diff --git a/src/main.cpp b/src/main.cpp
index 6c16588..f8d35c7 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -4,6 +4,7 @@
 #include "metric.hpp"
 #include "perfetto_categories.hpp"
 #include "process_collector.hpp"
+#include "reference.hpp"
 #include "server.hpp"
 #include <csignal>
 #include <cstring>
@@ -181,7 +182,7 @@ int main(int argc, char *argv[]) {
 #endif
 
   // Register the process collector for default metrics.
-  metric::register_collector(std::make_shared<ProcessCollector>());
+  metric::register_collector(make_ref<ProcessCollector>());
 
   std::string config_file = "config.toml";
 
diff --git a/src/metric.cpp b/src/metric.cpp
index 09eef40..e1194f5 100644
--- a/src/metric.cpp
+++ b/src/metric.cpp
@@ -444,7 +444,7 @@ struct Metric {
   }
 
   static auto &get_collectors() {
-    using CollectorRegistry = std::vector<std::shared_ptr<Collector>>;
+    using CollectorRegistry = std::vector<Ref<Collector>>;
     static CollectorRegistry *collectors = new CollectorRegistry();
     return *collectors;
   }
@@ -1803,7 +1803,7 @@ void reset_metrics_for_testing() {
   // when threads exit naturally
 }
 
-void register_collector(std::shared_ptr<Collector> collector) {
+void register_collector(Ref<Collector> collector) {
   std::unique_lock<std::mutex> _{Metric::mutex};
   ++Metric::registration_version;
   Metric::get_collectors().push_back(std::move(collector));
diff --git a/src/metric.hpp b/src/metric.hpp
index dbd2ea5..457cd72 100644
--- a/src/metric.hpp
+++ b/src/metric.hpp
@@ -51,6 +51,7 @@
 #include <vector>
 
 #include "arena.hpp"
+#include "reference.hpp"
 
 namespace metric {
 
@@ -255,12 +256,12 @@ struct Collector {
 /**
  * @brief Register a collector with the metrics system.
  *
- * The system will hold a shared_ptr to the collector and call its collect()
+ * The system will hold a Ref to the collector and call its collect()
  * method during each metric rendering.
  *
- * @param collector A shared_ptr to the collector to be registered.
+ * @param collector A Ref to the collector to be registered.
  */
-void register_collector(std::shared_ptr<Collector> collector);
+void register_collector(Ref<Collector> collector);
 
 // Note: Histograms do not support callbacks due to their multi-value nature
 // (buckets + sum + count). Use static histogram metrics only.
diff --git a/src/reference.hpp b/src/reference.hpp
index 53d32d6..ca56a84 100644
--- a/src/reference.hpp
+++ b/src/reference.hpp
@@ -135,6 +135,18 @@ template <typename T> struct Ref {
     }
   }
 
+  /**
+   * @brief Converting copy constructor for polymorphism (Derived -> Base)
+   */
+  template <typename U>
+  Ref(const Ref<U> &other) noexcept
+    requires std::is_convertible_v<U *, T *>
+      : ptr(other.ptr), control_block(other.control_block) {
+    if (control_block) {
+      control_block->increment_strong();
+    }
+  }
+
   /**
    * @brief Copy assignment operator
    */
@@ -150,6 +162,22 @@ template <typename T> struct Ref {
     return *this;
   }
 
+  /**
+   * @brief Converting assignment operator for polymorphism (Derived -> Base)
+   */
+  template <typename U>
+  Ref &operator=(const Ref<U> &other) noexcept
+    requires std::is_convertible_v<U *, T *>
+  {
+    release();
+    ptr = other.ptr;
+    control_block = other.control_block;
+    if (control_block) {
+      control_block->increment_strong();
+    }
+    return *this;
+  }
+
   /**
    * @brief Move constructor - transfers ownership
    */
@@ -159,6 +187,17 @@ template <typename T> struct Ref {
     other.control_block = nullptr;
   }
 
