diff --git a/tests/integration/providers/test_azure_ai_chat_wire.py b/tests/integration/providers/test_azure_ai_chat_wire.py
new file mode 100644
index 00000000000..57acb9773b9
--- /dev/null
+++ b/tests/integration/providers/test_azure_ai_chat_wire.py
@@ -0,0 +1,85 @@
+import json
+import uuid
+from typing import Final
+
+import pytest
+from integration._support.client import Gateway
+from integration._support.wire import Reply, Request, wire_server
+from pydantic import JsonValue, TypeAdapter
+
+_BACKEND: Final = "kimi-k2-thinking"
+_API_KEY: Final = "synthetic-azure-ai-key"
+_JSON_OBJECT: Final = TypeAdapter(dict[str, JsonValue])
+_THINKING_BLOCK: Final[JsonValue] = {
+    "type": "thinking",
+    "thinking": "The user wants the sum of 17 and 26.",
+    "signature": "synthetic-signature",
+}
+_HISTORY_WITH_ANTHROPIC_FIELDS: Final[JsonValue] = [
+    {
+        "role": "system",
+        "content": "You are a calculator.",
+        "cache_control": {"type": "ephemeral"},
+    },
+    {"role": "user", "content": "What is 17 + 26?"},
+    {
+        "role": "assistant",
+        "content": "43",
+        "thinking_blocks": [_THINKING_BLOCK],
+        "provider_specific_fields": {"citations": None},
+    },
+    {"role": "user", "content": "And doubled?"},
+]
+_HISTORY_AS_OPENAI_SPEC: Final[JsonValue] = [
+    {"role": "system", "content": "You are a calculator."},
+    {"role": "user", "content": "What is 17 + 26?"},
+    {"role": "assistant", "content": "43"},
+    {"role": "user", "content": "And doubled?"},
+]
+
+
+def _completion(identity: str) -> bytes:
+    return json.dumps(
+        {
+            "id": identity,
+            "object": "chat.completion",
+            "created": 1,
+            "model": _BACKEND,
+            "choices": [{"index": 0, "message": {"role": "assistant", "content": "86"}, "finish_reason": "stop"}],
+            "usage": {"prompt_tokens": 31, "completion_tokens": 2, "total_tokens": 33},
+        }
+    ).encode()
+
+
+@pytest.mark.covers("providers.azure_ai.anthropic_message_fields_are_stripped_before_foundry")
+def test_azure_ai_strips_thinking_blocks_and_cache_control_from_forwarded_messages(gateway: Gateway) -> None:
+    identity: Final = f"azure-ai-strip-{uuid.uuid4().hex}"
+
+    def respond(request: Request) -> Reply:
+        assert request.method == "POST"
+        assert request.target == "/chat/completions"
+        assert request.headers["authorization"] == f"Bearer {_API_KEY}"
+        body: Final = _JSON_OBJECT.validate_json(request.body)
+        assert body["model"] == _BACKEND
+        assert body["messages"] == _HISTORY_AS_OPENAI_SPEC
+        return Reply(body=_completion(identity))
+
+    with wire_server(respond) as wire, gateway.scenario() as scenario:
+        model: Final = scenario.model(model=f"azure_ai/{_BACKEND}", api_base=wire.url, api_key=_API_KEY)
+        response: Final = gateway.request(
+            "POST",
+            "/v1/chat/completions",
+            {"model": model, "messages": _HISTORY_WITH_ANTHROPIC_FIELDS},
+        )
+        assert response.status_code == 200, response.text
+        payload: Final = _JSON_OBJECT.validate_json(response.content)
+        assert payload["id"] == identity
+        assert payload["choices"] == [
+            {
+                "finish_reason": "stop",
+                "index": 0,
+                "message": {"role": "assistant", "content": "86"},
+                "provider_specific_fields": {},
+            }
+        ]
+        assert [(request.method, request.target) for request in wire.drain()] == [("POST", "/chat/completions")]