diff --git a/src/Squidex/Areas/Api/Controllers/Assets/AssetContentController.cs b/src/Squidex/Areas/Api/Controllers/Assets/AssetContentController.cs
index bd91cfa81..f2a68ba7a 100644
--- a/src/Squidex/Areas/Api/Controllers/Assets/AssetContentController.cs
+++ b/src/Squidex/Areas/Api/Controllers/Assets/AssetContentController.cs
@@ -67,10 +67,12 @@ namespace Squidex.Areas.Api.Controllers.Assets
                 return NotFound();
             }
 
-            var assetId = entity.Id.ToString();
+            Response.Headers["ETag"] = $"{entity.FileVersion};{width};{height};{mode}";
 
             return new FileCallbackResult(entity.MimeType, entity.FileName, async bodyStream =>
             {
+                var assetId = entity.Id.ToString();
+
                 if (entity.IsImage && (width.HasValue || height.HasValue))
                 {
                     var assetSuffix = $"{width}_{height}_{mode}";
diff --git a/src/Squidex/Areas/Api/Controllers/Languages/LanguagesController.cs b/src/Squidex/Areas/Api/Controllers/Languages/LanguagesController.cs
index 7e8fea639..98d89eda9 100644
--- a/src/Squidex/Areas/Api/Controllers/Languages/LanguagesController.cs
+++ b/src/Squidex/Areas/Api/Controllers/Languages/LanguagesController.cs
@@ -43,6 +43,8 @@ namespace Squidex.Areas.Api.Controllers.Languages
         {
             var response = Language.AllLanguages.Select(LanguageDto.FromLanguage).ToList();
 
+            Response.Headers["Etag"] = "1";
+
             return Ok(response);
         }
     }
diff --git a/src/Squidex/Areas/Api/Controllers/Rules/Models/RuleDto.cs b/src/Squidex/Areas/Api/Controllers/Rules/Models/RuleDto.cs
index c94056f37..7e3f7c85a 100644
--- a/src/Squidex/Areas/Api/Controllers/Rules/Models/RuleDto.cs
+++ b/src/Squidex/Areas/Api/Controllers/Rules/Models/RuleDto.cs
@@ -14,10 +14,11 @@ using Squidex.Domain.Apps.Core.Rules;
 using Squidex.Domain.Apps.Entities.Rules;
 using Squidex.Infrastructure;
 using Squidex.Infrastructure.Reflection;
+using Squidex.Pipeline;
 
 namespace Squidex.Areas.Api.Controllers.Rules.Models
 {
-    public sealed class RuleDto
+    public sealed class RuleDto : IGenerateEtag
     {
         /// <summary>
         /// The id of the rule.
@@ -49,7 +50,7 @@ namespace Squidex.Areas.Api.Controllers.Rules.Models
         /// <summary>
         /// The version of the rule.
         /// </summary>
-        public int Version { get; set; }
+        public long Version { get; set; }
 
         /// <summary>
         /// Determines if the rule is enabled.
diff --git a/src/Squidex/Areas/Api/Controllers/Rules/RulesController.cs b/src/Squidex/Areas/Api/Controllers/Rules/RulesController.cs
index 28ee52be9..ed2e0b1df 100644
--- a/src/Squidex/Areas/Api/Controllers/Rules/RulesController.cs
+++ b/src/Squidex/Areas/Api/Controllers/Rules/RulesController.cs
@@ -9,6 +9,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using IdentityServer4.Models;
 using Microsoft.AspNetCore.Mvc;
 using NodaTime;
 using Squidex.Areas.Api.Controllers.Rules.Models;
@@ -32,6 +33,8 @@ namespace Squidex.Areas.Api.Controllers.Rules
     [MustBeAppDeveloper]
     public sealed class RulesController : ApiController
     {
+        private static readonly string RuleActionsEtag = string.Join(";", RuleElementRegistry.Actions.Select(x => x.Key)).Sha256();
+        private static readonly string RuleTriggersEtag = string.Join(";", RuleElementRegistry.Triggers.Select(x => x.Key)).Sha256();
         private readonly IAppProvider appProvider;
         private readonly IRuleEventRepository ruleEventsRepository;
 
@@ -58,6 +61,8 @@ namespace Squidex.Areas.Api.Controllers.Rules
         {
             var response = RuleElementRegistry.Actions.ToDictionary(x => x.Key, x => SimpleMapper.Map(x.Value, new RuleElementDto()));
 
+            Response.Headers["Etag"] = RuleActionsEtag;
+
             return Ok(response);
         }
 
@@ -75,6 +80,8 @@ namespace Squidex.Areas.Api.Controllers.Rules
         {
             var response = RuleElementRegistry.Triggers.ToDictionary(x => x.Key, x => SimpleMapper.Map(x.Value, new RuleElementDto()));
 
+            Response.Headers["Etag"] = RuleTriggersEtag;
+
             return Ok(response);
         }
 
@@ -96,6 +103,8 @@ namespace Squidex.Areas.Api.Controllers.Rules
 
             var response = entities.Select(RuleDto.FromRule);
 
+            Response.Headers["ETag"] = response.ToManyEtag(0);
+
             return Ok(response);
         }
 
diff --git a/src/Squidex/Areas/Api/Controllers/Schemas/Models/SchemaDetailsDto.cs b/src/Squidex/Areas/Api/Controllers/Schemas/Models/SchemaDetailsDto.cs
index 0dc33bc92..11d441abd 100644
--- a/src/Squidex/Areas/Api/Controllers/Schemas/Models/SchemaDetailsDto.cs
+++ b/src/Squidex/Areas/Api/Controllers/Schemas/Models/SchemaDetailsDto.cs
@@ -108,7 +108,7 @@ namespace Squidex.Areas.Api.Controllers.Schemas.Models
         /// <summary>
         /// The version of the schema.
         /// </summary>
-        public int Version { get; set; }
+        public long Version { get; set; }
 
         public static SchemaDetailsDto FromSchema(ISchemaEntity schema)
         {
diff --git a/src/Squidex/app/shared/services/assets.service.ts b/src/Squidex/app/shared/services/assets.service.ts
index 680d905b2..25884f5f0 100644
--- a/src/Squidex/app/shared/services/assets.service.ts
+++ b/src/Squidex/app/shared/services/assets.service.ts
@@ -195,9 +195,7 @@ export class AssetsService {
     public uploadFile(appName: string, file: File, user: string, now: DateTime): Observable<number | AssetDto> {
         const url = this.apiUrl.buildUrl(`api/apps/${appName}/assets`);
 
-        const req = new HttpRequest('POST', url, getFormData(file), {
-            reportProgress: true
-        });
+        const req = new HttpRequest('POST', url, getFormData(file), { reportProgress: true });
 
         return this.http.request<any>(req).pipe(
                 filter(event =>
@@ -276,12 +274,7 @@ export class AssetsService {
     public replaceFile(appName: string, id: string, file: File, version: Version): Observable<number | Versioned<AssetReplacedDto>> {
         const url = this.apiUrl.buildUrl(`api/apps/${appName}/assets/${id}/content`);
 
-        const req = new HttpRequest('PUT', url, getFormData(file), {
-            headers: new HttpHeaders({
-                'If-Match': version.value
-            }),
-            reportProgress: true
-        });
+        const req = new HttpRequest('PUT', url, getFormData(file), { headers: new HttpHeaders().set('If-Match', version.value), reportProgress: true });
 
         return this.http.request(req).pipe(
                 filter(event =>