diff --git a/src/main/java/me/lucko/luckperms/extension/rest/controller/GroupController.java b/src/main/java/me/lucko/luckperms/extension/rest/controller/GroupController.java
index 1047cd8..b433612 100644
--- a/src/main/java/me/lucko/luckperms/extension/rest/controller/GroupController.java
+++ b/src/main/java/me/lucko/luckperms/extension/rest/controller/GroupController.java
@@ -251,11 +251,19 @@ public void nodesAddSingle(Context ctx) throws JsonProcessingException {
         String name = ctx.pathParam("id");
         Node node = ctx.bodyAsClass(Node.class);
         TemporaryNodeMergeStrategy mergeStrategy = ParamUtils.queryParamAsTemporaryNodeMergeStrategy(this.objectMapper, ctx);
+        boolean replace = ParamUtils.readBoolean(ctx, "replace", false);
 
         CompletableFuture<Collection<Node>> future = this.groupManager.loadGroup(name).thenCompose(opt -> {
             if (opt.isPresent()) {
                 Group group = opt.get();
-                group.data().add(node, mergeStrategy);
+
+                if (replace) {
+                    group.data().remove(node);
+                    group.data().add(node);
+                } else {
+                    group.data().add(node, mergeStrategy);
+                }
+
                 return this.groupManager.saveGroup(group).thenApply(v -> {
                     this.messagingService.pushUpdate();
                     return group.getNodes();
diff --git a/src/main/java/me/lucko/luckperms/extension/rest/controller/UserController.java b/src/main/java/me/lucko/luckperms/extension/rest/controller/UserController.java
index d3aa742..d8dde10 100644
--- a/src/main/java/me/lucko/luckperms/extension/rest/controller/UserController.java
+++ b/src/main/java/me/lucko/luckperms/extension/rest/controller/UserController.java
@@ -258,9 +258,16 @@ public void nodesAddSingle(Context ctx) throws JsonProcessingException {
         UUID uniqueId = pathParamAsUuid(ctx);
         Node node = ctx.bodyAsClass(Node.class);
         TemporaryNodeMergeStrategy mergeStrategy = ParamUtils.queryParamAsTemporaryNodeMergeStrategy(this.objectMapper, ctx);
+        boolean replace = ParamUtils.readBoolean(ctx, "replace", false);
 
         CompletableFuture<Collection<Node>> future = this.userManager.loadUser(uniqueId).thenCompose(user -> {
-            user.data().add(node, mergeStrategy);
+            if (replace) {
+                user.data().remove(node);
+                user.data().add(node);
+            } else {
+                user.data().add(node, mergeStrategy);
+            }
+
             return this.userManager.saveUser(user).thenApply(v -> {
                 this.messagingService.pushUserUpdate(user);
                 return user.getNodes();
diff --git a/src/main/java/me/lucko/luckperms/extension/rest/util/ParamUtils.java b/src/main/java/me/lucko/luckperms/extension/rest/util/ParamUtils.java
index 34d9937..6c520e9 100644
--- a/src/main/java/me/lucko/luckperms/extension/rest/util/ParamUtils.java
+++ b/src/main/java/me/lucko/luckperms/extension/rest/util/ParamUtils.java
@@ -47,4 +47,18 @@ public static TemporaryNodeMergeStrategy queryParamAsTemporaryNodeMergeStrategy(
             return objectMapper.readValue("\"" + string + "\"", TemporaryNodeMergeStrategy.class);
         }
     }
+
+    public static boolean readBoolean(Context ctx, String name, boolean defaultIfMissing) {
+        final String string = ctx.queryParam(name);
+
+        if (string == null) {
+            return defaultIfMissing;
+        } else if (string.equals("true")) {
+            return true;
+        } else if (string.equals("false")) {
+            return false;
+        } else {
+            throw new IllegalArgumentException("invalid boolean '" + string + "' for query param '" + name + "'");
+        }
+    }
 }
diff --git a/src/main/resources/luckperms-openapi.yml b/src/main/resources/luckperms-openapi.yml
index 23283c0..35eee0d 100644
--- a/src/main/resources/luckperms-openapi.yml
+++ b/src/main/resources/luckperms-openapi.yml
@@ -323,6 +323,7 @@ paths:
       operationId: add-user-node
       parameters:
         - $ref: '#/components/parameters/temporaryNodeMergeStrategy'
+        - $ref: '#/components/parameters/replace'
       responses:
         '200':
           description: Ok - returns the updated nodes
@@ -862,6 +863,7 @@ paths:
       operationId: add-group-node
       parameters:
         - $ref: '#/components/parameters/temporaryNodeMergeStrategy'
+        - $ref: '#/components/parameters/replace'
       responses:
         '200':
           description: Ok - returns the updated nodes
@@ -1848,5 +1850,12 @@ components:
         $ref: '#/components/schemas/TemporaryNodeMergeStrategy'
       required: false
       description: The node merge strategy
+    replace:
+      name: replace
+      in: query
+      schema:
+        type: boolean
+      required: false
+      description: If the node should replace an existing node with the same key (delete and add)
 security:
   - apikey: []