diff --git a/src/Wumpus.Net.Rest/Net/IDiscordRestApi.cs b/src/Wumpus.Net.Rest/Net/IDiscordRestApi.cs
index 5088bb0..de8a64a 100644
--- a/src/Wumpus.Net.Rest/Net/IDiscordRestApi.cs
+++ b/src/Wumpus.Net.Rest/Net/IDiscordRestApi.cs
@@ -43,9 +43,9 @@ internal interface IDiscordRestApi : IDisposable
         ///     If modifying a category, individual Channel Update events will fire for each child channel that also changes.
         /// </summary>
         [Patch("channels/{channelId}")]
-        Task<Channel> ModifyChannelAsync([Path] Snowflake channelId, [Body] ModifyChannelParams args);
+        Task<Channel> ModifyChannelAsync([Path] Snowflake channelId, [Body] ModifyChannelParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Delete("channels/{channelId}")]
-        Task<Channel> DeleteChannelAsync([Path] Snowflake channelId);
+        Task<Channel> DeleteChannelAsync([Path] Snowflake channelId, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
 
         /// <summary>
         ///     Returns the <see cref="Entities.Message"/> for a <see cref="Entities.Channel"/>. If operating on a <see cref="Entities.Guild"/> <see cref="Entities.Channel"/>, this endpoint requires the <see cref="Entities.ChannelPermissions.ViewChannel"/> to be present on the current <see cref="Entities.User"/>.
@@ -68,7 +68,7 @@ internal interface IDiscordRestApi : IDisposable
         [Patch("channels/{channelId}/messages/{messageId}")]
         Task<Message> ModifyMessageAsync([Path] Snowflake channelId, [Path] Snowflake messageId, [Body] ModifyMessageParams args);
         [Delete("channels/{channelId}/messages/{messageId}")]
-        Task DeleteMessageAsync([Path] Snowflake channelId, [Path] Snowflake messageId);
+        Task DeleteMessageAsync([Path] Snowflake channelId, [Path] Snowflake messageId, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Post("channels/{channelId}/messages/bulk-delete")]
         Task DeleteMessagesAsync([Path] Snowflake channelId, [Body] DeleteMessagesParams args);
 
@@ -84,9 +84,9 @@ internal interface IDiscordRestApi : IDisposable
         Task DeleteAllReactionsAsync([Path] Snowflake channelId, [Path] Snowflake messageId);
 
         [Put("channels/{channelId}/permissions/{overwriteId}")]
-        Task EditChannelPermissionsAsync([Path] Snowflake channelId, [Path] Snowflake overwriteId, [Body] ModifyChannelPermissionsParams args);
+        Task EditChannelPermissionsAsync([Path] Snowflake channelId, [Path] Snowflake overwriteId, [Body] ModifyChannelPermissionsParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Delete("channels/{channelId}/permissions/{overwriteId}")]
-        Task DeleteChannelPermissionsAsync([Path] Snowflake channelId, [Path] Snowflake overwriteId);
+        Task DeleteChannelPermissionsAsync([Path] Snowflake channelId, [Path] Snowflake overwriteId, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
 
         [Get("channels/{channelId}/invites")]
         Task<Invite[]> GetChannelInvitesAsync([Path] Snowflake channelId);
@@ -115,11 +115,11 @@ internal interface IDiscordRestApi : IDisposable
         [Get("guilds/{guildId}/emoji/{emojiId}")]
         Task<Emoji> GetGuildEmojiAsync([Path] Snowflake guildId, [Path] Snowflake emojiId);
         [Post("guilds/{guildId}/emojis")]
-        Task<Emoji> CreateGuildEmojiAsync([Path] Snowflake guildId, [Body] CreateGuildEmojiParams args);
+        Task<Emoji> CreateGuildEmojiAsync([Path] Snowflake guildId, [Body] CreateGuildEmojiParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Patch("guilds/{guildId}/emoji/{emojiId}")]
-        Task<Emoji> ModifyGuildEmojiAsync([Path] Snowflake guildId, [Path] Snowflake emojiId, [Body] ModifyGuildEmojiParams args);
+        Task<Emoji> ModifyGuildEmojiAsync([Path] Snowflake guildId, [Path] Snowflake emojiId, [Body] ModifyGuildEmojiParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Delete("guilds/{guildId}/emoji/{emojiId}")]
-        Task DeleteGuildEmojiAsync([Path] Snowflake guildId, [Path] Snowflake emojiId);
+        Task DeleteGuildEmojiAsync([Path] Snowflake guildId, [Path] Snowflake emojiId, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
 
