diff --git a/idl/RuntimeContext.json5 b/idl/RuntimeContext.json5
index fe1254b..481d0cb 100644
--- a/idl/RuntimeContext.json5
+++ b/idl/RuntimeContext.json5
@@ -31,6 +31,11 @@
             definition: "xo::mm::AAllocator",
             doc: [ "xo memory allocator" ],
         },
+        {
+            name: "ACollector",
+            definition: "xo::mm::ACollector",
+            doc: [ "xo garbage collector" ],
+        },
         {
             name: "MemorySizeVisitor",
             definition: "xo::mm::MemorySizeVisitor",
@@ -47,6 +52,15 @@
             noexcept: true,
             attributes: [],
         },
+        {
+            name: "collector",
+            doc: [ "collector facet for allocator. If non-null, same data pointer as allocator" ],
+            return_type: "obj<ACollector>",
+            args: [],
+            const: true,
+            noexcept: true,
+            attributes: [],
+        },
         {
             name: "stringtable",
             doc: [ "stringtable for unique symbols" ],
diff --git a/include/xo/procedure2/DSimpleRcx.hpp b/include/xo/procedure2/DSimpleRcx.hpp
index 6a7163d..f6bee0b 100644
--- a/include/xo/procedure2/DSimpleRcx.hpp
+++ b/include/xo/procedure2/DSimpleRcx.hpp
@@ -19,13 +19,15 @@ namespace xo {
         class DSimpleRcx {
         public:
             using AAllocator = xo::mm::AAllocator;
+            using ACollector = xo::mm::ACollector;
             using MemorySizeVisitor = xo::mm::MemorySizeVisitor;
 
         public:
             DSimpleRcx(obj<AAllocator> mm, StringTable * st)
-                : allocator_{mm}, stringtable_{st} {}
+            : allocator_{mm}, stringtable_{st} {}
 
             obj<AAllocator> allocator() const noexcept { return allocator_; }
+            obj<ACollector> collector() const noexcept;
             StringTable * stringtable() const noexcept { return stringtable_; }
             void visit_pools(const MemorySizeVisitor & visitor) const;
 
diff --git a/include/xo/procedure2/detail/ARuntimeContext.hpp b/include/xo/procedure2/detail/ARuntimeContext.hpp
index 716463d..626e2ba 100644
--- a/include/xo/procedure2/detail/ARuntimeContext.hpp
+++ b/include/xo/procedure2/detail/ARuntimeContext.hpp
@@ -42,6 +42,8 @@ public:
     using Opaque = void *;
     /** xo memory allocator **/
     using AAllocator = xo::mm::AAllocator;
+    /** xo garbage collector **/
+    using ACollector = xo::mm::ACollector;
     /** function to visit memory pools **/
     using MemorySizeVisitor = xo::mm::MemorySizeVisitor;
     ///@}
@@ -55,6 +57,8 @@ public:
     virtual void _drop(Opaque d) const noexcept = 0;
     /** default allocator to use for objects **/
     virtual obj<AAllocator> allocator(Copaque data)  const  noexcept = 0;
+    /** collector facet for allocator. If non-null, same data pointer as allocator **/
+    virtual obj<ACollector> collector(Copaque data)  const  noexcept = 0;
     /** stringtable for unique symbols **/
     virtual StringTable * stringtable(Copaque data)  const  noexcept = 0;
     /** invoke visitor for each distinct memory pool **/
diff --git a/include/xo/procedure2/detail/IRuntimeContext_Any.hpp b/include/xo/procedure2/detail/IRuntimeContext_Any.hpp
index b72f934..d0789e5 100644
--- a/include/xo/procedure2/detail/IRuntimeContext_Any.hpp
+++ b/include/xo/procedure2/detail/IRuntimeContext_Any.hpp
@@ -45,6 +45,7 @@ namespace scm {
         /** integer identifying a type **/
         using typeseq = xo::facet::typeseq;
         using AAllocator = ARuntimeContext::AAllocator;
+        using ACollector = ARuntimeContext::ACollector;
         using MemorySizeVisitor = ARuntimeContext::MemorySizeVisitor;
 
         ///@}
@@ -61,6 +62,7 @@ namespace scm {
 
         // const methods
         [[noreturn]] obj<AAllocator> allocator(Copaque)  const  noexcept override { _fatal(); }
+        [[noreturn]] obj<ACollector> collector(Copaque)  const  noexcept override { _fatal(); }
         [[noreturn]] StringTable * stringtable(Copaque)  const  noexcept override { _fatal(); }
         [[noreturn]] void visit_pools(Copaque, MemorySizeVisitor)  const override { _fatal(); }
 
