Make McpJsonUtilities public and remove IVT to sample

stephentoub · stephentoub · commit 89b9556ecf99 · 2025-03-19T18:07:16.000-04:00
Also adds in the same encoder used by AIJsonUtilities.
diff --git a/samples/AspNetCoreSseServer/McpEndpointRouteBuilderExtensions.cs b/samples/AspNetCoreSseServer/McpEndpointRouteBuilderExtensions.cs
@@ -45,7 +45,7 @@ public static IEndpointConventionBuilder MapMcpSse(this IEndpointRouteBuilder en
                 return;
             }
 
-            var message = await context.Request.ReadFromJsonAsync<IJsonRpcMessage>(JsonSerializerOptionsExtensions.DefaultOptions, context.RequestAborted);
+            var message = await context.Request.ReadFromJsonAsync<IJsonRpcMessage>(McpJsonUtilities.DefaultOptions, context.RequestAborted);
             if (message is null)
             {
                 await Results.BadRequest("No message in request body.").ExecuteAsync(context);
diff --git a/samples/AspNetCoreSseServer/SseServerStreamTransport.cs b/samples/AspNetCoreSseServer/SseServerStreamTransport.cs
@@ -28,7 +28,7 @@ void WriteJsonRpcMessageToBuffer(SseItem<IJsonRpcMessage?> item, IBufferWriter<b
                 return;
             }
 
-            JsonSerializer.Serialize(GetUtf8JsonWriter(writer), item.Data, JsonSerializerOptionsExtensions.DefaultOptions);
+            JsonSerializer.Serialize(GetUtf8JsonWriter(writer), item.Data, McpJsonUtilities.DefaultOptions);
         }
 
         // The very first SSE event isn't really an IJsonRpcMessage, but there's no API to write a single item of a different type,
diff --git a/src/ModelContextProtocol/Client/McpClient.cs b/src/ModelContextProtocol/Client/McpClient.cs
@@ -139,8 +139,8 @@ private async Task InitializeAsync(CancellationToken cancellationToken)
 
             // Store server information
             _logger.ServerCapabilitiesReceived(EndpointName, 
-                capabilities: JsonSerializer.Serialize(initializeResponse.Capabilities, JsonSerializerOptionsExtensions.JsonContext.Default.ServerCapabilities),
-                serverInfo: JsonSerializer.Serialize(initializeResponse.ServerInfo, JsonSerializerOptionsExtensions.JsonContext.Default.Implementation));
+                capabilities: JsonSerializer.Serialize(initializeResponse.Capabilities, McpJsonUtilities.JsonContext.Default.ServerCapabilities),
+                serverInfo: JsonSerializer.Serialize(initializeResponse.ServerInfo, McpJsonUtilities.JsonContext.Default.Implementation));
 
             ServerCapabilities = initializeResponse.Capabilities;
             ServerInfo = initializeResponse.ServerInfo;
diff --git a/src/ModelContextProtocol/Client/McpClientExtensions.cs b/src/ModelContextProtocol/Client/McpClientExtensions.cs
@@ -483,7 +483,7 @@ private sealed class McpAIFunction(IMcpClient client, Tool tool) : AIFunction
                 ["description"] = tool.Description ?? string.Empty,
                 ["properties"] = tool.InputSchema?.Properties ?? [],
                 ["required"] = tool.InputSchema?.Required ?? []
-            }, JsonSerializerOptionsExtensions.JsonContext.Default.DictionaryStringObject);
+            }, McpJsonUtilities.JsonContext.Default.DictionaryStringObject);
 
         /// <inheritdoc/>
         protected async override Task<object?> InvokeCoreAsync(
@@ -501,7 +501,7 @@ private sealed class McpAIFunction(IMcpClient client, Tool tool) : AIFunction
             }
 