+  /**
+   * @brief Converting move constructor for polymorphism (Derived -> Base)
+   */
+  template <typename U>
+  Ref(Ref<U> &&other) noexcept
+    requires std::is_convertible_v<U *, T *>
+      : ptr(other.ptr), control_block(other.control_block) {
+    other.ptr = nullptr;
+    other.control_block = nullptr;
+  }
+
   /**
    * @brief Move assignment operator
    */
@@ -173,6 +212,22 @@ template <typename T> struct Ref {
     return *this;
   }
 
+  /**
+   * @brief Converting move assignment operator for polymorphism (Derived ->
+   * Base)
+   */
+  template <typename U>
+  Ref &operator=(Ref<U> &&other) noexcept
+    requires std::is_convertible_v<U *, T *>
+  {
+    release();
+    ptr = other.ptr;
+    control_block = other.control_block;
+    other.ptr = nullptr;
+    other.control_block = nullptr;
+    return *this;
+  }
+
   /**
    * @brief Reset to empty state
    */
@@ -233,6 +288,7 @@ private:
   friend Ref<U> make_ref(Args &&...args);
 
   template <typename U> friend struct WeakRef;
+  template <typename U> friend struct Ref;
 };
 
 /**
@@ -302,6 +358,83 @@ template <typename T> struct WeakRef {
     }
   }
 
+  /**
+   * @brief Converting copy constructor from WeakRef for polymorphism
+   */
+  template <typename U>
+  WeakRef(const WeakRef<U> &other) noexcept
+    requires std::is_convertible_v<U *, T *>
+      : control_block(other.control_block) {
+    if (control_block) {
+      control_block->increment_weak();
+    }
+  }
+
+  /**
+   * @brief Converting copy constructor from Ref for polymorphism
+   */
+  template <typename U>
+  WeakRef(const Ref<U> &ref) noexcept
+    requires std::is_convertible_v<U *, T *>
+      : control_block(ref.control_block) {
+    if (control_block) {
+      control_block->increment_weak();
+    }
+  }
+
+  /**
+   * @brief Converting copy assignment from WeakRef for polymorphism
+   */
+  template <typename U>
+  WeakRef &operator=(const WeakRef<U> &other) noexcept
+    requires std::is_convertible_v<U *, T *>
+  {
+    release();
+    control_block = other.control_block;
+    if (control_block) {
+      control_block->increment_weak();
+    }
+    return *this;
+  }
+
+  /**
+   * @brief Converting copy assignment from Ref for polymorphism
+   */
+  template <typename U>
+  WeakRef &operator=(const Ref<U> &ref) noexcept
+    requires std::is_convertible_v<U *, T *>
+  {
+    release();
+    control_block = ref.control_block;
+    if (control_block) {
+      control_block->increment_weak();
+    }
+    return *this;
+  }
+
+  /**
+   * @brief Converting move constructor from WeakRef for polymorphism
+   */
+  template <typename U>
+  WeakRef(WeakRef<U> &&other) noexcept
+    requires std::is_convertible_v<U *, T *>
+      : control_block(other.control_block) {
+    other.control_block = nullptr;
+  }
+
+  /**
+   * @brief Converting move assignment from WeakRef for polymorphism
+   */
+  template <typename U>
+  WeakRef &operator=(WeakRef<U> &&other) noexcept
+    requires std::is_convertible_v<U *, T *>
+  {
+    release();
+    control_block = other.control_block;
+    other.control_block = nullptr;
+    return *this;
+  }
+
   /**
    * @brief Copy assignment from WeakRef
    */
@@ -393,6 +526,7 @@ private:
   }
 
   template <typename U> friend struct Ref;
+  template <typename U> friend struct WeakRef;
 };
 
 /**
diff --git a/src/server.hpp b/src/server.hpp
index 2db4710..357b911 100644
--- a/src/server.hpp
+++ b/src/server.hpp
@@ -9,6 +9,7 @@
 #include "config.hpp"
 #include "connection_handler.hpp"
 #include "connection_registry.hpp"
+#include "reference.hpp"
 
