Added a property (TokenTypeHint) to the options class. The property has access token as default value for backward compatibility.

Author: mikaelstrid

src/IdentityModel.AspNetCore.OAuth2Introspection/OAuth2IntrospectionHandler.cs

@@ -144,7 +144,7 @@ private async Task<IntrospectionResponse> LoadClaimsForToken(string token)
             return await introspectionClient.SendAsync(new IntrospectionRequest
             {
                 Token = token,
-                TokenTypeHint = OidcConstants.TokenTypes.AccessToken,
+                TokenTypeHint = Options.TokenTypeHint,
                 ClientId = Options.ClientId,
                 ClientSecret = Options.ClientSecret
             }).ConfigureAwait(false);

src/IdentityModel.AspNetCore.OAuth2Introspection/OAuth2IntrospectionOptions.cs

@@ -9,6 +9,7 @@
 using IdentityModel.Client;
 using IdentityModel.AspNetCore.OAuth2Introspection.Infrastructure;
 using System.Collections.Concurrent;
+using IdentityModel;
 
 namespace Microsoft.AspNetCore.Builder
 {
@@ -39,6 +40,11 @@ public class OAuth2IntrospectionOptions : AuthenticationSchemeOptions
         /// </summary>
         public string ClientSecret { get; set; }
 
+        /// <summary>
+        /// Specifies the token type hint of the introspection client.
+        /// </summary>
+        public string TokenTypeHint { get; set; } = OidcConstants.TokenTypes.AccessToken;
+
         /// <summary>
         /// Specifies the claim type to use for the name claim (defaults to 'name')
         /// </summary>