--- /dev/null
+#include <opentracing/ext/tags.h>
+
+namespace opentracing {
+BEGIN_OPENTRACING_ABI_NAMESPACE
+namespace ext {
+const opentracing::string_view span_kind = "span.kind";
+const opentracing::string_view span_kind_rpc_client = "client";
+const opentracing::string_view span_kind_rpc_server = "server";
+
+const opentracing::string_view error = "error";
+
+const opentracing::string_view component = "component";
+
+const opentracing::string_view sampling_priority = "sampling.priority";
+
+const opentracing::string_view peer_service = "peer.service";
+
+extern const opentracing::string_view peer_hostname = "peer.hostname";
+extern const opentracing::string_view peer_address = "peer.address";
+extern const opentracing::string_view peer_host_ipv4 = "peer.ipv4";
+extern const opentracing::string_view peer_host_ipv6 = "peer.ipv6";
+extern const opentracing::string_view peer_port = "peer.port";
+
+extern const opentracing::string_view http_url = "http.url";
+extern const opentracing::string_view http_method = "http.method";
+extern const opentracing::string_view http_status_code = "http.status_code";
+
+extern const opentracing::string_view database_instance = "db.instance";
+extern const opentracing::string_view database_statement = "db.statement";
+extern const opentracing::string_view database_type = "db.type";
+extern const opentracing::string_view database_user = "db.user";
+
+extern const opentracing::string_view message_bus_destination =
+ "message_bus.destination";
+} // namespace ext
+END_OPENTRACING_ABI_NAMESPACE
+} // namespace opentracing