         // Gateway
 
@@ -135,14 +135,14 @@ internal interface IDiscordRestApi : IDisposable
         [Post("guilds")]
         Task<Guild> CreateGuildAsync([Body] CreateGuildParams args);
         [Patch("guilds/{guildId}")]
-        Task<Guild> ModifyGuildAsync([Path] Snowflake guildId, [Body] ModifyGuildParams args);
+        Task<Guild> ModifyGuildAsync([Path] Snowflake guildId, [Body] ModifyGuildParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Delete("guilds/{guildId}")]
         Task DeleteGuildAsync([Path] Snowflake guildId);
 
         [Get("guilds/{guildId}/channels")]
         Task<Channel[]> GetGuildChannelsAsync([Path] Snowflake guildId);
         [Post("guilds/{guildId}/channels")]
-        Task<Channel> CreateGuildChannelAsync([Path] Snowflake guildId, [Body] CreateGuildChannelParams args);
+        Task<Channel> CreateGuildChannelAsync([Path] Snowflake guildId, [Body] CreateGuildChannelParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Patch("guilds/{guildId}/channels")]
         Task<Channel[]> ModifyGuildChannelPositionsAsync([Path] Snowflake guildId, [Body] ModifyGuildChannelPositionParams[] args);
 
@@ -153,7 +153,7 @@ internal interface IDiscordRestApi : IDisposable
         [Put("guilds/{guildId}/members/{userId}")]
         Task<GuildMember> AddGuildMemberAsync([Path] Snowflake guildId, [Path] Snowflake userId, [Body] AddGuildMemberParams args);
         [Delete("guilds/{guildId}/members/{userId}")]
-        Task RemoveGuildMemberAsync([Path] Snowflake guildId, [Path] Snowflake userId);
+        Task RemoveGuildMemberAsync([Path] Snowflake guildId, [Path] Snowflake userId, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Patch("guilds/{guildId}/members/{userId}")]
         Task ModifyGuildMemberAsync([Path] Snowflake guildId, [Path] Snowflake userId, [Body] ModifyGuildMemberParams args);
         [Patch("guilds/{guildId}/members/@me/nick")]
@@ -167,25 +167,25 @@ internal interface IDiscordRestApi : IDisposable
         [Get("guilds/{guildId}/bans")]
         Task<Ban[]> GetGuildBansAsync([Path] Snowflake guildId);
         [Put("guilds/{guildId}/bans/{userId}")]
-        Task CreateGuildBanAsync([Path] Snowflake guildId, [Path] Snowflake userId, [QueryMap] CreateGuildBanParams args);
+        Task CreateGuildBanAsync([Path] Snowflake guildId, [Path] Snowflake userId, [QueryMap] CreateGuildBanParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Delete("guilds/{guildId}/bans/{userId}")]
-        Task DeleteGuildBanAsync([Path] Snowflake guildId, [Path] Snowflake userId);
+        Task DeleteGuildBanAsync([Path] Snowflake guildId, [Path] Snowflake userId, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
 
         [Get("guilds/{guildId}/roles")]
         Task<Role[]> GetGuildRolesAsync([Path] Snowflake guildId);
         [Post("guilds/{guildId}/roles")]
-        Task<Role> CreateGuildRoleAsync([Path] Snowflake guildId, [Body] CreateGuildRoleParams args);
+        Task<Role> CreateGuildRoleAsync([Path] Snowflake guildId, [Body] CreateGuildRoleParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Delete("guilds/{guildId}/roles/{roleId}")]
-        Task<Role> DeleteGuildRoleAsync([Path] Snowflake guildId, [Path] Snowflake roleId);
+        Task<Role> DeleteGuildRoleAsync([Path] Snowflake guildId, [Path] Snowflake roleId, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Patch("guilds/{guildId}/roles/{roleId}")]
-        Task<Role> ModifyGuildRoleAsync([Path] Snowflake guildId, [Path] Snowflake roleId, [Body] ModifyGuildRoleParams args);
+        Task<Role> ModifyGuildRoleAsync([Path] Snowflake guildId, [Path] Snowflake roleId, [Body] ModifyGuildRoleParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Patch("guilds/{guildId}/roles")]
         Task ModifyGuildRolePositionsAsync([Path] Snowflake guildId, [Body] ModifyGuildRolePositionParams[] args);
 
