Reject invalid Amazon Bedrock model IDs in the Anthropic provider

providers/anthropic/src/airflow/providers/anthropic/hooks/anthropic.py

@@ -297,6 +297,20 @@ def _workload_identity_credentials(wif: dict[str, Any]) -> WorkloadIdentityCrede
             kwargs["scope"] = wif["scope"]
         return WorkloadIdentityCredentials(**kwargs)
 
+    def _resolve_model(self, model: str | None) -> str:
+        """Resolve the effective model id; Bedrock rejects a bare id, so require its prefix."""
+        resolved = model or self.default_model
+        # Valid Bedrock ids either start with the ``anthropic.`` provider prefix or carry a
+        # region/profile prefix as a dotted component (e.g. ``us.anthropic.``, ``global.anthropic.``).
+        is_bedrock_model_id = resolved.startswith("anthropic.") or ".anthropic." in resolved
+        if self.platform == "bedrock" and not is_bedrock_model_id:
+            raise AnthropicError(
+                f"Model {resolved!r} is not a valid Amazon Bedrock model id. Bedrock ids carry a "
+                "provider/region prefix (e.g. 'global.anthropic.claude-opus-4-6-v1'); set one via "
+                "the 'model' argument or the connection's extra['model']."
+            )
+        return resolved
+
     def _require_first_party(self, feature: str) -> None:
         if self.platform not in FIRST_PARTY_PLATFORMS:
             raise AnthropicError(
@@ -348,7 +362,7 @@ def create_message(
         :param system: Optional system prompt.
         """
         params: dict[str, Any] = {
-            "model": model or self.default_model,
+            "model": self._resolve_model(model),
             "max_tokens": max_tokens,
             "messages": messages,
             **kwargs,

providers/anthropic/tests/unit/anthropic/hooks/test_anthropic.py

@@ -185,6 +185,40 @@ def test_create_agent_uses_connection_model(self):
         hook.create_agent(name="a")
         assert client.beta.agents.create.call_args.kwargs["model"] == "claude-sonnet-4-6"
 
+    @pytest.mark.parametrize(
+        "model",
+        [None, "my-anthropic.model"],  # bare default id and a substring that is not a real prefix
+    )
+    def test_bedrock_rejects_invalid_model_id(self, model):
+        extra = {"platform": "bedrock", **({"model": model} if model else {})}
+        hook, client = _make_hook(extra=extra)
+        with pytest.raises(AnthropicError, match="not a valid Amazon Bedrock model id"):
+            hook.create_message([{"role": "user", "content": "hi"}])
+        client.messages.create.assert_not_called()
+
+    @pytest.mark.parametrize(
+        ("platform", "model", "expected"),
+        [
+            (
+                "bedrock",
+                "anthropic.claude-sonnet-4-5-20250929-v1:0",
+                "anthropic.claude-sonnet-4-5-20250929-v1:0",
+            ),
+            ("bedrock", "global.anthropic.claude-opus-4-6-v1", "global.anthropic.claude-opus-4-6-v1"),
+            (
+                "bedrock",
+                "us.anthropic.claude-sonnet-4-5-20250929-v1:0",
+                "us.anthropic.claude-sonnet-4-5-20250929-v1:0",
+            ),
+            ("vertex", None, DEFAULT_MODEL),  # non-Bedrock platforms skip the guard
+        ],
+    )
+    def test_accepts_valid_model_id(self, platform, model, expected):
+        extra = {"platform": platform, **({"model": model} if model else {})}
+        hook, client = _make_hook(extra=extra)
+        hook.create_message([{"role": "user", "content": "hi"}])
+        assert client.messages.create.call_args.kwargs["model"] == expected
+
 
 class TestManagedAgentsHook:
     def _hook_with_client(self, extra=None):