Support Sending Message Flags (#2131)

* Add message flags

* Add webhook message flags

src/Discord.Net.Core/Entities/Channels/IMessageChannel.cs

@@ -31,11 +31,12 @@ namespace Discord
         /// <param name="components">The message components to be included with this message. Used for interactions.</param>
         /// <param name="stickers">A collection of stickers to send with the message.</param>
         /// <param name="embeds">A array of <see cref="Embed"/>s to send with this response. Max 10.</param>
+        /// <param name="flags">A message flag to be applied to the sent message, only <see cref="MessageFlags.SuppressEmbeds"/> is permitted.</param>
         /// <returns>
         ///     A task that represents an asynchronous send operation for delivering the message. The task result
         ///     contains the sent message.
         /// </returns>
-        Task<IUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null);
+        Task<IUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None);
         /// <summary>
         ///     Sends a file to this message channel with an optional caption.
         /// </summary>
@@ -71,11 +72,12 @@ namespace Discord
         /// <param name="components">The message components to be included with this message. Used for interactions.</param>
         /// <param name="stickers">A collection of stickers to send with the file.</param>
         /// <param name="embeds">A array of <see cref="Embed"/>s to send with this response. Max 10.</param>
+        /// <param name="flags">A message flag to be applied to the sent message, only <see cref="MessageFlags.SuppressEmbeds"/> is permitted.</param>
         /// <returns>
         ///     A task that represents an asynchronous send operation for delivering the message. The task result
         ///     contains the sent message.
         /// </returns>
-        Task<IUserMessage> SendFileAsync(string filePath, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null);
+        Task<IUserMessage> SendFileAsync(string filePath, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None);
         /// <summary>
         ///     Sends a file to this message channel with an optional caption.
         /// </summary>
@@ -108,11 +110,12 @@ namespace Discord
         /// <param name="components">The message components to be included with this message. Used for interactions.</param>
         /// <param name="stickers">A collection of stickers to send with the file.</param>
         /// <param name="embeds">A array of <see cref="Embed"/>s to send with this response. Max 10.</param>
+        /// <param name="flags">A message flag to be applied to the sent message, only <see cref="MessageFlags.SuppressEmbeds"/> is permitted.</param>
         /// <returns>
         ///     A task that represents an asynchronous send operation for delivering the message. The task result
         ///     contains the sent message.
         /// </returns>
-        Task<IUserMessage> SendFileAsync(Stream stream, string filename, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null);
+        Task<IUserMessage> SendFileAsync(Stream stream, string filename, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None);
         /// <summary>
         ///     Sends a file to this message channel with an optional caption.
         /// </summary>
@@ -137,11 +140,12 @@ namespace Discord
         /// <param name="components">The message components to be included with this message. Used for interactions.</param>
         /// <param name="stickers">A collection of stickers to send with the file.</param>
         /// <param name="embeds">A array of <see cref="Embed"/>s to send with this response. Max 10.</param>
+        /// <param name="flags">A message flag to be applied to the sent message, only <see cref="MessageFlags.SuppressEmbeds"/> is permitted.</param>
         /// <returns>
         ///     A task that represents an asynchronous send operation for delivering the message. The task result
         ///     contains the sent message.
         /// </returns>
-        Task<IUserMessage> SendFileAsync(FileAttachment attachment, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null);
+        Task<IUserMessage> SendFileAsync(FileAttachment attachment, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None);
         /// <summary>
         ///     Sends a collection of files to this message channel.
         /// </summary>
@@ -166,11 +170,12 @@ namespace Discord
         /// <param name="components">The message components to be included with this message. Used for interactions.</param>
         /// <param name="stickers">A collection of stickers to send with the file.</param>
         /// <param name="embeds">A array of <see cref="Embed"/>s to send with this response. Max 10.</param>
+        /// <param name="flags">A message flag to be applied to the sent message, only <see cref="MessageFlags.SuppressEmbeds"/> is permitted.</param>
         /// <returns>
         ///     A task that represents an asynchronous send operation for delivering the message. The task result
         ///     contains the sent message.
         /// </returns>
-        Task<IUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null);
+        Task<IUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None);
 
         /// <summary>
         ///     Gets a message from this message channel.

src/Discord.Net.Rest/API/Rest/CreateMessageParams.cs

@@ -28,6 +28,9 @@ namespace Discord.API.Rest
 
         [JsonProperty("sticker_ids")]
         public Optional<ulong[]> Stickers { get; set; }
+        
+        [JsonProperty("flags")]
+        public Optional<MessageFlags> Flags { get; set; }
 
         public CreateMessageParams(string content)
         {

src/Discord.Net.Rest/Entities/Channels/ChannelHelper.cs

@@ -266,8 +266,10 @@ namespace Discord.Rest
         }
 
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
         public static async Task<RestUserMessage> SendMessageAsync(IMessageChannel channel, BaseDiscordClient client,
-            string text, bool isTTS, Embed embed, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, RequestOptions options, Embed[] embeds)
+            string text, bool isTTS, Embed embed, AllowedMentions allowedMentions, MessageReference messageReference, 
+            MessageComponent components, ISticker[] stickers, RequestOptions options, Embed[] embeds, MessageFlags flags)
         {
             embeds ??= Array.Empty<Embed>();
             if (embed != null)
@@ -298,6 +300,10 @@ namespace Discord.Rest
                 Preconditions.AtMost(stickers.Length, 3, nameof(stickers), "A max of 3 stickers are allowed.");
             }
 
+
+            if (flags is not MessageFlags.None and not MessageFlags.SuppressEmbeds)
+                throw new ArgumentException("The only valid MessageFlags are SuppressEmbeds and none.", nameof(flags));
+
             var args = new CreateMessageParams(text)
             {
                 IsTTS = isTTS,
@@ -305,7 +311,8 @@ namespace Discord.Rest
                 AllowedMentions = allowedMentions?.ToModel(),
                 MessageReference = messageReference?.ToModel(),
                 Components = components?.Components.Select(x => new API.ActionRowComponent(x)).ToArray() ?? Optional<API.ActionRowComponent[]>.Unspecified,
-                Stickers = stickers?.Any() ?? false ? stickers.Select(x => x.Id).ToArray() : Optional<ulong[]>.Unspecified
+                Stickers = stickers?.Any() ?? false ? stickers.Select(x => x.Id).ToArray() : Optional<ulong[]>.Unspecified,
+                Flags = flags
             };
             var model = await client.ApiClient.CreateMessageAsync(channel.Id, args, options).ConfigureAwait(false);
             return RestUserMessage.Create(client, channel, client.CurrentUser, model);
@@ -335,29 +342,44 @@ namespace Discord.Rest
         /// <exception cref="NotSupportedException"><paramref name="filePath" /> is in an invalid format.</exception>
         /// <exception cref="IOException">An I/O error occurred while opening the file.</exception>
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
         public static async Task<RestUserMessage> SendFileAsync(IMessageChannel channel, BaseDiscordClient client,
-            string filePath, string text, bool isTTS, Embed embed, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, RequestOptions options, bool isSpoiler, Embed[] embeds)
+            string filePath, string text, bool isTTS, Embed embed, AllowedMentions allowedMentions, 
+            MessageReference messageReference, MessageComponent components, ISticker[] stickers, RequestOptions options, 
+            bool isSpoiler, Embed[] embeds, MessageFlags flags = MessageFlags.None)
         {
             string filename = Path.GetFileName(filePath);
             using (var file = File.OpenRead(filePath))
-                return await SendFileAsync(channel, client, file, filename, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds).ConfigureAwait(false);
+                return await SendFileAsync(channel, client, file, filename, text, isTTS, embed, allowedMentions, 
+                messageReference, components, stickers, options, isSpoiler, embeds, flags).ConfigureAwait(false);
         }
 
