https://developers.google.com/protocol-buffers/>protobuf</a> message.</p><p>You configure each adapter by creating <a href=https://istio.io/v1.6/docs/reference/config/policy-and-telemetry/mixer-overview/#handlers><em>handlers</em></a> for them. A handler is a
configuration resource which represents a fully configured adapter ready for use. There can be any number of handlers for a single adapter, making it possible to reuse an adapter in different scenarios.</p><h2 id=templates-adapter-input-schema>Template