diff --git a/src/helpers/commands/create_slash_command.ts b/src/helpers/commands/create_slash_command.ts
index fafa506fb..8baa84490 100644
--- a/src/helpers/commands/create_slash_command.ts
+++ b/src/helpers/commands/create_slash_command.ts
@@ -1,7 +1,11 @@
 import { applicationId } from "../../bot.ts";
 import { rest } from "../../rest/rest.ts";
+import { CreateGlobalApplicationCommand } from "../../types/interactions/create_global_application_command.ts";
 import { endpoints } from "../../util/constants.ts";
-import { validateSlashCommands } from "../../util/utils.ts";
+import {
+  camelKeysToSnakeCase,
+  validateSlashCommands,
+} from "../../util/utils.ts";
 
 /**
  * There are two kinds of Slash Commands: global commands and guild commands. Global commands are available for every guild that adds your app; guild commands are specific to the guild you specify when making them. Command names are unique per application within each scope (global and guild). That means:
@@ -14,17 +18,18 @@ import { validateSlashCommands } from "../../util/utils.ts";
  * Global commands are cached for **1 hour**. That means that new global commands will fan out slowly across all guilds, and will be guaranteed to be updated in an hour.
  * Guild commands update **instantly**. We recommend you use guild commands for quick testing, and global commands when they're ready for public use.
  */
-export async function createSlashCommand(options: CreateSlashCommandOptions) {
+export async function createSlashCommand(
+  options: CreateGlobalApplicationCommand,
+  guildId: string,
+) {
   validateSlashCommands([options], true);
 
   const result = await rest.runMethod(
     "post",
-    options.guildId
-      ? endpoints.COMMANDS_GUILD(applicationId, options.guildId)
+    guildId
+      ? endpoints.COMMANDS_GUILD(applicationId, guildId)
       : endpoints.COMMANDS(applicationId),
-    {
-      ...options,
-    },
+    camelKeysToSnakeCase(options),
   );
 
   return result;
diff --git a/src/helpers/commands/delete_slash_command.ts b/src/helpers/commands/delete_slash_command.ts
index 1eda08083..0b9580e15 100644
--- a/src/helpers/commands/delete_slash_command.ts
+++ b/src/helpers/commands/delete_slash_command.ts
@@ -3,12 +3,16 @@ import { rest } from "../../rest/rest.ts";
 import { endpoints } from "../../util/constants.ts";
 
 /** Deletes a slash command. */
-export function deleteSlashCommand(id: string, guildId?: string) {
-  if (!guildId) {
-    return rest.runMethod("delete", endpoints.COMMANDS_ID(applicationId, id));
-  }
-  return rest.runMethod(
+export async function deleteSlashCommand(
+  id: string,
+  guildId?: string,
+): Promise<undefined> {
+  const result = await rest.runMethod(
     "delete",
-    endpoints.COMMANDS_GUILD_ID(applicationId, guildId, id),
+    guildId
+      ? endpoints.COMMANDS_GUILD_ID(applicationId, guildId, id)
+      : endpoints.COMMANDS_ID(applicationId, id),
   );
+
+  return result;
 }
diff --git a/src/helpers/commands/delete_slash_response.ts b/src/helpers/commands/delete_slash_response.ts
index 1a9d480e0..14523c3a5 100644
--- a/src/helpers/commands/delete_slash_response.ts
+++ b/src/helpers/commands/delete_slash_response.ts
@@ -3,7 +3,10 @@ import { rest } from "../../rest/rest.ts";
 import { endpoints } from "../../util/constants.ts";
 
 /** To delete your response to a slash command. If a message id is not provided, it will default to deleting the original response. */
-export async function deleteSlashResponse(token: string, messageId?: string) {
+export async function deleteSlashResponse(
+  token: string,
+  messageId?: string,
+): Promise<undefined> {
   const result = await rest.runMethod(
     "delete",
     messageId
diff --git a/src/helpers/commands/edit_slash_response.ts b/src/helpers/commands/edit_slash_response.ts
index fa81ac460..f3c49f34d 100644
--- a/src/helpers/commands/edit_slash_response.ts
+++ b/src/helpers/commands/edit_slash_response.ts
@@ -1,13 +1,16 @@
 import { applicationId } from "../../bot.ts";
 import { rest } from "../../rest/rest.ts";
 import { structures } from "../../structures/mod.ts";
+import { DiscordenoEditWebhookMessage } from "../../types/discordeno/edit_webhook_message.ts";
+import { DiscordAllowedMentionsTypes } from "../../types/messages/allowed_mentions_types.ts";
+import { DiscordMessage } from "../../types/messages/message.ts";
 import { Errors } from "../../types/misc/errors.ts";
 import { endpoints } from "../../util/constants.ts";
 
