fix(session/runner): force MiniMax XML tool-call mode for threatbook-…

flocks/session/runner.py

@@ -1338,11 +1338,19 @@ def _build_tool_catalog_prompt(self, agent: AgentInfo) -> Optional[str]:
         )
 
     def _should_use_text_tool_call_mode(self) -> bool:
+        # MiniMax models exposed through ThreatBook-managed gateways do not
+        # forward the OpenAI ``tool_calls`` field on their streaming chunks
+        # (observed on ``threatbook-cn-llm`` 2026-04: first ``ChoiceDelta``
+        # only contains ``content`` / ``role``). Without this opt-in the
+        # model can never request a tool and ends every turn with
+        # ``finish_reason=stop`` and zero tool calls. Force the MiniMax XML
+        # text-call protocol for these provider/model pairs so tools work.
         model_lower = (self.model_id or "").lower()
         provider_lower = (self.provider_id or "").lower()
         minimax_text_tool_call_providers = {
             "custom-threatbook-internal",
             "custom-tb-inner",
+            "threatbook-cn-llm",
         }
         return (
             "minimax" in model_lower

tests/session/test_runner_step.py

@@ -622,6 +622,38 @@ def test_enabled_for_custom_tb_inner_minimax(self):
         )
         assert runner._should_use_text_tool_call_mode() is True
 
+    def test_enabled_for_threatbook_cn_llm_minimax(self):
+        # Regression: threatbook-cn-llm gateway strips the OpenAI tool_calls
+        # field for MiniMax models, so the XML text-call protocol must be
+        # forced or every turn ends with finish_reason=stop and zero tools.
+        session = _make_session("ses_minimax_threatbook_cn_llm")
+        runner = SessionRunner(
+            session=session,
+            provider_id="threatbook-cn-llm",
+            model_id="minimax-m2.7",
+        )
+        assert runner._should_use_text_tool_call_mode() is True
+
+    def test_enabled_for_threatbook_cn_llm_minimax_case_insensitive(self):
+        session = _make_session("ses_minimax_threatbook_cn_llm_case")
+        runner = SessionRunner(
+            session=session,
+            provider_id="ThreatBook-CN-LLM",
+            model_id="MiniMax-M2.5",
+        )
+        assert runner._should_use_text_tool_call_mode() is True
+
+    def test_disabled_for_threatbook_cn_llm_non_minimax(self):
+        # Other models routed through the same gateway (e.g. qwen, GLM) keep
+        # the standard OpenAI native function-calling path.
+        session = _make_session("ses_threatbook_cn_llm_qwen")
+        runner = SessionRunner(
+            session=session,
+            provider_id="threatbook-cn-llm",
+            model_id="qwen3.6-plus",
+        )
+        assert runner._should_use_text_tool_call_mode() is False
+
     def test_disabled_for_other_models(self):
         session = _make_session("ses_normal_mode")
         runner = SessionRunner(