diff --git a/src/primitives/logdensity.jl b/src/primitives/logdensity.jl
index 81fa4cd..4d13367 100644
--- a/src/primitives/logdensity.jl
+++ b/src/primitives/logdensity.jl
@@ -43,3 +43,55 @@ end
     end
 end
 
+###############################################################################
+
+
+function MeasureBase.logdensity_def(c::ConditionalModel{A,B,M}, x=NamedTuple()) where {A,B,M}
+    _logdensity_def(M, Model(c), argvals(c), observations(c), x)
+end
+
+export sourceLogdensityDef
+
+sourceLogdensityDef(m::AbstractModel) = sourceLogdensityDef()(Model(m))
+
+# function Base.convert(nt::NamedTuple, args...)
+#     @show nt
+#     @show args
+#     for (n, t) in enumerate(stacktrace())
+#         print("\t",n,". ")
+#         println(t)
+#     end
+
+# end
+
+function sourceLogdensityDef()
+    function(_m::Model)
+        proc(_m, st :: Assign)     = :($(st.x) = $(st.rhs))
+        proc(_m, st :: Return)     = nothing
+        proc(_m, st :: LineNumber) = nothing
+        function proc(_m, st :: Sample)
+            x = st.x
+            rhs = st.rhs
+            @q begin
+                _ℓ += Soss.logdensity_def($rhs, $x)
+                $x = Soss.predict($rhs, $x)
+            end
+        end
+
+        wrap(kernel) = @q begin
+            _ℓ = 0.0
+            $kernel
+            return _ℓ
+        end
+
+        buildSource(_m, proc, wrap) |> MacroTools.flatten
+    end
+end
+
+@gg function _logdensity_def(M::Type{<:TypeLevel}, _m::Model, _args, _data, _pars)
+    body = type2model(_m) |> sourceLogdensityDef() |> loadvals(_args, _data, _pars)
+    @under_global from_type(_unwrap_type(M)) @q let M
+        $body
+    end
+end
+