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
         public static async Task<RestUserMessage> SendFileAsync(IMessageChannel channel, BaseDiscordClient client,
-            Stream stream, string filename, string text, bool isTTS, Embed embed, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, RequestOptions options, bool isSpoiler, Embed[] embeds)
+            Stream stream, string filename, string text, bool isTTS, Embed embed, AllowedMentions allowedMentions, 
+            MessageReference messageReference, MessageComponent components, ISticker[] stickers, RequestOptions options, 
+            bool isSpoiler, Embed[] embeds, MessageFlags flags = MessageFlags.None)
         {
             using (var file = new FileAttachment(stream, filename, isSpoiler: isSpoiler))
-                return await SendFileAsync(channel, client, file, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds).ConfigureAwait(false);
+                return await SendFileAsync(channel, client, file, text, isTTS, embed, allowedMentions, messageReference, 
+                components, stickers, options, embeds, flags).ConfigureAwait(false);
         }
 
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
         public static Task<RestUserMessage> SendFileAsync(IMessageChannel channel, BaseDiscordClient client,
-            FileAttachment attachment, string text, bool isTTS, Embed embed, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, RequestOptions options, Embed[] embeds)
-            => SendFilesAsync(channel, client, new[] { attachment }, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+            FileAttachment attachment, string text, bool isTTS, Embed embed, AllowedMentions allowedMentions, 
+            MessageReference messageReference, MessageComponent components, ISticker[] stickers, RequestOptions options, 
+            Embed[] embeds, MessageFlags flags = MessageFlags.None)
+            => SendFilesAsync(channel, client, new[] { attachment }, text, isTTS, embed, allowedMentions, messageReference, 
+                components, stickers, options, embeds, flags);
 
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
         public static async Task<RestUserMessage> SendFilesAsync(IMessageChannel channel, BaseDiscordClient client,
-            IEnumerable<FileAttachment> attachments, string text, bool isTTS, Embed embed, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, RequestOptions options,  Embed[] embeds)
+            IEnumerable<FileAttachment> attachments, string text, bool isTTS, Embed embed, AllowedMentions allowedMentions, 
+            MessageReference messageReference, MessageComponent components, ISticker[] stickers, RequestOptions options, 
+            Embed[] embeds, MessageFlags flags)
         {
             embeds ??= Array.Empty<Embed>();
             if (embed != null)
@@ -366,7 +388,7 @@ namespace Discord.Rest
             Preconditions.AtMost(allowedMentions?.RoleIds?.Count ?? 0, 100, nameof(allowedMentions.RoleIds), "A max of 100 role Ids are allowed.");
             Preconditions.AtMost(allowedMentions?.UserIds?.Count ?? 0, 100, nameof(allowedMentions.UserIds), "A max of 100 user Ids are allowed.");
             Preconditions.AtMost(embeds.Length, 10, nameof(embeds), "A max of 10 embeds are allowed.");
-
+            
             foreach(var attachment in attachments)
             {
                 Preconditions.NotNullOrEmpty(attachment.FileName, nameof(attachment.FileName), "File Name must not be empty or null");
@@ -398,12 +420,26 @@ namespace Discord.Rest
                 }
             }
 
+            if (flags is not MessageFlags.None and not MessageFlags.SuppressEmbeds)
+                throw new ArgumentException("The only valid MessageFlags are SuppressEmbeds and none.", nameof(flags));
+
             if (stickers != null)
             {
                 Preconditions.AtMost(stickers.Length, 3, nameof(stickers), "A max of 3 stickers are allowed.");
             }
 
-            var args = new UploadFileParams(attachments.ToArray()) { Content = text, IsTTS = isTTS, Embeds = embeds.Any() ? embeds.Select(x => x.ToModel()).ToArray() : Optional<API.Embed[]>.Unspecified, AllowedMentions = allowedMentions?.ToModel() ?? Optional<API.AllowedMentions>.Unspecified, MessageReference = messageReference?.ToModel() ?? Optional<API.MessageReference>.Unspecified, MessageComponent = components?.Components.Select(x => new API.ActionRowComponent(x)).ToArray() ?? Optional<API.ActionRowComponent[]>.Unspecified, Stickers = stickers?.Any() ?? false ? stickers.Select(x => x.Id).ToArray() : Optional<ulong[]>.Unspecified };
+            var args = new UploadFileParams(attachments.ToArray()) 
+            { 
+                Content = text, 
+                IsTTS = isTTS,
+                Embeds = embeds.Any() ? embeds.Select(x => x.ToModel()).ToArray() : Optional<API.Embed[]>.Unspecified, 
+                AllowedMentions = allowedMentions?.ToModel() ?? Optional<API.AllowedMentions>.Unspecified, 
+                MessageReference = messageReference?.ToModel() ?? Optional<API.MessageReference>.Unspecified, 
+                MessageComponent = components?.Components.Select(x => new API.ActionRowComponent(x)).ToArray() ?? Optional<API.ActionRowComponent[]>.Unspecified,
+                Stickers = stickers?.Any() ?? false ? stickers.Select(x => x.Id).ToArray() : Optional<ulong[]>.Unspecified,
+                Flags = flags
+            };
+            
             var model = await client.ApiClient.UploadFileAsync(channel.Id, args, options).ConfigureAwait(false);
             return RestUserMessage.Create(client, channel, client.CurrentUser, model);
         }

