AWS WAF adds dynamic label interpolation for request/response handling

AI Impact Summary

AWS WAF now supports dynamic label interpolation, allowing you to forward an entire label namespace to origins using the ${namespace:} syntax in custom request headers, response headers, and response bodies. This reduces rule maintenance by enabling a single rule to convey multiple signals (for example, all IP reputation signals) and introduces synthetic labels like client IP, WAF request ID, and JA3/JA4 fingerprints for use in adaptive responses and debugging. The feature is namespace-agnostic (works with AWS Managed Rules, AWS Marketplace rule groups, and custom labels) and automatically adapts headers as new labels are added, with multiple labels resolving to a comma-separated list. No API changes or configuration steps are required, and the capability is available in all regions at no extra cost, enabling faster deployment of context-rich protections with minimal overhead.