feat: add .env support for API keys, update docs, and add python-dotenv

.env.sample

@@ -0,0 +1,14 @@
+# Finnhub API Key
+FINNHUB_API_KEY="YOUR_FINNHUB_API_KEY"
+
+# OpenAI API Key
+OPENAI_API_KEY="YOUR_OPENAI_API_KEY"
+
+# Data directory
+DATA_DIR="/Users/yluo/Documents/Code/ScAI/FR1-data"
+
+# LLM settings
+LLM_PROVIDER="openai"
+DEEP_THINK_LLM="o4-mini"
+QUICK_THINK_LLM="gpt-4o-mini"
+BACKEND_URL="https://api.openai.com/v1"

README.md

@@ -114,15 +114,15 @@ pip install -r requirements.txt
 
 ### Required APIs
 
-You will also need the FinnHub API for financial data. All of our code is implemented with the free tier.
+You will need API keys from FinnHub and OpenAI. You can provide them by creating a `.env` file in the root of the project. Rename the `.env.sample` file to `.env` and add your API keys:
+
 ```bash
-export FINNHUB_API_KEY=$YOUR_FINNHUB_API_KEY
+# .env
+FINNHUB_API_KEY="YOUR_FINNHUB_API_KEY"
+OPENAI_API_KEY="YOUR_OPENAI_API_KEY"
 ```
 
-You will need the OpenAI API for all the agents.
-```bash
-export OPENAI_API_KEY=$YOUR_OPENAI_API_KEY
-```
+The application will automatically load these keys. Alternatively, you can still use environment variables if you prefer.
 
 ### CLI Usage
 

requirements.txt

@@ -24,3 +24,5 @@ rich
 questionary
 langchain_anthropic
 langchain-google-genai
+
+python-dotenv

tradingagents/default_config.py

@@ -1,4 +1,8 @@
 import os
+from dotenv import load_dotenv
+
+# Load environment variables from .env file
+load_dotenv()
 
 DEFAULT_CONFIG = {
     "project_dir": os.path.abspath(os.path.join(os.path.dirname(__file__), ".")),