diff --git a/nanobot/providers/openai_compat_provider.py b/nanobot/providers/openai_compat_provider.py
index 8281d7d20..cd6dd300b 100644
--- a/nanobot/providers/openai_compat_provider.py
+++ b/nanobot/providers/openai_compat_provider.py
@@ -428,6 +428,10 @@ class OpenAICompatProvider(LLMProvider):
             return tool_call_id
         return hashlib.sha1(tool_call_id.encode()).hexdigest()[:9]
 
+    def _should_normalize_tool_call_ids(self) -> bool:
+        """Return True for providers that reject normal OpenAI tool call IDs."""
+        return bool(self._spec and self._spec.name == "mistral")
+
     @staticmethod
     def _normalize_tool_call_arguments(arguments: Any) -> str:
         """Force function.arguments into a valid JSON object string."""
@@ -466,10 +470,13 @@ class OpenAICompatProvider(LLMProvider):
         id_map: dict[str, str] = {}
         pending_tool_ids: dict[str, deque[str]] = {}
         force_string_content = bool(self._spec and self._spec.name == "deepseek")
+        normalize_tool_ids = self._should_normalize_tool_call_ids()
 
         def map_id(value: Any) -> Any:
             if not isinstance(value, str):
                 return value
+            if not normalize_tool_ids:
+                return value
             return id_map.setdefault(value, self._normalize_tool_call_id(value))
 
         def unique_tool_id(value: Any, used_ids: set[str], idx: int) -> str:
@@ -956,7 +963,7 @@ class OpenAICompatProvider(LLMProvider):
                     args = json_repair.loads(args)
                 ec, prov, fn_prov = _extract_tc_extras(tc)
                 parsed_tool_calls.append(ToolCallRequest(
-                    id=_short_tool_id(),
+                    id=str(tc_map.get("id") or _short_tool_id()),
                     name=str(fn.get("name") or ""),
                     arguments=args if isinstance(args, dict) else {},
                     extra_content=ec,
@@ -999,7 +1006,7 @@ class OpenAICompatProvider(LLMProvider):
                 args = json_repair.loads(args)
             ec, prov, fn_prov = _extract_tc_extras(tc)
             tool_calls.append(ToolCallRequest(
-                id=_short_tool_id(),
+                id=str(getattr(tc, "id", None) or _short_tool_id()),
                 name=tc.function.name,
                 arguments=args,
                 extra_content=ec,
diff --git a/tests/providers/test_litellm_kwargs.py b/tests/providers/test_litellm_kwargs.py
index 6e00cba19..d786aad3e 100644
--- a/tests/providers/test_litellm_kwargs.py
+++ b/tests/providers/test_litellm_kwargs.py
@@ -602,6 +602,7 @@ async def test_openai_compat_preserves_extra_content_on_tool_calls() -> None:
 
     assert len(result.tool_calls) == 1
     tool_call = result.tool_calls[0]
+    assert tool_call.id == "call_123"
     assert tool_call.extra_content == {"google": {"thought_signature": "signed-token"}}
     assert tool_call.function_provider_specific_fields == {"inner": "value"}
 
@@ -994,7 +995,7 @@ def test_deepseek_thinking_keeps_tool_history_with_reasoning_content() -> None:
     assert kwargs["messages"][2]["role"] == "tool"
 
 
-def test_openai_compat_keeps_tool_calls_after_consecutive_assistant_messages() -> None:
+def test_openai_compat_preserves_tool_call_ids_after_consecutive_assistant_messages() -> None:
     with patch("nanobot.providers.openai_compat_provider.AsyncOpenAI"):
         provider = OpenAICompatProvider()
 
@@ -1016,6 +1017,34 @@ def test_openai_compat_keeps_tool_calls_after_consecutive_assistant_messages() -
         {"role": "user", "content": "多少star了呢"},
     ])
 
+    assert sanitized[1]["role"] == "assistant"
+    assert sanitized[1]["content"] is None
+    assert sanitized[1]["tool_calls"][0]["id"] == "call_function_akxp3wqzn7ph_1"
+    assert sanitized[2]["tool_call_id"] == "call_function_akxp3wqzn7ph_1"
+
+
+def test_mistral_normalizes_tool_call_ids_after_consecutive_assistant_messages() -> None:
+    with patch("nanobot.providers.openai_compat_provider.AsyncOpenAI"):
+        provider = OpenAICompatProvider(spec=find_by_name("mistral"))
+
+    sanitized = provider._sanitize_messages([
+        {"role": "user", "content": "不错"},
+        {"role": "assistant", "content": "对，破 4 万指日可待"},
+        {
+            "role": "assistant",
+            "content": "<think>我再查一下</think>",
+            "tool_calls": [
+                {
+                    "id": "call_function_akxp3wqzn7ph_1",
+                    "type": "function",
+                    "function": {"name": "exec", "arguments": "{}"},
+                }
+            ],
+        },
+        {"role": "tool", "tool_call_id": "call_function_akxp3wqzn7ph_1", "name": "exec", "content": "ok"},
+        {"role": "user", "content": "多少star了呢"},
+    ])
+
     assert sanitized[1]["role"] == "assistant"
     assert sanitized[1]["content"] is None
     assert sanitized[1]["tool_calls"][0]["id"] == "3ec83c30d"