         [Get("guilds/{guildId}/prune")]
         Task<GuildPruneCountResponse> GetGuildPruneCountAsync([Path] Snowflake guildId, [QueryMap] GuildPruneParams args);
         [Post("guilds/{guildId}/prune")]
-        Task<GuildPruneCountResponse> PruneGuildMembersAsync([Path] Snowflake guildId, [QueryMap] GuildPruneParams args);
+        Task<GuildPruneCountResponse> PruneGuildMembersAsync([Path] Snowflake guildId, [QueryMap] GuildPruneParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
 
         [Get("guilds/{guildId}/regions")]
         Task<VoiceRegion[]> GetGuildVoiceRegionsAsync([Path] Snowflake guildId);
@@ -217,7 +217,7 @@ internal interface IDiscordRestApi : IDisposable
         [Get("invites/{code}")]
         Task<Invite> GetInviteAsync([Path] Utf8String code, [QueryMap] GetInviteParams args);
         [Delete("invites/{code}")]
-        Task<Invite> DeleteInviteAsync([Path] Utf8String code);
+        Task<Invite> DeleteInviteAsync([Path] Utf8String code, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
 
         // OAuth
 
@@ -265,19 +265,19 @@ internal interface IDiscordRestApi : IDisposable
         Task<Webhook> GetWebhookAsync([Path] Snowflake webhookId, [Path] Utf8String webhookToken);
 
         [Post("channels/{channelId}/webhooks")]
-        Task<Webhook> CreateWebhookAsync([Path] Snowflake channelId, [Body] CreateWebhookParams args);
+        Task<Webhook> CreateWebhookAsync([Path] Snowflake channelId, [Body] CreateWebhookParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
 
         [Delete("webhooks/{webhookId}")]
-        Task DeleteWebhookAsync([Path] Snowflake webhookId);
+        Task DeleteWebhookAsync([Path] Snowflake webhookId, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Delete("webhooks/{webhookId}/{webhookToken}")]
         [Header("Authorization", null)]
-        Task DeleteWebhookAsync([Path] Snowflake webhookId, [Path] Utf8String webhookToken);
+        Task DeleteWebhookAsync([Path] Snowflake webhookId, [Path] Utf8String webhookToken, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
 
         [Patch("webhooks/{webhookId}")]
-        Task<Webhook> ModifyWebhookAsync([Path] Snowflake webhookId, ModifyWebhookParams args);
+        Task<Webhook> ModifyWebhookAsync([Path] Snowflake webhookId, ModifyWebhookParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
         [Patch("webhooks/{webhookId}/{webhookToken}")]
         [Header("Authorization", null)]
-        Task<Webhook> ModifyWebhookAsync([Path] Snowflake webhookId, [Path] Utf8String webhookToken, ModifyWebhookParams args);
+        Task<Webhook> ModifyWebhookAsync([Path] Snowflake webhookId, [Path] Utf8String webhookToken, ModifyWebhookParams args, [Header(WumpusRestClient.ReasonHeader)] Utf8String reason = null);
 
