Changed IServiceProvider in CommandService.ExecuteAsync to a scoped provider. Added a command context accessor, and setting the value before beginning the execute. This will allow injected services in modules to access the current command context. This mirrors the behavior of Asp.Net Core's HttpContextAccessor.

src/Discord.Net.Commands/CommandService.cs

@@ -1,3 +1,6 @@
+using Discord.Commands.Builders;
+using Discord.Logging;
+using Microsoft.Extensions.DependencyInjection;
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -350,8 +353,25 @@ namespace Discord.Commands
             => ExecuteAsync(context, context.Message.Content.Substring(argPos), services, multiMatchHandling);
         public async Task<IResult> ExecuteAsync(ICommandContext context, string input, IServiceProvider services, MultiMatchHandling multiMatchHandling = MultiMatchHandling.Exception)
         {
+            // Create service scope and command context so dependent services can consume the command context, with a scoped lifespan
             services = services ?? EmptyServiceProvider.Instance;
+            using (var serviceScope = services.CreateScope())
+            {
+                var scopedServices = serviceScope.ServiceProvider;
 
+                // If the context accessor is registered in the IoC container, set it
+                var contextAccessor = scopedServices.GetService<ICommandContextAccessor>();
+                if (contextAccessor != null)
+                {
+                    contextAccessor.CommandContext = context;
+                }
+                return await ExecuteAsyncInternal(context, input, scopedServices, multiMatchHandling);
+            }
+        }
+
+        internal async Task<IResult> ExecuteAsyncInternal(ICommandContext context, string input,
+            IServiceProvider services, MultiMatchHandling multiMatchHandling = MultiMatchHandling.Exception)
+        {
             var searchResult = Search(input);
             if (!searchResult.IsSuccess)
                 return searchResult;

src/Discord.Net.Core/Commands/CommandContextAccessor.cs

@@ -0,0 +1,16 @@
+using System.Threading;
+
+namespace Discord.Commands
+{
+    public class CommandContextAccessor : ICommandContextAccessor
+    {
+        private static AsyncLocal<ICommandContext> _commandContextCurrent = new AsyncLocal<ICommandContext>();
+
+        public ICommandContext CommandContext
+        {
+            get => _commandContextCurrent.Value;
+            set => _commandContextCurrent.Value = value;
+        }
+
+    }
+}

src/Discord.Net.Core/Commands/ICommandContextAccessor.cs

@@ -0,0 +1,7 @@
+namespace Discord.Commands
+{
+    public interface ICommandContextAccessor
+    {
+        ICommandContext CommandContext { get; set; }
+    }
+}