src/Discord.Net.Rest/Entities/Channels/IRestMessageChannel.cs

@@ -9,84 +9,14 @@ namespace Discord.Rest
     /// </summary>
     public interface IRestMessageChannel : IMessageChannel
     {
-        /// <summary>
-        ///     Sends a message to this message channel.
-        /// </summary>
-        /// <remarks>
-        ///     This method follows the same behavior as described in <see cref="IMessageChannel.SendMessageAsync"/>.
-        ///     Please visit its documentation for more details on this method.
-        /// </remarks>
-        /// <param name="text">The message to be sent.</param>
-        /// <param name="isTTS">Determines whether the message should be read aloud by Discord or not.</param>
-        /// <param name="embed">The <see cref="Discord.EmbedType.Rich"/> <see cref="Embed"/> to be sent.</param>
-        /// <param name="options">The options to be used when sending the request.</param>
-        /// <param name="allowedMentions">
-        ///     Specifies if notifications are sent for mentioned users and roles in the message <paramref name="text"/>.
-        ///     If <c>null</c>, all mentioned roles and users will be notified.
-        /// </param>
-        /// <param name="messageReference">The message references to be included. Used to reply to specific messages.</param>
-        /// <param name="components">The message components to be included with this message. Used for interactions.</param>
-        /// <param name="stickers">A collection of stickers to send with the message.</param>
-        /// <param name="embeds">A array of <see cref="Embed"/>s to send with this response. Max 10.</param>
-        /// <returns>
-        ///     A task that represents an asynchronous send operation for delivering the message. The task result
-        ///     contains the sent message.
-        /// </returns>
-        new Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null);
-        /// <summary>
-        ///     Sends a file to this message channel with an optional caption.
-        /// </summary>
-        /// <remarks>
-        ///     This method follows the same behavior as described in
-        ///     <see cref="IMessageChannel.SendFileAsync(string, string, bool, Embed, RequestOptions, bool, AllowedMentions, MessageReference, MessageComponent, ISticker[], Embed[])"/>. Please visit
-        ///     its documentation for more details on this method.
-        /// </remarks>
-        /// <param name="filePath">The file path of the file.</param>
-        /// <param name="text">The message to be sent.</param>
-        /// <param name="isTTS">Whether the message should be read aloud by Discord or not.</param>
-        /// <param name="embed">The <see cref="Discord.EmbedType.Rich" /> <see cref="Embed" /> to be sent.</param>
-        /// <param name="options">The options to be used when sending the request.</param>
-        /// <param name="isSpoiler">Whether the message attachment should be hidden as a spoiler.</param>
-        /// <param name="allowedMentions">
-        ///     Specifies if notifications are sent for mentioned users and roles in the message <paramref name="text"/>.
-        ///     If <c>null</c>, all mentioned roles and users will be notified.
-        /// </param>
-        /// <param name="messageReference">The message references to be included. Used to reply to specific messages.</param>
-        /// <param name="components">The message components to be included with this message. Used for interactions.</param>
-        /// <param name="stickers">A collection of stickers to send with the message.</param>
-        /// <param name="embeds">A array of <see cref="Embed"/>s to send with this response. Max 10.</param>
-        /// <returns>
-        ///     A task that represents an asynchronous send operation for delivering the message. The task result
-        ///     contains the sent message.
-        /// </returns>
-        new Task<RestUserMessage> SendFileAsync(string filePath, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null);
-        /// <summary>
-        ///     Sends a file to this message channel with an optional caption.
-        /// </summary>
-        /// <remarks>
-        ///     This method follows the same behavior as described in <see cref="IMessageChannel.SendFileAsync(Stream, string, string, bool, Embed, RequestOptions, bool, AllowedMentions, MessageReference, MessageComponent, ISticker[], Embed[])"/>.
-        ///     Please visit its documentation for more details on this method.
-        /// </remarks>
-        /// <param name="stream">The <see cref="Stream" /> of the file to be sent.</param>
-        /// <param name="filename">The name of the attachment.</param>
-        /// <param name="text">The message to be sent.</param>
-        /// <param name="isTTS">Whether the message should be read aloud by Discord or not.</param>
-        /// <param name="embed">The <see cref="Discord.EmbedType.Rich"/> <see cref="Embed"/> to be sent.</param>
-        /// <param name="options">The options to be used when sending the request.</param>
-        /// <param name="isSpoiler">Whether the message attachment should be hidden as a spoiler.</param>
-        /// <param name="allowedMentions">
-        ///     Specifies if notifications are sent for mentioned users and roles in the message <paramref name="text"/>.
-        ///     If <c>null</c>, all mentioned roles and users will be notified.
-        /// </param>
-        /// <param name="messageReference">The message references to be included. Used to reply to specific messages.</param>
-        /// <param name="components">The message components to be included with this message. Used for interactions.</param>
-        /// <param name="stickers">A collection of stickers to send with the message.</param>
-        /// <param name="embeds">A array of <see cref="Embed"/>s to send with this response. Max 10.</param>
-        /// <returns>
-        ///     A task that represents an asynchronous send operation for delivering the message. The task result
-        ///     contains the sent message.
-        /// </returns>
-        new Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null);
+        /// <inheritdoc cref="IMessageChannel.SendMessageAsync(string, bool, Embed, RequestOptions, AllowedMentions, MessageReference, MessageComponent, ISticker[], Embed[], MessageFlags)"/>
+        new Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None);
+        
+        /// <inheritdoc cref="IMessageChannel.SendFileAsync(string, string, bool, Embed, RequestOptions, bool, AllowedMentions, MessageReference, MessageComponent, ISticker[], Embed[], MessageFlags)"/>
+        new Task<RestUserMessage> SendFileAsync(string filePath, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None);
+        
+        /// <inheritdoc cref="IMessageChannel.SendFileAsync(Stream, string, string, bool, Embed, RequestOptions, bool, AllowedMentions, MessageReference, MessageComponent, ISticker[], Embed[], MessageFlags)"/>
+        new Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None);
 
         /// <summary>
         ///     Gets a message from this message channel.

src/Discord.Net.Rest/Entities/Channels/RestDMChannel.cs

@@ -94,8 +94,12 @@ namespace Discord.Rest
 
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, 
+            RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, 
+            MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference, 
+                components, stickers, options, embeds, flags);
 
         /// <inheritdoc />
         /// <exception cref="ArgumentException">
@@ -122,22 +126,39 @@ namespace Discord.Rest
         /// <exception cref="NotSupportedException"><paramref name="filePath" /> is in an invalid format.</exception>
         /// <exception cref="IOException">An I/O error occurred while opening the file.</exception>
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null,
+            RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference, 
+            components, stickers, options, isSpoiler, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds);
+        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false, 
+            Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions,
+                messageReference, components, stickers, options, isSpoiler, embeds, flags);
 
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, attachment, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        public Task<RestUserMessage> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false, 
+            Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, attachment, text, isTTS, embed, allowedMentions, messageReference,
+                components, stickers, options, embeds, flags);
 
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFilesAsync(this, Discord, attachments, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        public Task<RestUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false, 
+            Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFilesAsync(this, Discord, attachments, text, isTTS, embed, allowedMentions, messageReference, 
+                components, stickers, options, embeds, flags);
 