         [Post("webhooks/{webhookId}/{webhookToken}")]
         [Header("Authorization", null)]
diff --git a/src/Wumpus.Net.Rest/WumpusRestClient.cs b/src/Wumpus.Net.Rest/WumpusRestClient.cs
index 8bbebf0..5575d73 100644
--- a/src/Wumpus.Net.Rest/WumpusRestClient.cs
+++ b/src/Wumpus.Net.Rest/WumpusRestClient.cs
@@ -16,6 +16,11 @@ namespace Wumpus
     public class WumpusRestClient : IDiscordRestApi, IDisposable
     {
         public const int ApiVersion = 6;
+        public const string ReasonHeader = "X-Audit-Log-Reason";
+        /// <summary>
+        ///     The maximum valid length of the audit log reason header string.
+        /// </summary>
+        public const int MaxReasonHeaderLength = 512;
         public static string Version { get; } =
             typeof(WumpusRestClient).GetTypeInfo().Assembly.GetCustomAttribute<AssemblyInformationalVersionAttribute>()?.InformationalVersion ??
             typeof(WumpusRestClient).GetTypeInfo().Assembly.GetName().Version.ToString(3) ??
@@ -64,17 +69,19 @@ public Task<Channel> ReplaceChannelAsync(Snowflake channelId, ModifyChannelParam
             args.Validate();
             return _api.ReplaceChannelAsync(channelId, args);
         }
-        public Task<Channel> ModifyChannelAsync(Snowflake channelId, ModifyChannelParams args)
+        public Task<Channel> ModifyChannelAsync(Snowflake channelId, ModifyChannelParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(channelId, nameof(channelId));
             Preconditions.NotNull(args, nameof(args));
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
             args.Validate();
-            return _api.ModifyChannelAsync(channelId, args);
+            return _api.ModifyChannelAsync(channelId, args, reason);
         }
-        public Task<Channel> DeleteChannelAsync(Snowflake channelId)
+        public Task<Channel> DeleteChannelAsync(Snowflake channelId, Utf8String reason = null)
         {
             Preconditions.NotZero(channelId, nameof(channelId));
-            return _api.DeleteChannelAsync(channelId);
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
+            return _api.DeleteChannelAsync(channelId, reason);
         }
 
         public Task<Message[]> GetChannelMessagesAsync(Snowflake channelId, GetChannelMessagesParams args)
@@ -105,11 +112,12 @@ public Task<Message> ModifyMessageAsync(Snowflake channelId, Snowflake messageId
             args.Validate();
             return _api.ModifyMessageAsync(channelId, messageId, args);
         }
-        public Task DeleteMessageAsync(Snowflake channelId, Snowflake messageId)
+        public Task DeleteMessageAsync(Snowflake channelId, Snowflake messageId, Utf8String reason = null)
         {
             Preconditions.NotZero(channelId, nameof(channelId));
             Preconditions.NotZero(messageId, nameof(messageId));
-            return _api.DeleteMessageAsync(channelId, messageId);
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
+            return _api.DeleteMessageAsync(channelId, messageId, reason);
         }
         public Task DeleteMessagesAsync(Snowflake channelId, DeleteMessagesParams args)
         {
@@ -155,19 +163,21 @@ public Task DeleteAllReactionsAsync(Snowflake channelId, Snowflake messageId)
             return _api.DeleteAllReactionsAsync(channelId, messageId);
         }
 
-        public Task EditChannelPermissionsAsync(Snowflake channelId, Snowflake overwriteId, ModifyChannelPermissionsParams args)
+        public Task EditChannelPermissionsAsync(Snowflake channelId, Snowflake overwriteId, ModifyChannelPermissionsParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(channelId, nameof(channelId));
             Preconditions.NotZero(overwriteId, nameof(overwriteId));
             Preconditions.NotNull(args, nameof(args));
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
             args.Validate();
-            return _api.EditChannelPermissionsAsync(channelId, overwriteId, args);
+            return _api.EditChannelPermissionsAsync(channelId, overwriteId, args, reason);
         }
-        public Task DeleteChannelPermissionsAsync(Snowflake channelId, Snowflake overwriteId)
+        public Task DeleteChannelPermissionsAsync(Snowflake channelId, Snowflake overwriteId, Utf8String reason = null)
         {
             Preconditions.NotZero(channelId, nameof(channelId));
             Preconditions.NotZero(overwriteId, nameof(overwriteId));
-            return _api.DeleteChannelPermissionsAsync(channelId, overwriteId);
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
+            return _api.DeleteChannelPermissionsAsync(channelId, overwriteId, reason);
         }
 
