diff --git a/docs/_sidebar.md b/docs/_sidebar.md
index 2dfda79c..3f474cf1 100644
--- a/docs/_sidebar.md
+++ b/docs/_sidebar.md
@@ -18,6 +18,7 @@
 - Rest API
   - [List stubs](api-stubs-list)
   - [List unused stubs](api-unused-stubs-list)
+  - [List used stubs](api-used-stubs-list)
   - [Add stub](api-stubs-add)
   - [Delete stub](api-stubs-delete)
   - [Search stub](api-stubs-search)
diff --git a/docs/api-used-stubs-list.md b/docs/api-used-stubs-list.md
new file mode 100644
index 00000000..5afa1541
--- /dev/null
+++ b/docs/api-used-stubs-list.md
@@ -0,0 +1,77 @@
+## Rest API. Stubs Used List
+
+Stubs Used List — endpoint returns a list of used stubs (all stubs that were found through the search).
+The method inverts the logic of unused operation.
+
+Let's imagine that our contract `simple.proto` looks something like this:
+```protobuf
+syntax = "proto3";
+option go_package = "github.com/bavix/gripmock/protogen/example/simple";
+
+package simple;
+
+service Gripmock {
+  rpc SayHello (Request) returns (Reply);
+}
+
+message Request {
+  string name = 1;
+}
+
+message Reply {
+  string message = 1;
+  int32 return_code = 2;
+}
+```
+
+Enough to knock on the handle `GET /api/stubs/used`:
+```bash
+curl http://127.0.0.1:4771/api/stubs/used
+```
+
+Response:
+```json
+[]
+```
+
+Find stub by ID. Enough to knock on the handle `POST /api/stubs/search`:
+```bash
+curl -X POST -d '{ \
+  "id": "6c85b0fa-caaf-4640-a672-f56b7dd8074d", \
+  "service": "Gripmock", \
+  "method": "SayHello", \
+  "data":{} \
+}' http://127.0.0.1:4771/api/stubs/search
+```
+
+Now the stub is marked as used. Let's try to get a list of used stubs.
+```bash
+curl http://127.0.0.1:4771/api/stubs/used
+```
+
+Response:
+```json
+[
+  {
+    "id": "6c85b0fa-caaf-4640-a672-f56b7dd8074d",
+    "service": "Gripmock",
+    "method": "SayHello",
+    "input": {
+      "equals": {
+        "name": "gripmock"
+      },
+      "contains": null,
+      "matches": null
+    },
+    "output": {
+      "data": {
+        "message": "Hello GripMock",
+        "return_code": 42
+      },
+      "error": ""
+    }
+  }
+]
+```
+
+It worked!
\ No newline at end of file
diff --git a/internal/app/rest_server.go b/internal/app/rest_server.go
index d22eb9b9..29c1baa5 100644
--- a/internal/app/rest_server.go
+++ b/internal/app/rest_server.go
@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"os"
 	"strings"
+	"sync/atomic"
 
 	"github.com/bavix/gripmock/internal/domain/rest"
 	"github.com/bavix/gripmock/pkg/clock"
@@ -24,7 +25,7 @@ type StubsServer struct {
 	convertor *yaml2json.Convertor
 	caser     cases.Caser
 	clock     *clock.Clock
-	ok        bool
+	ok        atomic.Bool
 }
 
 func NewRestServer(path string) (*StubsServer, error) {
@@ -57,7 +58,7 @@ type findStubPayload struct {
 }
 
 func (h *StubsServer) ServiceReady() {
-	h.ok = true
+	h.ok.Store(true)
 }
 
 func (h *StubsServer) Liveness(w http.ResponseWriter, _ *http.Request) {
@@ -65,7 +66,7 @@ func (h *StubsServer) Liveness(w http.ResponseWriter, _ *http.Request) {
 }
 
 func (h *StubsServer) Readiness(w http.ResponseWriter, _ *http.Request) {
-	if !h.ok {
+	if !h.ok.Load() {
 		w.WriteHeader(http.StatusServiceUnavailable)
 
 		return