 /**
  * High-performance multi-threaded server for handling network connections.
diff --git a/tests/test_reference.cpp b/tests/test_reference.cpp
index 7cd7d84..6968779 100644
--- a/tests/test_reference.cpp
+++ b/tests/test_reference.cpp
@@ -19,6 +19,28 @@ struct Node {
 
   explicit Node(int d) : data(d) {}
 };
+
+// Classes for polymorphism testing
+struct Base {
+  int base_value;
+  explicit Base(int v) : base_value(v) {}
+  virtual ~Base() = default;
+  virtual int get_value() const { return base_value; }
+};
+
+struct Derived : public Base {
+  int derived_value;
+  explicit Derived(int base_v, int derived_v)
+      : Base(base_v), derived_value(derived_v) {}
+  int get_value() const override { return base_value + derived_value; }
+};
+
+struct AnotherDerived : public Base {
+  int another_value;
+  explicit AnotherDerived(int base_v, int another_v)
+      : Base(base_v), another_value(another_v) {}
+  int get_value() const override { return base_value * another_value; }
+};
 } // anonymous namespace
 
 TEST_CASE("Ref basic functionality") {
@@ -257,3 +279,169 @@ TEST_CASE("WeakRef prevents circular references") {
     CHECK(!child->parent.lock());
   }
 }
+
+TEST_CASE("Polymorphic Ref conversions") {
+  SUBCASE("copy construction from derived to base") {
+    auto derived_ref = make_ref<Derived>(10, 20);
+    CHECK(derived_ref->get_value() == 30); // 10 + 20
+
+    // Convert Ref<Derived> to Ref<Base>
+    Ref<Base> base_ref = derived_ref;
+    CHECK(base_ref);
+    CHECK(base_ref->get_value() == 30); // Virtual dispatch works
+    CHECK(base_ref->base_value == 10);
+
+    // Both should point to same object
+    CHECK(base_ref.get() == derived_ref.get());
+  }
+
+  SUBCASE("copy assignment from derived to base") {
+    auto derived_ref = make_ref<Derived>(5, 15);
+    auto base_ref = make_ref<Base>(100);
+
+    // Before assignment
+    CHECK(base_ref->get_value() == 100);
+
+    // Assign derived to base
+    base_ref = derived_ref;
+    CHECK(base_ref->get_value() == 20); // 5 + 15
+    CHECK(base_ref.get() == derived_ref.get());
+  }
+
+  SUBCASE("move construction from derived to base") {
+    auto derived_ref = make_ref<Derived>(7, 3);
+    Base *original_ptr = derived_ref.get();
+
+    // Move construct base from derived
+    Ref<Base> base_ref = std::move(derived_ref);
+    CHECK(base_ref);
+    CHECK(base_ref->get_value() == 10); // 7 + 3
+    CHECK(base_ref.get() == original_ptr);
+    CHECK(!derived_ref); // Original should be empty after move
+  }
+
+  SUBCASE("move assignment from derived to base") {
+    auto derived_ref = make_ref<Derived>(8, 12);
+    auto base_ref = make_ref<Base>(200);
+    Base *derived_ptr = derived_ref.get();
+
+    // Move assign
+    base_ref = std::move(derived_ref);
+    CHECK(base_ref);
+    CHECK(base_ref->get_value() == 20); // 8 + 12
+    CHECK(base_ref.get() == derived_ptr);
+    CHECK(!derived_ref); // Should be empty after move
+  }
+
+  SUBCASE("multiple inheritance levels") {
+    auto another_derived = make_ref<AnotherDerived>(6, 4);
+    CHECK(another_derived->get_value() == 24); // 6 * 4
+
+    // Convert to base
