diff --git a/ai_agents/agents/ten_packages/extension/grok_python/tests/conftest.py b/ai_agents/agents/ten_packages/extension/grok_python/tests/conftest.py
new file mode 100644
index 0000000000..3d3c44ca60
--- /dev/null
+++ b/ai_agents/agents/ten_packages/extension/grok_python/tests/conftest.py
@@ -0,0 +1,69 @@
+#
+# This file is part of TEN Framework, an open source project.
+# Licensed under the Apache License, Version 2.0.
+# See the LICENSE file for more information.
+#
+# conftest.py — stub out ten_runtime and ten_ai_base before the extension
+# package is imported, so that unit tests for pure-Python helpers can run
+# without a full TEN runtime installation.
+#
+import sys
+import types
+from unittest.mock import MagicMock
+
+
+def _make_mock_module(name: str) -> types.ModuleType:
+    mod = types.ModuleType(name)
+    mod.__spec__ = None  # type: ignore[assignment]
+    mod.__getattr__ = lambda attr: MagicMock()  # type: ignore[method-assign]
+    return mod
+
+
+_STUB_MODULES = [
+    "ten_runtime",
+    "ten_runtime.async_ten_env",
+    "ten_ai_base",
+    "ten_ai_base.llm",
+    "ten_ai_base.llm2",
+    "ten_ai_base.struct",
+    "ten_ai_base.types",
+    "ten_ai_base.config",
+    "ten_ai_base.const",
+    "ten_ai_base.helper",
+    "ten_ai_base.message",
+    "PIL",
+    "openai",
+    "requests",
+]
+
+for _name in _STUB_MODULES:
+    if _name not in sys.modules:
+        sys.modules[_name] = _make_mock_module(_name)
+
+_ten_runtime = sys.modules["ten_runtime"]
+for _attr in (
+    "Addon",
+    "AsyncExtension",
+    "AsyncTenEnv",
+    "Cmd",
+    "CmdResult",
+    "Data",
+    "StatusCode",
+    "TenEnv",
+    "register_addon_as_extension",
+):
+    setattr(_ten_runtime, _attr, MagicMock())
+
+# ten_ai_base.config.BaseConfig must be a real class so grokConfig can
+# inherit from it without errors.
+import dataclasses
+
+
+@dataclasses.dataclass
+class _BaseConfig:
+    @classmethod
+    async def create_async(cls, ten_env=None):
+        return cls()
+
+
+sys.modules["ten_ai_base.config"].BaseConfig = _BaseConfig
diff --git a/ai_agents/agents/ten_packages/extension/grok_python/tests/test_helpers.py b/ai_agents/agents/ten_packages/extension/grok_python/tests/test_helpers.py
new file mode 100644
index 0000000000..656a07d9cf
--- /dev/null
+++ b/ai_agents/agents/ten_packages/extension/grok_python/tests/test_helpers.py
@@ -0,0 +1,219 @@
+#
+# This file is part of TEN Framework, an open source project.
+# Licensed under the Apache License, Version 2.0.
+# See the LICENSE file for more information.
+#
+import importlib.util
+from pathlib import Path
+
+# Load helper and openai modules directly from source files to avoid importing
+# the extension package __init__ (which requires ten_runtime).
+_ext_dir = Path(__file__).resolve().parents[1]
+
+
+def _load(filename):
+    path = _ext_dir / filename
+    spec = importlib.util.spec_from_file_location(path.stem, path)
+    mod = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(mod)
+    return mod
+
+
+_helper = _load("helper.py")
+parse_sentences = _helper.parse_sentences
+is_punctuation = _helper.is_punctuation
+
+
+# ============================================================
+# is_punctuation
+# ============================================================
+
+
+def test_is_punctuation_english():
+    for ch in [",", ".", "?", "!"]:
+        assert is_punctuation(ch), f"Expected '{ch}' to be punctuation"
+
+
+def test_is_punctuation_chinese():
+    for ch in ["，", "。", "？", "！"]:
+        assert is_punctuation(ch), f"Expected '{ch}' to be punctuation"
+
+
+def test_is_punctuation_letter_is_false():
+    assert not is_punctuation("a")
+    assert not is_punctuation("Z")
+    assert not is_punctuation("1")
+    assert not is_punctuation(" ")
+
+
+# ============================================================
+# parse_sentences
+# ============================================================
+
+
+def test_parse_sentences_single_sentence():
+    sentences, remain = parse_sentences("", "Hello world.")
+    assert sentences == ["Hello world."]
+    assert remain == ""
+
+
+def test_parse_sentences_multiple_sentences():
+    sentences, remain = parse_sentences("", "First. Second. Third.")