             CallToolResponse result = await client.CallToolAsync(tool.Name, argDict, cancellationToken).ConfigureAwait(false);
-            return JsonSerializer.SerializeToElement(result, JsonSerializerOptionsExtensions.JsonContext.Default.CallToolResponse);
+            return JsonSerializer.SerializeToElement(result, McpJsonUtilities.JsonContext.Default.CallToolResponse);
         }
     }
 }
diff --git a/src/ModelContextProtocol/Configuration/McpServerBuilderExtensions.Tools.cs b/src/ModelContextProtocol/Configuration/McpServerBuilderExtensions.Tools.cs
@@ -96,7 +96,7 @@ public static IMcpServerBuilder WithTools(this IMcpServerBuilder builder, params
             {
                 Name = function.Name,
                 Description = function.Description,
-                InputSchema = JsonSerializer.Deserialize(function.JsonSchema, JsonSerializerOptionsExtensions.JsonContext.Default.JsonSchema),
+                InputSchema = JsonSerializer.Deserialize(function.JsonSchema, McpJsonUtilities.JsonContext.Default.JsonSchema),
             });
 
             callbacks.Add(function.Name, async (request, cancellationToken) =>
diff --git a/src/ModelContextProtocol/ModelContextProtocol.csproj b/src/ModelContextProtocol/ModelContextProtocol.csproj
@@ -12,12 +12,11 @@
   <PropertyGroup Condition="'$(TargetFramework)' != 'netstandard2.0'">
     <IsAotCompatible>true</IsAotCompatible>
   </PropertyGroup>
-
+  
   <ItemGroup>
     <InternalsVisibleTo Include="ModelContextProtocol.Tests" />
-    <InternalsVisibleTo Include="AspNetCoreSseServer" />
   </ItemGroup>
-  
+
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.AI.Abstractions"/>
     <PackageReference Include="Microsoft.Extensions.AI" />
diff --git a/src/ModelContextProtocol/Protocol/Transport/HttpListenerSseServerTransport.cs b/src/ModelContextProtocol/Protocol/Transport/HttpListenerSseServerTransport.cs
@@ -42,7 +42,7 @@ public HttpListenerSseServerTransport(string serverName, int port, ILoggerFactor
     {
         _serverName = serverName;
         _logger = loggerFactory.CreateLogger<HttpListenerSseServerTransport>();
-        _jsonOptions = JsonSerializerOptionsExtensions.DefaultOptions;
+        _jsonOptions = McpJsonUtilities.DefaultOptions;
         _httpServerProvider = new HttpListenerServerProvider(port);
     }
 
diff --git a/src/ModelContextProtocol/Protocol/Transport/SseClientTransport.cs b/src/ModelContextProtocol/Protocol/Transport/SseClientTransport.cs
@@ -65,7 +65,7 @@ public SseClientTransport(SseClientTransportOptions transportOptions, McpServerC
         _httpClient = httpClient;
         _connectionCts = new CancellationTokenSource();
         _logger = (ILogger?)loggerFactory?.CreateLogger<SseClientTransport>() ?? NullLogger.Instance;
-        _jsonOptions = JsonSerializerOptionsExtensions.DefaultOptions;
+        _jsonOptions = McpJsonUtilities.DefaultOptions;
         _connectionEstablished = new TaskCompletionSource<bool>();
         _ownsHttpClient = ownsHttpClient;
     }
diff --git a/src/ModelContextProtocol/Protocol/Transport/StdioClientTransport.cs b/src/ModelContextProtocol/Protocol/Transport/StdioClientTransport.cs
@@ -43,7 +43,7 @@ public StdioClientTransport(StdioClientTransportOptions options, McpServerConfig
         _options = options;
         _serverConfig = serverConfig;
         _logger = (ILogger?)loggerFactory?.CreateLogger<StdioClientTransport>() ?? NullLogger.Instance;
-        _jsonOptions = JsonSerializerOptionsExtensions.DefaultOptions;
+        _jsonOptions = McpJsonUtilities.DefaultOptions;
     }
 
     /// <inheritdoc/>
diff --git a/src/ModelContextProtocol/Protocol/Transport/StdioServerTransport.cs b/src/ModelContextProtocol/Protocol/Transport/StdioServerTransport.cs
@@ -21,7 +21,7 @@ public sealed class StdioServerTransport : TransportBase, IServerTransport
     private readonly string _serverName;
     private readonly ILogger _logger;
 