+    Ref<Base> base_ref = another_derived;
+    CHECK(base_ref->get_value() == 24); // Virtual dispatch
+    CHECK(base_ref.get() == another_derived.get());
+  }
+}
+
+TEST_CASE("Polymorphic WeakRef conversions") {
+  SUBCASE("WeakRef copy construction from derived to base") {
+    auto derived_ref = make_ref<Derived>(3, 7);
+
+    // Create WeakRef<Derived>
+    WeakRef<Derived> weak_derived = derived_ref;
+
+    // Convert to WeakRef<Base>
+    WeakRef<Base> weak_base = weak_derived;
+
+    // Both should lock to same object
+    auto locked_derived = weak_derived.lock();
+    auto locked_base = weak_base.lock();
+
+    CHECK(locked_derived);
+    CHECK(locked_base);
+    CHECK(locked_derived.get() == locked_base.get());
+    CHECK(locked_base->get_value() == 10); // 3 + 7
+  }
+
+  SUBCASE("WeakRef copy assignment from derived to base") {
+    auto derived_ref = make_ref<Derived>(4, 6);
+    auto base_ref = make_ref<Base>(999);
+
+    WeakRef<Derived> weak_derived = derived_ref;
+    WeakRef<Base> weak_base = base_ref;
+
+    // Assign derived weak ref to base weak ref
+    weak_base = weak_derived;
+
+    auto locked = weak_base.lock();
+    CHECK(locked);
+    CHECK(locked->get_value() == 10); // 4 + 6
+    CHECK(locked.get() == derived_ref.get());
+  }
+
+  SUBCASE("WeakRef from Ref<Derived> to WeakRef<Base>") {
+    auto derived_ref = make_ref<Derived>(2, 8);
+
+    // Create WeakRef<Base> directly from Ref<Derived>
+    WeakRef<Base> weak_base = derived_ref;
+
+    auto locked = weak_base.lock();
+    CHECK(locked);
+    CHECK(locked->get_value() == 10); // 2 + 8
+    CHECK(locked.get() == derived_ref.get());
+  }
+
+  SUBCASE("WeakRef move operations") {
+    auto derived_ref = make_ref<Derived>(1, 9);
+    WeakRef<Derived> weak_derived = derived_ref;
+
+    // Move construct
+    WeakRef<Base> weak_base = std::move(weak_derived);
+
+    // Original should be empty, new should work
+    CHECK(!weak_derived.lock());
+
+    auto locked = weak_base.lock();
+    CHECK(locked);
+    CHECK(locked->get_value() == 10); // 1 + 9
+  }
+}
+
+TEST_CASE("Polymorphic edge cases") {
+  SUBCASE("empty Ref conversions") {
+    Ref<Derived> empty_derived;
+    CHECK(!empty_derived);
+
+    // Convert empty derived to base
+    Ref<Base> empty_base = empty_derived;
+    CHECK(!empty_base);
+
+    // Move empty derived to base
+    Ref<Base> moved_base = std::move(empty_derived);
+    CHECK(!moved_base);
+  }
+
+  SUBCASE("empty WeakRef conversions") {
+    WeakRef<Derived> empty_weak_derived;
+    CHECK(!empty_weak_derived.lock());
+
+    // Convert empty weak derived to weak base
+    WeakRef<Base> empty_weak_base = empty_weak_derived;
+    CHECK(!empty_weak_base.lock());
+  }
+
+  SUBCASE("mixed Ref and WeakRef conversions") {
+    auto derived_ref = make_ref<Derived>(5, 5);
+
+    // Ref<Derived> → WeakRef<Base>
+    WeakRef<Base> weak_base_from_ref = derived_ref;
+
+    // WeakRef<Base> → Ref<Base> via lock
+    auto base_ref_from_weak = weak_base_from_ref.lock();
+
+    CHECK(base_ref_from_weak);
+    CHECK(base_ref_from_weak->get_value() == 10); // 5 + 5
+    CHECK(base_ref_from_weak.get() == derived_ref.get());
+  }
+}