         public Task<Invite[]> GetChannelInvitesAsync(Snowflake channelId)
@@ -235,24 +245,27 @@ public Task<Emoji> GetGuildEmojiAsync(Snowflake guildId, Snowflake emojiId)
             Preconditions.NotZero(emojiId, nameof(emojiId));
             return _api.GetGuildEmojiAsync(guildId, emojiId);
         }
-        public Task<Emoji> CreateGuildEmojiAsync(Snowflake guildId, CreateGuildEmojiParams args)
+        public Task<Emoji> CreateGuildEmojiAsync(Snowflake guildId, CreateGuildEmojiParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(guildId, nameof(guildId));
             Preconditions.NotNull(args, nameof(args));
-            return _api.CreateGuildEmojiAsync(guildId, args);
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
+            return _api.CreateGuildEmojiAsync(guildId, args, reason);
         }
-        public Task<Emoji> ModifyGuildEmojiAsync(Snowflake guildId, Snowflake emojiId, ModifyGuildEmojiParams args)
+        public Task<Emoji> ModifyGuildEmojiAsync(Snowflake guildId, Snowflake emojiId, ModifyGuildEmojiParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(guildId, nameof(guildId));
             Preconditions.NotZero(emojiId, nameof(emojiId));
             Preconditions.NotNull(args, nameof(args));
-            return _api.ModifyGuildEmojiAsync(guildId, emojiId, args);
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
+            return _api.ModifyGuildEmojiAsync(guildId, emojiId, args, reason);
         }
-        public Task DeleteGuildEmojiAsync(Snowflake guildId, Snowflake emojiId)
+        public Task DeleteGuildEmojiAsync(Snowflake guildId, Snowflake emojiId, Utf8String reason = null)
         {
             Preconditions.NotZero(guildId, nameof(guildId));
             Preconditions.NotZero(emojiId, nameof(emojiId));
-            return _api.DeleteGuildEmojiAsync(guildId, emojiId);
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
+            return _api.DeleteGuildEmojiAsync(guildId, emojiId, reason);
         }
 
         // Gateway
@@ -279,12 +292,13 @@ public Task<Guild> CreateGuildAsync(CreateGuildParams args)
             args.Validate();
             return _api.CreateGuildAsync(args);
         }
-        public Task<Guild> ModifyGuildAsync(Snowflake guildId, ModifyGuildParams args)
+        public Task<Guild> ModifyGuildAsync(Snowflake guildId, ModifyGuildParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(guildId, nameof(guildId));
             Preconditions.NotNull(args, nameof(args));
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
             args.Validate();
-            return _api.ModifyGuildAsync(guildId, args);
+            return _api.ModifyGuildAsync(guildId, args, reason);
         }
         public Task DeleteGuildAsync(Snowflake guildId)
         {
@@ -297,12 +311,13 @@ public Task<Channel[]> GetGuildChannelsAsync(Snowflake guildId)
             Preconditions.NotZero(guildId, nameof(guildId));
             return _api.GetGuildChannelsAsync(guildId);
         }
-        public Task<Channel> CreateGuildChannelAsync(Snowflake guildId, CreateGuildChannelParams args)
+        public Task<Channel> CreateGuildChannelAsync(Snowflake guildId, CreateGuildChannelParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(guildId, nameof(guildId));
             Preconditions.NotNull(args, nameof(args));
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
             args.Validate();
-            return _api.CreateGuildChannelAsync(guildId, args);
+            return _api.CreateGuildChannelAsync(guildId, args, reason);
         }
         public Task<Channel[]> ModifyGuildChannelPositionsAsync(Snowflake guildId, ModifyGuildChannelPositionParams[] args)
         {
@@ -334,11 +349,12 @@ public Task<GuildMember> AddGuildMemberAsync(Snowflake guildId, Snowflake userId
             args.Validate();
             return _api.AddGuildMemberAsync(guildId, userId, args);
         }
-        public Task RemoveGuildMemberAsync(Snowflake guildId, Snowflake userId)
+        public Task RemoveGuildMemberAsync(Snowflake guildId, Snowflake userId, Utf8String reason = null)
         {
             Preconditions.NotZero(guildId, nameof(guildId));
             Preconditions.NotZero(userId, nameof(userId));
-            return _api.RemoveGuildMemberAsync(guildId, userId);
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
+            return _api.RemoveGuildMemberAsync(guildId, userId, reason);
         }
         public Task ModifyGuildMemberAsync(Snowflake guildId, Snowflake userId, ModifyGuildMemberParams args)
         {
@@ -376,19 +392,21 @@ public Task<Ban[]> GetGuildBansAsync(Snowflake guildId)
             Preconditions.NotZero(guildId, nameof(guildId));
             return _api.GetGuildBansAsync(guildId);
         }
-        public Task CreateGuildBanAsync(Snowflake guildId, Snowflake userId, CreateGuildBanParams args)
+        public Task CreateGuildBanAsync(Snowflake guildId, Snowflake userId, CreateGuildBanParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(guildId, nameof(guildId));
             Preconditions.NotZero(userId, nameof(userId));
             Preconditions.NotNull(args, nameof(args));
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
             args.Validate();
-            return _api.CreateGuildBanAsync(guildId, userId, args);
+            return _api.CreateGuildBanAsync(guildId, userId, args, reason);
         }
-        public Task DeleteGuildBanAsync(Snowflake guildId, Snowflake userId)
+        public Task DeleteGuildBanAsync(Snowflake guildId, Snowflake userId, Utf8String reason = null)
         {
             Preconditions.NotZero(guildId, nameof(guildId));
             Preconditions.NotZero(userId, nameof(userId));
-            return _api.DeleteGuildBanAsync(guildId, userId);
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
+            return _api.DeleteGuildBanAsync(guildId, userId, reason);
         }
 
