From 51f6794b96b997cfbf4ffbb391d527382f2b8ffd Mon Sep 17 00:00:00 2001
From: Stephen Toub <stoub@microsoft.com>
Date: Thu, 5 Jun 2025 15:26:05 -0700
Subject: [PATCH] Add context to complete requests

---
 .../Protocol/CompleteContext.cs               | 19 +++++++++++++++++++
 .../Protocol/CompleteRequestParams.cs         |  8 +++++++-
 2 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 src/ModelContextProtocol.Core/Protocol/CompleteContext.cs

diff --git a/src/ModelContextProtocol.Core/Protocol/CompleteContext.cs b/src/ModelContextProtocol.Core/Protocol/CompleteContext.cs
new file mode 100644
index 00000000..eda5a50c
--- /dev/null
+++ b/src/ModelContextProtocol.Core/Protocol/CompleteContext.cs
@@ -0,0 +1,19 @@
+using System.Text.Json.Serialization;
+
+namespace ModelContextProtocol.Protocol;
+
+/// <summary>
+/// Represents additional context information for completion requests.
+/// </summary>
+/// <remarks>
+/// This context provides information that helps the server generate more relevant 
+/// completion suggestions, such as previously resolved variables in a template.
+/// </remarks>
+public class CompleteContext
+{
+    /// <summary>
+    /// Gets or sets previously-resolved variables in a URI template or prompt.
+    /// </summary>
+    [JsonPropertyName("arguments")]
+    public IDictionary<string, string>? Arguments { get; init; }
+}
diff --git a/src/ModelContextProtocol.Core/Protocol/CompleteRequestParams.cs b/src/ModelContextProtocol.Core/Protocol/CompleteRequestParams.cs
index a64d2a55..1514ad3d 100644
--- a/src/ModelContextProtocol.Core/Protocol/CompleteRequestParams.cs
+++ b/src/ModelContextProtocol.Core/Protocol/CompleteRequestParams.cs
@@ -30,5 +30,11 @@ public class CompleteRequestParams : RequestParams
     /// and the current partial input.
     /// </summary>
     [JsonPropertyName("argument")]
-    public required Argument Argument { get; init; }    
+    public required Argument Argument { get; init; }
+
+    /// <summary>
+    /// Gets or sets additional, optional context for completions.
+    /// </summary>
+    [JsonPropertyName("context")]
+    public CompleteContext? Context { get; init; }
 }