diff --git a/dawn.json b/dawn.json
index e2e86c7..23d4c4a 100644
--- a/dawn.json
+++ b/dawn.json
@@ -162,6 +162,7 @@
         "tags": ["dawn", "native"],
         "category": "structure",
         "chained": "in",
+        "chain roots": ["device descriptor"],
         "members": [
             {"name": "force enabled toggles count", "type": "uint32_t", "default": 0},
             {"name": "force enabled toggles", "type": "char", "annotation": "const*const*", "length": "force enabled toggles count"},
@@ -173,6 +174,7 @@
         "tags": ["dawn", "native"],
         "category": "structure",
         "chained": "in",
+        "chain roots": ["device descriptor"],
         "members": [
             {"name": "isolation key", "type": "char", "annotation": "const*", "length": "strlen", "default": "\"\""}
         ]
@@ -306,6 +308,7 @@
     "external texture binding entry": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["bind group entry"],
         "tags": ["dawn"],
         "members": [
             {"name": "external texture", "type": "external texture"}
@@ -315,6 +318,7 @@
     "external texture binding layout": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["bind group layout entry"],
         "tags": ["dawn"],
         "members": []
     },
@@ -1445,6 +1449,7 @@
         "tags": ["dawn", "native"],
         "category": "structure",
         "chained": "in",
+        "chain roots": ["instance descriptor"],
         "members": [
             {"name": "additional runtime search paths count", "type": "uint32_t", "default": 0},
             {"name": "additional runtime search paths", "type": "char", "annotation": "const*const*", "length": "additional runtime search paths count"}
@@ -1891,6 +1896,7 @@
     "render pass descriptor max draw count": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["render pass descriptor"],
         "members": [
             {"name": "max draw count", "type": "uint64_t", "default": 50000000}
         ]
@@ -2147,6 +2153,7 @@
     "primitive depth clamping state": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["primitive state"],
         "tags": ["dawn", "emscripten"],
         "members": [
             {"name": "clamp depth", "type": "bool", "default": "false"}
@@ -2156,6 +2163,7 @@
     "primitive depth clip control": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["primitive state"],
         "members": [
             {"name": "unclipped depth", "type": "bool", "default": "false"}
         ]
@@ -2302,6 +2310,7 @@
     "shader module SPIRV descriptor": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["shader module descriptor"],
         "members": [
             {"name": "code size", "type": "uint32_t"},
             {"name": "code", "type": "uint32_t", "annotation": "const*", "length": "code size"}
@@ -2310,6 +2319,7 @@
     "shader module WGSL descriptor": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["shader module descriptor"],
         "members": [
             {"name": "source", "type": "char", "annotation": "const*", "length": "strlen", "tags": ["dawn", "emscripten"]},
             {"name": "code", "type": "char", "annotation": "const*", "length": "strlen", "tags": ["upstream"]}
@@ -2370,6 +2380,7 @@
     "surface descriptor from android native window": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["surface descriptor"],
         "tags": ["native"],
         "members": [
             {"name": "window", "type": "void", "annotation": "*"}
@@ -2378,6 +2389,7 @@
     "surface descriptor from canvas HTML selector": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["surface descriptor"],
         "members": [
             {"name": "selector", "type": "char", "annotation": "const*", "length": "strlen"}
         ]
@@ -2385,6 +2397,7 @@
     "surface descriptor from metal layer": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["surface descriptor"],
         "tags": ["native"],
         "members": [
             {"name": "layer", "type": "void", "annotation": "*"}
@@ -2393,6 +2406,7 @@
     "surface descriptor from windows HWND": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["surface descriptor"],
         "tags": ["native"],
         "members": [
             {"name": "hinstance", "type": "void", "annotation": "*"},
@@ -2402,6 +2416,7 @@
     "surface descriptor from xcb window": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["surface descriptor"],
         "tags": ["upstream"],
         "members": [
             {"name": "connection", "type": "void", "annotation": "*"},
@@ -2411,6 +2426,7 @@
     "surface descriptor from xlib window": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["surface descriptor"],
         "tags": ["native"],
         "members": [
             {"name": "display", "type": "void", "annotation": "*"},
@@ -2420,6 +2436,7 @@
     "surface descriptor from wayland surface": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["surface descriptor"],
         "tags": ["native"],
         "members": [
             {"name": "display", "type": "void", "annotation": "*"},
@@ -2429,6 +2446,7 @@
     "surface descriptor from windows core window": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["surface descriptor"],
         "tags": ["dawn"],
         "members": [
             {"name": "core window", "type": "void", "annotation": "*"}
@@ -2437,6 +2455,7 @@
     "surface descriptor from windows swap chain panel": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["surface descriptor"],
         "tags": ["dawn"],
         "members": [
             {"name": "swap chain panel", "type": "void", "annotation": "*"}
@@ -2886,6 +2905,7 @@
     "dawn texture internal usage descriptor": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["texture descriptor"],
         "tags": ["dawn"],
         "members": [
             {"name": "internal usage", "type": "texture usage", "default": "none"}
@@ -2894,6 +2914,7 @@
     "dawn encoder internal usage descriptor": {
         "category": "structure",
         "chained": "in",
+        "chain roots": ["command encoder descriptor"],
         "tags": ["dawn"],
         "members": [
             {"name": "use internal usages", "type": "bool", "default": "false"}
diff --git a/docs/dawn/codegen.md b/docs/dawn/codegen.md
index 315364c..d6b9ee2 100644
--- a/docs/dawn/codegen.md
+++ b/docs/dawn/codegen.md
@@ -68,7 +68,8 @@
 **`"structure"`**
  - `"members"` a **record**, so an array of **record members**
  - `"extensible"` (defaults to false) a boolean defining if this is an "extensible" WebGPU structure (i.e. has `nextInChain`). "descriptor" structures should usually have this set to true.
- - `"chained"` (defaults to false) a boolean defining if this is a structure that can be "chained" in a WebGPU structure (i.e. has `nextInChain` and `sType`)
+ - `"chained"` (defaults to None) a string defining if this is a structure that can be "chained" in a WebGPU structure (i.e. has `nextInChain` and `sType`) and in which direction ('in' for inputs to WebGPU, 'out' for outputs)
+ - `"chain roots"` (defaults to []) a list of strings that are the canonical names of structures that can be extended by this structure.
 
