diff --git a/src/shrpx.cc b/src/shrpx.cc
index fac5ae34..cbde333a 100644
--- a/src/shrpx.cc
+++ b/src/shrpx.cc
@@ -2942,6 +2942,7 @@ void reload_config(WorkerProcess *wp) {
   new_config->daemon = cur_config->daemon;
   // loop is reused, and ev_loop_flags gets ignored
   new_config->ev_loop_flags = cur_config->ev_loop_flags;
+  new_config->config_revision = cur_config->config_revision + 1;
 
   rv = process_options(new_config.get(), suconfig.cmdcfgs);
   if (rv != 0) {
diff --git a/src/shrpx_api_downstream_connection.cc b/src/shrpx_api_downstream_connection.cc
index 46413652..2be26bea 100644
--- a/src/shrpx_api_downstream_connection.cc
+++ b/src/shrpx_api_downstream_connection.cc
@@ -41,6 +41,10 @@ const APIEndpoint apis[] = {
         (1 << API_METHOD_POST) | (1 << API_METHOD_PUT),
         &APIDownstreamConnection::handle_backendconfig,
     },
+    APIEndpoint{
+        StringRef::from_lit("/api/v1beta1/configrevision"), true,
+        (1 << API_METHOD_GET), &APIDownstreamConnection::handle_configrevision,
+    },
 };
 } // namespace
 
@@ -82,7 +86,7 @@ enum {
 };
 
 int APIDownstreamConnection::send_reply(unsigned int http_status,
-                                        int api_status) {
+                                        int api_status, const StringRef &data) {
   shutdown_read_ = true;
 
   auto upstream = downstream_->get_upstream();
@@ -112,7 +116,8 @@ int APIDownstreamConnection::send_reply(unsigned int http_status,
 
   // 3 is the number of digits in http_status, assuming it is 3 digits
   // number.
-  auto buflen = M1.size() + M2.size() + M3.size() + api_status_str.size() + 3;
+  auto buflen = M1.size() + M2.size() + M3.size() + data.size() +
+                api_status_str.size() + 3;
 
   auto buf = make_byte_ref(balloc, buflen);
   auto p = buf.base;
@@ -121,6 +126,7 @@ int APIDownstreamConnection::send_reply(unsigned int http_status,
   p = std::copy(std::begin(api_status_str), std::end(api_status_str), p);
   p = std::copy(std::begin(M2), std::end(M2), p);
   p = util::utos(p, http_status);
+  p = std::copy(std::begin(data), std::end(data), p);
   p = std::copy(std::begin(M3), std::end(M3), p);
 
   buf.len = p - buf.base;
@@ -147,6 +153,32 @@ int APIDownstreamConnection::send_reply(unsigned int http_status,
   return 0;
 }
 
+namespace {
+const APIEndpoint *lookup_api(const StringRef &path) {
+  switch (path.size()) {
+  case 26:
+    switch (path[25]) {
+    case 'g':
+      if (util::streq_l("/api/v1beta1/backendconfi", std::begin(path), 25)) {
+        return &apis[0];
+      }
+      break;
+    }
+    break;
+  case 27:
+    switch (path[26]) {
+    case 'n':
+      if (util::streq_l("/api/v1beta1/configrevisio", std::begin(path), 26)) {
+        return &apis[1];
+      }
+      break;
+    }
+    break;
+  }
+  return nullptr;
+}
+} // namespace
+
 int APIDownstreamConnection::push_request_headers() {
   auto &req = downstream_->request();
 
@@ -154,12 +186,7 @@ int APIDownstreamConnection::push_request_headers() {
       StringRef{std::begin(req.path),
                 std::find(std::begin(req.path), std::end(req.path), '?')};
 
-  for (auto &p : apis) {
-    if (p.path == path) {
-      api_ = &p;
-      break;
-    }
-  }
+  api_ = lookup_api(path);
 
   if (!api_) {
     send_reply(404, API_FAILURE);
@@ -365,6 +392,25 @@ int APIDownstreamConnection::handle_backendconfig() {
   return 0;
 }
 
+int APIDownstreamConnection::handle_configrevision() {
+  auto config = get_config();
+  auto &balloc = downstream_->get_block_allocator();
+
+  // Construct the following string:
+  //   ,
+  //   "data":{
+  //     "configRevision": N
+  //   }
+  auto data = concat_string_ref(
+      balloc, StringRef::from_lit(R"(,"data":{"configRevision":)"),
+      util::make_string_ref_uint(balloc, config->config_revision),
+      StringRef::from_lit("}"));
+
+  send_reply(200, API_SUCCESS, data);
+
+  return 0;
+}
+
 void APIDownstreamConnection::pause_read(IOCtrlReason reason) {}
 
 int APIDownstreamConnection::resume_read(IOCtrlReason reason, size_t consumed) {
diff --git a/src/shrpx_api_downstream_connection.h b/src/shrpx_api_downstream_connection.h
index 2a0c4b1e..356ee53d 100644
--- a/src/shrpx_api_downstream_connection.h
+++ b/src/shrpx_api_downstream_connection.h
@@ -83,11 +83,14 @@ public:
   get_downstream_addr_group() const;
   virtual DownstreamAddr *get_addr() const;
 
-  int send_reply(unsigned int http_status, int api_status);
+  int send_reply(unsigned int http_status, int api_status,
+                 const StringRef &data = StringRef{});
   int error_method_not_allowed();
 
   // Handles backendconfig API request.
   int handle_backendconfig();
+  // Handles configrevision API request.
+  int handle_configrevision();
 
 private:
   Worker *worker_;
diff --git a/src/shrpx_config.h b/src/shrpx_config.h
index 8efdb40d..79293441 100644
--- a/src/shrpx_config.h
+++ b/src/shrpx_config.h
@@ -850,6 +850,7 @@ struct Config {
         conn{},
         api{},
         dns{},
+        config_revision{0},
         num_worker{0},
         padding{0},
         rlimit_nofile{0},
@@ -883,6 +884,13 @@ struct Config {
   StringRef conf_path;
   StringRef user;
   StringRef mruby_file;
+  // The revision of configuration which is opaque string, and changes
+  // on each configuration reloading.  This does not change on
+  // backendconfig API call.  This value is returned in health check
+  // as "nghttpx-conf-rev" response header field.  The external
+  // program can check this value to know whether reloading has
+  // completed or not.
+  uint64_t config_revision;
   size_t num_worker;
   size_t padding;
   size_t rlimit_nofile;