diff --git a/.chronus/changes/python-usage-namespace-test-2026-5-26-23-18-25.md b/.chronus/changes/python-usage-namespace-test-2026-5-26-23-18-25.md
new file mode 100644
index 00000000000..255a67569a5
--- /dev/null
+++ b/.chronus/changes/python-usage-namespace-test-2026-5-26-23-18-25.md
@@ -0,0 +1,7 @@
+---
+changeKind: internal
+packages:
+  - "@typespec/http-client-python"
+---
+
+Add sync and async mock API tests for the Azure client-generator-core usage namespace usage scenario from azure-http-specs.
diff --git a/packages/http-client-python/package-lock.json b/packages/http-client-python/package-lock.json
index cc9078bf7e4..10a7f975977 100644
--- a/packages/http-client-python/package-lock.json
+++ b/packages/http-client-python/package-lock.json
@@ -17,7 +17,7 @@
         "tsx": "^4.21.0"
       },
       "devDependencies": {
-        "@azure-tools/azure-http-specs": "0.1.0-alpha.41-dev.1",
+        "@azure-tools/azure-http-specs": "^0.1.0-alpha.41-dev.2",
         "@azure-tools/typespec-autorest": "~0.68.0",
         "@azure-tools/typespec-azure-core": "~0.68.0",
         "@azure-tools/typespec-azure-resource-manager": "~0.68.0",
@@ -66,9 +66,9 @@
       }
     },
     "node_modules/@azure-tools/azure-http-specs": {
-      "version": "0.1.0-alpha.41-dev.1",
-      "resolved": "https://registry.npmjs.org/@azure-tools/azure-http-specs/-/azure-http-specs-0.1.0-alpha.41-dev.1.tgz",
-      "integrity": "sha512-GaFmm7KP19YtxgdE2eyA37XusQCqoxo7UA6Lj9iLnXE77XPeDppE1pKstWFAbMcv/Jrc/EGqkl+TOGApej/JoA==",
+      "version": "0.1.0-alpha.41-dev.2",
+      "resolved": "https://registry.npmjs.org/@azure-tools/azure-http-specs/-/azure-http-specs-0.1.0-alpha.41-dev.2.tgz",
+      "integrity": "sha512-bx3thSgOwuLjqiYbyFal6d7q29Wo8lyNCVs8CIgoZzOievXM7dzJTfCI1RplPYydObcMeYAnAaPH32/YoFj93w==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
diff --git a/packages/http-client-python/package.json b/packages/http-client-python/package.json
index ef31a825df2..5146ccc8acc 100644
--- a/packages/http-client-python/package.json
+++ b/packages/http-client-python/package.json
@@ -66,13 +66,13 @@
     "@azure-tools/typespec-azure-rulesets": ">=0.68.0 <1.0.0",
     "@azure-tools/typespec-client-generator-core": ">=0.68.0 <1.0.0",
     "@typespec/compiler": "^1.12.0",
+    "@typespec/events": ">=0.82.0 <1.0.0",
     "@typespec/http": "^1.12.0",
     "@typespec/openapi": "^1.12.0",
     "@typespec/rest": ">=0.82.0 <1.0.0",
-    "@typespec/versioning": ">=0.82.0 <1.0.0",
-    "@typespec/events": ">=0.82.0 <1.0.0",
     "@typespec/sse": ">=0.82.0 <1.0.0",
     "@typespec/streams": ">=0.82.0 <1.0.0",
+    "@typespec/versioning": ">=0.82.0 <1.0.0",
     "@typespec/xml": ">=0.82.0 <1.0.0"
   },
   "playgroundConfig": {
@@ -98,27 +98,27 @@
     "tsx": "^4.21.0"
   },
   "devDependencies": {
+    "@azure-tools/azure-http-specs": "^0.1.0-alpha.41-dev.2",
     "@azure-tools/typespec-autorest": "~0.68.0",
     "@azure-tools/typespec-azure-core": "~0.68.0",
     "@azure-tools/typespec-azure-resource-manager": "~0.68.0",
     "@azure-tools/typespec-azure-rulesets": "~0.68.0",
     "@azure-tools/typespec-client-generator-core": "~0.68.2",
-    "@azure-tools/azure-http-specs": "0.1.0-alpha.41-dev.1",
+    "@types/js-yaml": "~4.0.5",
+    "@types/node": "~25.0.2",
+    "@types/semver": "7.5.8",
     "@typespec/compiler": "^1.12.0",
+    "@typespec/events": "~0.82.0",
     "@typespec/http": "^1.12.0",
+    "@typespec/http-specs": "0.1.0-alpha.37",
     "@typespec/openapi": "^1.12.0",
     "@typespec/rest": "~0.82.0",
-    "@typespec/versioning": "~0.82.0",
-    "@typespec/events": "~0.82.0",
-    "@typespec/spector": "0.1.0-alpha.25",
     "@typespec/spec-api": "0.1.0-alpha.14",
+    "@typespec/spector": "0.1.0-alpha.25",
     "@typespec/sse": "~0.82.0",
     "@typespec/streams": "~0.82.0",
+    "@typespec/versioning": "~0.82.0",
     "@typespec/xml": "~0.82.0",
-    "@typespec/http-specs": "0.1.0-alpha.37",
-    "@types/js-yaml": "~4.0.5",
-    "@types/node": "~25.0.2",
-    "@types/semver": "7.5.8",
     "c8": "^10.1.3",
     "picocolors": "~1.1.1",
     "rimraf": "~6.1.2",
diff --git a/packages/http-client-python/tests/mock_api/azure/asynctests/test_azure_client_generator_core_usage_async.py b/packages/http-client-python/tests/mock_api/azure/asynctests/test_azure_client_generator_core_usage_async.py
index 816279eeb94..9a82c7e573a 100644
--- a/packages/http-client-python/tests/mock_api/azure/asynctests/test_azure_client_generator_core_usage_async.py
+++ b/packages/http-client-python/tests/mock_api/azure/asynctests/test_azure_client_generator_core_usage_async.py
@@ -37,3 +37,9 @@ async def test_orphan_model_serializable(client: UsageClient):
     await client.model_in_operation.orphan_model_serializable(
         body=models.OrphanModel(model_name="name", description="desc")
     )
+
+
+@pytest.mark.asyncio
+async def test_namespace_model_serializable(client: UsageClient):
+    namespace_model = models.NamespaceModel(name="test")
+    await client.namespace_usage.namespace_model_serializable(body=namespace_model)
diff --git a/packages/http-client-python/tests/mock_api/azure/test_azure_client_generator_core_usage.py b/packages/http-client-python/tests/mock_api/azure/test_azure_client_generator_core_usage.py
index 0094bef89a1..4bc9b912324 100644
--- a/packages/http-client-python/tests/mock_api/azure/test_azure_client_generator_core_usage.py
+++ b/packages/http-client-python/tests/mock_api/azure/test_azure_client_generator_core_usage.py
@@ -30,3 +30,8 @@ def test_model_usage(client: UsageClient):
 
 def test_orphan_model_serializable(client: UsageClient):
     client.model_in_operation.orphan_model_serializable(body=models.OrphanModel(model_name="name", description="desc"))
+
+
+def test_namespace_model_serializable(client: UsageClient):
+    namespace_model = models.NamespaceModel(name="test")
+    client.namespace_usage.namespace_model_serializable(body=namespace_model)