diff --git a/backend/src/Squidex.Domain.Apps.Core.Operations/HandleRules/RuleService.cs b/backend/src/Squidex.Domain.Apps.Core.Operations/HandleRules/RuleService.cs
index f1a0af6bd..fbfecd219 100644
--- a/backend/src/Squidex.Domain.Apps.Core.Operations/HandleRules/RuleService.cs
+++ b/backend/src/Squidex.Domain.Apps.Core.Operations/HandleRules/RuleService.cs
@@ -357,7 +357,6 @@ public sealed class RuleService : IRuleService
         var actionWatch = ValueStopwatch.StartNew();
 
         Result result;
-
         try
         {
             var actionType = typeRegistry.GetType<RuleAction>(actionName);
diff --git a/backend/src/Squidex.Domain.Apps.Core.Operations/Scripting/Extensions/HttpJintExtension.cs b/backend/src/Squidex.Domain.Apps.Core.Operations/Scripting/Extensions/HttpJintExtension.cs
index 9a49685e5..669efd510 100644
--- a/backend/src/Squidex.Domain.Apps.Core.Operations/Scripting/Extensions/HttpJintExtension.cs
+++ b/backend/src/Squidex.Domain.Apps.Core.Operations/Scripting/Extensions/HttpJintExtension.cs
@@ -53,7 +53,7 @@ public sealed class HttpJintExtension : IJintExtension, IScriptDescriptor
         describe(JsonType.Function, "patchJSON(url, body, callback, headers?)",
             Resources.ScriptingPatchJson);
 
-        describe(JsonType.Function, "deleteJSON(url, body, callback, headers?)",
+        describe(JsonType.Function, "deleteJSON(url, callback, headers?)",
             Resources.ScriptingDeleteJson);
     }
 
@@ -81,11 +81,6 @@ public sealed class HttpJintExtension : IJintExtension, IScriptDescriptor
     {
         context.Schedule(async (scheduler, ct) =>
         {
-            if (callback == null)
-            {
-                throw new JavaScriptException("Callback cannot be null.");
-            }
-
             if (!Uri.TryCreate(url, UriKind.Absolute, out var uri))
             {
                 throw new JavaScriptException("URL is not valid.");
@@ -100,7 +95,10 @@ public sealed class HttpJintExtension : IJintExtension, IScriptDescriptor
 
             var responseObject = await ParseResponseasync(context, response, ct);
 
-            scheduler.Run(callback, responseObject);
+            if (callback != null)
+            {
+                scheduler.Run(callback, responseObject);
+            }
         });
     }
 
diff --git a/backend/src/Squidex.Domain.Apps.Core.Operations/Scripting/ScriptExecutionContext.cs b/backend/src/Squidex.Domain.Apps.Core.Operations/Scripting/ScriptExecutionContext.cs
index 74ea573c7..eac3d77f9 100644
--- a/backend/src/Squidex.Domain.Apps.Core.Operations/Scripting/ScriptExecutionContext.cs
+++ b/backend/src/Squidex.Domain.Apps.Core.Operations/Scripting/ScriptExecutionContext.cs
@@ -140,23 +140,29 @@ public sealed class ScriptExecutionContext<T> : ScriptExecutionContext, ISchedul
 
     void IScheduler.Run(Action? action)
     {
-        if (IsCompleted || action == null)
+        lock (Engine)
         {
-            return;
-        }
+            if (IsCompleted || action == null)
+            {
+                return;
+            }
 
-        Engine.ResetConstraints();
-        action();
+            Engine.ResetConstraints();
+            action();
+        }
     }
 
     void IScheduler.Run<TArg>(Action<TArg>? action, TArg argument)
     {
-        if (IsCompleted || action == null)
+        lock (Engine)
         {
-            return;
-        }
+            if (IsCompleted || action == null)
+            {
+                return;
+            }
 
-        Engine.ResetConstraints();
-        action(argument);
+            Engine.ResetConstraints();
+            action(argument);
+        }
     }
 }
diff --git a/backend/src/Squidex/Config/Domain/SerializationServices.cs b/backend/src/Squidex/Config/Domain/SerializationServices.cs
index d2cb722fe..242986521 100644
--- a/backend/src/Squidex/Config/Domain/SerializationServices.cs
+++ b/backend/src/Squidex/Config/Domain/SerializationServices.cs
@@ -20,6 +20,7 @@ using Squidex.Domain.Apps.Core.Apps.Json;
 using Squidex.Domain.Apps.Core.Contents;
 using Squidex.Domain.Apps.Core.Contents.Json;
 using Squidex.Domain.Apps.Core.Rules;
+using Squidex.Domain.Apps.Core.Rules.EnrichedEvents;
 using Squidex.Domain.Apps.Core.Rules.Json;
 using Squidex.Domain.Apps.Core.Schemas;
 using Squidex.Domain.Apps.Core.Schemas.Json;
@@ -47,6 +48,7 @@ public static class SerializationServices
         options.ConfigureForNodaTime(DateTimeZoneProviders.Tzdb);
         options.Converters.Add(new GeoJsonConverterFactory());
         options.Converters.Add(new PolymorphicConverter<IEvent>(typeRegistry));
+        options.Converters.Add(new PolymorphicConverter<EnrichedEvent>(typeRegistry));
         options.Converters.Add(new PolymorphicConverter<FieldProperties>(typeRegistry));
         options.Converters.Add(new PolymorphicConverter<FieldPropertiesDto>(typeRegistry));
         options.Converters.Add(new PolymorphicConverter<RuleAction>(typeRegistry));
@@ -95,6 +97,9 @@ public static class SerializationServices
         services.AddSingleton<ITypeProvider>(
             new AssemblyTypeProvider<RuleTriggerDto>("triggerType"));
 