diff --git a/include/xo/procedure2/detail/IRuntimeContext_DSimpleRcx.hpp b/include/xo/procedure2/detail/IRuntimeContext_DSimpleRcx.hpp
index 82ab521..496b593 100644
--- a/include/xo/procedure2/detail/IRuntimeContext_DSimpleRcx.hpp
+++ b/include/xo/procedure2/detail/IRuntimeContext_DSimpleRcx.hpp
@@ -40,6 +40,7 @@ namespace xo {
             /** @defgroup scm-runtimecontext-dsimplercx-type-traits **/
             ///@{
             using AAllocator = xo::scm::ARuntimeContext::AAllocator;
+            using ACollector = xo::scm::ARuntimeContext::ACollector;
             using MemorySizeVisitor = xo::scm::ARuntimeContext::MemorySizeVisitor;
             using Copaque = xo::scm::ARuntimeContext::Copaque;
             using Opaque = xo::scm::ARuntimeContext::Opaque;
@@ -49,6 +50,8 @@ namespace xo {
             // const methods
             /** default allocator to use for objects **/
             static obj<AAllocator> allocator(const DSimpleRcx & self) noexcept;
+            /** collector facet for allocator. If non-null, same data pointer as allocator **/
+            static obj<ACollector> collector(const DSimpleRcx & self) noexcept;
             /** stringtable for unique symbols **/
             static StringTable * stringtable(const DSimpleRcx & self) noexcept;
             /** invoke visitor for each distinct memory pool **/
diff --git a/include/xo/procedure2/detail/IRuntimeContext_Xfer.hpp b/include/xo/procedure2/detail/IRuntimeContext_Xfer.hpp
index 5dc9de5..2c4e80e 100644
--- a/include/xo/procedure2/detail/IRuntimeContext_Xfer.hpp
+++ b/include/xo/procedure2/detail/IRuntimeContext_Xfer.hpp
@@ -31,6 +31,7 @@ namespace scm {
         /** integer identifying a type **/
         using typeseq = ARuntimeContext::typeseq;
         using AAllocator = ARuntimeContext::AAllocator;
+        using ACollector = ARuntimeContext::ACollector;
         using MemorySizeVisitor = ARuntimeContext::MemorySizeVisitor;
         ///@}
 
@@ -50,6 +51,9 @@ namespace scm {
         obj<AAllocator> allocator(Copaque data)  const  noexcept override {
             return I::allocator(_dcast(data));
         }
+        obj<ACollector> collector(Copaque data)  const  noexcept override {
+            return I::collector(_dcast(data));
+        }
         StringTable * stringtable(Copaque data)  const  noexcept override {
             return I::stringtable(_dcast(data));
         }
diff --git a/include/xo/procedure2/detail/RRuntimeContext.hpp b/include/xo/procedure2/detail/RRuntimeContext.hpp
index 6553648..b80cfce 100644
--- a/include/xo/procedure2/detail/RRuntimeContext.hpp
+++ b/include/xo/procedure2/detail/RRuntimeContext.hpp
@@ -32,6 +32,7 @@ public:
     using DataPtr = Object::DataPtr;
     using typeseq = xo::reflect::typeseq;
     using AAllocator = ARuntimeContext::AAllocator;
+    using ACollector = ARuntimeContext::ACollector;
     using MemorySizeVisitor = ARuntimeContext::MemorySizeVisitor;
     ///@}
 
@@ -57,6 +58,9 @@ public:
     obj<AAllocator> allocator()  const  noexcept {
         return O::iface()->allocator(O::data());
     }
+    obj<ACollector> collector()  const  noexcept {
+        return O::iface()->collector(O::data());
+    }
     StringTable * stringtable()  const  noexcept {
         return O::iface()->stringtable(O::data());
     }
diff --git a/src/procedure2/DSimpleRcx.cpp b/src/procedure2/DSimpleRcx.cpp
index 30ec9c9..471cad7 100644
--- a/src/procedure2/DSimpleRcx.cpp
+++ b/src/procedure2/DSimpleRcx.cpp
@@ -4,10 +4,20 @@
  **/
 
 #include "DSimpleRcx.hpp"
+#include <xo/alloc2/Collector.hpp>
+#include <xo/facet/FacetRegistry.hpp>
 
 namespace xo {
+    using xo::mm::ACollector;
+
     namespace scm {
 
+        obj<ACollector>
+        DSimpleRcx::collector() const noexcept
+        {
+            return allocator_.try_to_facet<ACollector>();
+        }
+
         void
         DSimpleRcx::visit_pools(const MemorySizeVisitor & visitor) const
         {
diff --git a/src/procedure2/facet/IRuntimeContext_DSimpleRcx.cpp b/src/procedure2/facet/IRuntimeContext_DSimpleRcx.cpp
index 82dd310..ba56096 100644
--- a/src/procedure2/facet/IRuntimeContext_DSimpleRcx.cpp
+++ b/src/procedure2/facet/IRuntimeContext_DSimpleRcx.cpp
@@ -21,6 +21,12 @@ namespace xo {
             return self.allocator();
         }
 
+        auto
+        IRuntimeContext_DSimpleRcx::collector(const DSimpleRcx & self) noexcept -> obj<ACollector>
+        {
+            return self.collector();
+        }
+
         auto
         IRuntimeContext_DSimpleRcx::stringtable(const DSimpleRcx & self) noexcept -> StringTable *
         {