         /// <inheritdoc />
         public Task DeleteMessageAsync(ulong messageId, RequestOptions options = null)
@@ -219,20 +240,38 @@ namespace Discord.Rest
         async Task<IReadOnlyCollection<IMessage>> IMessageChannel.GetPinnedMessagesAsync(RequestOptions options)
             => await GetPinnedMessagesAsync(options).ConfigureAwait(false);
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed,
+            RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference,
+            components, stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS,
+            Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference,
+                components, stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(FileAttachment attachment, string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(attachment, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(FileAttachment attachment, string text, bool isTTS,
+            Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(attachment, text, isTTS, embed, options, allowedMentions, messageReference, components,
+                stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-           => await SendFilesAsync(attachments, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFilesAsync(IEnumerable<FileAttachment> attachments, string text,
+            bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+           => await SendFilesAsync(attachments, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options,
+            AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components,
+            ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds, flags).ConfigureAwait(false);
+            
         #endregion
 
         #region IChannel

src/Discord.Net.Rest/Entities/Channels/RestGroupChannel.cs

@@ -104,8 +104,12 @@ namespace Discord.Rest
 
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, 
+            RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, 
+            MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference, 
+                components, stickers, options, embeds, flags);
 
         /// <inheritdoc />
         /// <exception cref="ArgumentException">
@@ -132,20 +136,40 @@ namespace Discord.Rest
         /// <exception cref="NotSupportedException"><paramref name="filePath" /> is in an invalid format.</exception>
         /// <exception cref="IOException">An I/O error occurred while opening the file.</exception>
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null, 
+            RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference, 
+                components, stickers, options, isSpoiler, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false, 
+            Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null,
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions, 
+                messageReference, components, stickers, options, isSpoiler, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, attachment, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false, 
+            Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null,
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, attachment, text, isTTS, embed, allowedMentions, messageReference,
+                components, stickers, options, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFilesAsync(this, Discord, attachments, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false, 
+            Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null,
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFilesAsync(this, Discord, attachments, text, isTTS, embed, allowedMentions, 
+                messageReference, components, stickers, options, embeds, flags);
         /// <inheritdoc />
         public Task TriggerTypingAsync(RequestOptions options = null)
             => ChannelHelper.TriggerTypingAsync(this, Discord, options);
@@ -197,17 +221,41 @@ namespace Discord.Rest
         async Task<IReadOnlyCollection<IMessage>> IMessageChannel.GetPinnedMessagesAsync(RequestOptions options)
             => await GetPinnedMessagesAsync(options).ConfigureAwait(false);
 
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
-
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(FileAttachment attachment, string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(attachment, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
-        async Task<IUserMessage> IMessageChannel.SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-           => await SendFilesAsync(attachments, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
-        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        /// <inheritdoc />
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed,
+            RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference,
+            components, stickers, embeds, flags).ConfigureAwait(false);
+
+        /// <inheritdoc />
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS,
+            Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference,
+                components, stickers, embeds, flags).ConfigureAwait(false);
+
+        /// <inheritdoc />
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(FileAttachment attachment, string text, bool isTTS,
+            Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(attachment, text, isTTS, embed, options, allowedMentions, messageReference, components,
+                stickers, embeds, flags).ConfigureAwait(false);
+
+        /// <inheritdoc />
+        async Task<IUserMessage> IMessageChannel.SendFilesAsync(IEnumerable<FileAttachment> attachments, string text,
+            bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFilesAsync(attachments, text, isTTS, embed, options, allowedMentions, messageReference, components, 
+            stickers, embeds, flags).ConfigureAwait(false);
+
+        /// <inheritdoc />
+        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options,
+            AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components,
+            ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference, components, 
+            stickers, embeds, flags).ConfigureAwait(false);
+            
         #endregion
 
         #region IAudioChannel

src/Discord.Net.Rest/Entities/Channels/RestTextChannel.cs

@@ -103,8 +103,12 @@ namespace Discord.Rest
 
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, 
+            RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null,
+            MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference, 
+                components, stickers, options, embeds, flags);
 
         /// <inheritdoc />
         /// <exception cref="ArgumentException">
@@ -131,23 +135,42 @@ namespace Discord.Rest
         /// <exception cref="NotSupportedException"><paramref name="filePath" /> is in an invalid format.</exception>
         /// <exception cref="IOException">An I/O error occurred while opening the file.</exception>
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null, 
+            RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference, 
+                components, stickers, options, isSpoiler, embeds, flags);
 
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false, 
+            Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions, messageReference, 
+                components, stickers, options, isSpoiler, embeds, flags);
 
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, attachment, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false, 
+            Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, attachment, text, isTTS, embed, allowedMentions, messageReference, 
+                components, stickers, options, embeds, flags);
 
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFilesAsync(this, Discord, attachments, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false, 
+            Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFilesAsync(this, Discord, attachments, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds, flags);
 
         /// <inheritdoc />
         public Task DeleteMessageAsync(ulong messageId, RequestOptions options = null)
@@ -332,24 +355,37 @@ namespace Discord.Rest
             => await GetPinnedMessagesAsync(options).ConfigureAwait(false);
 
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed,
+            RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, 
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, 
+            components, stickers, embeds, flags).ConfigureAwait(false);
 
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS, 
+            Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, 
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference,
+                components, stickers, embeds, flags).ConfigureAwait(false);
 
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(FileAttachment attachment, string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(attachment, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(FileAttachment attachment, string text, bool isTTS, 
+            Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, 
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(attachment, text, isTTS, embed, options, allowedMentions, messageReference, components,
+                stickers, embeds, flags).ConfigureAwait(false);
 
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-           => await SendFilesAsync(attachments, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, 
+            bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFilesAsync(attachments, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds, flags).ConfigureAwait(false);
 
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options, 
+            AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, 
+            ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds, flags).ConfigureAwait(false);
         #endregion
 
         #region IGuildChannel

src/Discord.Net.WebSocket/Entities/Channels/ISocketMessageChannel.cs

@@ -18,83 +18,22 @@ namespace Discord.WebSocket
         /// </returns>
         IReadOnlyCollection<SocketMessage> CachedMessages { get; }
 
