Authorization Support (Using ASP.NET Core Native AuthN/AuthZ Integration) (#377)

samples/ProtectedMCPServer/Tools/HttpClientExt.cs

@@ -0,0 +1,13 @@
+using System.Text.Json;
+
+namespace ModelContextProtocol;
+
+internal static class HttpClientExt
+{
+    public static async Task<JsonDocument> ReadJsonDocumentAsync(this HttpClient client, string requestUri)
+    {
+        using var response = await client.GetAsync(requestUri);
+        response.EnsureSuccessStatusCode();
+        return await JsonDocument.ParseAsync(await response.Content.ReadAsStreamAsync());
+    }
+}

samples/ProtectedMCPServer/Tools/WeatherTools.cs

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+using ModelContextProtocol;
+using ModelContextProtocol.Server;
+using System.ComponentModel;
+using System.Globalization;
+using System.Text.Json;
+
+namespace ProtectedMCPServer.Tools;
+
+[McpServerToolType]
+public sealed class WeatherTools
+{
+    private readonly IHttpClientFactory _httpClientFactory;
+
+    public WeatherTools(IHttpClientFactory httpClientFactory)
+    {
+        _httpClientFactory = httpClientFactory;
+    }
+
+    [McpServerTool, Description("Get weather alerts for a US state.")]
+    public async Task<string> GetAlerts(
+        [Description("The US state to get alerts for. Use the 2 letter abbreviation for the state (e.g. NY).")] string state)
+    {
+        var client = _httpClientFactory.CreateClient("WeatherApi");
+        using var jsonDocument = await client.ReadJsonDocumentAsync($"/alerts/active/area/{state}");
+        var jsonElement = jsonDocument.RootElement;
+        var alerts = jsonElement.GetProperty("features").EnumerateArray();
+
+        if (!alerts.Any())
+        {
+            return "No active alerts for this state.";
+        }
+
+        return string.Join("\n--\n", alerts.Select(alert =>
+        {
+            JsonElement properties = alert.GetProperty("properties");
+            return $"""
+                    Event: {properties.GetProperty("event").GetString()}
+                    Area: {properties.GetProperty("areaDesc").GetString()}
+                    Severity: {properties.GetProperty("severity").GetString()}
+                    Description: {properties.GetProperty("description").GetString()}
+                    Instruction: {properties.GetProperty("instruction").GetString()}
+                    """;
+        }));
+    }
+
+    [McpServerTool, Description("Get weather forecast for a location.")]
+    public async Task<string> GetForecast(
+        [Description("Latitude of the location.")] double latitude,
+        [Description("Longitude of the location.")] double longitude)
+    {
+        var client = _httpClientFactory.CreateClient("WeatherApi");
+        var pointUrl = string.Create(CultureInfo.InvariantCulture, $"/points/{latitude},{longitude}");
+        using var jsonDocument = await client.ReadJsonDocumentAsync(pointUrl);
+        var forecastUrl = jsonDocument.RootElement.GetProperty("properties").GetProperty("forecast").GetString()
+            ?? throw new Exception($"No forecast URL provided by {client.BaseAddress}points/{latitude},{longitude}");
+
+        using var forecastDocument = await client.ReadJsonDocumentAsync(forecastUrl);
+        var periods = forecastDocument.RootElement.GetProperty("properties").GetProperty("periods").EnumerateArray();
+
+        return string.Join("\n---\n", periods.Select(period => $"""
+                {period.GetProperty("name").GetString()}
+                Temperature: {period.GetProperty("temperature").GetInt32()}°F
+                Wind: {period.GetProperty("windSpeed").GetString()} {period.GetProperty("windDirection").GetString()}
+                Forecast: {period.GetProperty("detailedForecast").GetString()}
+                """));
+    }
+}