 **`"object"`**
  - `**methods**` an array of methods for this object. Note that "release" and "reference" don't need to be specified. Each method is a dictionary containing:
diff --git a/generator/dawn_json_generator.py b/generator/dawn_json_generator.py
index d02213d..cf8f3e8 100644
--- a/generator/dawn_json_generator.py
+++ b/generator/dawn_json_generator.py
@@ -237,12 +237,13 @@
                 m for m in json_data['members'] if is_enabled(m)
             ]
         Type.__init__(self, name, dict(json_data, **json_data_override))
-        self.chained = json_data.get("chained", None)
-        self.extensible = json_data.get("extensible", None)
+        self.chained = json_data.get('chained', None)
+        self.extensible = json_data.get('extensible', None)
         if self.chained:
-            assert (self.chained == "in" or self.chained == "out")
+            assert self.chained == 'in' or self.chained == 'out'
+            assert 'chain roots' in json_data
         if self.extensible:
-            assert (self.extensible == "in" or self.extensible == "out")
+            assert self.extensible == 'in' or self.extensible == 'out'
         # Chained structs inherit from wgpu::ChainedStruct, which has
         # nextInChain, so setting both extensible and chained would result in
         # two nextInChain members.
@@ -348,6 +349,8 @@
 
 def link_structure(struct, types):
     struct.members = linked_record_members(struct.json_data['members'], types)
+    struct.chain_roots = [types[root] for root in struct.json_data.get('chain roots', [])]
+    assert all((root.category == 'structure' for root in struct.chain_roots))
 
 
 def link_function_pointer(function_pointer, types):
diff --git a/generator/templates/api.h b/generator/templates/api.h
index 2694456..c4def22 100644
--- a/generator/templates/api.h
+++ b/generator/templates/api.h
@@ -89,6 +89,9 @@
 } {{c_prefix}}ChainedStructOut;
 
 {% for type in by_category["structure"] %}
+    {% for root in type.chain_roots %}
+        // Can be chained in {{as_cType(root.name)}}
+    {% endfor %}
     typedef struct {{as_cType(type.name)}} {
         {% set Out = "Out" if type.output else "" %}
         {% set const = "const " if not type.output else "" %}
diff --git a/generator/templates/api_cpp.h b/generator/templates/api_cpp.h
index 6ef3316..94acde2 100644
--- a/generator/templates/api_cpp.h
+++ b/generator/templates/api_cpp.h
@@ -225,6 +225,9 @@
         {% set Out = "Out" if type.output else "" %}
         {% set const = "const" if not type.output else "" %}
         {% if type.chained %}
+            {% for root in type.chain_roots %}
+                // Can be chained in {{as_cppType(root.name)}}
+            {% endfor %}
             struct {{as_cppType(type.name)}} : ChainedStruct{{Out}} {
                 {{as_cppType(type.name)}}() {
                     sType = SType::{{type.name.CamelCase()}};