>List</a></li><li> <a title="Adapter for a simple in-memory quota management system." href="/v0.6/docs/reference/config/adapters/memquota.html">Memory quota</a></li><li> <a title="Adapter that implements an Open Policy Agent engine" href="/v0.6/docs/reference/config/adapters/opa.html">OPA</a></li><li> <a title="Adapter that exposes Istio metrics for ingestion by a Prometheus harvester." href="/v0.6/docs/reference/config/adapters/prometheus.html">Prometheus</a></li><li> <a title="Adapter that exposes Istio's