feat(config): TRADINGAGENTS_* env-var overlay for DEFAULT_CONFIG

Adds a single _ENV_OVERRIDES table in default_config.py with type-aware
coercion (str/int/bool), so users can switch llm_provider, deep/quick
models, backend URL, output language, debate rounds, and the checkpoint
flag purely via .env. Centralizes load_dotenv in the package __init__
so the overlay applies for every entry point (CLI, main.py, programmatic).
Drops the hardcoded model assignments and duplicate dotenv loads in
main.py and cli/main.py. Verified live with OpenAI and Gemini.

#602

.env.example

@@ -11,3 +11,16 @@ ZHIPU_CN_API_KEY=
 MINIMAX_API_KEY=
 MINIMAX_CN_API_KEY=
 OPENROUTER_API_KEY=
+
+# Optional: override DEFAULT_CONFIG without editing code.
+# Any TRADINGAGENTS_* variable below, when set, replaces the matching key
+# in tradingagents/default_config.py. Values are coerced to the type of
+# the existing default (bool / int / str), so "true"/"3" work as expected.
+#TRADINGAGENTS_LLM_PROVIDER=openai
+#TRADINGAGENTS_DEEP_THINK_LLM=gpt-5.4
+#TRADINGAGENTS_QUICK_THINK_LLM=gpt-5.4-mini
+#TRADINGAGENTS_LLM_BACKEND_URL=
+#TRADINGAGENTS_OUTPUT_LANGUAGE=English
+#TRADINGAGENTS_MAX_DEBATE_ROUNDS=1
+#TRADINGAGENTS_MAX_RISK_ROUNDS=1
+#TRADINGAGENTS_CHECKPOINT_ENABLED=false

cli/main.py

@@ -5,13 +5,6 @@ import questionary
 from pathlib import Path
 from functools import wraps
 from rich.console import Console
-from dotenv import find_dotenv, load_dotenv
-
-# Search starts from the user's CWD so the installed `tradingagents`
-# console script picks up the project's .env instead of walking up from
-# site-packages.
-load_dotenv(find_dotenv(usecwd=True))
-load_dotenv(find_dotenv(".env.enterprise", usecwd=True), override=False)
 from rich.panel import Panel
 from rich.spinner import Spinner
 from rich.live import Live
@@ -569,6 +562,11 @@ def get_user_selections():
     elif selected_llm_provider == "glm":
         selected_llm_provider, backend_url = ask_glm_region()
 
+    # Confirm the provider's API key is present; prompt the user to paste
+    # one and persist it to .env if it's missing, so the analysis run
+    # doesn't fail later at the first API call.
+    ensure_api_key(selected_llm_provider)
+
     # Step 7: Thinking agents
     console.print(
         create_question_box(

main.py

@@ -1,23 +1,12 @@
 from tradingagents.graph.trading_graph import TradingAgentsGraph
 from tradingagents.default_config import DEFAULT_CONFIG
 
-from dotenv import find_dotenv, load_dotenv
-
-load_dotenv(find_dotenv(usecwd=True))
-
-# Create a custom config
+# DEFAULT_CONFIG already applies TRADINGAGENTS_* env-var overrides
+# (llm_provider, deep_think_llm, quick_think_llm, backend_url, etc.),
+# so users can switch models or endpoints purely via .env without
+# editing this script. Override individual keys here only when you
+# want a hard-coded value that should ignore the environment.
 config = DEFAULT_CONFIG.copy()
-config["deep_think_llm"] = "gpt-5.4-mini"  # Use a different model
-config["quick_think_llm"] = "gpt-5.4-mini"  # Use a different model
-config["max_debate_rounds"] = 1  # Increase debate rounds
-
-# Configure data vendors (default uses yfinance, no extra API keys needed)
-config["data_vendors"] = {
-    "core_stock_apis": "yfinance",           # Options: alpha_vantage, yfinance
-    "technical_indicators": "yfinance",      # Options: alpha_vantage, yfinance
-    "fundamental_data": "yfinance",          # Options: alpha_vantage, yfinance
-    "news_data": "yfinance",                 # Options: alpha_vantage, yfinance
-}
 
