diff --git a/tests/test_route_compatibility.py b/tests/test_route_compatibility.py
new file mode 100644
index 0000000..57c1ab7
--- /dev/null
+++ b/tests/test_route_compatibility.py
@@ -0,0 +1,161 @@
+import asyncio
+import importlib.util
+import sys
+from types import ModuleType, SimpleNamespace
+from unittest.mock import AsyncMock, patch
+
+import pytest
+from aiohttp import web
+
+from core.routes import base_models, model_info, search, workflow
+
+
+class _Routes:
+    def __init__(self):
+        self.handlers = {}
+
+    def get(self, path):
+        def decorator(handler):
+            self.handlers[("GET", path)] = handler
+            return handler
+
+        return decorator
+
+    def post(self, path):
+        def decorator(handler):
+            self.handlers[("POST", path)] = handler
+            return handler
+
+        return decorator
+
+
+def _identity_endpoint(_name, **_kwargs):
+    return lambda handler: handler
+
+
+def test_model_info_compatibility_registers_all_model_routes():
+    context = object()
+    with (
+        patch.object(model_info, "register_civitai_search_routes") as civitai,
+        patch.object(model_info, "register_custom_url_routes") as custom_url,
+        patch.object(model_info, "register_model_details_routes") as details,
+    ):
+        model_info.register_model_info_routes(context)
+
+    civitai.assert_called_once_with(context)
+    custom_url.assert_called_once_with(context)
+    details.assert_called_once_with(context)
+
+
+def test_search_compatibility_registers_source_and_support_routes():
+    context = object()
+    with (
+        patch.object(search, "register_source_search_routes") as sources,
+        patch.object(search, "register_search_support_routes") as support,
+    ):
+        search.register_search_routes(context)
+
+    sources.assert_called_once_with(context)
+    support.assert_called_once_with(context)
+
+
+def test_workflow_compatibility_registers_analysis_and_hash_routes():
+    context = object()
+    with (
+        patch.object(workflow, "register_workflow_analysis_routes") as analysis,
+        patch.object(workflow, "register_hash_routes") as hashes,
+    ):
+        workflow.register_workflow_routes(context)
+
+    analysis.assert_called_once_with(context)
+    hashes.assert_called_once_with(context)
+
+
+@pytest.mark.asyncio
+async def test_base_model_routes_return_configured_data_and_status(monkeypatch):
+    routes = _Routes()
+    config = {"base_models": [{"name": "SDXL"}]}
+    status = {"is_up_to_date": True}
+    monkeypatch.setattr(base_models, "get_base_models_config", lambda: config)
+    monkeypatch.setattr(base_models, "get_base_models_status", lambda check: status)
+    base_models.register_base_model_routes(routes, web, _identity_endpoint)
+
+    config_response = await routes.handlers[("GET", "/model_resolver/base-models")](
+        SimpleNamespace(query={})
+    )
+    status_response = await routes.handlers[
+        ("GET", "/model_resolver/base-models/status")
+    ](SimpleNamespace(query={"check_remote": "1"}))
+
+    assert config_response.status == 200
+    assert config_response.text == '{"base_models": [{"name": "SDXL"}]}'
+    assert status_response.status == 200
+    assert status_response.text == '{"is_up_to_date": true}'
+
+
+@pytest.mark.asyncio
+async def test_base_model_update_route_runs_in_background_thread(monkeypatch):
+    routes = _Routes()
+    update_result = {"updated": True}
+    monkeypatch.setattr(
+        base_models,
+        "update_base_models_from_remote",
+        lambda: update_result,
+    )
+    monkeypatch.setattr(
+        asyncio,
+        "to_thread",
+        AsyncMock(return_value=update_result),
+    )
+    base_models.register_base_model_routes(routes, web, _identity_endpoint)
+
+    response = await routes.handlers[("POST", "/model_resolver/base-models/update")](
+        SimpleNamespace()
+    )
+
+    assert response.status == 200
+    assert response.text == '{"updated": true}'
+
+
+def test_node_definitions_support_the_comfyui_v3_api_branch():
+    class FakeComfyNode:
+        pass
+
+    class FakeComfyExtension:
+        pass
+
+    class FakeNodeOutput:
+        pass
+
+    class FakeSchema:
+        def __init__(self, **kwargs):
+            self.kwargs = kwargs
+
+    fake_io = SimpleNamespace(
+        ComfyNode=FakeComfyNode,
+        NodeOutput=FakeNodeOutput,
+        Schema=FakeSchema,
+    )
+    fake_comfy_api = ModuleType("comfy_api")
+    fake_comfy_api.__path__ = []
+    fake_latest = ModuleType("comfy_api.latest")
+    fake_latest.ComfyExtension = FakeComfyExtension
+    fake_latest.io = fake_io
+    fake_comfy_api.latest = fake_latest
+
+    module_name = "core.node_definitions_v3_test"
+    module_path = "core/node_definitions.py"
+    spec = importlib.util.spec_from_file_location(module_name, module_path)
+    module = importlib.util.module_from_spec(spec)
+    with patch.dict(
+        sys.modules,
+        {"comfy_api": fake_comfy_api, "comfy_api.latest": fake_latest},
+    ):
+        spec.loader.exec_module(module)
+
+    assert issubclass(module.ModelResolverDependencyNode, FakeComfyNode)
+    assert issubclass(module.ModelResolverNodeExtension, FakeComfyExtension)
+    assert module.ModelResolverDependencyNode.define_schema().kwargs["node_id"] == (
+        "ModelResolverDependency"
+    )
+    assert isinstance(module.ModelResolverDependencyNode.execute(), FakeNodeOutput)