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diff --git a/toolkit/components/glean/bindings/private/Event.h b/toolkit/components/glean/bindings/private/Event.h
new file mode 100644
index 0000000000..c0907252a5
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+++ b/toolkit/components/glean/bindings/private/Event.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_glean_GleanEvent_h
+#define mozilla_glean_GleanEvent_h
+
+#include "nsIGleanMetrics.h"
+#include "mozilla/glean/bindings/EventGIFFTMap.h"
+#include "mozilla/glean/fog_ffi_generated.h"
+#include "mozilla/ResultVariant.h"
+
+#include "nsString.h"
+#include "nsTArray.h"
+
+namespace mozilla::glean {
+
+// forward declaration
+class GleanEvent;
+
+namespace impl {
+
+/**
+ * Represents the recorded data for a single event
+ */
+struct RecordedEvent {
+ public:
+  uint64_t mTimestamp;
+  nsCString mCategory;
+  nsCString mName;
+
+  nsTArray<std::tuple<nsCString, nsCString>> mExtra;
+};
+
+template <class T>
+class EventMetric {
+  friend class mozilla::glean::GleanEvent;
+
+ public:
+  constexpr explicit EventMetric(uint32_t id) : mId(id) {}
+
+  /**
+   * Record an event.
+   *
+   * @param aExtras The list of (extra key, value) pairs. Allowed extra keys are
+   *                defined in the metric definition.
+   *                If the wrong keys are used or values are too large
+   *                an error is report and no event is recorded.
+   */
+  void Record(const Maybe<T>& aExtras = Nothing()) const {
+    auto id = EventIdForMetric(mId);
+    if (id) {
+      // NB. In case `aExtras` is filled we call `ToFfiExtra`, causing
+      // twice the required allocation. We could be smarter and reuse the data.
+      // But this is GIFFT-only allocation, so wait to be told it's a problem.
+      Maybe<CopyableTArray<Telemetry::EventExtraEntry>> telExtras;
+      if (aExtras) {
+        CopyableTArray<Telemetry::EventExtraEntry> extras;
+        auto serializedExtras = aExtras->ToFfiExtra();
+        auto keys = std::move(std::get<0>(serializedExtras));
+        auto values = std::move(std::get<1>(serializedExtras));
+        for (size_t i = 0; i < keys.Length(); i++) {
+          extras.EmplaceBack(Telemetry::EventExtraEntry{keys[i], values[i]});
+        }
+        telExtras = Some(extras);
+      }
+      Telemetry::RecordEvent(id.extract(), Nothing(), telExtras);
+    }
+    if (aExtras) {
+      auto extra = aExtras->ToFfiExtra();
+      fog_event_record(mId, &std::get<0>(extra), &std::get<1>(extra));
+    } else {
+      nsTArray<nsCString> keys;
+      nsTArray<nsCString> vals;
+      fog_event_record(mId, &keys, &vals);
+    }
+  }
+
+  /**
+   * **Test-only API**
+   *
+   * Get a list of currently stored events for this event metric.
+   *
+   * This function will attempt to await the last parent-process task (if any)
+   * writing to the the metric's storage engine before returning a value.
+   * This function will not wait for data from child processes.
+   *
+   * This doesn't clear the stored value.
+   * Parent process only. Panics in child processes.
+   *
+   * @param aPingName The (optional) name of the ping to retrieve the metric
+   *        for. Defaults to the first value in `send_in_pings`.
+   *
+   * @return value of the stored metric, or Nothing() if there is no value.
+   */
+  Result<Maybe<nsTArray<RecordedEvent>>, nsCString> TestGetValue(
+      const nsACString& aPingName = nsCString()) const {
+    nsCString err;
+    if (fog_event_test_get_error(mId, &err)) {
+      return Err(err);
+    }
+
+    if (!fog_event_test_has_value(mId, &aPingName)) {
+      return Maybe<nsTArray<RecordedEvent>>();
+    }
+
+    nsTArray<FfiRecordedEvent> events;
+    fog_event_test_get_value(mId, &aPingName, &events);
+
+    nsTArray<RecordedEvent> result;
+    for (const auto& event : events) {
+      auto ev = result.AppendElement();
+      ev->mTimestamp = event.timestamp;
+      ev->mCategory.Append(event.category);
+      ev->mName.Assign(event.name);
+
+      MOZ_ASSERT(event.extras.Length() % 2 == 0);
+      ev->mExtra.SetCapacity(event.extras.Length() / 2);
+      for (unsigned int i = 0; i < event.extras.Length(); i += 2) {
+        // keys & values are interleaved.
+        nsCString key = std::move(event.extras[i]);
+        nsCString value = std::move(event.extras[i + 1]);
+        ev->mExtra.AppendElement(
+            std::make_tuple(std::move(key), std::move(value)));
+      }
+    }
+    return Some(std::move(result));
+  }
+
+ private:
+  static const nsCString ExtraStringForKey(uint32_t aKey);
+
+  const uint32_t mId;
+};
+
+}  // namespace impl
+
+struct NoExtraKeys {
+  std::tuple<nsTArray<nsCString>, nsTArray<nsCString>> ToFfiExtra() const {
+    nsTArray<nsCString> extraKeys;
+    nsTArray<nsCString> extraValues;
+    return std::make_tuple(std::move(extraKeys), std::move(extraValues));
+  }
+};
+
+class GleanEvent final : public nsIGleanEvent {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIGLEANEVENT
+
+  explicit GleanEvent(uint32_t id) : mEvent(id){};
+
+ private:
+  virtual ~GleanEvent() = default;
+
+  const impl::EventMetric<NoExtraKeys> mEvent;
+};
+
+}  // namespace mozilla::glean
+
+#endif /* mozilla_glean_GleanEvent.h */