Fix core build breaks

Author: mikekistler

samples/EverythingServer/Tools/SampleLlmTool.cs

@@ -15,7 +15,7 @@ public static async Task<string> SampleLLM(
         CancellationToken cancellationToken)
     {
         var samplingParams = CreateRequestSamplingParams(prompt ?? string.Empty, "sampleLLM", maxTokens);
-        var sampleResult = await server.SampleAsync(samplingParams, cancellationToken);
+        var sampleResult = await server.SampleAsync(samplingParams, meta: null, cancellationToken);
 
         return $"LLM sampling result: {sampleResult.Content.OfType<TextContentBlock>().FirstOrDefault()?.Text}";
     }

samples/TestServerWithHosting/Tools/SampleLlmTool.cs

@@ -18,7 +18,7 @@ public static async Task<string> SampleLLM(
         CancellationToken cancellationToken)
     {
         var samplingParams = CreateRequestSamplingParams(prompt ?? string.Empty, "sampleLLM", maxTokens);
-        var sampleResult = await thisServer.SampleAsync(samplingParams, cancellationToken);
+        var sampleResult = await thisServer.SampleAsync(samplingParams, meta: null, cancellationToken);
 
         return $"LLM sampling result: {sampleResult.Content.OfType<TextContentBlock>().FirstOrDefault()?.Text}";
     }

src/ModelContextProtocol.Core/Server/McpServer.Methods.cs

@@ -488,7 +488,7 @@ private sealed class SamplingChatClient(McpServer server) : IChatClient
 
         /// <inheritdoc/>
         public Task<ChatResponse> GetResponseAsync(IEnumerable<ChatMessage> messages, ChatOptions? options = null, CancellationToken cancellationToken = default) =>
-            _server.SampleAsync(messages, options, cancellationToken);
+            _server.SampleAsync(messages, options, meta: null, cancellationToken);
 
         /// <inheritdoc/>
         async IAsyncEnumerable<ChatResponseUpdate> IChatClient.GetStreamingResponseAsync(

src/ModelContextProtocol.Core/Server/McpServerOptions.cs

@@ -158,7 +158,7 @@ public McpServerHandlers Handlers
     /// </summary>
     /// <remarks>
     /// <para>
-    /// This value is used in <see cref="McpServer.SampleAsync(IEnumerable{Microsoft.Extensions.AI.ChatMessage}, Microsoft.Extensions.AI.ChatOptions?, CancellationToken)"/>
+    /// This value is used in <see cref="McpServer.SampleAsync(IEnumerable{Microsoft.Extensions.AI.ChatMessage}, Microsoft.Extensions.AI.ChatOptions?, System.Text.Json.Nodes.JsonObject?, CancellationToken)"/>
     /// when <see cref="Microsoft.Extensions.AI.ChatOptions.MaxOutputTokens"/> is not set in the request options.
     /// </para>
     /// <para>

src/ModelContextProtocol.Core/TokenProgress.cs

@@ -11,6 +11,6 @@ internal sealed class TokenProgress(McpSession session, ProgressToken progressTo
     /// <inheritdoc />
     public void Report(ProgressNotificationValue value)
     {
-        _ = session.NotifyProgressAsync(progressToken, value, CancellationToken.None);
+        _ = session.NotifyProgressAsync(progressToken, value, meta: null, CancellationToken.None);
     }
 }

tests/ModelContextProtocol.TestServer/Program.cs

@@ -193,7 +193,7 @@ private static void ConfigureTools(McpServerOptions options, string? cliArg)
                     throw new McpProtocolException("Missing required arguments 'prompt' and 'maxTokens'", McpErrorCode.InvalidParams);
                 }
                 var sampleResult = await request.Server.SampleAsync(CreateRequestSamplingParams(prompt.ToString(), "sampleLLM", Convert.ToInt32(maxTokens.GetRawText())),
-                    cancellationToken);
+                    meta: null, cancellationToken);
 
                 return new CallToolResult
                 {

tests/ModelContextProtocol.TestSseServer/Program.cs

@@ -187,7 +187,7 @@ static CreateMessageRequestParams CreateRequestSamplingParams(string context, st
                         throw new McpProtocolException("Missing required arguments 'prompt' and 'maxTokens'", McpErrorCode.InvalidParams);
                     }
                     var sampleResult = await request.Server.SampleAsync(CreateRequestSamplingParams(prompt.ToString(), "sampleLLM", Convert.ToInt32(maxTokens.ToString())),
-                        cancellationToken);
+                        meta: null, cancellationToken);
 
                     return new CallToolResult
                     {