diff --git a/xo-facet/codegen/genfacet b/xo-facet/codegen/genfacet
index 8edadc1c..062683be 100755
--- a/xo-facet/codegen/genfacet
+++ b/xo-facet/codegen/genfacet
@@ -458,7 +458,7 @@ def main():
     # --output-impl-hpp: putting this in .json5, will be able to drop this.
     parser.add_argument('--output-impl-hpp', required=True, help='.hpp detail subdir')
     parser.add_argument('--output-hpp', required=True, help='.hpp output directory')
-    parser.add_argument('--output-cpp', required=True, help='.cpp output directory')
+    parser.add_argument('--output-cpp', required=False, help='.cpp output directory')
 
     args = parser.parse_args()
 
@@ -473,7 +473,12 @@ def main():
     output_impl_hpp_dir = Path(args.output_hpp) / output_impl_hpp_subdir
     output_impl_hpp_dir.mkdir(parents=False, exist_ok=True)
 
-    output_cpp_dir = Path(args.output_cpp)
+    if 'output_cpp_dir' in idl:
+        output_cpp_dir = Path(idl['output_cpp_dir'])
+    elif args.output_cpp:
+        output_cpp_dir = Path(args.output_cpp)
+    else:
+        parser.error("--output-cpp required when .json5 lacks output_cpp_dir")
     output_cpp_dir.mkdir(parents=False, exist_ok=True)
 
     # setup jinja2
diff --git a/xo-procedure2/idl/IGCObject_DPrimitive_gco_2_gco_gco.json5 b/xo-procedure2/idl/IGCObject_DPrimitive_gco_2_gco_gco.json5
index b2fb4014..79ee61d4 100644
--- a/xo-procedure2/idl/IGCObject_DPrimitive_gco_2_gco_gco.json5
+++ b/xo-procedure2/idl/IGCObject_DPrimitive_gco_2_gco_gco.json5
@@ -1,5 +1,6 @@
 {
     mode: "implementation",
+    output_cpp_dir: "src/procedure2",
     includes: [
         //<xo/procedure2/GCObjectConversion_DPrimitive_gco_2_gco_gco.hpp>
         "<xo/gc/GCObject.hpp>",
diff --git a/xo-procedure2/idl/IPrintable_DPrimitive_gco_2_gco_gco.json5 b/xo-procedure2/idl/IPrintable_DPrimitive_gco_2_gco_gco.json5
index 15cff1b4..5eb7bf34 100644
--- a/xo-procedure2/idl/IPrintable_DPrimitive_gco_2_gco_gco.json5
+++ b/xo-procedure2/idl/IPrintable_DPrimitive_gco_2_gco_gco.json5
@@ -1,5 +1,6 @@
 {
     mode: "implementation",
+    output_cpp_dir: "src/procedure2",
     includes: [
         "<xo/printable2/Printable.hpp>",
         "<xo/printable2/detail/IPrintable_Xfer.hpp>",
diff --git a/xo-procedure2/idl/IProcedure_DPrimitive_gco_2_gco_gco.json5 b/xo-procedure2/idl/IProcedure_DPrimitive_gco_2_gco_gco.json5
index fb22bad5..b0a770fd 100644
--- a/xo-procedure2/idl/IProcedure_DPrimitive_gco_2_gco_gco.json5
+++ b/xo-procedure2/idl/IProcedure_DPrimitive_gco_2_gco_gco.json5
@@ -1,5 +1,6 @@
 {
     mode: "implementation",
+    output_cpp_dir: "src/procedure2",
     includes: [
         "<xo/procedure2/RuntimeContext.hpp>",
         "<xo/procedure2/detail/IRuntimeContext_Xfer.hpp>",
diff --git a/xo-procedure2/idl/IRuntimeContext_DSimpleRcx.json5 b/xo-procedure2/idl/IRuntimeContext_DSimpleRcx.json5
index ed838629..4765285d 100644
--- a/xo-procedure2/idl/IRuntimeContext_DSimpleRcx.json5
+++ b/xo-procedure2/idl/IRuntimeContext_DSimpleRcx.json5
@@ -1,5 +1,6 @@
 {
     mode: "implementation",
+    output_cpp_dir: "src/procedure2",
     includes: [
         //"<xo/procedure2/RuntimeContext.hpp>",
         //"<xo/procedure2/detail/IRuntimeContext_Xfer.hpp>",
diff --git a/xo-procedure2/idl/Procedure.json5 b/xo-procedure2/idl/Procedure.json5
index 449414f0..7933c3a2 100644
--- a/xo-procedure2/idl/Procedure.json5
+++ b/xo-procedure2/idl/Procedure.json5
@@ -4,6 +4,7 @@
 
 {
     mode: "facet",
+    output_cpp_dir: "src/procedure2",
     // includes in ASyntaxStateMachine.hpp
     includes: [
         "\"RuntimeContext.hpp\"",
diff --git a/xo-procedure2/idl/RuntimeContext.json5 b/xo-procedure2/idl/RuntimeContext.json5
index e80c0bc5..c896cc64 100644
--- a/xo-procedure2/idl/RuntimeContext.json5
+++ b/xo-procedure2/idl/RuntimeContext.json5
@@ -1,5 +1,6 @@
 {
     mode: "facet",
+    output_cpp_dir: "src/procedure2",
     // includes in ARuntimeContext.hpp
     includes: [
         "<xo/alloc2/Allocator.hpp>"
diff --git a/xo-procedure2/include/xo/procedure2/detail/RProcedure.hpp b/xo-procedure2/include/xo/procedure2/detail/RProcedure.hpp
index 61bcb7f7..191bd37e 100644
--- a/xo-procedure2/include/xo/procedure2/detail/RProcedure.hpp
+++ b/xo-procedure2/include/xo/procedure2/detail/RProcedure.hpp
@@ -46,6 +46,8 @@ public:
     /** @defgroup scm-procedure-router-methods **/
     ///@{
 
+    // explicit injected content
+
     // builtin methods
     typeseq _typeseq() const noexcept { return O::iface()->_typeseq(); }
     void _drop() const noexcept { O::iface()->_drop(O::data()); }
diff --git a/xo-procedure2/include/xo/procedure2/detail/RRuntimeContext.hpp b/xo-procedure2/include/xo/procedure2/detail/RRuntimeContext.hpp
index a6df812e..a9e161ed 100644
--- a/xo-procedure2/include/xo/procedure2/detail/RRuntimeContext.hpp
+++ b/xo-procedure2/include/xo/procedure2/detail/RRuntimeContext.hpp
@@ -46,6 +46,8 @@ public:
     /** @defgroup scm-runtimecontext-router-methods **/
     ///@{
 
+    // explicit injected content
+
     // builtin methods
     typeseq _typeseq() const noexcept { return O::iface()->_typeseq(); }
     void _drop() const noexcept { O::iface()->_drop(O::data()); }