# Appendix J: Troubleshooting & Common Issues

# Troubleshooting

## Authentication Issues
- **401**: Check API key in X-BL-API-Key header
- **403**: Verify user permissions

## Request Issues
- **400**: Validate required fields and data types
- **404**: Verify resource ID and endpoint path

## Rate Limiting
- **429**: Implement exponential backoff
- Check X-RateLimit-Remaining header
- Batch requests efficiently

## Timeouts
- Set appropriate timeout values
- Reduce per_page if slow
- Check network connectivity

## Debugging Checklist
- Verify API key is correct
- Check HTTP status code
- Review error message
- Test with cURL
- Check rate limits
- Verify environment (domain)