Environment Variable Support for API Customization

Claude Code now supports a new environment variable CLAUDE_CODE_EXTRA_BODY that allows users to inject additional parameters into API requests.

Usage:

# Set custom API parameters as a JSON object
export CLAUDE_CODE_EXTRA_BODY='{"temperature": 0.8, "max_tokens": 4000}'
claude "Your prompt here"

This feature enables:

• Customization of API request parameters without modifying code
• Fine-tuning of Claude's response behavior (temperature, max tokens, etc.)
• Advanced users to experiment with API options

Error Handling:

• The value must be a valid JSON object (not an array or primitive)
• Invalid JSON will be logged to stderr and ignored
• Parsing errors are gracefully handled with descriptive error messages