 # Initialize with custom config
 ta = TradingAgentsGraph(debug=True, config=config)

tests/test_env_overrides.py

@@ -0,0 +1,98 @@
+"""Tests for TRADINGAGENTS_* env-var overlay onto DEFAULT_CONFIG."""
+
+from __future__ import annotations
+
+import importlib
+
+import pytest
+
+import tradingagents.default_config as default_config_module
+
+
+def _reload_with_env(monkeypatch, **overrides):
+    """Set/clear env vars then reload default_config to re-evaluate DEFAULT_CONFIG."""
+    for key in list(default_config_module._ENV_OVERRIDES):
+        monkeypatch.delenv(key, raising=False)
+    for key, val in overrides.items():
+        monkeypatch.setenv(key, val)
+    return importlib.reload(default_config_module)
+
+
+def test_no_env_uses_built_in_defaults(monkeypatch):
+    dc = _reload_with_env(monkeypatch)
+    assert dc.DEFAULT_CONFIG["llm_provider"] == "openai"
+    assert dc.DEFAULT_CONFIG["deep_think_llm"] == "gpt-5.4"
+    assert dc.DEFAULT_CONFIG["quick_think_llm"] == "gpt-5.4-mini"
+    assert dc.DEFAULT_CONFIG["backend_url"] is None
+    assert dc.DEFAULT_CONFIG["max_debate_rounds"] == 1
+    assert dc.DEFAULT_CONFIG["checkpoint_enabled"] is False
+
+
+def test_string_overrides(monkeypatch):
+    dc = _reload_with_env(
+        monkeypatch,
+        TRADINGAGENTS_LLM_PROVIDER="google",
+        TRADINGAGENTS_DEEP_THINK_LLM="gemini-3-pro-preview",
+        TRADINGAGENTS_QUICK_THINK_LLM="gemini-3-flash-preview",
+        TRADINGAGENTS_LLM_BACKEND_URL="https://example.invalid/v1",
+        TRADINGAGENTS_OUTPUT_LANGUAGE="Chinese",
+    )
+    assert dc.DEFAULT_CONFIG["llm_provider"] == "google"
+    assert dc.DEFAULT_CONFIG["deep_think_llm"] == "gemini-3-pro-preview"
+    assert dc.DEFAULT_CONFIG["quick_think_llm"] == "gemini-3-flash-preview"
+    assert dc.DEFAULT_CONFIG["backend_url"] == "https://example.invalid/v1"
+    assert dc.DEFAULT_CONFIG["output_language"] == "Chinese"
+
+
+def test_int_coercion(monkeypatch):
+    dc = _reload_with_env(
+        monkeypatch,
+        TRADINGAGENTS_MAX_DEBATE_ROUNDS="3",
+        TRADINGAGENTS_MAX_RISK_ROUNDS="2",
+    )
+    assert dc.DEFAULT_CONFIG["max_debate_rounds"] == 3
+    assert isinstance(dc.DEFAULT_CONFIG["max_debate_rounds"], int)
+    assert dc.DEFAULT_CONFIG["max_risk_discuss_rounds"] == 2
+    assert isinstance(dc.DEFAULT_CONFIG["max_risk_discuss_rounds"], int)
+
+
+@pytest.mark.parametrize(
+    "raw,expected",
+    [
+        ("true", True), ("True", True), ("1", True), ("yes", True), ("on", True),
+        ("false", False), ("False", False), ("0", False), ("no", False), ("off", False),
+    ],
+)
+def test_bool_coercion(monkeypatch, raw, expected):
+    dc = _reload_with_env(monkeypatch, TRADINGAGENTS_CHECKPOINT_ENABLED=raw)
+    assert dc.DEFAULT_CONFIG["checkpoint_enabled"] is expected
+
+
+def test_empty_env_value_is_passthrough(monkeypatch):
+    """Empty TRADINGAGENTS_* values must not clobber the built-in default."""
+    dc = _reload_with_env(
+        monkeypatch,
+        TRADINGAGENTS_LLM_PROVIDER="",
+        TRADINGAGENTS_MAX_DEBATE_ROUNDS="",
+    )
+    assert dc.DEFAULT_CONFIG["llm_provider"] == "openai"
+    assert dc.DEFAULT_CONFIG["max_debate_rounds"] == 1
+
+
+def test_invalid_int_raises(monkeypatch):
+    """Garbage int values should surface a ValueError at import, not silently misconfigure."""
+    monkeypatch.setenv("TRADINGAGENTS_MAX_DEBATE_ROUNDS", "not-a-number")
+    with pytest.raises(ValueError):
+        importlib.reload(default_config_module)
+    # Restore module state for subsequent tests in this process
+    monkeypatch.delenv("TRADINGAGENTS_MAX_DEBATE_ROUNDS", raising=False)
+    importlib.reload(default_config_module)
+
+
+def test_unknown_env_var_is_ignored(monkeypatch):
+    """Env vars outside _ENV_OVERRIDES must not bleed into DEFAULT_CONFIG."""
+    dc = _reload_with_env(
+        monkeypatch,
+        TRADINGAGENTS_NONEXISTENT_KEY="oops",
+    )
+    assert "nonexistent_key" not in dc.DEFAULT_CONFIG