         public Task<Role[]> GetGuildRolesAsync(Snowflake guildId)
@@ -396,26 +414,29 @@ public Task<Role[]> GetGuildRolesAsync(Snowflake guildId)
             Preconditions.NotZero(guildId, nameof(guildId));
             return _api.GetGuildRolesAsync(guildId);
         }
-        public Task<Role> CreateGuildRoleAsync(Snowflake guildId, CreateGuildRoleParams args)
+        public Task<Role> CreateGuildRoleAsync(Snowflake guildId, CreateGuildRoleParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(guildId, nameof(guildId));
             Preconditions.NotNull(args, nameof(args));
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
             args.Validate();
-            return _api.CreateGuildRoleAsync(guildId, args);
+            return _api.CreateGuildRoleAsync(guildId, args, reason);
         }
-        public Task<Role> DeleteGuildRoleAsync(Snowflake guildId, Snowflake roleId)
+        public Task<Role> DeleteGuildRoleAsync(Snowflake guildId, Snowflake roleId, Utf8String reason = null)
         {
             Preconditions.NotZero(guildId, nameof(guildId));
             Preconditions.NotZero(roleId, nameof(roleId));
-            return _api.DeleteGuildRoleAsync(guildId, roleId);
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
+            return _api.DeleteGuildRoleAsync(guildId, roleId, reason);
         }
-        public Task<Role> ModifyGuildRoleAsync(Snowflake guildId, Snowflake roleId, ModifyGuildRoleParams args)
+        public Task<Role> ModifyGuildRoleAsync(Snowflake guildId, Snowflake roleId, ModifyGuildRoleParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(guildId, nameof(guildId));
             Preconditions.NotZero(roleId, nameof(roleId));
             Preconditions.NotNull(args, nameof(args));
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
             args.Validate();
-            return _api.ModifyGuildRoleAsync(guildId, roleId, args);
+            return _api.ModifyGuildRoleAsync(guildId, roleId, args, reason);
         }
         public Task ModifyGuildRolePositionsAsync(Snowflake guildId, ModifyGuildRolePositionParams[] args)
         {
@@ -433,12 +454,13 @@ public Task<GuildPruneCountResponse> GetGuildPruneCountAsync(Snowflake guildId,
             args.Validate();
             return _api.GetGuildPruneCountAsync(guildId, args);
         }
-        public Task<GuildPruneCountResponse> PruneGuildMembersAsync(Snowflake guildId, GuildPruneParams args)
+        public Task<GuildPruneCountResponse> PruneGuildMembersAsync(Snowflake guildId, GuildPruneParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(guildId, nameof(guildId));
             Preconditions.NotNull(args, nameof(args));
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
             args.Validate();
-            return _api.PruneGuildMembersAsync(guildId, args);
+            return _api.PruneGuildMembersAsync(guildId, args, reason);
         }
 
