diff --git a/MCPify/Core/McpifyOptions.cs b/MCPify/Core/McpifyOptions.cs
index c769539..0b728c0 100644
--- a/MCPify/Core/McpifyOptions.cs
+++ b/MCPify/Core/McpifyOptions.cs
@@ -64,6 +64,11 @@ public class McpifyOptions
     /// Defaults to <see cref="BrowserLaunchBehavior.Auto"/> which detects headless environments at runtime.
     /// </summary>
     public BrowserLaunchBehavior LoginBrowserBehavior { get; set; } = BrowserLaunchBehavior.Auto;
+    
+    /// <summary>
+    /// Optional list of OAuth2 configurations to be added to the OAuthConfigurationStore.
+    /// </summary>
+    public List<OAuth2Configuration> OAuthConfigurations { get; set; } = new();
 }
 
 /// <summary>
diff --git a/MCPify/Hosting/McpOAuthAuthenticationMiddleware.cs b/MCPify/Hosting/McpOAuthAuthenticationMiddleware.cs
index ffd3885..ed5c35c 100644
--- a/MCPify/Hosting/McpOAuthAuthenticationMiddleware.cs
+++ b/MCPify/Hosting/McpOAuthAuthenticationMiddleware.cs
@@ -63,7 +63,7 @@ public async Task InvokeAsync(HttpContext context)
 
             context.Response.StatusCode = StatusCodes.Status401Unauthorized;
             context.Response.Headers[HeaderNames.WWWAuthenticate] = 
-                $"Bearer realm=\"MCPify\", resource=\"{resourceUrl}\", resource_metadata_url=\"{metadataUrl}\"";
+                $"Bearer realm=\"MCPify\", resource=\"{resourceUrl}\", resource_metadata=\"{metadataUrl}\"";
             
             return;
         }
diff --git a/MCPify/Hosting/McpifyEndpointExtensions.cs b/MCPify/Hosting/McpifyEndpointExtensions.cs
index c01e37f..9837f3b 100644
--- a/MCPify/Hosting/McpifyEndpointExtensions.cs
+++ b/MCPify/Hosting/McpifyEndpointExtensions.cs
@@ -129,27 +129,29 @@ string BaseUrlProvider()
 
             static IEnumerable<string> ResolveAuthorizationServers(OAuth2Configuration config)
             {
-                if (config.AuthorizationServers.Count > 0)
-                {
-                    foreach (var server in config.AuthorizationServers)
-                    {
-                        yield return server;
-                    }
-
-                    yield break;
-                }
-
                 if (Uri.TryCreate(config.AuthorizationUrl, UriKind.Absolute, out var uri))
                 {
                     yield return uri.GetLeftPart(UriPartial.Authority);
                 }
             }
 
-            // Prefer explicitly configured authorization servers, fall back to derived authorities.
-            var issuers = configs
-                .SelectMany(ResolveAuthorizationServers)
-                .Distinct(StringComparer.OrdinalIgnoreCase)
-                .ToList();
+            // If any config has AuthorizationServers, only use those; otherwise, fall back to AuthorizationUrl authority.
+            List<string> issuers;
+            if (configs.Any(c => c.AuthorizationServers?.Any() == true))
+            {
+                issuers = configs
+                    .Where(c => c.AuthorizationServers?.Any() == true)
+                    .SelectMany(c => c.AuthorizationServers)
+                    .Distinct(StringComparer.OrdinalIgnoreCase)
+                    .ToList();
+            }
+            else
+            {
+                issuers = configs
+                    .SelectMany(ResolveAuthorizationServers)
+                    .Distinct(StringComparer.OrdinalIgnoreCase)
+                    .ToList();
+            }
 
             return Results.Ok(new
             {
diff --git a/MCPify/Hosting/McpifyServiceExtensions.cs b/MCPify/Hosting/McpifyServiceExtensions.cs
index 23a57c1..b79f0a2 100644
--- a/MCPify/Hosting/McpifyServiceExtensions.cs
+++ b/MCPify/Hosting/McpifyServiceExtensions.cs
@@ -95,7 +95,13 @@ public static IServiceCollection AddMcpify(
         });
 
         services.AddSingleton<OpenApiOAuthParser>();
-        services.AddSingleton<OAuthConfigurationStore>();
+
+        var oauthStore = new OAuthConfigurationStore();
+        foreach (var config in opts.OAuthConfigurations)
+        {
+            oauthStore.AddConfiguration(config);
+        }
+        services.AddSingleton(oauthStore);
 
         return services;
     }
diff --git a/Sample/README.md b/Sample/README.md
index 3a874f6..bf13419 100644
--- a/Sample/README.md
+++ b/Sample/README.md
@@ -80,7 +80,7 @@ To run the server in HTTP mode (using Server-Sent Events):
 
 This sample demonstrates how clients can authenticate with MCPify using OAuth 2.0 Authorization Code flow.
 
-1.  **Discover Authentication**: When an unauthenticated client attempts to use a protected tool (e.g., `api_secrets_get`), MCPify will respond with a `401 Unauthorized` HTTP status code and a `WWW-Authenticate` header, including `resource_metadata_url`. The client should then fetch this metadata.
+1.  **Discover Authentication**: When an unauthenticated client attempts to use a protected tool (e.g., `api_secrets_get`), MCPify will respond with a `401 Unauthorized` HTTP status code and a `WWW-Authenticate` header, including `resource_metadata`. The client should then fetch this metadata.
 2.  **Initiate Login**: The client (e.g., Claude Desktop) will call the `login_auth_code_pkce` tool provided by MCPify. This tool returns an authorization URL.
 3.  **User Authorization**: The user opens the authorization URL in a browser, logs in (using the OpenIddict provider in this sample), and grants consent.
 4.  **Callback and Token Exchange**: After user authorization, the browser redirects to MCPify's callback endpoint (`/auth/callback`). MCPify handles the code exchange and stores the token securely for the specific session.
diff --git a/Tests/MCPify.Tests/Integration/OAuthMiddlewareTests.cs b/Tests/MCPify.Tests/Integration/OAuthMiddlewareTests.cs
index 37653ac..04cfe31 100644
--- a/Tests/MCPify.Tests/Integration/OAuthMiddlewareTests.cs
+++ b/Tests/MCPify.Tests/Integration/OAuthMiddlewareTests.cs
@@ -29,7 +29,7 @@ public async Task Request_Returns401_WhenNoToken_And_OAuthConfigured()
         Assert.Equal(HttpStatusCode.Unauthorized, response.StatusCode);
         Assert.Contains("WWW-Authenticate", response.Headers.ToDictionary(h => h.Key, h => string.Join(", ", h.Value)).Keys);
         var authHeader = response.Headers.WwwAuthenticate.ToString();
-        Assert.Contains("resource_metadata_url", authHeader);
+        Assert.Contains("resource_metadata", authHeader);
     }
 
     [Fact]
@@ -53,7 +53,7 @@ public async Task Request_Challenge_UsesResourceOverride()
         Assert.Equal(HttpStatusCode.Unauthorized, response.StatusCode);
         var authHeader = response.Headers.WwwAuthenticate.ToString();
         Assert.Contains($"resource=\"{publicUrl}\"", authHeader);
-        Assert.Contains($"resource_metadata_url=\"{publicUrl}/.well-known/oauth-protected-resource\"", authHeader);
+        Assert.Contains($"resource_metadata=\"{publicUrl}/.well-known/oauth-protected-resource\"", authHeader);
     }
 
     [Fact]