diff --git a/src/Squidex.Infrastructure/Commands/ReadonlyCommandMiddleware.cs b/src/Squidex.Infrastructure/Commands/ReadonlyCommandMiddleware.cs
new file mode 100644
index 000000000..dcd1ca88b
--- /dev/null
+++ b/src/Squidex.Infrastructure/Commands/ReadonlyCommandMiddleware.cs
@@ -0,0 +1,35 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Options;
+
+namespace Squidex.Infrastructure.Commands
+{
+    public sealed class ReadonlyCommandMiddleware : ICommandMiddleware
+    {
+        private readonly IOptions<ReadonlyOptions> options;
+
+        public ReadonlyCommandMiddleware(IOptions<ReadonlyOptions> options)
+        {
+            Guard.NotNull(options, nameof(options));
+
+            this.options = options;
+        }
+
+        public Task HandleAsync(CommandContext context, Func<Task> next)
+        {
+            if (options.Value.IsReadonly)
+            {
+                throw new DomainException("Application is in readonly mode at the moment.");
+            }
+
+            return next();
+        }
+    }
+}
diff --git a/src/Squidex.Infrastructure/Commands/ReadonlyOptions.cs b/src/Squidex.Infrastructure/Commands/ReadonlyOptions.cs
new file mode 100644
index 000000000..b5682c63d
--- /dev/null
+++ b/src/Squidex.Infrastructure/Commands/ReadonlyOptions.cs
@@ -0,0 +1,14 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+namespace Squidex.Infrastructure.Commands
+{
+    public sealed class ReadonlyOptions
+    {
+        public bool IsReadonly { get; set; }
+    }
+}
diff --git a/src/Squidex/AppServices.cs b/src/Squidex/AppServices.cs
index 3a6e0e91f..ff21cc224 100644
--- a/src/Squidex/AppServices.cs
+++ b/src/Squidex/AppServices.cs
@@ -13,6 +13,7 @@ using Squidex.Config;
 using Squidex.Config.Authentication;
 using Squidex.Config.Domain;
 using Squidex.Config.Web;
+using Squidex.Infrastructure.Commands;
 
 namespace Squidex
 {
@@ -40,6 +41,8 @@ namespace Squidex
             services.AddMySwaggerSettings();
             services.AddMySubscriptionServices(config);
 
+            services.Configure<ReadonlyOptions>(
+                config.GetSection("mode"));
             services.Configure<MyUrlsOptions>(
                 config.GetSection("urls"));
             services.Configure<MyIdentityOptions>(
diff --git a/src/Squidex/Config/Domain/EntitiesServices.cs b/src/Squidex/Config/Domain/EntitiesServices.cs
index 48804c635..96ee162e2 100644
--- a/src/Squidex/Config/Domain/EntitiesServices.cs
+++ b/src/Squidex/Config/Domain/EntitiesServices.cs
@@ -83,6 +83,9 @@ namespace Squidex.Config.Domain
             services.AddSingletonAs<InMemoryCommandBus>()
                 .As<ICommandBus>();
 
+            services.AddSingletonAs<ReadonlyCommandMiddleware>()
+                .As<ICommandMiddleware>();
+
             services.AddSingletonAs<ETagCommandMiddleware>()
                 .As<ICommandMiddleware>();
 