-        /// <summary>
-        ///     Sends a message to this message channel.
-        /// </summary>
-        /// <remarks>
-        ///     This method follows the same behavior as described in <see cref="IMessageChannel.SendMessageAsync"/>.
-        ///     Please visit its documentation for more details on this method.
-        /// </remarks>
-        /// <param name="text">The message to be sent.</param>
-        /// <param name="isTTS">Determines whether the message should be read aloud by Discord or not.</param>
-        /// <param name="embed">The <see cref="Discord.EmbedType.Rich"/> <see cref="Embed"/> to be sent.</param>
-        /// <param name="options">The options to be used when sending the request.</param>
-        /// <param name="allowedMentions">
-        ///     Specifies if notifications are sent for mentioned users and roles in the message <paramref name="text"/>.
-        ///     If <c>null</c>, all mentioned roles and users will be notified.
-        /// </param>
-        /// <param name="messageReference">The message references to be included. Used to reply to specific messages.</param>
-        /// <param name="components">The message components to be included with this message. Used for interactions.</param>
-        /// <param name="stickers">A collection of stickers to send with the message.</param>
-        /// <param name="embeds">A array of <see cref="Embed"/>s to send with this response. Max 10.</param>
-        /// <returns>
-        ///     A task that represents an asynchronous send operation for delivering the message. The task result
-        ///     contains the sent message.
-        /// </returns>
-        new Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null);
-        /// <summary>
-        ///     Sends a file to this message channel with an optional caption.
-        /// </summary>
-        /// <remarks>
-        ///     This method follows the same behavior as described in <see cref="IMessageChannel.SendFileAsync(string, string, bool, Embed, RequestOptions, bool, AllowedMentions, MessageReference, MessageComponent, ISticker[], Embed[])"/>.
-        ///     Please visit its documentation for more details on this method.
-        /// </remarks>
-        /// <param name="filePath">The file path of the file.</param>
-        /// <param name="text">The message to be sent.</param>
-        /// <param name="isTTS">Whether the message should be read aloud by Discord or not.</param>
-        /// <param name="embed">The <see cref="Discord.EmbedType.Rich" /> <see cref="Embed" /> to be sent.</param>
-        /// <param name="options">The options to be used when sending the request.</param>
-        /// <param name="isSpoiler">Whether the message attachment should be hidden as a spoiler.</param>
-        /// <param name="allowedMentions">
-        ///     Specifies if notifications are sent for mentioned users and roles in the message <paramref name="text"/>.
-        ///     If <c>null</c>, all mentioned roles and users will be notified.
-        /// </param>
-        /// <param name="messageReference">The message references to be included. Used to reply to specific messages.</param>
-        /// <param name="components">The message components to be included with this message. Used for interactions.</param>
-        /// <param name="stickers">A collection of stickers to send with the file.</param>
-        /// <param name="embeds">A array of <see cref="Embed"/>s to send with this response. Max 10.</param>
-        /// <returns>
-        ///     A task that represents an asynchronous send operation for delivering the message. The task result
-        ///     contains the sent message.
-        /// </returns>
-        new Task<RestUserMessage> SendFileAsync(string filePath, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null);
-        /// <summary>
-        ///     Sends a file to this message channel with an optional caption.
-        /// </summary>
-        /// <remarks>
-        ///     This method follows the same behavior as described in <see cref="IMessageChannel.SendFileAsync(Stream, string, string, bool, Embed, RequestOptions, bool, AllowedMentions, MessageReference, MessageComponent, ISticker[], Embed[])"/>.
-        ///     Please visit its documentation for more details on this method.
-        /// </remarks>
-        /// <param name="stream">The <see cref="Stream" /> of the file to be sent.</param>
-        /// <param name="filename">The name of the attachment.</param>
-        /// <param name="text">The message to be sent.</param>
-        /// <param name="isTTS">Whether the message should be read aloud by Discord or not.</param>
-        /// <param name="embed">The <see cref="Discord.EmbedType.Rich"/> <see cref="Embed"/> to be sent.</param>
-        /// <param name="options">The options to be used when sending the request.</param>
-        /// <param name="isSpoiler">Whether the message attachment should be hidden as a spoiler.</param>
-        /// <param name="allowedMentions">
-        ///     Specifies if notifications are sent for mentioned users and roles in the message <paramref name="text"/>.
-        ///     If <c>null</c>, all mentioned roles and users will be notified.
-        /// </param>
-        /// <param name="messageReference">The message references to be included. Used to reply to specific messages.</param>
-        /// <param name="components">The message components to be included with this message. Used for interactions.</param>
-        /// <param name="stickers">A collection of stickers to send with the file.</param>
-        /// <param name="embeds">A array of <see cref="Embed"/>s to send with this response. Max 10.</param>
-        /// <returns>
-        ///     A task that represents an asynchronous send operation for delivering the message. The task result
-        ///     contains the sent message.
-        /// </returns>
-        new Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null);
+        /// <inheritdoc cref="IMessageChannel.SendMessageAsync(string, bool, Embed, RequestOptions, AllowedMentions, MessageReference, MessageComponent, ISticker[], Embed[], MessageFlags)"/>
+        new Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, 
+            RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null,
+            MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None);
+        
+        /// <inheritdoc cref="IMessageChannel.SendFileAsync(string, string, bool, Embed, RequestOptions, bool, AllowedMentions, MessageReference, MessageComponent, ISticker[], Embed[], MessageFlags)"/>
+        new Task<RestUserMessage> SendFileAsync(string filePath, string text = null, bool isTTS = false, Embed embed = null, 
+            RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None);
+            
+        /// <inheritdoc cref="IMessageChannel.SendFileAsync(Stream, string, string, bool, Embed, RequestOptions, bool, AllowedMentions, MessageReference, MessageComponent, ISticker[], Embed[], MessageFlags)"/>
+        new Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text = null, bool isTTS = false, 
+            Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None);
 
         /// <summary>
         ///     Gets a cached message from this channel.

src/Discord.Net.WebSocket/Entities/Channels/SocketDMChannel.cs

@@ -139,24 +139,48 @@ namespace Discord.WebSocket
 
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, 
+            RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, 
+            MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference, 
+                components, stickers, options, embeds, flags);
 
         /// <inheritdoc />
-        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null, 
+            RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null,
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference,
+                components, stickers, options, isSpoiler, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false,
+            Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions, 
+                messageReference, components, stickers, options, isSpoiler, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, attachment, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false, 
+            Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, attachment, text, isTTS, embed, allowedMentions, 
+                messageReference, components, stickers, options, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFilesAsync(this, Discord, attachments, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false, 
+            Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, 
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, 
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFilesAsync(this, Discord, attachments, text, isTTS, embed, allowedMentions, 
+                messageReference, components, stickers, options, embeds, flags);
 
         /// <inheritdoc />
         public Task DeleteMessageAsync(ulong messageId, RequestOptions options = null)
@@ -255,20 +279,37 @@ namespace Discord.WebSocket
         async Task<IReadOnlyCollection<IMessage>> IMessageChannel.GetPinnedMessagesAsync(RequestOptions options)
             => await GetPinnedMessagesAsync(options).ConfigureAwait(false);
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed,
+            RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference,
+            components, stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS,
+            Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference,
+                components, stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(FileAttachment attachment, string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(attachment, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(FileAttachment attachment, string text, bool isTTS,
+            Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(attachment, text, isTTS, embed, options, allowedMentions, messageReference, components,
+                stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-           => await SendFilesAsync(attachments, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFilesAsync(IEnumerable<FileAttachment> attachments, string text,
+            bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+           => await SendFilesAsync(attachments, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options,
+            AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components,
+            ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds, flags).ConfigureAwait(false);
         #endregion
 
         #region IChannel

src/Discord.Net.WebSocket/Entities/Channels/SocketGroupChannel.cs

@@ -178,24 +178,48 @@ namespace Discord.WebSocket
 
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null,
+            RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null,
+            MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference,
+                components, stickers, options, embeds, flags);
 
