add redoc

Jellyfin.Api/Jellyfin.Api.csproj

@@ -10,7 +10,8 @@
     <PackageReference Include="Microsoft.AspNetCore.Authentication" Version="2.2.0" />
     <PackageReference Include="Microsoft.AspNetCore.Authorization" Version="3.1.3" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.2.0" />
-    <PackageReference Include="Swashbuckle.AspNetCore" Version="5.0.0" />
+    <PackageReference Include="Swashbuckle.AspNetCore" Version="5.3.2" />
+    <PackageReference Include="Swashbuckle.AspNetCore.ReDoc" Version="5.3.2" />
   </ItemGroup>
 
   <ItemGroup>

Jellyfin.Server/Extensions/ApiApplicationBuilderExtensions.cs

@@ -14,14 +14,18 @@ namespace Jellyfin.Server.Extensions
         /// <returns>The updated application builder.</returns>
         public static IApplicationBuilder UseJellyfinApiSwagger(this IApplicationBuilder applicationBuilder)
         {
-            applicationBuilder.UseSwagger();
-
             // Enable middleware to serve swagger-ui (HTML, JS, CSS, etc.),
             // specifying the Swagger JSON endpoint.
-            return applicationBuilder.UseSwaggerUI(c =>
-            {
-                c.SwaggerEndpoint("/swagger/v1/swagger.json", "Jellyfin API V1");
-            });
+            const string specEndpoint = "/swagger/v1/swagger.json";
+            return applicationBuilder.UseSwagger()
+                .UseSwaggerUI(c =>
+                {
+                    c.SwaggerEndpoint(specEndpoint, "Jellyfin API V1");
+                })
+                .UseReDoc(c =>
+                {
+                    c.SpecUrl(specEndpoint);
+                });
         }
     }
 }