Do more with AWS WAF labels using dynamic label interpolation

This article introduces dynamic label interpolation in AWS WAF, a feature that allows rules to reference label namespaces using ${namespace:} syntax instead of enumerating individual labels.

• Use ${namespace:} syntax in custom request headers, response bodies, and response headers to resolve matched label values at evaluation time
• Synthetic labels provide request-specific data like client IP (${awswaf:ip:}), request ID, and TLS fingerprints (JA3/JA4)
• Forward Bot Control classifications to origins as headers for application-level decision making without hundreds of individual rules
• Embed debug information in custom block/challenge pages using synthetic labels for improved support workflows
• Segment CloudFront cache by bot category using interpolated headers in cache keys
• Works with AWS Managed Rules, Marketplace rule groups, and custom labels defined in your own rules

Dynamic label interpolation simplifies AWS WAF rule configuration by collapsing namespace-based rules from hundreds of individual rules into single rules that automatically adapt as detection catalogs grow.