diff --git a/src/Microsoft.AspNetCore.Http.Features/IHttpResponseTrailersFeature.cs b/src/Microsoft.AspNetCore.Http.Features/IHttpResponseTrailersFeature.cs
new file mode 100644
index 00000000..c0df8e23
--- /dev/null
+++ b/src/Microsoft.AspNetCore.Http.Features/IHttpResponseTrailersFeature.cs
@@ -0,0 +1,30 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Threading.Tasks;
+
+namespace Microsoft.AspNetCore.Http.Features
+{
+ public interface IHttpResponseTrailersFeature
+ {
+ ///
+ /// The response trailers to send.
+ ///
+ IHeaderDictionary Trailers { get; set; }
+
+ ///
+ /// Indicates if the server has started writing the response trailers.
+ /// If true, the are now immutable, and should no longer be called.
+ ///
+ bool HasStarted { get; }
+
+ ///
+ /// Registers a callback to be invoked just before writing the response trailers.
+ /// This is the last chance to modify the .
+ ///
+ /// The callback to invoke before writing the trailers.
+ /// The state to pass into the callback.
+ void OnStarting(Func