refactor(llm_clients): extract config loading logic into separate module

Move config loading and validation functions from openai_client.py and factory.py into a new shared config_loader.py module. This centralizes configuration handling, reduces code duplication, and improves maintainability. The factory now gracefully falls back to default provider types if config loading fails.

tradingagents/llm_clients/config_loader.py

@@ -0,0 +1,41 @@
+import json
+from pathlib import Path
+from typing import Any
+
+CONFIG_PATH = Path(__file__).resolve().parents[2] / "config.json"
+
+
+def load_config() -> dict:
+    try:
+        with CONFIG_PATH.open("r", encoding="utf-8") as config_file:
+            config = json.load(config_file)
+    except FileNotFoundError as exc:
+        raise RuntimeError(f"Config file not found: {CONFIG_PATH}") from exc
+    except json.JSONDecodeError as exc:
+        raise RuntimeError(f"Invalid JSON in config file: {CONFIG_PATH}") from exc
+    except OSError as exc:
+        raise RuntimeError(f"Unable to read config file: {CONFIG_PATH}") from exc
+    if not isinstance(config, dict):
+        raise RuntimeError(f"Invalid config format in file: {CONFIG_PATH}")
+    return config
+
+
+def get_config_section(config: dict, key: str, expected_type: type) -> Any:
+    value = config.get(key)
+    if not isinstance(value, expected_type):
+        raise RuntimeError(f"Invalid or missing '{key}' in config file: {CONFIG_PATH}")
+    return value
+
+
+def get_base_urls_map(config: dict) -> dict[str, str]:
+    base_urls = get_config_section(config, "BASE_URLS", list)
+    mapped_urls: dict[str, str] = {}
+    for item in base_urls:
+        if (
+            isinstance(item, list)
+            and len(item) == 2
+            and isinstance(item[0], str)
+            and isinstance(item[1], str)
+        ):
+            mapped_urls[item[0].lower()] = item[1]
+    return mapped_urls

tradingagents/llm_clients/factory.py

@@ -1,40 +1,39 @@
-import json
-from pathlib import Path
+import warnings
 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 .config_loader import load_config, get_config_section
 
-CONFIG_PATH = Path(__file__).resolve().parents[2] / "config.json"
-
-
-def _load_config() -> dict:
-    try:
-        with CONFIG_PATH.open("r", encoding="utf-8") as config_file:
-            config = json.load(config_file)
-    except FileNotFoundError as exc:
-        raise RuntimeError(f"Config file not found: {CONFIG_PATH}") from exc
-    except json.JSONDecodeError as exc:
-        raise RuntimeError(f"Invalid JSON in config file: {CONFIG_PATH}") from exc
-    except OSError as exc:
-        raise RuntimeError(f"Unable to read config file: {CONFIG_PATH}") from exc
-    if not isinstance(config, dict):
-        raise RuntimeError(f"Invalid config format in file: {CONFIG_PATH}")
-    return config
+DEFAULT_PROVIDER_TYPES: dict[str, str] = {
+    "openai": "openai",
+    "anthropic": "anthropic",
+    "google": "google",
+    "xai": "openai",
+    "openrouter": "openai",
+    "ollama": "openai",
+    "lmstudio": "openai",
+}
 
 
 def _load_provider_types() -> dict[str, str]:
-    provider_types = _load_config().get("LLM_PROVIDER_TYPES")
-    if not isinstance(provider_types, dict):
-        raise RuntimeError(
-            f"Invalid or missing 'LLM_PROVIDER_TYPES' in config file: {CONFIG_PATH}"
+    try:
+        config = load_config()
+        provider_types = get_config_section(config, "LLM_PROVIDER_TYPES", dict)
+        return {
+            str(name).lower(): str(client_type).lower()
+            for name, client_type in provider_types.items()
+        }
+    except RuntimeError as exc:
+        warnings.warn(
+            f"Failed to load LLM_PROVIDER_TYPES from config.json: {exc}. "
+            "Using built-in provider mapping.",
+            RuntimeWarning,
+            stacklevel=2,
         )
-    return {
-        str(name).lower(): str(client_type).lower()
-        for name, client_type in provider_types.items()
-    }
+        return DEFAULT_PROVIDER_TYPES.copy()
 
 
 _PROVIDER_TYPES: dict[str, str] | None = None

tradingagents/llm_clients/openai_client.py

@@ -1,12 +1,11 @@
-import json
 import os
-from pathlib import Path
 from typing import Any, Optional
 
 from dotenv import load_dotenv
 from langchain_openai import ChatOpenAI
 
 from .base_client import BaseLLMClient, normalize_content
+from .config_loader import load_config, get_base_urls_map
 from .validators import validate_model
 
 
@@ -27,47 +26,11 @@ _PASSTHROUGH_KWARGS = (
     "api_key", "callbacks", "http_client", "http_async_client",
 )
 
-CONFIG_PATH = Path(__file__).resolve().parents[2] / "config.json"
-
-
-def _load_config() -> dict:
-    try:
-        with CONFIG_PATH.open("r", encoding="utf-8") as config_file:
-            config = json.load(config_file)
-    except FileNotFoundError as exc:
-        raise RuntimeError(f"Config file not found: {CONFIG_PATH}") from exc
-    except json.JSONDecodeError as exc:
-        raise RuntimeError(f"Invalid JSON in config file: {CONFIG_PATH}") from exc
-    except OSError as exc:
-        raise RuntimeError(f"Unable to read config file: {CONFIG_PATH}") from exc
-
-    if not isinstance(config, dict):
-        raise RuntimeError(f"Invalid config format in file: {CONFIG_PATH}")
-    return config
-
-
-def _get_base_urls(config: dict) -> dict[str, str]:
-    base_urls = config.get("BASE_URLS")
-    if not isinstance(base_urls, list):
-        raise RuntimeError(f"Invalid or missing 'BASE_URLS' in config file: {CONFIG_PATH}")
-
-    mapped_urls: dict[str, str] = {}
-    for item in base_urls:
-        if (
-            isinstance(item, list)
-            and len(item) == 2
-            and isinstance(item[0], str)
-            and isinstance(item[1], str)
-        ):
-            mapped_urls[item[0].lower()] = item[1]
-    return mapped_urls
-
-
-CONFIG = _load_config()
+CONFIG = load_config()
 
 load_dotenv()
 
-_BASE_URLS = _get_base_urls(CONFIG)
+_BASE_URLS = get_base_urls_map(CONFIG)
 _PROVIDER_BASE_URLS = {
     "xai": _BASE_URLS.get("xai", "https://api.x.ai/v1"),
     "openrouter": _BASE_URLS.get("openrouter", "https://openrouter.ai/api/v1"),