ktor-server-caching-headers/io.ktor.server.plugins.cachingheaders/CachingHeaders

CachingHeaders

val CachingHeaders: RouteScopedPlugin<CachingHeadersConfig>

A plugin that adds the capability to configure the Cache-Control and Expires headers used for HTTP caching. The example below shows how to add the Cache-Control header with the max-age option for CSS and JSON:

install(CachingHeaders) {
    options { call, outgoingContent ->
        when (outgoingContent.contentType?.withoutParameters()) {
            ContentType.Text.CSS -> CachingOptions(CacheControl.MaxAge(maxAgeSeconds = 3600))
            ContentType.Application.Json -> CachingOptions(CacheControl.MaxAge(maxAgeSeconds = 60))
            else -> null
        }
    }
}

You can learn more from Caching headers.