diff --git a/include/xo/gc/SetupGc.hpp b/include/xo/gc/SetupGc.hpp
new file mode 100644
index 0000000..bf5c5c6
--- /dev/null
+++ b/include/xo/gc/SetupGc.hpp
@@ -0,0 +1,20 @@
+/** @file SetupGc.hpp
+ *
+ *  @author Roland Conybeare, Mar 2026
+ **/
+
+#pragma once
+
+namespace xo {
+    namespace mm {
+
+        class SetupGc {
+        public:
+            /** Register gc (facet,impl) combinations with FacetRegistry **/
+            static bool register_facets();
+        };
+
+    } /*namespace mm*/
+} /*namespace xo*/
+
+/* end SetupGc.hpp */
diff --git a/include/xo/gc/init_gc.hpp b/include/xo/gc/init_gc.hpp
new file mode 100644
index 0000000..7270eea
--- /dev/null
+++ b/include/xo/gc/init_gc.hpp
@@ -0,0 +1,21 @@
+/** @file init_gc.hpp
+ *
+ *  @author Roland Conybeare, Mar 2026
+ **/
+
+#pragma once
+
+#include <xo/subsys/Subsystem.hpp>
+
+namespace xo {
+    /* tag to represent the xo-gc/ subsystem within ordered initialization */
+    enum S_gc_tag {};
+
+    template <>
+    struct InitSubsys<S_gc_tag> {
+        static void init();
+        static InitEvidence require();
+    };
+} /*namespace xo*/
+
+/* end init_gc.hpp */
diff --git a/src/gc/MutationLogEntry.cpp b/src/gc/MutationLogEntry.cpp
new file mode 100644
index 0000000..6e3a0ed
--- /dev/null
+++ b/src/gc/MutationLogEntry.cpp
@@ -0,0 +1,22 @@
+/** @file MutationLogEntry.cpp
+ *
+ *  @author Roland Conybeare, Mar 2026
+ **/
+
+#include "MutationLogEntry.hpp"
+
+namespace xo {
+    namespace mm {
+
+        MutationLogEntry::MutationLogEntry(void * parent,
+                                           void ** p_data,
+                                           obj<AGCObject> snap)
+                : parent_{parent},
+                  p_data_{p_data},
+                  snap_{snap}
+        {}
+
+    } /*namespace mm*/
+} /*namespace xo*/
+
+/* end MutationLogEntry.cpp */
diff --git a/src/gc/SetupGc.cpp b/src/gc/SetupGc.cpp
new file mode 100644
index 0000000..f99ea4e
--- /dev/null
+++ b/src/gc/SetupGc.cpp
@@ -0,0 +1,36 @@
+/** @file SetupGc.cpp
+ *
+ *  @author Roland Conybeare, Mar 2026
+ **/
+
+#include "SetupGc.hpp"
+#include "X1Collector.hpp"
+#include <xo/facet/FacetRegistry.hpp>
+#include <xo/indentlog/scope.hpp>
+
+namespace xo {
+    using xo::mm::AAllocator;
+    using xo::mm::ACollector;
+    using xo::mm::DX1Collector;
+    using xo::facet::FacetRegistry;
+    using xo::reflect::typeseq;
+
+    namespace mm {
+
+        bool
+        SetupGc::register_facets()
+        {
+            scope log(XO_DEBUG(true));
+
+            FacetRegistry::register_impl<AAllocator, DX1Collector>();
+            FacetRegistry::register_impl<ACollector, DX1Collector>();
+
+            log && log(xtag("DX1Collector.tseq", typeseq::id<DX1Collector>()));
+            log && log(xtag("ACollector.tseq",  typeseq::id<ACollector>()));
+
+            return true;
+        }
+    }
+} /*namespace xo*/
+
+/* end SetupGc.cpp */
diff --git a/src/gc/X1CollectorConfig.cpp b/src/gc/X1CollectorConfig.cpp
new file mode 100644
index 0000000..812e276
--- /dev/null
+++ b/src/gc/X1CollectorConfig.cpp
@@ -0,0 +1,46 @@
+/** @file X1CollectorConfig.cpp
+ *
+ *  @author Roland Conybeare, Mar 2026
+ **/
+
+#include "X1CollectorConfig.hpp"
+
+namespace xo {
+    namespace mm {
+
+        X1CollectorConfig
+        X1CollectorConfig::with_name(std::string name)
+        {
+            X1CollectorConfig copy = *this;
+            copy.name_ = std::move(name);
+            return copy;
+        }
+
+        X1CollectorConfig
+        X1CollectorConfig::with_size(std::size_t gen_z)
+        {
+            X1CollectorConfig copy = *this;
+            copy.arena_config_ = arena_config_.with_size(gen_z);
+            return copy;
+        }
+
+        X1CollectorConfig
+        X1CollectorConfig::with_debug_flag(bool x)
+        {
+            X1CollectorConfig copy = *this;
+            copy.debug_flag_ = x;
+            return copy;
+        }
+
+        X1CollectorConfig
+        X1CollectorConfig::with_sanitize_flag(bool x)
+        {
+            X1CollectorConfig copy = *this;
+            copy.sanitize_flag_ = x;
+            return copy;
+        }
+
+    } /*namespace mm*/
+} /*namespace xo*/
+
+/* end X1CollectorConfig.cpp */
diff --git a/src/gc/init_gc.cpp b/src/gc/init_gc.cpp
new file mode 100644
index 0000000..8747229
--- /dev/null
+++ b/src/gc/init_gc.cpp
@@ -0,0 +1,34 @@
+/** @file init_gc.cpp
+ *
+ *  @author Roland Conybeare, Mar 2026
+ **/
+
+#include "init_gc.hpp"
+#include "SetupGc.hpp"
+#include <xo/alloc2/init_alloc2.hpp>
+
+namespace xo {
+    using xo::mm::SetupGc;
+
+    void
+    InitSubsys<S_gc_tag>::init()
+    {
+        SetupGc::register_facets();
+    }
+
+    InitEvidence
+    InitSubsys<S_gc_tag>::require() {
+        InitEvidence retval;
+
+        /* recursive subsystem deps for xo-gc/ */
+        retval ^= InitSubsys<S_alloc2_tag>::require();
+
+        /* xo-gc/'s own initialization code */
+        retval ^= Subsystem::provide<S_gc_tag>("gc", &init);
+
+        return retval;
+    }
+
+} /*namespace xo*/
+
+/* end init_gc.cpp */