         /// <inheritdoc />
-        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null,
+            RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null,
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null,
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference,
+                components, stickers, options, isSpoiler, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false,
+            Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null,
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null,
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions,
+                messageReference, components, stickers, options, isSpoiler, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, attachment, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false,
+            Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null,
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null,
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, attachment, text, isTTS, embed, allowedMentions,
+                messageReference, components, stickers, options, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFilesAsync(this, Discord, attachments, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false,
+            Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null,
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null,
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFilesAsync(this, Discord, attachments, text, isTTS, embed, allowedMentions,
+                messageReference, components, stickers, options, embeds, flags);
 
         /// <inheritdoc />
         public Task DeleteMessageAsync(ulong messageId, RequestOptions options = null)
@@ -327,21 +351,37 @@ namespace Discord.WebSocket
             => await GetPinnedMessagesAsync(options).ConfigureAwait(false);
 
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed,
+            RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference,
+            components, stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS,
+            Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference,
+                components, stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(FileAttachment attachment, string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(attachment, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(FileAttachment attachment, string text, bool isTTS,
+            Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(attachment, text, isTTS, embed, options, allowedMentions, messageReference, components,
+                stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-           => await SendFilesAsync(attachments, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFilesAsync(IEnumerable<FileAttachment> attachments, string text,
+            bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+           => await SendFilesAsync(attachments, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds, flags).ConfigureAwait(false);
 
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options,
+            AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components,
+            ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds, flags).ConfigureAwait(false);
         #endregion
 
         #region IAudioChannel

src/Discord.Net.WebSocket/Entities/Channels/SocketTextChannel.cs

@@ -212,27 +212,48 @@ namespace Discord.WebSocket
 
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
-
-        /// <inheritdoc />
-        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds);
-
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null,
+            RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null,
+            MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendMessageAsync(this, Discord, text, isTTS, embed, allowedMentions, messageReference,
+                components, stickers, options, embeds, flags);
+
+        /// <inheritdoc />
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(string filePath, string text, bool isTTS = false, Embed embed = null,
+            RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null,
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null,
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, filePath, text, isTTS, embed, allowedMentions, messageReference,
+                components, stickers, options, isSpoiler, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, isSpoiler, embeds);
-
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false,
+            Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null,
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null,
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, stream, filename, text, isTTS, embed, allowedMentions,
+                messageReference, components, stickers, options, isSpoiler, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFileAsync(this, Discord, attachment, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
-
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false,
+            Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null,
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null,
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFileAsync(this, Discord, attachment, text, isTTS, embed, allowedMentions,
+                messageReference, components, stickers, options, embeds, flags);
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public Task<RestUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null, Embed[] embeds = null)
-            => ChannelHelper.SendFilesAsync(this, Discord, attachments, text, isTTS, embed, allowedMentions, messageReference, components, stickers, options, embeds);
+        /// <exception cref="ArgumentException">The only valid <see cref="MessageFlags"/> are <see cref="MessageFlags.SuppressEmbeds"/> and <see cref="MessageFlags.None"/>.</exception>
+        public Task<RestUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false,
+            Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null,
+            MessageReference messageReference = null, MessageComponent components = null, ISticker[] stickers = null,
+            Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
+            => ChannelHelper.SendFilesAsync(this, Discord, attachments, text, isTTS, embed, allowedMentions,
+                messageReference, components, stickers, options, embeds, flags);
 
         /// <inheritdoc />
         public Task DeleteMessagesAsync(IEnumerable<IMessage> messages, RequestOptions options = null)
@@ -396,20 +417,38 @@ namespace Discord.WebSocket
             => await GetPinnedMessagesAsync(options).ConfigureAwait(false);
 
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(string filePath, string text, bool isTTS, Embed embed,
+            RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(filePath, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference,
+            components, stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS, Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(Stream stream, string filename, string text, bool isTTS,
+            Embed embed, RequestOptions options, bool isSpoiler, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(stream, filename, text, isTTS, embed, options, isSpoiler, allowedMentions, messageReference,
+                components, stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFileAsync(FileAttachment attachment, string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendFileAsync(attachment, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFileAsync(FileAttachment attachment, string text, bool isTTS,
+            Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendFileAsync(attachment, text, isTTS, embed, options, allowedMentions, messageReference, components,
+                stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-           => await SendFilesAsync(attachments, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendFilesAsync(IEnumerable<FileAttachment> attachments, string text,
+            bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference,
+            MessageComponent components, ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+           => await SendFilesAsync(attachments, text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds, flags).ConfigureAwait(false);
+
         /// <inheritdoc />
-        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options, AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components, ISticker[] stickers, Embed[] embeds)
-            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds).ConfigureAwait(false);
+        async Task<IUserMessage> IMessageChannel.SendMessageAsync(string text, bool isTTS, Embed embed, RequestOptions options,
+            AllowedMentions allowedMentions, MessageReference messageReference, MessageComponent components,
+            ISticker[] stickers, Embed[] embeds, MessageFlags flags)
+            => await SendMessageAsync(text, isTTS, embed, options, allowedMentions, messageReference, components, stickers, embeds, flags).ConfigureAwait(false);
+        
         #endregion
 
         #region  INestedChannel

src/Discord.Net.Webhook/DiscordWebhookClient.cs

@@ -87,8 +87,9 @@ namespace Discord.Webhook
         /// <summary> Sends a message to the channel for this webhook. </summary>
         /// <returns> Returns the ID of the created message. </returns>
         public Task<ulong> SendMessageAsync(string text = null, bool isTTS = false, IEnumerable<Embed> embeds = null,
-            string username = null, string avatarUrl = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageComponent components = null)
-            => WebhookClientHelper.SendMessageAsync(this, text, isTTS, embeds, username, avatarUrl, allowedMentions, options, components);
+            string username = null, string avatarUrl = null, RequestOptions options = null, AllowedMentions allowedMentions = null,
+            MessageComponent components = null, MessageFlags flags = MessageFlags.None)
+            => WebhookClientHelper.SendMessageAsync(this, text, isTTS, embeds, username, avatarUrl, allowedMentions, options, components, flags);
 
         /// <summary>
         ///     Modifies a message posted using this webhook.
@@ -124,33 +125,35 @@ namespace Discord.Webhook
         public Task<ulong> SendFileAsync(string filePath, string text, bool isTTS = false,
             IEnumerable<Embed> embeds = null, string username = null, string avatarUrl = null,
             RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null,
-            MessageComponent components = null)
+            MessageComponent components = null, MessageFlags flags = MessageFlags.None)
             => WebhookClientHelper.SendFileAsync(this, filePath, text, isTTS, embeds, username, avatarUrl,
-                allowedMentions, options, isSpoiler, components);
+                allowedMentions, options, isSpoiler, components, flags);
         /// <summary> Sends a message to the channel for this webhook with an attachment. </summary>
         /// <returns> Returns the ID of the created message. </returns>
         public Task<ulong> SendFileAsync(Stream stream, string filename, string text, bool isTTS = false,
             IEnumerable<Embed> embeds = null, string username = null, string avatarUrl = null,
             RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null,
-            MessageComponent components = null)
+            MessageComponent components = null, MessageFlags flags = MessageFlags.None)
             => WebhookClientHelper.SendFileAsync(this, stream, filename, text, isTTS, embeds, username,
-                avatarUrl, allowedMentions, options, isSpoiler, components);
+                avatarUrl, allowedMentions, options, isSpoiler, components, flags);
 