 /** To edit your response to a slash command. If a messageId is not provided it will default to editing the original response. */
 export async function editSlashResponse(
   token: string,
-  options: EditSlashResponseOptions,
+  options: DiscordenoEditWebhookMessage,
 ) {
   if (options.content && options.content.length > 2000) {
     throw Error(Errors.MESSAGE_MAX_LENGTH);
@@ -17,31 +20,39 @@ export async function editSlashResponse(
     options.embeds.splice(10);
   }
 
-  if (options.allowed_mentions) {
-    if (options.allowed_mentions.users?.length) {
-      if (options.allowed_mentions.parse.includes("users")) {
-        options.allowed_mentions.parse = options.allowed_mentions.parse.filter(
+  if (options.allowedMentions) {
+    if (options.allowedMentions.users?.length) {
+      if (
+        options.allowedMentions.parse.includes(
+          DiscordAllowedMentionsTypes.UserMentions,
+        )
+      ) {
+        options.allowedMentions.parse = options.allowedMentions.parse.filter(
           (p) => p !== "users",
         );
       }
 
-      if (options.allowed_mentions.users.length > 100) {
-        options.allowed_mentions.users = options.allowed_mentions.users.slice(
+      if (options.allowedMentions.users.length > 100) {
+        options.allowedMentions.users = options.allowedMentions.users.slice(
           0,
           100,
         );
       }
     }
 
-    if (options.allowed_mentions.roles?.length) {
-      if (options.allowed_mentions.parse.includes("roles")) {
-        options.allowed_mentions.parse = options.allowed_mentions.parse.filter(
+    if (options.allowedMentions.roles?.length) {
+      if (
+        options.allowedMentions.parse.includes(
+          DiscordAllowedMentionsTypes.RoleMentions,
+        )
+      ) {
+        options.allowedMentions.parse = options.allowedMentions.parse.filter(
           (p) => p !== "roles",
         );
       }
 
-      if (options.allowed_mentions.roles.length > 100) {
-        options.allowed_mentions.roles = options.allowed_mentions.roles.slice(
+      if (options.allowedMentions.roles.length > 100) {
+        options.allowedMentions.roles = options.allowedMentions.roles.slice(
           0,
           100,
         );
@@ -61,7 +72,7 @@ export async function editSlashResponse(
   if (!options.messageId) return result;
 
   const message = await structures.createMessageStruct(
-    result as MessageCreateOptions,
+    result as DiscordMessage,
   );
   return message;
 }
diff --git a/src/helpers/commands/get_slash_command.ts b/src/helpers/commands/get_slash_command.ts
index 3cc50bc28..72c61b3f6 100644
--- a/src/helpers/commands/get_slash_command.ts
+++ b/src/helpers/commands/get_slash_command.ts
@@ -1,5 +1,6 @@
 import { applicationId } from "../../bot.ts";
 import { rest } from "../../rest/rest.ts";
+import { ApplicationCommand } from "../../types/interactions/application_command.ts";
 import { endpoints } from "../../util/constants.ts";
 
 /** Fetchs the global command for the given Id. If a guildId is provided, the guild command will be fetched. */
@@ -11,5 +12,5 @@ export async function getSlashCommand(commandId: string, guildId?: string) {
       : endpoints.COMMANDS_ID(applicationId, commandId),
   );
 
-  return result as SlashCommand;
+  return result as ApplicationCommand;
 }
diff --git a/src/helpers/commands/get_slash_commands.ts b/src/helpers/commands/get_slash_commands.ts
index ce2cc50bf..3337baf49 100644
--- a/src/helpers/commands/get_slash_commands.ts
+++ b/src/helpers/commands/get_slash_commands.ts
@@ -1,5 +1,6 @@
 import { applicationId } from "../../bot.ts";
 import { rest } from "../../rest/rest.ts";
+import { ApplicationCommand } from "../../types/interactions/application_command.ts";
 import { Collection } from "../../util/collection.ts";
 import { endpoints } from "../../util/constants.ts";
 
