Add ModelContextProtocol.Core package (#428)

src/ModelContextProtocol.Core/Protocol/Root.cs

@@ -0,0 +1,37 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace ModelContextProtocol.Protocol;
+
+/// <summary>
+/// Represents a root URI and its metadata in the Model Context Protocol.
+/// </summary>
+/// <remarks>
+/// Root URIs serve as entry points for resource navigation, typically representing
+/// top-level directories or container resources that can be accessed and traversed.
+/// Roots provide a hierarchical structure for organizing and accessing resources within the protocol.
+/// Each root has a URI that uniquely identifies it and optional metadata like a human-readable name.
+/// </remarks>
+public class Root
+{
+    /// <summary>
+    /// Gets or sets the URI of the root.
+    /// </summary>
+    [JsonPropertyName("uri")]
+    public required string Uri { get; init; }
+
+    /// <summary>
+    /// Gets or sets a human-readable name for the root.
+    /// </summary>
+    [JsonPropertyName("name")]
+    public string? Name { get; init; }
+
+    /// <summary>
+    /// Gets or sets additional metadata for the root.
+    /// </summary>
+    /// <remarks>
+    /// This is reserved by the protocol for future use.
+    /// </remarks>
+    [JsonPropertyName("meta")]
+    public JsonElement? Meta { get; init; }
+}