tradingagents/__init__.py

@@ -1,5 +1,20 @@
 import warnings
 
+# Load .env files at package import so DEFAULT_CONFIG's env-var overlay
+# (and every llm_clients consumer) sees the user's keys regardless of
+# which entry point started the process. find_dotenv(usecwd=True) walks
+# from the CWD, so the installed `tradingagents` console script picks up
+# the project's .env instead of stepping up from site-packages.
+# load_dotenv defaults to override=False, so it never clobbers values
+# the caller has already exported.
+try:
+    from dotenv import find_dotenv, load_dotenv
+
+    load_dotenv(find_dotenv(usecwd=True))
+    load_dotenv(find_dotenv(".env.enterprise", usecwd=True), override=False)
+except ImportError:
+    pass
+
 # langchain-core 1.3.3 calls surface_langchain_deprecation_warnings() in
 # its own __init__, which prepends default-action filters for its
 # subclassed warning categories. To suppress a specific warning we must

tradingagents/default_config.py

@@ -2,7 +2,45 @@ import os
 
 _TRADINGAGENTS_HOME = os.path.join(os.path.expanduser("~"), ".tradingagents")
 
-DEFAULT_CONFIG = {
+# Single source of truth for env-var → config-key overrides. To expose
+# a new config key for environment-based override, add a row here — no
+# entry-point script changes required. Coercion is driven by the type
+# of the existing default, so users can keep writing plain strings in
+# their .env file.
+_ENV_OVERRIDES = {
+    "TRADINGAGENTS_LLM_PROVIDER":         "llm_provider",
+    "TRADINGAGENTS_DEEP_THINK_LLM":       "deep_think_llm",
+    "TRADINGAGENTS_QUICK_THINK_LLM":      "quick_think_llm",
+    "TRADINGAGENTS_LLM_BACKEND_URL":      "backend_url",
+    "TRADINGAGENTS_OUTPUT_LANGUAGE":      "output_language",
+    "TRADINGAGENTS_MAX_DEBATE_ROUNDS":    "max_debate_rounds",
+    "TRADINGAGENTS_MAX_RISK_ROUNDS":      "max_risk_discuss_rounds",
+    "TRADINGAGENTS_CHECKPOINT_ENABLED":   "checkpoint_enabled",
+}
+
+
+def _coerce(value: str, reference):
+    """Coerce env-var string to the type of the existing default value."""
+    if isinstance(reference, bool):
+        return value.strip().lower() in ("true", "1", "yes", "on")
+    if isinstance(reference, int) and not isinstance(reference, bool):
+        return int(value)
+    if isinstance(reference, float):
+        return float(value)
+    return value
+
+
+def _apply_env_overrides(config: dict) -> dict:
+    """Apply TRADINGAGENTS_* env vars to the config dict in-place."""
+    for env_var, key in _ENV_OVERRIDES.items():
+        raw = os.environ.get(env_var)
+        if raw is None or raw == "":
+            continue
+        config[key] = _coerce(raw, config.get(key))
+    return config
+
+
+DEFAULT_CONFIG = _apply_env_overrides({
     "project_dir": os.path.abspath(os.path.join(os.path.dirname(__file__), ".")),
     "results_dir": os.getenv("TRADINGAGENTS_RESULTS_DIR", os.path.join(_TRADINGAGENTS_HOME, "logs")),
     "data_cache_dir": os.getenv("TRADINGAGENTS_CACHE_DIR", os.path.join(_TRADINGAGENTS_HOME, "cache")),
@@ -62,4 +100,4 @@ DEFAULT_CONFIG = {
     "tool_vendors": {
         # Example: "get_stock_data": "alpha_vantage",  # Override category default
     },
-}
+})