@@ -10,7 +11,7 @@ export async function getSlashCommands(guildId?: string) {
     guildId
       ? endpoints.COMMANDS_GUILD(applicationId, guildId)
       : endpoints.COMMANDS(applicationId),
-  )) as SlashCommand[];
+  )) as ApplicationCommand[];
 
   return new Collection(result.map((command) => [command.name, command]));
 }
diff --git a/src/helpers/commands/send_interaction_response.ts b/src/helpers/commands/send_interaction_response.ts
index c60ea83ef..6d9fb0022 100644
--- a/src/helpers/commands/send_interaction_response.ts
+++ b/src/helpers/commands/send_interaction_response.ts
@@ -1,6 +1,7 @@
 import { applicationId } from "../../bot.ts";
 import { cache } from "../../cache.ts";
 import { rest } from "../../rest/rest.ts";
+import { DiscordenoInteractionResponse } from "../../types/discordeno/interaction_response.ts";
 import { endpoints } from "../../util/constants.ts";
 
 /**
@@ -12,7 +13,7 @@ import { endpoints } from "../../util/constants.ts";
 export async function sendInteractionResponse(
   id: string,
   token: string,
-  options: SlashCommandResponseOptions,
+  options: DiscordenoInteractionResponse,
 ) {
   // If its already been executed, we need to send a followup response
   if (cache.executedSlashCommands.has(token)) {
@@ -30,12 +31,12 @@ export async function sendInteractionResponse(
 
   // If the user wants this as a private message mark it ephemeral
   if (options.private) {
-    options.data.flags = 64;
+    options.data = { ...options.data, flags: 64 };
   }
 
   // If no mentions are provided, force disable mentions
-  if (!options.data.allowed_mentions) {
-    options.data.allowed_mentions = { parse: [] };
+  if (!options.data?.allowedMentions) {
+    options.data = { ...options.data, allowedMentions: { parse: [] } };
   }
 
   const result = await rest.runMethod(
diff --git a/src/helpers/commands/upsert_slash_command.ts b/src/helpers/commands/upsert_slash_command.ts
index 21091f18e..66c064780 100644
--- a/src/helpers/commands/upsert_slash_command.ts
+++ b/src/helpers/commands/upsert_slash_command.ts
@@ -1,5 +1,6 @@
 import { applicationId } from "../../bot.ts";
 import { rest } from "../../rest/rest.ts";
+import { EditGlobalApplicationCommand } from "../../types/interactions/edit_global_application_command.ts";
 import { endpoints } from "../../util/constants.ts";
 import { validateSlashCommands } from "../../util/utils.ts";
 
@@ -8,7 +9,7 @@ import { validateSlashCommands } from "../../util/utils.ts";
  */
 export async function upsertSlashCommand(
   commandId: string,
-  options: UpsertSlashCommandOptions,
+  options: EditGlobalApplicationCommand,
   guildId?: string,
 ) {
   validateSlashCommands([options]);
diff --git a/src/helpers/commands/upsert_slash_commands.ts b/src/helpers/commands/upsert_slash_commands.ts
index a5befc957..ce0bdeee2 100644
--- a/src/helpers/commands/upsert_slash_commands.ts
+++ b/src/helpers/commands/upsert_slash_commands.ts
@@ -1,5 +1,6 @@
 import { applicationId } from "../../bot.ts";
 import { rest } from "../../rest/rest.ts";
+import { EditGlobalApplicationCommand } from "../../types/interactions/edit_global_application_command.ts";
 import { endpoints } from "../../util/constants.ts";
 import { validateSlashCommands } from "../../util/utils.ts";
 
