diff --git a/pyproject.toml b/pyproject.toml
index 98385e32..11061163 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -40,3 +40,15 @@ include = ["tradingagents*", "cli*"]
 
 [tool.setuptools.package-data]
 cli = ["static/*"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+addopts = "-ra --strict-markers"
+markers = [
+    "unit: fast isolated unit tests",
+    "integration: tests requiring external services",
+    "smoke: quick sanity-check tests",
+]
+filterwarnings = [
+    "ignore::DeprecationWarning",
+]
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 00000000..67554305
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,67 @@
+"""Shared pytest fixtures that prevent CI hangs when API keys are absent."""
+
+import os
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+# ---------------------------------------------------------------------------
+# Custom markers
+# ---------------------------------------------------------------------------
+
+
+def pytest_configure(config):
+    for marker in ("unit", "integration", "smoke"):
+        config.addinivalue_line("markers", f"{marker}: {marker}-level tests")
+
+
+# ---------------------------------------------------------------------------
+# Auto-use: placeholder API keys so LLM client init never blocks
+# ---------------------------------------------------------------------------
+
+_API_KEY_ENV_VARS = [
+    "OPENAI",
+    "GOOGLE",
+    "ANTHROPIC",
+    "XAI",
+    "ALPHA_VANTAGE",
+]
+
+
+@pytest.fixture(autouse=True)
+def _dummy_api_keys(monkeypatch):
+    for provider in _API_KEY_ENV_VARS:
+        env_var = f"{provider}_API_KEY"
+        monkeypatch.setenv(env_var, os.environ.get(env_var, "placeholder"))
+
+
+# ---------------------------------------------------------------------------
+# Auto-use: safe DEFAULT_CONFIG override (no real API calls)
+# ---------------------------------------------------------------------------
+
+_SAFE_CONFIG = {
+    "llm_provider": "openai",
+    "deep_think_llm": "gpt-5.4-mini",
+    "quick_think_llm": "gpt-5.4-mini",
+    "max_debate_rounds": 1,
+    "max_risk_discuss_rounds": 1,
+}
+
+
+@pytest.fixture(autouse=True)
+def _safe_default_config():
+    with patch.dict("tradingagents.default_config.DEFAULT_CONFIG", _SAFE_CONFIG):
+        yield
+
+
+# ---------------------------------------------------------------------------
+# Reusable mock LLM client
+# ---------------------------------------------------------------------------
+
+
+@pytest.fixture()
+def mock_llm_client():
+    client = MagicMock()
+    client.get_llm.return_value = MagicMock()
+    with patch("tradingagents.llm_clients.create_llm_client", return_value=client):
+        yield client
diff --git a/tests/test_google_api_key.py b/tests/test_google_api_key.py
index e1607c49..53376ab1 100644
--- a/tests/test_google_api_key.py
+++ b/tests/test_google_api_key.py
@@ -1,9 +1,12 @@
 import unittest
 from unittest.mock import patch
 
+import pytest
+
 from tradingagents.llm_clients.google_client import GoogleClient
 
 
+@pytest.mark.unit
 class TestGoogleApiKeyStandardization(unittest.TestCase):
     """Verify GoogleClient accepts unified api_key parameter."""
 
diff --git a/tests/test_model_validation.py b/tests/test_model_validation.py
index 50f26318..5392d7cd 100644
--- a/tests/test_model_validation.py
+++ b/tests/test_model_validation.py
@@ -1,6 +1,8 @@
 import unittest
 import warnings
 
+import pytest
+
 from tradingagents.llm_clients.base_client import BaseLLMClient
 from tradingagents.llm_clients.model_catalog import get_known_models
 from tradingagents.llm_clients.validators import validate_model
@@ -19,6 +21,7 @@ class DummyLLMClient(BaseLLMClient):
         return validate_model(self.provider, self.model)
 
 
+@pytest.mark.unit
 class ModelValidationTests(unittest.TestCase):
     def test_cli_catalog_models_are_all_validator_approved(self):
         for provider, models in get_known_models().items():
diff --git a/tests/test_ticker_symbol_handling.py b/tests/test_ticker_symbol_handling.py
index 858d26cd..7fbe5315 100644
--- a/tests/test_ticker_symbol_handling.py
+++ b/tests/test_ticker_symbol_handling.py
@@ -1,9 +1,12 @@
 import unittest
 
+import pytest
+
 from cli.utils import normalize_ticker_symbol
 from tradingagents.agents.utils.agent_utils import build_instrument_context
 
 
+@pytest.mark.unit
 class TickerSymbolHandlingTests(unittest.TestCase):
     def test_normalize_ticker_symbol_preserves_exchange_suffix(self):
         self.assertEqual(normalize_ticker_symbol(" cnc.to "), "CNC.TO")
diff --git a/tradingagents/llm_clients/factory.py b/tradingagents/llm_clients/factory.py
index a9a7e83d..49041f29 100644
--- a/tradingagents/llm_clients/factory.py
+++ b/tradingagents/llm_clients/factory.py
@@ -1,10 +1,6 @@
 from typing import Optional
 
 from .base_client import BaseLLMClient
-from .openai_client import OpenAIClient
-from .anthropic_client import AnthropicClient
-from .google_client import GoogleClient
-from .azure_client import AzureOpenAIClient
 
 # Providers that use the OpenAI-compatible chat completions API
 _OPENAI_COMPATIBLE = (
@@ -20,6 +16,9 @@ def create_llm_client(
 ) -> BaseLLMClient:
     """Create an LLM client for the specified provider.
 
+    Client modules are imported lazily so that collecting tests or importing
+    the package does not trigger heavy LLM SDK initialization.
+
     Args:
         provider: LLM provider name
         model: Model name/identifier
@@ -35,15 +34,19 @@ def create_llm_client(
     provider_lower = provider.lower()
 
     if provider_lower in _OPENAI_COMPATIBLE:
+        from .openai_client import OpenAIClient
         return OpenAIClient(model, base_url, provider=provider_lower, **kwargs)
 
     if provider_lower == "anthropic":
+        from .anthropic_client import AnthropicClient
         return AnthropicClient(model, base_url, **kwargs)
 
     if provider_lower == "google":
+        from .google_client import GoogleClient
         return GoogleClient(model, base_url, **kwargs)
 
     if provider_lower == "azure":
+        from .azure_client import AzureOpenAIClient
         return AzureOpenAIClient(model, base_url, **kwargs)
 
     raise ValueError(f"Unsupported LLM provider: {provider}")