Fully stabilize now-stable protocol properties (modelcontextprotocol#1686)

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: eiriktsarpalis

src/ModelContextProtocol.Core/Protocol/ClientCapabilities.cs

@@ -1,4 +1,3 @@
-using System.ComponentModel;
 using System.Text.Json.Serialization;
 using ModelContextProtocol.Client;
 using ModelContextProtocol.Server;
@@ -83,15 +82,6 @@ public sealed class ClientCapabilities
     /// interoperability. Clients advertise extension support via this field during the initialization handshake.
     /// </para>
     /// </remarks>
-    [JsonIgnore]
-    public IDictionary<string, object>? Extensions
-    {
-        get => ExtensionsCore;
-        set => ExtensionsCore = value;
-    }
-
-    // See ExperimentalInternalPropertyTests.cs before modifying this property.
-    [JsonInclude]
     [JsonPropertyName("extensions")]
-    internal IDictionary<string, object>? ExtensionsCore { get; set; }
+    public IDictionary<string, object>? Extensions { get; set; }
 }

src/ModelContextProtocol.Core/Protocol/RequestParams.cs

@@ -35,17 +35,8 @@ private protected RequestParams()
     /// the value is the client's response to that input request.
     /// </para>
     /// </remarks>
-    [JsonIgnore]
-    public IDictionary<string, InputResponse>? InputResponses
-    {
-        get => InputResponsesCore;
-        set => InputResponsesCore = value;
-    }
-
-    // See ExperimentalInternalPropertyTests.cs before modifying this property.
-    [JsonInclude]
     [JsonPropertyName("inputResponses")]
-    internal IDictionary<string, InputResponse>? InputResponsesCore { get; set; }
+    public IDictionary<string, InputResponse>? InputResponses { get; set; }
 
     /// <summary>
     /// Gets or sets opaque request state echoed back from a previous <see cref="InputRequiredResult"/>.
@@ -57,17 +48,8 @@ public IDictionary<string, InputResponse>? InputResponses
     /// exact value without modification.
     /// </para>
     /// </remarks>
-    [JsonIgnore]
-    public string? RequestState
-    {
-        get => RequestStateCore;
-        set => RequestStateCore = value;
-    }
-
-    // See ExperimentalInternalPropertyTests.cs before modifying this property.
-    [JsonInclude]
     [JsonPropertyName("requestState")]
-    internal string? RequestStateCore { get; set; }
+    public string? RequestState { get; set; }
 
     /// <summary>
     /// Gets the opaque token that will be attached to any subsequent progress notifications.

src/ModelContextProtocol.Core/Protocol/ServerCapabilities.cs

@@ -1,4 +1,3 @@
-using System.ComponentModel;
 using System.Text.Json.Serialization;
 using ModelContextProtocol.Server;
 
@@ -81,15 +80,6 @@ public sealed class ServerCapabilities
     /// interoperability. Servers advertise extension support via this field during the initialization handshake.
     /// </para>
     /// </remarks>
-    [JsonIgnore]
-    public IDictionary<string, object>? Extensions
-    {
-        get => ExtensionsCore;
-        set => ExtensionsCore = value;
-    }
-
-    // See ExperimentalInternalPropertyTests.cs before modifying this property.
-    [JsonInclude]
     [JsonPropertyName("extensions")]
-    internal IDictionary<string, object>? ExtensionsCore { get; set; }
+    public IDictionary<string, object>? Extensions { get; set; }
 }