Gateway API v1.3.0: Advancements in Request Mirroring, CORS, Gateway Merging, and Retry Budgets

Gateway API v1.3.0: Advancements in Request Mirroring, CORS, Gateway Merging, and Retry Budgets Graduation to Standard channel Percentage-based request mirroring Additions to Experimental channel CORS filtering XListenerSets (standardized mechanism for Listener and Gateway merging) Retry budgets (XBackendTrafficPolicy) Try it out Get involved Related Kubernetes blog articles Join us in the Kubernetes SIG Network community in celebrating the general availability of Gateway API v1.3.0! We are also pleased to announce that there are already a number of conformant implementations to try, made possible by postponing this blog announcement. Version 1.3.0 of the API was released about a month ago on April 24, 2025. Gateway API v1.3.0 brings a new feature to the Standard channel (Gateway API's GA release channel): percentage-based request mirroring , and introduces three new experimental features: cross-origin resource sharing (CORS) filters, a standardized mechanism for listener and gateway merging, and retry budgets. Also see the full release notes and applaud the v1.3.0 release team next time you see them. Graduation to the Standard channel is a notable achievement for Gateway API features, as inclusion in the Standard release channel denotes a high level of confidence in the API surface and provides guarantees of backward compatibility. Of course, as with any other Kubernetes API, Standard channel features can continue to evolve with backward-compatible additions over time, and we (SIG Network) certainly expect further refinements and improvements in the future. For more information on how all of this works, refer to the Gateway API Versioning Policy. Leads: Lior Lieberman , Jake Bennert GEP-3171: Percentage-Based Request Mirroring Percentage-based request mirroring is an enhancement to the existing support for HTTP request mirroring , which allows HTTP requests to be duplicated to another backend using the RequestMirror filter type. Request mirroring is particularly useful in blue-green deployment. It can be used to assess the impact of request scaling on application performance without impacting responses to clients. The previous mirroring capability worked on all the requests to a backendRef. Percentage-based request mirroring allows users to specify a subset of requests they want to be mirrored, either by percentage or fraction.