loadScript(POSTHOG_SRC, function () {
+      if (typeof window.posthog === "undefined") return;
+      window.posthog.init(POSTHOG_KEY, {
+        api_host: POSTHOG_HOST,
+        ui_host: "https://eu.posthog.com",
+        disable_external_dependency_loading: true,
+        before_send: beforeSend,
+        autocapture: false,
+        capture_dead_clicks: false,
+        rageclick: false,
+        enable_heatmaps: false,
+        disable_session_recording: true,
+        disable_surveys: true,
+        capture_exceptions: false,
+        person_profiles: "identified_only",
+        // Mintlify navigates client-side, so count route changes as pageviews.
+        capture_pageview: "history_change",
+        capture_pageleave: true,
+        persistence: "localStorage+cookie",
+        advanced_disable_decide: true,
+      });
+    });
+  }
+
+  // GA4 (gtag) through the first-party analytics.fly.io proxy, as on fly.io. No GTM: ui-ex
+  // dropped it because it double-reported conversions to GA4.
+  function initGoogle() {
+    window.dataLayer = window.dataLayer || [];
+    window.gtag =
+      window.gtag ||
+      function () {
+        window.dataLayer.push(arguments);
+      };
+    window.gtag("js", new Date());
+    window.gtag("config", GA_ID, { transport_url: ANALYTICS_BASE, first_party_collection: true });
+    loadScript(ANALYTICS_BASE + "/gtag/js?id=" + GA_ID);
+  }
+
+  function loadScript(src, onload) {
+    var s = document.createElement("script");
+    s.async = true;
+    s.src = src;
+    if (onload) s.onload = onload;
+    document.head.appendChild(s);
+  }
+})();