-    private readonly JsonSerializerOptions _jsonOptions = JsonSerializerOptionsExtensions.DefaultOptions;
+    private readonly JsonSerializerOptions _jsonOptions = McpJsonUtilities.DefaultOptions;
     private readonly TextReader _stdin = Console.In;
     private readonly TextWriter _stdout = Console.Out;
 
diff --git a/src/ModelContextProtocol/Shared/McpJsonRpcEndpoint.cs b/src/ModelContextProtocol/Shared/McpJsonRpcEndpoint.cs
@@ -46,7 +46,7 @@ protected McpJsonRpcEndpoint(ITransport transport, ILoggerFactory? loggerFactory
         _pendingRequests = new();
         _notificationHandlers = new();
         _nextRequestId = 1;
-        _jsonOptions = JsonSerializerOptionsExtensions.DefaultOptions;
+        _jsonOptions = McpJsonUtilities.DefaultOptions;
         _logger = (ILogger?)loggerFactory?.CreateLogger<McpClient>() ?? NullLogger.Instance;
     }
 
diff --git a/src/ModelContextProtocol/Utils/Json/McpJsonUtilities.cs b/src/ModelContextProtocol/Utils/Json/McpJsonUtilities.cs
@@ -1,18 +1,39 @@
 ﻿using ModelContextProtocol.Protocol.Messages;
 using ModelContextProtocol.Protocol.Types;
 using System.Diagnostics.CodeAnalysis;
+using System.Text.Encodings.Web;
 using System.Text.Json;
 using System.Text.Json.Nodes;
 using System.Text.Json.Serialization;
 using System.Text.Json.Serialization.Metadata;
 
 namespace ModelContextProtocol.Utils.Json;
 
-/// <summary>
-/// Extensions for configuring System.Text.Json serialization options for MCP.
-/// </summary>
-internal static partial class JsonSerializerOptionsExtensions
+/// <summary>Provides a collection of utility methods for working with JSON data in the context of MCP.</summary>
+public static partial class McpJsonUtilities
 {
+    /// <summary>
+    /// Gets the <see cref="JsonSerializerOptions"/> singleton used as the default in JSON serialization operations.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// For Native AOT or applications disabling <see cref="JsonSerializer.IsReflectionEnabledByDefault"/>, this instance 
+    /// includes source generated contracts for all common exchange types contained in the ModelContextProtocol library.
+    /// </para>
+    /// <para>
+    /// It additionally turns on the following settings:
+    /// <list type="number">
+    /// <item>Enables string-based enum serialization as implemented by <see cref="JsonStringEnumConverter"/>.</item>
+    /// <item>Enables <see cref="JsonIgnoreCondition.WhenWritingNull"/> as the default ignore condition for properties.</item>
+    /// <item>Enables <see cref="JsonNumberHandling.AllowReadingFromString"/> as the default number handling for number types.</item>
+    /// <item>
+    /// Enables <see cref="JavaScriptEncoder.UnsafeRelaxedJsonEscaping"/> when escaping JSON strings.
+    /// Consuming applications must ensure that JSON outputs are adequately escaped before embedding in other document formats,
+    /// such as HTML and XML.
+    /// </item>
+    /// </list>
+    /// </para>
+    /// </remarks>
     public static JsonSerializerOptions DefaultOptions { get; } = CreateDefaultOptions();
 
     /// <summary>
@@ -26,23 +47,31 @@ private static JsonSerializerOptions CreateDefaultOptions()
         // If reflection-based serialization is enabled by default, use it, as it's the most permissive in terms of what it can serialize,
         // and we want to be flexible in terms of what can be put into the various collections in the object model.
         // Otherwise, use the source-generated options to enable trimming and Native AOT.
+        JsonSerializerOptions options;
 
         if (JsonSerializer.IsReflectionEnabledByDefault)
         {
             // Keep in sync with the JsonSourceGenerationOptions attribute on JsonContext below.
-            JsonSerializerOptions options = new(JsonSerializerDefaults.Web)
+            options = new(JsonSerializerDefaults.Web)
             {
                 TypeInfoResolver = new DefaultJsonTypeInfoResolver(),
                 Converters = { new JsonStringEnumConverter() },
                 DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
-                NumberHandling = JsonNumberHandling.AllowReadingFromString
+                NumberHandling = JsonNumberHandling.AllowReadingFromString,
+                Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
+            };
+        }
+        else
+        {
+            options = new(JsonContext.Default.Options)
+            {
+                // Compile-time encoder setting not yet available
+                Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
             };
-
-            options.MakeReadOnly();
-            return options;
         }
 
-        return JsonContext.Default.Options;
+        options.MakeReadOnly();
+        return options;
     }
 
     internal static JsonTypeInfo<T> GetTypeInfo<T>(this JsonSerializerOptions options) =>
@@ -62,6 +91,7 @@ internal static JsonTypeInfo<T> GetTypeInfo<T>(this JsonSerializerOptions option
     [JsonSerializable(typeof(JsonRpcResponse))]
     [JsonSerializable(typeof(JsonRpcError))]
     [JsonSerializable(typeof(ServerCapabilities))]
+    [JsonSerializable(typeof(ClientCapabilities))]
     [JsonSerializable(typeof(Implementation))]
     [JsonSerializable(typeof(CreateMessageResult))]
     [JsonSerializable(typeof(ListRootsResult))]
diff --git a/tests/ModelContextProtocol.Tests/Transport/StdioServerTransportTests.cs b/tests/ModelContextProtocol.Tests/Transport/StdioServerTransportTests.cs
@@ -78,7 +78,7 @@ public async Task SendMessageAsync_Should_Send_Message()
             await transport.SendMessageAsync(message);
 
             var result = output.ToString()?.Trim();
-            var expected = JsonSerializer.Serialize(message, JsonSerializerOptionsExtensions.DefaultOptions);
+            var expected = JsonSerializer.Serialize(message, McpJsonUtilities.DefaultOptions);
 
             Assert.Equal(expected, result);
         }
@@ -113,7 +113,7 @@ public async Task DisposeAsync_Should_Dispose_Resources()
     public async Task ReadMessagesAsync_Should_Read_Messages()
     {
         var message = new JsonRpcRequest { Method = "test", Id = RequestId.FromNumber(44) };
-        var json = JsonSerializer.Serialize(message, JsonSerializerOptionsExtensions.DefaultOptions);
+        var json = JsonSerializer.Serialize(message, McpJsonUtilities.DefaultOptions);
 
         TextReader oldIn = Console.In;
         TextWriter oldOut = Console.Out;

Original file line number	Diff line number	Diff line change
`@@ -45,7 +45,7 @@ public static IEndpointConventionBuilder MapMcpSse(this IEndpointRouteBuilder en`
`45`	`45`	`return;`
`46`	`46`	`}`
`47`	`47`
`48`		`- var message = await context.Request.ReadFromJsonAsync<IJsonRpcMessage>(JsonSerializerOptionsExtensions.DefaultOptions, context.RequestAborted);`
	`48`	`+ var message = await context.Request.ReadFromJsonAsync<IJsonRpcMessage>(McpJsonUtilities.DefaultOptions, context.RequestAborted);`
`49`	`49`	`if (message is null)`
`50`	`50`	`{`
`51`	`51`	`await Results.BadRequest("No message in request body.").ExecuteAsync(context);`
Original file line number	Diff line number	Diff line change
`@@ -28,7 +28,7 @@ void WriteJsonRpcMessageToBuffer(SseItem<IJsonRpcMessage?> item, IBufferWriter<b`
`28`	`28`	`return;`
`29`	`29`	`}`
`30`	`30`
`31`		`- JsonSerializer.Serialize(GetUtf8JsonWriter(writer), item.Data, JsonSerializerOptionsExtensions.DefaultOptions);`
	`31`	`+ JsonSerializer.Serialize(GetUtf8JsonWriter(writer), item.Data, McpJsonUtilities.DefaultOptions);`
`32`	`32`	`}`
`33`	`33`
`34`	`34`	`// The very first SSE event isn't really an IJsonRpcMessage, but there's no API to write a single item of a different type,`
Original file line number	Diff line number	Diff line change
`@@ -483,7 +483,7 @@ private sealed class McpAIFunction(IMcpClient client, Tool tool) : AIFunction`
`483`	`483`	`["description"] = tool.Description ?? string.Empty,`
`484`	`484`	`["properties"] = tool.InputSchema?.Properties ?? [],`
`485`	`485`	`["required"] = tool.InputSchema?.Required ?? []`
`486`		`- }, JsonSerializerOptionsExtensions.JsonContext.Default.DictionaryStringObject);`
	`486`	`+ }, McpJsonUtilities.JsonContext.Default.DictionaryStringObject);`
`487`	`487`
`488`	`488`	`/// <inheritdoc/>`
`489`	`489`	`protected async override Task<object?> InvokeCoreAsync(`
`@@ -501,7 +501,7 @@ private sealed class McpAIFunction(IMcpClient client, Tool tool) : AIFunction`
`501`	`501`	`}`
`502`	`502`
`503`	`503`	`CallToolResponse result = await client.CallToolAsync(tool.Name, argDict, cancellationToken).ConfigureAwait(false);`
`504`		`- return JsonSerializer.SerializeToElement(result, JsonSerializerOptionsExtensions.JsonContext.Default.CallToolResponse);`
	`504`	`+ return JsonSerializer.SerializeToElement(result, McpJsonUtilities.JsonContext.Default.CallToolResponse);`
`505`	`505`	`}`
`506`	`506`	`}`
`507`	`507`	`}`
Original file line number	Diff line number	Diff line change
`@@ -96,7 +96,7 @@ public static IMcpServerBuilder WithTools(this IMcpServerBuilder builder, params`
`96`	`96`	`{`
`97`	`97`	`Name = function.Name,`
`98`	`98`	`Description = function.Description,`
`99`		`- InputSchema = JsonSerializer.Deserialize(function.JsonSchema, JsonSerializerOptionsExtensions.JsonContext.Default.JsonSchema),`
	`99`	`+ InputSchema = JsonSerializer.Deserialize(function.JsonSchema, McpJsonUtilities.JsonContext.Default.JsonSchema),`
`100`	`100`	`});`
`101`	`101`
`102`	`102`	`callbacks.Add(function.Name, async (request, cancellationToken) =>`
Original file line number	Diff line number	Diff line change
`@@ -42,7 +42,7 @@ public HttpListenerSseServerTransport(string serverName, int port, ILoggerFactor`
`42`	`42`	`{`
`43`	`43`	`_serverName = serverName;`
`44`	`44`	`_logger = loggerFactory.CreateLogger<HttpListenerSseServerTransport>();`
`45`		`- _jsonOptions = JsonSerializerOptionsExtensions.DefaultOptions;`
	`45`	`+ _jsonOptions = McpJsonUtilities.DefaultOptions;`
`46`	`46`	`_httpServerProvider = new HttpListenerServerProvider(port);`
`47`	`47`	`}`
`48`	`48`
Original file line number	Diff line number	Diff line change
`@@ -65,7 +65,7 @@ public SseClientTransport(SseClientTransportOptions transportOptions, McpServerC`
`65`	`65`	`_httpClient = httpClient;`
`66`	`66`	`_connectionCts = new CancellationTokenSource();`
`67`	`67`	`_logger = (ILogger?)loggerFactory?.CreateLogger<SseClientTransport>() ?? NullLogger.Instance;`
`68`		`- _jsonOptions = JsonSerializerOptionsExtensions.DefaultOptions;`
	`68`	`+ _jsonOptions = McpJsonUtilities.DefaultOptions;`
`69`	`69`	`_connectionEstablished = new TaskCompletionSource<bool>();`
`70`	`70`	`_ownsHttpClient = ownsHttpClient;`
`71`	`71`	`}`
Original file line number	Diff line number	Diff line change
`@@ -43,7 +43,7 @@ public StdioClientTransport(StdioClientTransportOptions options, McpServerConfig`
`43`	`43`	`_options = options;`
`44`	`44`	`_serverConfig = serverConfig;`
`45`	`45`	`_logger = (ILogger?)loggerFactory?.CreateLogger<StdioClientTransport>() ?? NullLogger.Instance;`
`46`		`- _jsonOptions = JsonSerializerOptionsExtensions.DefaultOptions;`
	`46`	`+ _jsonOptions = McpJsonUtilities.DefaultOptions;`
`47`	`47`	`}`
`48`	`48`
`49`	`49`	`/// <inheritdoc/>`