diff --git a/tests/unit/tools/test_model_registry.py b/tests/unit/tools/test_model_registry.py
index eca6206cf..8fbb12c01 100644
--- a/tests/unit/tools/test_model_registry.py
+++ b/tests/unit/tools/test_model_registry.py
@@ -780,3 +780,96 @@ def test_required_quant_library(self, model_id, expected_library):
         )
 
         assert required_quant_library_for_model(model_id) == expected_library
+
+
+class TestRegistrySyncedWithFactory:
+    """Assert HF_SUPPORTED_ARCHITECTURES and CANONICAL_AUTHORS_BY_ARCH stay in
+    sync with architecture_adapter_factory.SUPPORTED_ARCHITECTURES.
+
+    The module docstring of transformer_lens.tools.model_registry states the
+    invariant: HF_SUPPORTED_ARCHITECTURES "must correspond to adapters
+    registered in architecture_adapter_factory.py", with two documented
+    exception groups (internal-only architectures and factory-internal alias
+    casings). This class enforces that invariant bidirectionally so a future
+    adapter PR that forgets the registry update fails CI.
+    """
+
+    # Factory keys that are NOT expected in the registry sets.
+    # Two groups, matching the module docstring on HF_SUPPORTED_ARCHITECTURES:
+    #   1. Internal-only architectures that never appear on HuggingFace Hub.
+    #   2. Factory-internal alias casings that route to canonical adapters
+    #      under names HF does not emit in config.architectures[].
+    INTENTIONAL_EXCLUDES = frozenset(
+        {
+            # Group 1: internal-only architectures that never appear on HuggingFace Hub.
+            "NanoGPTForCausalLM",
+            "MinGPTForCausalLM",
+            "NeelSoluOldForCausalLM",
+            "GPT2LMHeadCustomModel",
+            "TransformerLensNative",
+            # Group 2: factory-internal alias casings (HF emits the canonical name).
+            "Gemma1ForCausalLM",  # HF emits: GemmaForCausalLM
+            "NeoForCausalLM",  # HF emits: GPTNeoForCausalLM
+            "NeoXForCausalLM",  # HF emits: GPTNeoXForCausalLM
+        }
+    )
+
+    def test_every_factory_arch_is_in_hf_supported(self):
+        """Every non-excluded factory key must be present in HF_SUPPORTED_ARCHITECTURES."""
+        from transformer_lens.factories.architecture_adapter_factory import (
+            SUPPORTED_ARCHITECTURES,
+        )
+        from transformer_lens.tools.model_registry import HF_SUPPORTED_ARCHITECTURES
+
+        missing = sorted(
+            k
+            for k in SUPPORTED_ARCHITECTURES
+            if k not in self.INTENTIONAL_EXCLUDES and k not in HF_SUPPORTED_ARCHITECTURES
+        )
+        assert not missing, (
+            f"Factory keys missing from HF_SUPPORTED_ARCHITECTURES: {missing}. "
+            "Add them to HF_SUPPORTED_ARCHITECTURES, or list them in "
+            "INTENTIONAL_EXCLUDES with a one-line reason."
+        )
+
+    def test_every_factory_arch_has_canonical_authors(self):
+        """Every non-excluded factory key must have a CANONICAL_AUTHORS_BY_ARCH entry."""
+        from transformer_lens.factories.architecture_adapter_factory import (
+            SUPPORTED_ARCHITECTURES,
+        )
+        from transformer_lens.tools.model_registry import CANONICAL_AUTHORS_BY_ARCH
+
+        missing = sorted(
+            k
+            for k in SUPPORTED_ARCHITECTURES
+            if k not in self.INTENTIONAL_EXCLUDES and k not in CANONICAL_AUTHORS_BY_ARCH
+        )
+        assert not missing, (
+            f"Factory keys missing from CANONICAL_AUTHORS_BY_ARCH: {missing}. "
+            "Add them to CANONICAL_AUTHORS_BY_ARCH, or list them in "
+            "INTENTIONAL_EXCLUDES with a one-line reason."