+        services.AddSingleton<ITypeProvider>(
+            new AssemblyTypeProvider<EnrichedEvent>());
+
         services.AddSingletonAs<FieldTypeProvider>()
             .As<ITypeProvider>();
 
diff --git a/backend/tests/Squidex.Domain.Apps.Core.Tests/Operations/Scripting/JintScriptEngineTests.cs b/backend/tests/Squidex.Domain.Apps.Core.Tests/Operations/Scripting/JintScriptEngineTests.cs
index 5320ad325..d9ae4da6e 100644
--- a/backend/tests/Squidex.Domain.Apps.Core.Tests/Operations/Scripting/JintScriptEngineTests.cs
+++ b/backend/tests/Squidex.Domain.Apps.Core.Tests/Operations/Scripting/JintScriptEngineTests.cs
@@ -7,6 +7,7 @@
 
 using System.Net;
 using System.Security.Claims;
+using Jint.Native;
 using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.Options;
 using Squidex.Domain.Apps.Core.Contents;
@@ -39,7 +40,8 @@ public class JintScriptEngineTests : IClassFixture<TranslationsFixture>
             new DateTimeJintExtension(),
             new HttpJintExtension(httpClientFactory),
             new StringJintExtension(),
-            new StringWordsJintExtension()
+            new StringWordsJintExtension(),
+            new AsyncExtension(),
         };
 
         var httpResponse = new HttpResponseMessage(HttpStatusCode.OK)
@@ -61,6 +63,23 @@ public class JintScriptEngineTests : IClassFixture<TranslationsFixture>
             extensions);
     }
 
+    private sealed class AsyncExtension : IJintExtension
+    {
+        private delegate void Delay(Action callback);
+
+        public void ExtendAsync(ScriptExecutionContext context)
+        {
+            context.Engine.SetValue("setTimeout", new Delay(callback =>
+            {
+                context.Schedule(async (scheduler, ct) =>
+                {
+                    await Task.Delay(5, ct);
+                    scheduler.Run(callback);
+                });
+            }));
+        }
+    }
+
     [Fact]
     public async Task ExecuteAsync_should_catch_script_syntax_errors()
     {
@@ -598,4 +617,27 @@ public class JintScriptEngineTests : IClassFixture<TranslationsFixture>
 
         Assert.Equal(JsonValue.Create(28), actual["test"]!["iv"]);
     }
+
+    [Fact]
+    public async Task Should_not_run_callbacks_in_parallel()
+    {
+        var vars = new DataScriptVars
+        {
+            ["value"] = 13
+        };
+
+        const string script1 = @"
+                var x = ctx.value;
+                for (var i = 0; i < 100; i++) {
+                    setTimeout(function () {
+                        x++;
+                        ctx.shared = x;
+                    });
+                }
+            ";
+
+        await sut.ExecuteAsync(vars, script1, new ScriptOptions { AsContext = true });
+
+        Assert.Equal(113.0, vars["shared"]);
+    }
 }
diff --git a/tools/TestSuite/TestSuite.ApiTests/RuleRunnerTests.cs b/tools/TestSuite/TestSuite.ApiTests/RuleRunnerTests.cs
index 24aa152da..dbe23417f 100644
--- a/tools/TestSuite/TestSuite.ApiTests/RuleRunnerTests.cs
+++ b/tools/TestSuite/TestSuite.ApiTests/RuleRunnerTests.cs
@@ -83,6 +83,53 @@ public class RuleRunnerTests : IClassFixture<ClientFixture>, IClassFixture<Webho
         Assert.Single(eventsRule.Items);
     }
 
+    [Fact]
+    public async Task Should_run_scripting_rule_on_content_change()
+    {
+        // STEP 0: Create app.
+        await CreateAppAsync();
+
+
+        // STEP 1: Start webhook session
+        var (url, sessionId) = await webhookCatcher.CreateSessionAsync();
+
+
+        // STEP 2: Create rule
+        var createRule = new CreateRuleDto
+        {
+            Action = new ScriptRuleActionDto
+            {
+                Script = $@"
+                    postJSON('{url}', {{ schemaName: event.schemaId.Name }})
+                "
+            },
+            Trigger = new ContentChangedRuleTriggerDto
+            {
+                HandleAll = true
+            }
+        };
+
+        var rule = await _.Rules.PostRuleAsync(appName, createRule);
+
+
+        // STEP 3: Create test content
+        await CreateContentAsync();
+
+        // Get requests.
+        var requests = await webhookCatcher.WaitForRequestsAsync(sessionId, TimeSpan.FromMinutes(2));
+        var request = requests.FirstOrDefault(x => x.Method == "POST" && x.Content.Contains(schemaName, StringComparison.OrdinalIgnoreCase));
+
+        Assert.NotNull(request);
+
+
+        // STEP 4: Get events
+        var eventsAll = await _.Rules.GetEventsAsync(appName, rule.Id);
+        var eventsRule = await _.Rules.GetEventsAsync(appName);
+
+        Assert.Single(eventsAll.Items);
+        Assert.Single(eventsRule.Items);
+    }
+
     [Fact]
     public async Task Should_run_rules_on_asset_change()
     {