- Add comprehensive rate limiting (300 req/min) with automatic throttling
- Implement centralized API request method for consistent authentication
- Add support for Polar-specific webhook events (order.created, order.paid, subscription.active, customer.state_changed, benefit_grant.created)
- Update API endpoints to match Polar's official structure (remove /v1 prefix)
- Add external_id support for reliable customer-user mapping
- Implement sandbox mode with separate credentials configuration
- Add discount code support in checkout flow
- Add credential validation method for API connectivity testing
- Update webhook signature validation and event handling
- Enhance error handling and logging throughout provider
- Add proper metadata structure with user and plan information
- Update services configuration and environment variables for sandbox support
BREAKING CHANGE: Updated API endpoint structure and webhook event handling to comply with Polar.sh official API specification.