+        )
+
+    def test_hf_supported_keys_have_a_factory_adapter(self):
+        """Every HF_SUPPORTED_ARCHITECTURES entry must correspond to a wired factory adapter."""
+        from transformer_lens.factories.architecture_adapter_factory import (
+            SUPPORTED_ARCHITECTURES,
+        )
+        from transformer_lens.tools.model_registry import HF_SUPPORTED_ARCHITECTURES
+
+        orphaned = sorted(k for k in HF_SUPPORTED_ARCHITECTURES if k not in SUPPORTED_ARCHITECTURES)
+        assert (
+            not orphaned
+        ), f"HF_SUPPORTED_ARCHITECTURES entries with no factory adapter: {orphaned}"
+
+    def test_canonical_authors_keys_have_a_factory_adapter(self):
+        """Every CANONICAL_AUTHORS_BY_ARCH entry must correspond to a wired factory adapter."""
+        from transformer_lens.factories.architecture_adapter_factory import (
+            SUPPORTED_ARCHITECTURES,
+        )
+        from transformer_lens.tools.model_registry import CANONICAL_AUTHORS_BY_ARCH
+
+        orphaned = sorted(k for k in CANONICAL_AUTHORS_BY_ARCH if k not in SUPPORTED_ARCHITECTURES)
+        assert (
+            not orphaned
+        ), f"CANONICAL_AUTHORS_BY_ARCH entries with no factory adapter: {orphaned}"
diff --git a/transformer_lens/tools/model_registry/__init__.py b/transformer_lens/tools/model_registry/__init__.py
index 511ad01c0..424e4903c 100644
--- a/transformer_lens/tools/model_registry/__init__.py
+++ b/transformer_lens/tools/model_registry/__init__.py
@@ -39,10 +39,15 @@
 # These must match the exact strings found in HF model config.architectures[]
 # and correspond to adapters registered in architecture_adapter_factory.py.
 #
-# Internal-only architectures (NanoGPT, MinGPT, NeelSoluOld, GPT2LMHeadCustomModel)
-# are excluded since they never appear on HuggingFace Hub.
+# Internal-only architectures (NanoGPT, MinGPT, NeelSoluOld, GPT2LMHeadCustomModel,
+# TransformerLensNative) are excluded since they never appear on HuggingFace Hub.
+# Factory-internal alias casings (Gemma1, Neo, NeoX) are also excluded since they
+# route to canonical adapters but HF reports the canonical names (Gemma, GPTNeo,
+# GPTNeoX) in config.architectures instead.
 HF_SUPPORTED_ARCHITECTURES: set[str] = {
     "ApertusForCausalLM",
+    "BaiChuanForCausalLM",
+    "BaichuanForCausalLM",
     "BertForMaskedLM",
     "BloomForCausalLM",
     "CodeGenForCausalLM",
@@ -85,6 +90,7 @@
     "QwenForCausalLM",
     "Qwen2ForCausalLM",
     "Qwen3ForCausalLM",
+    "Qwen3MoeForCausalLM",
     "Qwen3NextForCausalLM",
     "Qwen3_5ForCausalLM",
     "StableLmForCausalLM",
@@ -97,6 +103,7 @@
 # download-threshold bypass and the docs table's "Canonical only" toggle.
 CANONICAL_AUTHORS_BY_ARCH: dict[str, list[str]] = {
     "ApertusForCausalLM": ["swiss-ai"],
+    "BaiChuanForCausalLM": ["baichuan-inc"],
     "BaichuanForCausalLM": ["baichuan-inc"],
     "BertForMaskedLM": ["google-bert"],
     "BloomForCausalLM": ["bigscience"],
@@ -140,6 +147,7 @@
     "PhiForCausalLM": ["microsoft"],
     "Qwen2ForCausalLM": ["Qwen", "nvidia"],
     "Qwen3ForCausalLM": ["Qwen", "nvidia"],
+    "Qwen3MoeForCausalLM": ["Qwen"],
     "Qwen3NextForCausalLM": ["Qwen"],
     "Qwen3_5ForCausalLM": ["Qwen"],
     "QwenForCausalLM": ["Qwen"],