diff --git a/crux_cli/fixtures-counter-actual.json b/crux_cli/fixtures-counter-actual.json
index 722604cdc..74a250aaf 100644
--- a/crux_cli/fixtures-counter-actual.json
+++ b/crux_cli/fixtures-counter-actual.json
@@ -40,15 +40,89 @@
       }
     }
   },
-  "ServerSentEvents": {
+  "HttpError": {
+    "ENUM": {
+      "0": {
+        "Url": {
+          "NEWTYPE": "STR"
+        }
+      },
+      "1": {
+        "Io": {
+          "NEWTYPE": "STR"
+        }
+      },
+      "2": {
+        "Timeout": "UNIT"
+      }
+    }
+  },
+  "HttpHeader": {
+    "STRUCT": [
+      {
+        "name": "STR"
+      },
+      {
+        "value": "STR"
+      }
+    ]
+  },
+  "HttpRequest": {
+    "STRUCT": [
+      {
+        "method": "STR"
+      },
+      {
+        "url": "STR"
+      },
+      {
+        "headers": {
+          "SEQ": {
+            "TYPENAME": "HttpHeader"
+          }
+        }
+      },
+      {
+        "body": "BYTES"
+      }
+    ]
+  },
+  "HttpResponse": {
     "STRUCT": [
       {
-        "context": {
-          "TYPENAME": "crux_core::capability::CapabilityContext"
+        "status": "U16"
+      },
+      {
+        "headers": {
+          "SEQ": {
+            "TYPENAME": "HttpHeader"
+          }
         }
+      },
+      {
+        "body": "BYTES"
       }
     ]
   },
+  "HttpResult": {
+    "ENUM": {
+      "0": {
+        "Ok": {
+          "NEWTYPE": {
+            "TYPENAME": "HttpResponse"
+          }
+        }
+      },
+      "1": {
+        "Err": {
+          "NEWTYPE": {
+            "TYPENAME": "crate::HttpError"
+          }
+        }
+      }
+    }
+  },
+  "RenderOperation": "UNITSTRUCT",
   "SseRequest": {
     "STRUCT": [
       {
diff --git a/crux_cli/src/codegen/filter.rs b/crux_cli/src/codegen/filter.rs
index 8d96c4168..132fc124b 100644
--- a/crux_cli/src/codegen/filter.rs
+++ b/crux_cli/src/codegen/filter.rs
@@ -122,11 +122,15 @@ ascent! {
     // set of all the edges we are interested in
     relation edge(ItemNode, ItemNode);
 
-    // root fields
+    // roots that are unit structs
+    edge(root, root) <--
+        root(root),
+        is_struct(root);
+    // roots that have fields
     edge(root, field) <--
         root(root),
         field(root, field);
-    // root variants
+    // roots that have variants
     edge(root, variant) <--
         root(root),
         variant(root, variant);
diff --git a/crux_cli/src/codegen/formatter.rs b/crux_cli/src/codegen/formatter.rs
index 66df3a3d7..261ed7a76 100644
--- a/crux_cli/src/codegen/formatter.rs
+++ b/crux_cli/src/codegen/formatter.rs
@@ -119,7 +119,18 @@ fn make_format(field: &ItemNode, all_fields: &Vec<ItemNode>) -> Option<Indexed<F
     match &field.0.inner {
         ItemEnum::StructField(type_) => Some(Indexed {
             index: index as u32,
-            value: type_.into(),
+            value: {
+                if let Some((_whole, serde_with)) = &field.0.attrs.iter().find_map(|attr| {
+                    lazy_regex::regex_captures!(r#"\[serde\(with\s*=\s*"(\w+)"\)\]"#, attr)
+                }) {
+                    match *serde_with {
+                        "serde_bytes" => Format::Bytes, // e.g. HttpRequest.body, HttpResponse.body
+                        _ => todo!(),
+                    }
+                } else {
+                    type_.into()
+                }
+            },
         }),
         _ => None,
     }
diff --git a/crux_cli/src/codegen/node.rs b/crux_cli/src/codegen/node.rs
index 61ad405e6..8fbd49384 100644
--- a/crux_cli/src/codegen/node.rs
+++ b/crux_cli/src/codegen/node.rs
@@ -80,11 +80,12 @@ impl ItemNode {
     }
 
     pub fn is_subset(&self) -> bool {
-        self.is_struct()
+        // from most likely to least likely
+        self.is_impl()
             || self.is_struct_field()
-            || self.is_enum()
             || self.is_enum_variant()
-            || self.is_impl()
+            || self.is_struct()
+            || self.is_enum()
             || self.is_associated_type()
     }