         /// <summary> Sends a message to the channel for this webhook with an attachment. </summary>
         /// <returns> Returns the ID of the created message. </returns>
         public Task<ulong> SendFileAsync(FileAttachment attachment, string text, bool isTTS = false,
             IEnumerable<Embed> embeds = null, string username = null, string avatarUrl = null,
-            RequestOptions options = null, AllowedMentions allowedMentions = null, MessageComponent components = null)
+            RequestOptions options = null, AllowedMentions allowedMentions = null, MessageComponent components = null, 
+            MessageFlags flags = MessageFlags.None)
             => WebhookClientHelper.SendFileAsync(this, attachment, text, isTTS, embeds, username,
-                avatarUrl, allowedMentions, components, options);
+                avatarUrl, allowedMentions, components, options, flags);
 
         /// <summary> Sends a message to the channel for this webhook with an attachment. </summary>
         /// <returns> Returns the ID of the created message. </returns>
         public Task<ulong> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text, bool isTTS = false,
             IEnumerable<Embed> embeds = null, string username = null, string avatarUrl = null,
-            RequestOptions options = null, AllowedMentions allowedMentions = null, MessageComponent components = null)
+            RequestOptions options = null, AllowedMentions allowedMentions = null, MessageComponent components = null, 
+            MessageFlags flags = MessageFlags.None)
             => WebhookClientHelper.SendFilesAsync(this, attachments, text, isTTS, embeds, username, avatarUrl,
-                allowedMentions, components, options);
+                allowedMentions, components, options, flags);
 
 
         /// <summary> Modifies the properties of this webhook. </summary>

src/Discord.Net.Webhook/WebhookClientHelper.cs

@@ -21,12 +21,14 @@ namespace Discord.Webhook
             return RestInternalWebhook.Create(client, model);
         }
         public static async Task<ulong> SendMessageAsync(DiscordWebhookClient client,
-            string text, bool isTTS, IEnumerable<Embed> embeds, string username, string avatarUrl, AllowedMentions allowedMentions, RequestOptions options, MessageComponent components)
+            string text, bool isTTS, IEnumerable<Embed> embeds, string username, string avatarUrl, 
+            AllowedMentions allowedMentions, RequestOptions options, MessageComponent components, MessageFlags flags)
         {
             var args = new CreateWebhookMessageParams
             {
                 Content = text,
-                IsTTS = isTTS
+                IsTTS = isTTS,
+                Flags = flags
             };
 
             if (embeds != null)
@@ -40,6 +42,9 @@ namespace Discord.Webhook
             if (components != null)
                 args.Components = components?.Components.Select(x => new API.ActionRowComponent(x)).ToArray();
 
+            if (flags is not MessageFlags.None and not MessageFlags.SuppressEmbeds)
+                throw new ArgumentException("The only valid MessageFlags are SuppressEmbeds and none.", nameof(flags));
+            
             var model = await client.ApiClient.CreateWebhookMessageAsync(client.Webhook.Id, args, options: options).ConfigureAwait(false);
             return model.Id;
         }
@@ -97,22 +102,27 @@ namespace Discord.Webhook
             await client.ApiClient.DeleteWebhookMessageAsync(client.Webhook.Id, messageId, options).ConfigureAwait(false);
         }
         public static async Task<ulong> SendFileAsync(DiscordWebhookClient client, string filePath, string text, bool isTTS,
-            IEnumerable<Embed> embeds, string username, string avatarUrl, AllowedMentions allowedMentions, RequestOptions options, bool isSpoiler, MessageComponent components)
+            IEnumerable<Embed> embeds, string username, string avatarUrl, AllowedMentions allowedMentions, RequestOptions options,
+            bool isSpoiler, MessageComponent components, MessageFlags flags = MessageFlags.None)
         {
             string filename = Path.GetFileName(filePath);
             using (var file = File.OpenRead(filePath))
-                return await SendFileAsync(client, file, filename, text, isTTS, embeds, username, avatarUrl, allowedMentions, options, isSpoiler, components).ConfigureAwait(false);
+                return await SendFileAsync(client, file, filename, text, isTTS, embeds, username, avatarUrl, allowedMentions, options, isSpoiler, components, flags).ConfigureAwait(false);
         }
         public static Task<ulong> SendFileAsync(DiscordWebhookClient client, Stream stream, string filename, string text, bool isTTS,
             IEnumerable<Embed> embeds, string username, string avatarUrl, AllowedMentions allowedMentions, RequestOptions options, bool isSpoiler,
-            MessageComponent components)
-            => SendFileAsync(client, new FileAttachment(stream, filename, isSpoiler: isSpoiler), text, isTTS, embeds, username, avatarUrl, allowedMentions, components, options);
+            MessageComponent components, MessageFlags flags)
+            => SendFileAsync(client, new FileAttachment(stream, filename, isSpoiler: isSpoiler), text, isTTS, embeds, username, avatarUrl, allowedMentions, components, options, flags);
 
-        public static Task<ulong> SendFileAsync(DiscordWebhookClient client, FileAttachment attachment, string text, bool isTTS, IEnumerable<Embed> embeds, string username, string avatarUrl, AllowedMentions allowedMentions, MessageComponent components, RequestOptions options)
-            => SendFilesAsync(client, new FileAttachment[] { attachment }, text, isTTS, embeds, username, avatarUrl, allowedMentions, components, options);
+        public static Task<ulong> SendFileAsync(DiscordWebhookClient client, FileAttachment attachment, string text, bool isTTS, 
+            IEnumerable<Embed> embeds, string username, string avatarUrl, AllowedMentions allowedMentions, 
+            MessageComponent components, RequestOptions options, MessageFlags flags)
+            => SendFilesAsync(client, new FileAttachment[] { attachment }, text, isTTS, embeds, username, avatarUrl, allowedMentions, components, options, flags);
 
         public static async Task<ulong> SendFilesAsync(DiscordWebhookClient client,
-            IEnumerable<FileAttachment> attachments, string text, bool isTTS, IEnumerable<Embed> embeds, string username, string avatarUrl, AllowedMentions allowedMentions, MessageComponent components, RequestOptions options)
+            IEnumerable<FileAttachment> attachments, string text, bool isTTS, IEnumerable<Embed> embeds, string username, 
+            string avatarUrl, AllowedMentions allowedMentions, MessageComponent components, RequestOptions options,
+            MessageFlags flags)
         {
             embeds ??= Array.Empty<Embed>();
            