@@ -9,7 +10,7 @@ import { validateSlashCommands } from "../../util/utils.ts";
  * **NOTE:** Any slash commands that are not specified in this function will be **deleted**. If you don't provide the commandId and rename your command, the command gets a new Id.
  */
 export async function upsertSlashCommands(
-  options: UpsertSlashCommandsOptions[],
+  options: EditGlobalApplicationCommand[],
   guildId?: string,
 ) {
   validateSlashCommands(options);
diff --git a/src/helpers/emojis/create_emoji.ts b/src/helpers/emojis/create_emoji.ts
index 1070bf7a9..4b2cdff67 100644
--- a/src/helpers/emojis/create_emoji.ts
+++ b/src/helpers/emojis/create_emoji.ts
@@ -1,14 +1,16 @@
 import { rest } from "../../rest/rest.ts";
+import { CreateGuildEmoji } from "../../types/emojis/create_guild_emoji.ts";
+import { Emoji } from "../../types/emojis/emoji.ts";
 import { endpoints } from "../../util/constants.ts";
 import { requireBotGuildPermissions } from "../../util/permissions.ts";
-import { urlToBase64 } from "../../util/utils.ts";
+import { snakeKeysToCamelCase, urlToBase64 } from "../../util/utils.ts";
 
 /** Create an emoji in the server. Emojis and animated emojis have a maximum file size of 256kb. Attempting to upload an emoji larger than this limit will fail and return 400 Bad Request and an error message, but not a JSON status code. If a URL is provided to the image parameter, Discordeno will automatically convert it to a base64 string internally. */
 export async function createEmoji(
   guildId: string,
   name: string,
   image: string,
-  options: CreateEmojisOptions,
+  options: CreateGuildEmoji,
 ) {
   await requireBotGuildPermissions(guildId, ["MANAGE_EMOJIS"]);
 
@@ -22,5 +24,5 @@ export async function createEmoji(
     image,
   });
 
-  return result;
+  return snakeKeysToCamelCase(result) as Emoji;
 }
diff --git a/src/helpers/emojis/delete_emoji.ts b/src/helpers/emojis/delete_emoji.ts
index 64154ccfe..97783b41c 100644
--- a/src/helpers/emojis/delete_emoji.ts
+++ b/src/helpers/emojis/delete_emoji.ts
@@ -7,7 +7,7 @@ export async function deleteEmoji(
   guildId: string,
   id: string,
   reason?: string,
-) {
+): Promise<undefined> {
   await requireBotGuildPermissions(guildId, ["MANAGE_EMOJIS"]);
 
   const result = await rest.runMethod(
diff --git a/src/helpers/emojis/edit_emoji.ts b/src/helpers/emojis/edit_emoji.ts
index 0c2e125a6..803dc8ea5 100644
--- a/src/helpers/emojis/edit_emoji.ts
+++ b/src/helpers/emojis/edit_emoji.ts
@@ -1,4 +1,5 @@
 import { rest } from "../../rest/rest.ts";
+import { ModifyGuildEmoji } from "../../types/emojis/modify_guild_emoji.ts";
 import { endpoints } from "../../util/constants.ts";
 import { requireBotGuildPermissions } from "../../util/permissions.ts";
 
@@ -6,7 +7,7 @@ import { requireBotGuildPermissions } from "../../util/permissions.ts";
 export async function editEmoji(
   guildId: string,
   id: string,
-  options: EditEmojisOptions,
+  options: ModifyGuildEmoji,
 ) {
   await requireBotGuildPermissions(guildId, ["MANAGE_EMOJIS"]);
 
diff --git a/src/helpers/emojis/get_emoji.ts b/src/helpers/emojis/get_emoji.ts
index edf3f4c25..c99baa1d0 100644
--- a/src/helpers/emojis/get_emoji.ts
+++ b/src/helpers/emojis/get_emoji.ts
@@ -1,5 +1,6 @@
 import { cacheHandlers } from "../../cache.ts";
 import { rest } from "../../rest/rest.ts";
+import { Emoji } from "../../types/emojis/emoji.ts";
 import { Errors } from "../../types/misc/errors.ts";
 import { endpoints } from "../../util/constants.ts";
 