+    assert len(sentences) == 3
+
+
+def test_parse_sentences_incomplete_sentence_remains():
+    sentences, remain = parse_sentences("", "Hello world")
+    assert sentences == []
+    assert remain == "Hello world"
+
+
+def test_parse_sentences_fragment_prepended():
+    sentences, remain = parse_sentences("Hello", " world.")
+    assert sentences == ["Hello world."]
+    assert remain == ""
+
+
+def test_parse_sentences_fragment_with_no_punctuation():
+    sentences, remain = parse_sentences("Part one", " and more")
+    assert sentences == []
+    assert remain == "Part one and more"
+
+
+def test_parse_sentences_chinese_punctuation():
+    sentences, remain = parse_sentences("", "你好。再见。")
+    assert len(sentences) == 2
+    assert remain == ""
+
+
+def test_parse_sentences_mixed_punctuation():
+    sentences, remain = parse_sentences("", "Hello! How are you? Fine.")
+    assert len(sentences) == 3
+
+
+def test_parse_sentences_punctuation_only_not_emitted():
+    """A token that is only punctuation (no alphanumeric) should be skipped."""
+    sentences, remain = parse_sentences("", "...")
+    assert sentences == []
+
+
+def test_parse_sentences_empty_content():
+    sentences, remain = parse_sentences("", "")
+    assert sentences == []
+    assert remain == ""
+
+
+def test_parse_sentences_empty_fragment_and_content():
+    sentences, remain = parse_sentences("", "")
+    assert sentences == []
+    assert remain == ""
+
+
+def test_parse_sentences_question_mark():
+    sentences, remain = parse_sentences("", "Are you there?")
+    assert sentences == ["Are you there?"]
+    assert remain == ""
+
+
+def test_parse_sentences_exclamation():
+    sentences, remain = parse_sentences("", "Watch out!")
+    assert sentences == ["Watch out!"]
+    assert remain == ""
+
+
+# ============================================================
+# ThinkParser (grok's simpler token-level parser)
+# ============================================================
+
+
+def _load_think_parser():
+    # grok_python/openai.py contains ThinkParser but also imports openai and
+    # requests at module level. Use importlib and patch those imports first.
+    import sys
+    import types
+    from unittest.mock import MagicMock
+
+    for mod_name in [
+        "openai",
+        "openai.types",
+        "openai.types.chat",
+        "openai.types.chat.chat_completion",
+        "requests",
+    ]:
+        if mod_name not in sys.modules:
+            m = types.ModuleType(mod_name)
+            m.__getattr__ = lambda attr: MagicMock()
+            sys.modules[mod_name] = m
+
+    path = _ext_dir / "openai.py"
+    spec = importlib.util.spec_from_file_location("grok_openai", path)
+    mod = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(mod)
+    return mod.ThinkParser
+
+
+ThinkParser = _load_think_parser()
+
+
+def test_think_parser_initial_state_normal():
+    parser = ThinkParser()
+    assert parser.state == "NORMAL"
+
+
+def test_think_parser_open_tag_changes_state():
+    parser = ThinkParser()
+    changed = parser.process("<think>")
+    assert changed is True
+    assert parser.state == "THINK"
+
+
+def test_think_parser_close_tag_changes_state():
+    parser = ThinkParser()
+    parser.process("<think>")
+    changed = parser.process("</think>")
+    assert changed is True
+    assert parser.state == "NORMAL"
+
+
+def test_think_parser_plain_text_no_state_change():
+    parser = ThinkParser()
+    changed = parser.process("hello")
+    assert changed is False
+    assert parser.state == "NORMAL"
+
+
+def test_think_parser_accumulates_think_content():
+    parser = ThinkParser()
+    parser.process("<think>")
+    parser.process("step one")
+    parser.process("step two")
+    assert "step one" in parser.think_content
+    assert "step two" in parser.think_content
+
+
+def test_think_parser_no_accumulation_in_normal_state():
+    parser = ThinkParser()
+    parser.process("visible text")
+    assert parser.think_content == ""
+
+
+def test_think_parser_process_by_reasoning_content_opens():
+    parser = ThinkParser()
+    changed = parser.process_by_reasoning_content("thinking...")
+    assert changed is True
+    assert parser.state == "THINK"
+    assert "thinking..." in parser.think_content
+
+
+def test_think_parser_process_by_reasoning_content_closes_on_empty():
+    parser = ThinkParser()
+    parser.process_by_reasoning_content("data")
+    changed = parser.process_by_reasoning_content("")
+    assert changed is True
+    assert parser.state == "NORMAL"
+
+
+def test_think_parser_process_by_reasoning_already_normal_no_change():
+    parser = ThinkParser()
+    changed = parser.process_by_reasoning_content("")
+    assert changed is False