@@ -141,7 +151,19 @@ namespace Discord.Webhook
                 }
             }
 
-            var args = new UploadWebhookFileParams(attachments.ToArray()) {AvatarUrl = avatarUrl, Username = username, Content = text, IsTTS = isTTS, Embeds = embeds.Any() ? embeds.Select(x => x.ToModel()).ToArray() : Optional<API.Embed[]>.Unspecified, AllowedMentions = allowedMentions?.ToModel() ?? Optional<API.AllowedMentions>.Unspecified, MessageComponents = components?.Components.Select(x => new API.ActionRowComponent(x)).ToArray() ?? Optional<API.ActionRowComponent[]>.Unspecified };
+            if (flags is not MessageFlags.None and not MessageFlags.SuppressEmbeds)
+                throw new ArgumentException("The only valid MessageFlags are SuppressEmbeds and none.", nameof(flags));
+
+            var args = new UploadWebhookFileParams(attachments.ToArray()) 
+            {
+                AvatarUrl = avatarUrl, 
+                Username = username, Content = text, 
+                IsTTS = isTTS, 
+                Embeds = embeds.Any() ? embeds.Select(x => x.ToModel()).ToArray() : Optional<API.Embed[]>.Unspecified, 
+                AllowedMentions = allowedMentions?.ToModel() ?? Optional<API.AllowedMentions>.Unspecified, 
+                MessageComponents = components?.Components.Select(x => new API.ActionRowComponent(x)).ToArray() ?? Optional<API.ActionRowComponent[]>.Unspecified,
+                Flags = flags
+            };
             var msg = await client.ApiClient.UploadWebhookFileAsync(client.Webhook.Id, args, options).ConfigureAwait(false);
             return msg.Id;
         }

test/Discord.Net.Tests.Unit/MockedEntities/MockedDMChannel.cs

@@ -83,10 +83,10 @@ namespace Discord
             throw new NotImplementedException();
         }
 
-        public Task<IUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null) => throw new NotImplementedException();
-        public Task<IUserMessage> SendFileAsync(string filePath, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null) => throw new NotImplementedException();
-        public Task<IUserMessage> SendFileAsync(Stream stream, string filename, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null) => throw new NotImplementedException();
-        public Task<IUserMessage> SendFileAsync(FileAttachment attachment, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null) => throw new NotImplementedException();
-        public Task<IUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null) => throw new NotImplementedException();
+        public Task<IUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None) => throw new NotImplementedException();
+        public Task<IUserMessage> SendFileAsync(string filePath, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None) => throw new NotImplementedException();
+        public Task<IUserMessage> SendFileAsync(Stream stream, string filename, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None) => throw new NotImplementedException();
+        public Task<IUserMessage> SendFileAsync(FileAttachment attachment, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None) => throw new NotImplementedException();
+        public Task<IUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None) => throw new NotImplementedException();
     }
 }

test/Discord.Net.Tests.Unit/MockedEntities/MockedGroupChannel.cs

@@ -93,17 +93,17 @@ namespace Discord
             throw new NotImplementedException();
         }
 
-        public Task<IUserMessage> SendFileAsync(string filePath, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null)
+        public Task<IUserMessage> SendFileAsync(string filePath, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
         {
             throw new NotImplementedException();
         }
 
-        public Task<IUserMessage> SendFileAsync(Stream stream, string filename, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null)
+        public Task<IUserMessage> SendFileAsync(Stream stream, string filename, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
         {
             throw new NotImplementedException();
         }
 
-        public Task<IUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null)
+        public Task<IUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
         {
             throw new NotImplementedException();
         }
@@ -113,7 +113,7 @@ namespace Discord
             throw new NotImplementedException();
         }
 
-        public Task<IUserMessage> SendFileAsync(FileAttachment attachment, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null) => throw new NotImplementedException();
-        public Task<IUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null) => throw new NotImplementedException();
+        public Task<IUserMessage> SendFileAsync(FileAttachment attachment, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None) => throw new NotImplementedException();
+        public Task<IUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None) => throw new NotImplementedException();
     }
 }

test/Discord.Net.Tests.Unit/MockedEntities/MockedTextChannel.cs

@@ -176,17 +176,17 @@ namespace Discord
             throw new NotImplementedException();
         }
 
-        public Task<IUserMessage> SendFileAsync(string filePath, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null)
+        public Task<IUserMessage> SendFileAsync(string filePath, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
         {
             throw new NotImplementedException();
         }
 
-        public Task<IUserMessage> SendFileAsync(Stream stream, string filename, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null)
+        public Task<IUserMessage> SendFileAsync(Stream stream, string filename, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, bool isSpoiler = false, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
         {
             throw new NotImplementedException();
         }
 
-        public Task<IUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null)
+        public Task<IUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None)
         {
             throw new NotImplementedException();
         }
@@ -211,9 +211,10 @@ namespace Discord
             throw new NotImplementedException();
         }
 
-        public Task<IUserMessage> SendFileAsync(FileAttachment attachment, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null) => throw new NotImplementedException();
-        public Task<IUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null) => throw new NotImplementedException();
-        public Task<IThreadChannel> CreateThreadAsync(string name, ThreadType type = ThreadType.PublicThread, ThreadArchiveDuration autoArchiveDuration = ThreadArchiveDuration.OneDay, IMessage message = null, bool? invitable = null, int? slowmode = null, RequestOptions options = null) => throw new NotImplementedException();
+        public Task<IUserMessage> SendFileAsync(FileAttachment attachment, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None) => throw new NotImplementedException();
+        public Task<IUserMessage> SendFilesAsync(IEnumerable<FileAttachment> attachments, string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null, MessageComponent component = null, ISticker[] stickers = null, Embed[] embeds = null, MessageFlags flags = MessageFlags.None) => throw new NotImplementedException();
+        public Task<IThreadChannel> CreateThreadAsync(string name, ThreadType type = ThreadType.PublicThread, ThreadArchiveDuration autoArchiveDuration = ThreadArchiveDuration.OneDay, IMessage message = null, bool? invitable = null, int? slowmode = null, RequestOptions options = null, MessageFlags flags = MessageFlags.None) => throw new NotImplementedException();
         public Task<IInviteMetadata> CreateInviteToApplicationAsync(DefaultApplications application, int? maxAge = 86400, int? maxUses = null, bool isTemporary = false, bool isUnique = false, RequestOptions options = null) => throw new NotImplementedException();
+        public Task<IThreadChannel> CreateThreadAsync(string name, ThreadType type = ThreadType.PublicThread, ThreadArchiveDuration autoArchiveDuration = ThreadArchiveDuration.OneDay, IMessage message = null, bool? invitable = null, int? slowmode = null, RequestOptions options = null) => throw new NotImplementedException();
     }
 }