From f97b503faf082205caad792310eb5eb1defd570f Mon Sep 17 00:00:00 2001
From: shrey kharbanda <shreshth@berri.ai>
Date: Thu, 24 Sep 2026 02:03:19 +0000
Subject: [PATCH] feat(openai_like): honour unsupported_params in JSON
 providers, declare Sail's

---
 litellm/llms/openai_like/dynamic_config.py    |  6 +++-
 litellm/llms/openai_like/json_loader.py       |  1 +
 litellm/llms/openai_like/providers.json       |  3 +-
 .../llms/openai_like/test_sail_provider.py    | 33 +++++++++++++++++++
 4 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/litellm/llms/openai_like/dynamic_config.py b/litellm/llms/openai_like/dynamic_config.py
index 19e29bcdcb2..9362f20cf48 100644
--- a/litellm/llms/openai_like/dynamic_config.py
+++ b/litellm/llms/openai_like/dynamic_config.py
@@ -94,7 +94,11 @@ def create_config_class(provider: SimpleProviderConfig):
             that don't support function calling."""
             from litellm.utils import supports_function_calling, supports_reasoning
 
-            supported_params: Final = super().get_supported_openai_params(model=model)
+            supported_params: Final = [
+                param
+                for param in super().get_supported_openai_params(model=model)
+                if param not in provider.unsupported_params
+            ]
 
             _supports_fc: Final = supports_function_calling(model=model, custom_llm_provider=provider.slug)
 
diff --git a/litellm/llms/openai_like/json_loader.py b/litellm/llms/openai_like/json_loader.py
index 5cdaff90d24..4bee08b03c5 100644
--- a/litellm/llms/openai_like/json_loader.py
+++ b/litellm/llms/openai_like/json_loader.py
@@ -22,6 +22,7 @@ class SimpleProviderConfig:
         self.constraints = data.get("constraints", {})
         self.special_handling = data.get("special_handling", {})
         self.supported_endpoints = data.get("supported_endpoints", [])
+        self.unsupported_params: Final = tuple(data.get("unsupported_params", ()))
 
 
 class JSONProviderRegistry:
diff --git a/litellm/llms/openai_like/providers.json b/litellm/llms/openai_like/providers.json
index 3d496047334..bd9f3b415df 100644
--- a/litellm/llms/openai_like/providers.json
+++ b/litellm/llms/openai_like/providers.json
@@ -208,6 +208,7 @@
     "supported_endpoints": ["/v1/chat/completions", "/v1/responses", "/v1/messages"],
     "param_mappings": {
       "max_tokens": "max_completion_tokens"
-    }
+    },
+    "unsupported_params": ["stop", "seed", "frequency_penalty", "presence_penalty", "logit_bias", "logprobs", "top_logprobs"]
   }
 }
diff --git a/tests/test_litellm/llms/openai_like/test_sail_provider.py b/tests/test_litellm/llms/openai_like/test_sail_provider.py
index e7a3c2005ea..6fffe0c81f0 100644
--- a/tests/test_litellm/llms/openai_like/test_sail_provider.py
+++ b/tests/test_litellm/llms/openai_like/test_sail_provider.py
@@ -250,6 +250,39 @@ class TestSailRequestShape:
 
         assert not route.called
 
+    @pytest.mark.respx()
+    def test_sail_unsupported_params_dropped_with_drop_params(self, respx_mock: respx.Router):
+        respx_mock.post(SAIL_CHAT_COMPLETIONS).respond(json=_chat_completion_payload())
+
+        litellm.completion(
+            model=MODEL,
+            messages=[{"role": "user", "content": "hi"}],
+            stop=["x"],
+            seed=1,
+            frequency_penalty=0.5,
+            drop_params=True,
+        )
+
+        body = json.loads(respx_mock.calls[0].request.content)
+        assert "stop" not in body
+        assert "seed" not in body
+        assert "frequency_penalty" not in body
+        assert body["model"] == "zai-org/GLM-5.3"
+        assert body["messages"] == [{"role": "user", "content": "hi"}]
+
+    @pytest.mark.respx(assert_all_called=False)
+    def test_sail_unsupported_params_raise_without_drop_params(self, respx_mock: respx.Router):
+        route = respx_mock.post(SAIL_CHAT_COMPLETIONS)
+
+        with pytest.raises(litellm.UnsupportedParamsError):
+            litellm.completion(
+                model=MODEL,
+                messages=[{"role": "user", "content": "hi"}],
+                stop=["x"],
+            )
+
+        assert not route.called
+
     @pytest.mark.asyncio
     @pytest.mark.respx()
     async def test_sail_anthropic_messages_posts_to_messages_endpoint(self, respx_mock: respx.Router):