         public Task<VoiceRegion[]> GetGuildVoiceRegionsAsync(Snowflake guildId)
@@ -514,10 +536,11 @@ public Task<Invite> GetInviteAsync(Utf8String code, GetInviteParams args)
             args.Validate();
             return _api.GetInviteAsync(code, args);
         }
-        public Task<Invite> DeleteInviteAsync(Utf8String code)
+        public Task<Invite> DeleteInviteAsync(Utf8String code, Utf8String reason = null)
         {
             Preconditions.NotNullOrWhitespace(code, nameof(code));
-            return _api.DeleteInviteAsync(code);
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
+            return _api.DeleteInviteAsync(code, reason);
         }
 
         // User
@@ -598,40 +621,45 @@ public Task<Webhook> GetWebhookAsync(Snowflake webhookId, Utf8String webhookToke
             return _api.GetWebhookAsync(webhookId, webhookToken);
         }
 
-        public Task<Webhook> CreateWebhookAsync(Snowflake channelId, CreateWebhookParams args)
+        public Task<Webhook> CreateWebhookAsync(Snowflake channelId, CreateWebhookParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(channelId, nameof(channelId));
             Preconditions.NotNull(args, nameof(args));
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
             args.Validate();
-            return _api.CreateWebhookAsync(channelId, args);
+            return _api.CreateWebhookAsync(channelId, args, reason);
         }
 
-        public Task DeleteWebhookAsync(Snowflake webhookId)
+        public Task DeleteWebhookAsync(Snowflake webhookId, Utf8String reason = null)
         {
             Preconditions.NotZero(webhookId, nameof(webhookId));
-            return _api.DeleteWebhookAsync(webhookId);
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
+            return _api.DeleteWebhookAsync(webhookId, reason);
         }
-        public Task DeleteWebhookAsync(Snowflake webhookId, Utf8String webhookToken)
+        public Task DeleteWebhookAsync(Snowflake webhookId, Utf8String webhookToken, Utf8String reason = null)
         {
             Preconditions.NotZero(webhookId, nameof(webhookId));
             Preconditions.NotNullOrWhitespace(webhookToken, nameof(webhookToken));
-            return _api.DeleteWebhookAsync(webhookId, webhookToken);
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
+            return _api.DeleteWebhookAsync(webhookId, webhookToken, reason);
         }
 
-        public Task<Webhook> ModifyWebhookAsync(Snowflake webhookId, ModifyWebhookParams args)
+        public Task<Webhook> ModifyWebhookAsync(Snowflake webhookId, ModifyWebhookParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(webhookId, nameof(webhookId));
             Preconditions.NotNull(args, nameof(args));
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
             args.Validate();
-            return _api.ModifyWebhookAsync(webhookId, args);
+            return _api.ModifyWebhookAsync(webhookId, args, reason);
         }
-        public Task<Webhook> ModifyWebhookAsync(Snowflake webhookId, Utf8String webhookToken, ModifyWebhookParams args)
+        public Task<Webhook> ModifyWebhookAsync(Snowflake webhookId, Utf8String webhookToken, ModifyWebhookParams args, Utf8String reason = null)
         {
             Preconditions.NotZero(webhookId, nameof(webhookId));
             Preconditions.NotNullOrWhitespace(webhookToken, nameof(webhookToken));
             Preconditions.NotNull(args, nameof(args));
+            Preconditions.LengthLessThan(reason, MaxReasonHeaderLength, nameof(reason));
             args.Validate();
-            return _api.ModifyWebhookAsync(webhookId, webhookToken, args);
+            return _api.ModifyWebhookAsync(webhookId, webhookToken, args, reason);
         }
 
         public Task ExecuteWebhookAsync(Snowflake webhookId, Utf8String webhookToken, ExecuteWebhookParams args)