From 4dfca3ad9124f13574406edb94b3d54ae9895044 Mon Sep 17 00:00:00 2001
From: Varad Pimpalkhute <pimpalkhutevarad@gmail.com>
Date: Thu, 2 Jul 2026 08:35:41 +0000
Subject: [PATCH 1/3] Keep raw string for tool-call args that literal_eval to
 non-JSON types

---
 .../srt/function_call/multi_format_detector.py       |  4 +++-
 .../function_call/test_multi_format_detector.py      | 12 ++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/python/sglang/srt/function_call/multi_format_detector.py b/python/sglang/srt/function_call/multi_format_detector.py
index 14a540a4706e..75da4a16c284 100644
--- a/python/sglang/srt/function_call/multi_format_detector.py
+++ b/python/sglang/srt/function_call/multi_format_detector.py
@@ -1046,7 +1046,9 @@ def _deserialize_glm_value(value: str) -> Any:
         except Exception:
             pass
         try:
-            return ast.literal_eval(value)
+            result = ast.literal_eval(value)
+            json.dumps(result)
+            return result
         except Exception:
             pass
         return value
diff --git a/test/registered/function_call/test_multi_format_detector.py b/test/registered/function_call/test_multi_format_detector.py
index a80f49def64f..d94b1cfda03f 100644
--- a/test/registered/function_call/test_multi_format_detector.py
+++ b/test/registered/function_call/test_multi_format_detector.py
@@ -276,6 +276,18 @@ def test_python_tuple_literal_value(self):
         # ast.literal handles tuple syntax; serialized as a JSON array.
         self.assertEqual(args["days"], [1, 2])
 
+    def test_python_set_literal_value_stays_string(self):
+        text = (
+            "<tool_call>get_weather"
+            "<arg_key>days</arg_key><arg_value>{1, 2}</arg_value>"
+            "</tool_call>"
+        )
+        result = self.det.detect_and_parse(text, self.tools)
+        args = json.loads(result.calls[0].parameters)
+        # ast.literal_eval yields a set, which JSON cannot represent; the raw
+        # string is kept so the arguments dict stays serializable.
+        self.assertEqual(args["days"], "{1, 2}")
+
 
 class TestGptOssDialect(unittest.TestCase):
     def setUp(self):

From aeec8f8bcf0f4e0c98cfe1c007ac48ee57cc3f3f Mon Sep 17 00:00:00 2001
From: Rupesh K Srivastava <rupspace@gmail.com>
Date: Thu, 2 Jul 2026 17:48:35 -0700
Subject: [PATCH 2/3] Apply suggestion from @flukeskywalker

---
 python/sglang/srt/function_call/multi_format_detector.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/python/sglang/srt/function_call/multi_format_detector.py b/python/sglang/srt/function_call/multi_format_detector.py
index 75da4a16c284..25eb1acc7d7e 100644
--- a/python/sglang/srt/function_call/multi_format_detector.py
+++ b/python/sglang/srt/function_call/multi_format_detector.py
@@ -1047,6 +1047,7 @@ def _deserialize_glm_value(value: str) -> Any:
             pass
         try:
             result = ast.literal_eval(value)
+           # Try json serialization here in case that raises
             json.dumps(result)
             return result
         except Exception:

From 6032806e809a010d130bfe9922445ebe3ab299e1 Mon Sep 17 00:00:00 2001
From: Varad Pimpalkhute <pimpalkhutevarad@gmail.com>
Date: Wed, 15 Jul 2026 20:44:45 +0000
Subject: [PATCH 3/3] Clarify GLM literal serialization fallback

---
 python/sglang/srt/function_call/multi_format_detector.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/python/sglang/srt/function_call/multi_format_detector.py b/python/sglang/srt/function_call/multi_format_detector.py
index 25eb1acc7d7e..fae320a38c2c 100644
--- a/python/sglang/srt/function_call/multi_format_detector.py
+++ b/python/sglang/srt/function_call/multi_format_detector.py
@@ -1047,7 +1047,7 @@ def _deserialize_glm_value(value: str) -> Any:
             pass
         try:
             result = ast.literal_eval(value)
-           # Try json serialization here in case that raises
+            # Keep literal_eval results only when they remain JSON-serializable.
             json.dumps(result)
             return result
         except Exception: