Use strong-typing of params in most remaining McpClientExtensions methods

Author: stephentoub

src/ModelContextProtocol/Client/McpClientExtensions.cs

@@ -22,7 +22,7 @@ public static Task PingAsync(this IMcpClient client, CancellationToken cancellat
         Throw.IfNull(client);
 
         return client.SendRequestAsync(
-            RequestMethods.Ping, 
+            RequestMethods.Ping,
             parameters: null,
             McpJsonUtilities.JsonContext.Default.Object!,
             McpJsonUtilities.JsonContext.Default.Object,
@@ -51,9 +51,9 @@ public static async Task<IList<McpClientTool>> ListToolsAsync(
         do
         {
             var toolResults = await client.SendRequestAsync(
-                RequestMethods.ToolsList, 
-                CreateCursorDictionary(cursor)!,
-                McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+                RequestMethods.ToolsList,
+                new() { Cursor = cursor },
+                McpJsonUtilities.JsonContext.Default.ListToolsRequestParams,
                 McpJsonUtilities.JsonContext.Default.ListToolsResult,
                 cancellationToken: cancellationToken).ConfigureAwait(false);
 
@@ -95,9 +95,9 @@ public static async IAsyncEnumerable<McpClientTool> EnumerateToolsAsync(
         do
         {
             var toolResults = await client.SendRequestAsync(
-                RequestMethods.ToolsList, 
-                CreateCursorDictionary(cursor)!,
-                McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+                RequestMethods.ToolsList,
+                new() { Cursor = cursor },
+                McpJsonUtilities.JsonContext.Default.ListToolsRequestParams,
                 McpJsonUtilities.JsonContext.Default.ListToolsResult,
                 cancellationToken: cancellationToken).ConfigureAwait(false);
 
@@ -127,9 +127,9 @@ public static async Task<IList<McpClientPrompt>> ListPromptsAsync(
         do
         {
             var promptResults = await client.SendRequestAsync(
-                RequestMethods.PromptsList, 
-                CreateCursorDictionary(cursor)!,
-                McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+                RequestMethods.PromptsList,
+                new() { Cursor = cursor },
+                McpJsonUtilities.JsonContext.Default.ListPromptsRequestParams,
                 McpJsonUtilities.JsonContext.Default.ListPromptsResult,
                 cancellationToken: cancellationToken).ConfigureAwait(false);
 
@@ -166,8 +166,8 @@ public static async IAsyncEnumerable<Prompt> EnumeratePromptsAsync(
         {
             var promptResults = await client.SendRequestAsync(
                 RequestMethods.PromptsList,
-                CreateCursorDictionary(cursor)!,
-                McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+                new() { Cursor = cursor },
+                McpJsonUtilities.JsonContext.Default.ListPromptsRequestParams,
                 McpJsonUtilities.JsonContext.Default.ListPromptsResult,
                 cancellationToken: cancellationToken).ConfigureAwait(false);
 
@@ -202,12 +202,10 @@ public static Task<GetPromptResult> GetPromptAsync(
         serializerOptions ??= McpJsonUtilities.DefaultOptions;
         serializerOptions.MakeReadOnly();
 
-        var parametersTypeInfo = serializerOptions.GetTypeInfo<IReadOnlyDictionary<string, object?>>();
-
         return client.SendRequestAsync(
             RequestMethods.PromptsGet,
-            CreateParametersDictionary(name, arguments),
-            parametersTypeInfo,
+            new() { Name = name, Arguments = arguments },
+            McpJsonUtilities.JsonContext.Default.GetPromptRequestParams,
             McpJsonUtilities.JsonContext.Default.GetPromptResult,
             cancellationToken: cancellationToken);
     }
@@ -229,9 +227,9 @@ public static async Task<IList<ResourceTemplate>> ListResourceTemplatesAsync(
         do
         {
             var templateResults = await client.SendRequestAsync(
-                RequestMethods.ResourcesTemplatesList, 
-                CreateCursorDictionary(cursor)!,
-                McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+                RequestMethods.ResourcesTemplatesList,
+                new() { Cursor = cursor },
+                McpJsonUtilities.JsonContext.Default.ListResourceTemplatesRequestParams,
                 McpJsonUtilities.JsonContext.Default.ListResourceTemplatesResult,
                 cancellationToken: cancellationToken).ConfigureAwait(false);
 
@@ -270,9 +268,9 @@ public static async IAsyncEnumerable<ResourceTemplate> EnumerateResourceTemplate
         do
         {
             var templateResults = await client.SendRequestAsync(
-                RequestMethods.ResourcesTemplatesList, 
-                CreateCursorDictionary(cursor)!,
-                McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+                RequestMethods.ResourcesTemplatesList,
+                new() { Cursor = cursor },
+                McpJsonUtilities.JsonContext.Default.ListResourceTemplatesRequestParams,
                 McpJsonUtilities.JsonContext.Default.ListResourceTemplatesResult,
                 cancellationToken: cancellationToken).ConfigureAwait(false);
 
@@ -303,9 +301,9 @@ public static async Task<IList<Resource>> ListResourcesAsync(
         do
         {
             var resourceResults = await client.SendRequestAsync(
-                RequestMethods.ResourcesList, 
-                CreateCursorDictionary(cursor)!,
-                McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+                RequestMethods.ResourcesList,
+                new() { Cursor = cursor },
+                McpJsonUtilities.JsonContext.Default.ListResourcesRequestParams,
                 McpJsonUtilities.JsonContext.Default.ListResourcesResult,
                 cancellationToken: cancellationToken).ConfigureAwait(false);
 
@@ -344,9 +342,9 @@ public static async IAsyncEnumerable<Resource> EnumerateResourcesAsync(
         do
         {
             var resourceResults = await client.SendRequestAsync(
-                RequestMethods.ResourcesList, 
-                CreateCursorDictionary(cursor)!,
-                McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+                RequestMethods.ResourcesList,
+                new() { Cursor = cursor },
+                McpJsonUtilities.JsonContext.Default.ListResourcesRequestParams,
                 McpJsonUtilities.JsonContext.Default.ListResourcesResult,
                 cancellationToken: cancellationToken).ConfigureAwait(false);
 
@@ -373,9 +371,9 @@ public static Task<ReadResourceResult> ReadResourceAsync(
         Throw.IfNullOrWhiteSpace(uri);
 
         return client.SendRequestAsync(
-            RequestMethods.ResourcesRead, 
-            new Dictionary<string, object> { ["uri"] = uri },
-            McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+            RequestMethods.ResourcesRead,
+            new() { Uri = uri },
+            McpJsonUtilities.JsonContext.Default.ReadResourceRequestParams,
             McpJsonUtilities.JsonContext.Default.ReadResourceResult,
             cancellationToken: cancellationToken);
     }
@@ -400,13 +398,13 @@ public static Task<CompleteResult> GetCompletionAsync(this IMcpClient client, Re
         }
 
         return client.SendRequestAsync(
-            RequestMethods.CompletionComplete, 
-            new Dictionary<string, object>
+            RequestMethods.CompletionComplete,
+            new()
             {
-                ["ref"] = reference,
-                ["argument"] = new Argument { Name = argumentName, Value = argumentValue }
+                Ref = reference,
+                Argument = new Argument { Name = argumentName, Value = argumentValue }
             },
-            McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+            McpJsonUtilities.JsonContext.Default.CompleteRequestParams,
             McpJsonUtilities.JsonContext.Default.CompleteResult,
             cancellationToken: cancellationToken);
     }
@@ -423,9 +421,9 @@ public static Task SubscribeToResourceAsync(this IMcpClient client, string uri,
         Throw.IfNullOrWhiteSpace(uri);
 
         return client.SendRequestAsync(
-            RequestMethods.ResourcesSubscribe, 
-            new Dictionary<string, object> { ["uri"] = uri },
-            McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+            RequestMethods.ResourcesSubscribe,
+            new() { Uri = uri },
+            McpJsonUtilities.JsonContext.Default.SubscribeRequestParams,
             McpJsonUtilities.JsonContext.Default.EmptyResult,
             cancellationToken: cancellationToken);
     }
@@ -443,8 +441,8 @@ public static Task UnsubscribeFromResourceAsync(this IMcpClient client, string u
 
         return client.SendRequestAsync(
             RequestMethods.ResourcesUnsubscribe,
-            new Dictionary<string, object> { ["uri"] = uri },
-            McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+            new() { Uri = uri },
+            McpJsonUtilities.JsonContext.Default.UnsubscribeRequestParams,
             McpJsonUtilities.JsonContext.Default.EmptyResult,
             cancellationToken: cancellationToken);
     }
@@ -473,7 +471,7 @@ public static Task<CallToolResponse> CallToolAsync(
         var parametersTypeInfo = serializerOptions.GetTypeInfo<IReadOnlyDictionary<string, object?>>();
 
         return client.SendRequestAsync(
-            RequestMethods.ToolsCall, 
+            RequestMethods.ToolsCall,
             CreateParametersDictionary(toolName, arguments),
             parametersTypeInfo,
             McpJsonUtilities.JsonContext.Default.CallToolResponse,
@@ -629,15 +627,12 @@ public static Task SetLoggingLevel(this IMcpClient client, LoggingLevel level, C
 
         return client.SendRequestAsync(
             RequestMethods.LoggingSetLevel,
-            new Dictionary<string, object> { ["level"] = level },
-            McpJsonUtilities.JsonContext.Default.DictionaryStringObject,
+            new() { Level = level },
+            McpJsonUtilities.JsonContext.Default.SetLevelRequestParams,
             McpJsonUtilities.JsonContext.Default.EmptyResult,
             cancellationToken: cancellationToken);
     }
 
-    private static Dictionary<string, object?>? CreateCursorDictionary(string? cursor) =>
-        cursor != null ? new() { ["cursor"] = cursor } : null;
-
     private static Dictionary<string, object?> CreateParametersDictionary(
         string nameParameter, IReadOnlyDictionary<string, object?>? arguments)
     {

src/ModelContextProtocol/Protocol/Types/CallToolRequestParams.cs

@@ -18,5 +18,5 @@ public class CallToolRequestParams : RequestParams
     /// Optional arguments to pass to the tool.
     /// </summary>
     [System.Text.Json.Serialization.JsonPropertyName("arguments")]
-    public Dictionary<string, JsonElement>? Arguments { get; init; }
+    public IReadOnlyDictionary<string, JsonElement>? Arguments { get; init; }
 }

src/ModelContextProtocol/Protocol/Types/GetPromptRequestParams.cs

@@ -16,5 +16,5 @@ public class GetPromptRequestParams : RequestParams
     /// Arguments to use for templating the prompt.
     /// </summary>
     [System.Text.Json.Serialization.JsonPropertyName("arguments")]
-    public Dictionary<string, object>? Arguments { get; init; }
+    public IReadOnlyDictionary<string, object?>? Arguments { get; init; }
 }

tests/ModelContextProtocol.Tests/Client/McpClientExtensionsTests.cs

@@ -340,15 +340,6 @@ public async Task SendNotificationAsync_HonorsJsonSerializerOptions()
         await Assert.ThrowsAsync<NotSupportedException>(() => client.SendNotificationAsync("Method4", new { Value = 42 }, emptyOptions, cancellationToken: TestContext.Current.CancellationToken));
     }
 
-    [Fact]
-    public async Task GetPromptsAsync_HonorsJsonSerializerOptions()
-    {
-        JsonSerializerOptions emptyOptions = new() { TypeInfoResolver = JsonTypeInfoResolver.Combine() };
-        IMcpClient client = await CreateMcpClientForServer();
-
-        await Assert.ThrowsAsync<NotSupportedException>(() => client.GetPromptAsync("Prompt", new Dictionary<string, object?> { ["i"] = 42 }, emptyOptions, cancellationToken: TestContext.Current.CancellationToken));
-    }
-
     [Fact]
     public async Task WithName_ChangesToolName()
     {