diff --git a/src/Squidex/appsettings.json b/src/Squidex/appsettings.json
index 7c1e57286..b72f5ec5c 100644
--- a/src/Squidex/appsettings.json
+++ b/src/Squidex/appsettings.json
@@ -1,4 +1,11 @@
 {
+  "mode": {
+    /*
+     * Use this flag to set Squidex to readonly, e.g. when you deploy a second instance for migration.
+     */
+    "isReadonly": false
+  },
+
   "urls": {
     /*
      * Set the base url of your application, to generate correct urls in background process.
diff --git a/tests/Squidex.Infrastructure.Tests/Commands/ReadonlyCommandMiddlewareTests.cs b/tests/Squidex.Infrastructure.Tests/Commands/ReadonlyCommandMiddlewareTests.cs
new file mode 100644
index 000000000..ac098a25b
--- /dev/null
+++ b/tests/Squidex.Infrastructure.Tests/Commands/ReadonlyCommandMiddlewareTests.cs
@@ -0,0 +1,62 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschränkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System.Threading.Tasks;
+using FakeItEasy;
+using Microsoft.Extensions.Options;
+using Squidex.Infrastructure.Tasks;
+using Xunit;
+
+namespace Squidex.Infrastructure.Commands
+{
+    public class ReadonlyCommandMiddlewareTests
+    {
+        private readonly ICommand command = A.Dummy<ICommand>();
+        private readonly ICommandBus commandBus = A.Dummy<ICommandBus>();
+        private readonly ReadonlyOptions options = new ReadonlyOptions();
+        private readonly ReadonlyCommandMiddleware sut;
+
+        public ReadonlyCommandMiddlewareTests()
+        {
+            sut = new ReadonlyCommandMiddleware(Options.Create(options));
+        }
+
+        [Fact]
+        public async Task Should_throw_exception_if_readonly()
+        {
+            var context = new CommandContext(command, commandBus);
+
+            options.IsReadonly = true;
+
+            await Assert.ThrowsAsync<DomainException>(() => MakeCallAsync(context));
+
+            Assert.False(context.IsCompleted);
+        }
+
+        [Fact]
+        public async Task Should_not_throw_exception_if_not_readonly()
+        {
+            var context = new CommandContext(command, commandBus);
+
+            options.IsReadonly = false;
+
+            await MakeCallAsync(context);
+
+            Assert.True(context.IsCompleted);
+        }
+
+        private async Task MakeCallAsync(CommandContext context)
+        {
+            await sut.HandleAsync(context, () =>
+            {
+                context.Complete(true);
+
+                return TaskHelper.Done;
+            });
+        }
+    }
+}
\ No newline at end of file
diff --git a/tests/Squidex.Tests/Pipeline/EnforceHttpsMiddlewareTests.cs b/tests/Squidex.Tests/Pipeline/EnforceHttpsMiddlewareTests.cs
index 5657141b1..705b398ca 100644
--- a/tests/Squidex.Tests/Pipeline/EnforceHttpsMiddlewareTests.cs
+++ b/tests/Squidex.Tests/Pipeline/EnforceHttpsMiddlewareTests.cs
@@ -17,6 +17,8 @@ namespace Squidex.Pipeline
     public class EnforceHttpsMiddlewareTests
     {
         private readonly RequestDelegate next;
+        private readonly MyUrlsOptions options = new MyUrlsOptions();
+        private readonly EnforceHttpsMiddleware sut;
         private bool isNextCalled;
 
         public EnforceHttpsMiddlewareTests()
@@ -27,6 +29,8 @@ namespace Squidex.Pipeline
 
                 return TaskHelper.Done;
             };
+
+            sut = new EnforceHttpsMiddleware(Options.Create(options));
         }
 
         [Fact]
@@ -34,9 +38,9 @@ namespace Squidex.Pipeline
         {
             var httpContext = CreateHttpContext();
 
-            var sut = new EnforceHttpsMiddleware(next, Options.Create(new MyUrlsOptions { EnforceHTTPS = true }));
+            options.EnforceHTTPS = true;
 
-            await sut.Invoke(httpContext);
+            await sut.InvokeAsync(httpContext, next);
 
             Assert.False(isNextCalled);
             Assert.Equal("https://squidex.local/path?query=1", httpContext.Response.Headers["Location"]);
@@ -47,9 +51,9 @@ namespace Squidex.Pipeline
         {
             var httpContext = CreateHttpContext("https");
 
-            var sut = new EnforceHttpsMiddleware(next, Options.Create(new MyUrlsOptions { EnforceHTTPS = true }));
+            options.EnforceHTTPS = true;
 
-            await sut.Invoke(httpContext);
+            await sut.InvokeAsync(httpContext, next);
 
             Assert.True(isNextCalled);
             Assert.Null((string)httpContext.Response.Headers["Location"]);
@@ -60,9 +64,9 @@ namespace Squidex.Pipeline
         {
             var httpContext = CreateHttpContext("http");
 
-            var sut = new EnforceHttpsMiddleware(next, Options.Create(new MyUrlsOptions { EnforceHTTPS = false }));
+            options.EnforceHTTPS = false;
 
-            await sut.Invoke(httpContext);
+            await sut.InvokeAsync(httpContext, next);
 
             Assert.True(isNextCalled);
             Assert.Null((string)httpContext.Response.Headers["Location"]);