refactor: extract Phase 1 gateway helpers

Move tool bridge and responses adapter helpers out of app.main so the main entrypoint can shrink without changing route orchestration behavior.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/test_tool_call_bridge.py

@@ -371,9 +371,14 @@ class ToolCallBridgeTests(unittest.IsolatedAsyncioTestCase):
             response = await main.v1_chat_completions(req, _make_request("/v1/chat/completions"))
             body = await _collect_stream(response)
 
+        chunks = [json.loads(line[6:]) for line in body.splitlines() if line.startswith("data: {")]
+        tool_call_chunk = next(chunk for chunk in chunks if chunk["choices"] and chunk["choices"][0]["delta"].get("tool_calls"))
+        tool_call = tool_call_chunk["choices"][0]["delta"]["tool_calls"][0]
+
         self.assertIn('"tool_calls"', body)
-        self.assertIn('"name": "lookup"', body)
-        self.assertIn('{"query": "gateway"}', body)
+        self.assertEqual(tool_call["function"]["name"], "lookup")
+        self.assertEqual(json.loads(tool_call["function"]["arguments"]), {"query": "gateway"})
+        self.assertNotIn('lookup(query=\\"gateway\\")', body)
         self.assertIn('"finish_reason": "tool_calls"', body)
         self.assertIn('data: [DONE]', body)
 
@@ -415,6 +420,41 @@ class ToolCallBridgeTests(unittest.IsolatedAsyncioTestCase):
         self.assertIn("data: [DONE]", body)
 
 
+    async def test_openai_stream_filters_tool_events_by_allowlist(self) -> None:
+        fake_client = _FakeClient(
+            stream_events=[
+                {"type": "tool", "tool": {"id": "call_blocked", "name": "write_file", "input": {"path": "a.txt"}}},
+                {"type": "tool", "tool": {"id": "call_allowed", "name": "lookup", "input": {"query": "gateway"}}},
+                {"type": "text", "text": "hello"},
+            ],
+            complete_result={},
+        )
+        req = ChatCompletionsRequest(
+            model="org_auto",
+            messages=[{"role": "user", "content": "hi"}],
+            stream=True,
+            tools=[
+                {"type": "function", "function": {"name": "lookup", "parameters": {}}},
+                {"type": "function", "function": {"name": "write_file", "parameters": {}}},
+            ],
+            tool_choice={"type": "function", "function": {"name": "lookup"}},
+        )
+
+        with (
+            patch.object(main, "pool", _FakePool(_FakeInstance(fake_client))),
+            patch.object(main, "chat_guard", _FakeGuard()),
+            patch.object(main, "_ensure_instance_logged_in", AsyncMock(return_value={"id": "u"})),
+            patch.object(main.stats_collector, "record_chat", AsyncMock(return_value=None)),
+            _SettingsPatch(tool_forward_enabled=True, tool_allowlist=["lookup"]),
+        ):
+            response = await main.v1_chat_completions(req, _make_request("/v1/chat/completions"))
+            body = await _collect_stream(response)
+
+        self.assertIn('"name": "lookup"', body)
+        self.assertNotIn('"name": "write_file"', body)
+        self.assertIn('"content": "hello"', body)
+        self.assertIn('"finish_reason": "tool_calls"', body)
+
     async def test_anthropic_non_stream_bridges_tool_blocks(self) -> None:
         fake_client = _FakeClient(
             stream_events=[],
@@ -670,6 +710,67 @@ class ToolCallBridgeTests(unittest.IsolatedAsyncioTestCase):
 
 
 
+    async def test_anthropic_stream_filters_tool_events_by_allowlist(self) -> None:
+        fake_client = _FakeClient(
+            stream_events=[
+                {
+                    "type": "tool",
+                    "tool": {
+                        "id": "toolu_blocked",
+                        "name": "write_file",
+                        "input": {"path": "a.txt"},
+                        "result": "blocked",
+                    },
+                },
+                {
+                    "type": "tool",
+                    "tool": {
+                        "id": "toolu_allowed",
+                        "name": "lookup",
+                        "input": {"file": "a.txt"},
+                        "result": "done",
+                    },
+                },
+                {"type": "text", "text": "world"},
+            ],
+            complete_result={},
+        )
+        req = AnthropicMessagesRequest(
+            model="claude-3-5-sonnet-20241022",
+            max_tokens=256,
+            messages=[{"role": "user", "content": "hi"}],
+            stream=True,
+            tools=[
+                {"name": "lookup", "input_schema": {"type": "object", "properties": {}}},
+                {"name": "write_file", "input_schema": {"type": "object", "properties": {}}},
+            ],
+            tool_choice={"type": "tool", "name": "lookup"},
+        )
+
+        with (
+            patch.object(main, "pool", _FakePool(_FakeInstance(fake_client))),
+            patch.object(main, "chat_guard", _FakeGuard()),
+            patch.object(main, "_ensure_instance_logged_in", AsyncMock(return_value={"id": "u"})),
+            patch.object(main.stats_collector, "record_chat", AsyncMock(return_value=None)),
+            patch.object(main.settings, "api_keys", ["test-key"]),
+            _SettingsPatch(tool_forward_enabled=True, tool_allowlist=["lookup"]),
+        ):
+            response = await main.v1_messages(
+                req,
+                _make_request(
+                    "/v1/messages",
+                    headers={"x-api-key": "test-key", "anthropic-version": "2023-06-01"},
+                ),
+            )
+            body = await _collect_stream(response)
+
+        self.assertIn('"name": "lookup"', body)
+        self.assertNotIn('"name": "write_file"', body)
+        self.assertIn('"type": "tool_result"', body)
+        self.assertIn('"stop_reason": "end_turn"', body)
+
+
+
     async def test_openai_non_stream_forwards_tool_config_when_enabled(self) -> None:
         spy_client = _SpyClient(stream_events=[], complete_result={"text": "ok", "toolEvents": []})
         req = ChatCompletionsRequest(