diff --git a/tradingagents/llm_clients/openai_client.py b/tradingagents/llm_clients/openai_client.py
index 94db7401..ca85ead0 100644
--- a/tradingagents/llm_clients/openai_client.py
+++ b/tradingagents/llm_clients/openai_client.py
@@ -1,106 +1,11 @@
-"""OpenAI-compatible LLM clients (OpenAI, xAI, OpenRouter, Ollama).
-
-OpenAI auth resolution order:
-  1. ``api_key`` kwarg (explicit key always wins)
-  2. ``OPENAI_API_KEY`` environment variable
-  3. ``~/.codex/auth.json`` — OpenAI Codex CLI OAuth token (auto-refreshed)
-"""
-
-import json
 import os
-import time
-from pathlib import Path
 from typing import Any, Optional
 
-import requests
 from langchain_openai import ChatOpenAI
 
 from .base_client import BaseLLMClient, normalize_content
 from .validators import validate_model
 
-# ---------------------------------------------------------------------------
-# Codex OAuth token reader (inlined from auth/codex_token.py)
-# ---------------------------------------------------------------------------
-
-_CODEX_AUTH_FILE = Path.home() / ".codex" / "auth.json"
-_CODEX_TOKEN_URL = "https://auth.openai.com/oauth/token"
-_EXPIRY_BUFFER_SECS = 60
-
-
-def _load_codex_auth() -> Optional[dict]:
-    if not _CODEX_AUTH_FILE.exists():
-        return None
-    try:
-        return json.loads(_CODEX_AUTH_FILE.read_text())
-    except (json.JSONDecodeError, OSError):
-        return None
-
-
-def _codex_token_expired(auth: dict) -> bool:
-    expires = auth.get("expires_at") or auth.get("tokens", {}).get("expires_at")
-    if expires is None:
-        try:
-            import base64
-            token = auth["tokens"]["access_token"]
-            payload = token.split(".")[1]
-            decoded = json.loads(base64.b64decode(payload + "=="))
-            expires = decoded.get("exp")
-        except Exception:
-            return False
-    return time.time() >= (expires - _EXPIRY_BUFFER_SECS)
-
-
-def _refresh_codex_token(auth: dict) -> dict:
-    refresh_token = auth["tokens"]["refresh_token"]
-    resp = requests.post(
-        _CODEX_TOKEN_URL,
-        json={"grant_type": "refresh_token", "refresh_token": refresh_token},
-        headers={"Content-Type": "application/json"},
-        timeout=15,
-    )
-    resp.raise_for_status()
-    new_tokens = resp.json()
-    auth["tokens"].update({
-        "access_token": new_tokens["access_token"],
-        "refresh_token": new_tokens.get("refresh_token", refresh_token),
-        "expires_at": new_tokens.get("expires_in") and int(time.time()) + int(new_tokens["expires_in"]),
-    })
-    auth["last_refresh"] = time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime())
-    _CODEX_AUTH_FILE.write_text(json.dumps(auth, indent=2))
-    return auth
-
-
-def _get_codex_token() -> Optional[str]:
-    """Return a valid OpenAI token from OPENAI_API_KEY or ~/.codex/auth.json."""
-    explicit = os.environ.get("OPENAI_API_KEY")
-    if explicit:
-        return explicit
-    auth = _load_codex_auth()
-    if not auth or "tokens" not in auth:
-        return None
-    if _codex_token_expired(auth):
-        try:
-            auth = _refresh_codex_token(auth)
-        except Exception:
-            pass
-    return auth["tokens"].get("access_token")
-
-
-# ---------------------------------------------------------------------------
-# OpenAI-compatible client
-# ---------------------------------------------------------------------------
-
-_PASSTHROUGH_KWARGS = (
-    "timeout", "max_retries", "reasoning_effort",
-    "api_key", "callbacks", "http_client", "http_async_client",
-)
-
-_PROVIDER_CONFIG = {
-    "xai":        ("https://api.x.ai/v1",            "XAI_API_KEY"),
-    "openrouter": ("https://openrouter.ai/api/v1",   "OPENROUTER_API_KEY"),
-    "ollama":     ("http://localhost:11434/v1",       None),
-}
-
 
 class NormalizedChatOpenAI(ChatOpenAI):
     """ChatOpenAI with normalized content output.
@@ -113,9 +18,22 @@ class NormalizedChatOpenAI(ChatOpenAI):
     def invoke(self, input, config=None, **kwargs):
         return normalize_content(super().invoke(input, config, **kwargs))
 
+# Kwargs forwarded from user config to ChatOpenAI
+_PASSTHROUGH_KWARGS = (
+    "timeout", "max_retries", "reasoning_effort",
+    "api_key", "callbacks", "http_client", "http_async_client",
+)
+
+# Provider base URLs and API key env vars
+_PROVIDER_CONFIG = {
+    "xai": ("https://api.x.ai/v1", "XAI_API_KEY"),
+    "openrouter": ("https://openrouter.ai/api/v1", "OPENROUTER_API_KEY"),
+    "ollama": ("http://localhost:11434/v1", None),
+}
+
 
 class OpenAIClient(BaseLLMClient):
-    """Client for OpenAI, xAI, OpenRouter, and Ollama providers.
+    """Client for OpenAI, Ollama, OpenRouter, and xAI providers.
 
     For native OpenAI models, uses the Responses API (/v1/responses) which
     supports reasoning_effort with function tools across all model families
@@ -137,6 +55,7 @@ class OpenAIClient(BaseLLMClient):
         """Return configured ChatOpenAI instance."""
         llm_kwargs = {"model": self.model}
 
+        # Provider-specific base URL and auth
         if self.provider in _PROVIDER_CONFIG:
             base_url, api_key_env = _PROVIDER_CONFIG[self.provider]
             llm_kwargs["base_url"] = base_url
@@ -149,19 +68,18 @@ class OpenAIClient(BaseLLMClient):
         elif self.base_url:
             llm_kwargs["base_url"] = self.base_url
 
+        # Forward user-provided kwargs
         for key in _PASSTHROUGH_KWARGS:
             if key in self.kwargs:
                 llm_kwargs[key] = self.kwargs[key]
 
+        # Native OpenAI: use Responses API for consistent behavior across
+        # all model families. Third-party providers use Chat Completions.
         if self.provider == "openai":
             llm_kwargs["use_responses_api"] = True
-            if "api_key" not in llm_kwargs:
-                token = _get_codex_token()
-                if token:
-                    llm_kwargs["api_key"] = token
 
         return NormalizedChatOpenAI(**llm_kwargs)
 
     def validate_model(self) -> bool:
-        return validate_model(self.provider, self.model)
-
+        """Validate model for the provider."""
+        return validate_model(self.provider, self.model)
\ No newline at end of file