@@ -21,7 +22,7 @@ export async function getEmoji(
   if (addToCache) {
     const guild = await cacheHandlers.get("guilds", guildId);
     if (!guild) throw new Error(Errors.GUILD_NOT_FOUND);
-    guild.emojis.set(result.id ?? result.name, result);
+    guild.emojis.set(emojiId, result);
     cacheHandlers.set(
       "guilds",
       guildId,
diff --git a/src/helpers/emojis/get_emojis.ts b/src/helpers/emojis/get_emojis.ts
index 133723114..6678c2b81 100644
--- a/src/helpers/emojis/get_emojis.ts
+++ b/src/helpers/emojis/get_emojis.ts
@@ -1,5 +1,6 @@
 import { cacheHandlers } from "../../cache.ts";
 import { rest } from "../../rest/rest.ts";
+import { Emoji } from "../../types/emojis/emoji.ts";
 import { Errors } from "../../types/misc/errors.ts";
 import { endpoints } from "../../util/constants.ts";
 
@@ -16,7 +17,7 @@ export async function getEmojis(guildId: string, addToCache = true) {
     const guild = await cacheHandlers.get("guilds", guildId);
     if (!guild) throw new Error(Errors.GUILD_NOT_FOUND);
 
-    result.forEach((emoji) => guild.emojis.set(emoji.id ?? emoji.name, emoji));
+    result.forEach((emoji) => guild.emojis.set(emoji.id!, emoji));
 
     cacheHandlers.set("guilds", guildId, guild);
   }
diff --git a/src/helpers/guilds/create_guild.ts b/src/helpers/guilds/create_guild.ts
index 144d260a4..cb58b92ac 100644
--- a/src/helpers/guilds/create_guild.ts
+++ b/src/helpers/guilds/create_guild.ts
@@ -1,14 +1,16 @@
 import { rest } from "../../rest/rest.ts";
 import { structures } from "../../structures/mod.ts";
+import { CreateGuild } from "../../types/guilds/create_guild.ts";
+import { DiscordGuild } from "../../types/guilds/guild.ts";
 import { endpoints } from "../../util/constants.ts";
 
 /** Create a new guild. Returns a guild object on success. Fires a Guild Create Gateway event. This endpoint can be used only by bots in less than 10 guilds. */
-export async function createGuild(options: CreateServerOptions) {
+export async function createGuild(options: CreateGuild) {
   const guild = (await rest.runMethod(
     "post",
     endpoints.GUILDS,
     options,
-  )) as CreateGuildPayload;
+  )) as DiscordGuild;
 
   return structures.createGuildStruct(guild, 0);
 }
diff --git a/src/helpers/guilds/delete_server.ts b/src/helpers/guilds/delete_server.ts
index 03da1f717..43a1085eb 100644
--- a/src/helpers/guilds/delete_server.ts
+++ b/src/helpers/guilds/delete_server.ts
@@ -3,7 +3,7 @@ import { endpoints } from "../../util/constants.ts";
 
 /** Delete a guild permanently. User must be owner. Returns 204 No Content on success. Fires a Guild Delete Gateway event.
  */
-export async function deleteServer(guildId: string) {
+export async function deleteServer(guildId: string): Promise<undefined> {
   const result = await rest.runMethod("delete", endpoints.GUILDS_BASE(guildId));
 
   return result;
diff --git a/src/helpers/guilds/edit_guild.ts b/src/helpers/guilds/edit_guild.ts
index 081b7a64b..a45217594 100644
--- a/src/helpers/guilds/edit_guild.ts
+++ b/src/helpers/guilds/edit_guild.ts
@@ -1,10 +1,13 @@
 import { rest } from "../../rest/rest.ts";
+import { structures } from "../../structures/mod.ts";
+import { DiscordGuild } from "../../types/guilds/guild.ts";
+import { ModifyGuild } from "../../types/guilds/modify_guild.ts";
 import { endpoints } from "../../util/constants.ts";
 import { requireBotGuildPermissions } from "../../util/permissions.ts";
 import { urlToBase64 } from "../../util/utils.ts";
 
 /** Modify a guilds settings. Requires the MANAGE_GUILD permission. */
-export async function editGuild(guildId: string, options: GuildEditOptions) {
+export async function editGuild(guildId: string, options: ModifyGuild) {
   await requireBotGuildPermissions(guildId, ["MANAGE_GUILD"]);
 
   if (options.icon && !options.icon.startsWith("data:image/")) {
@@ -23,7 +26,7 @@ export async function editGuild(guildId: string, options: GuildEditOptions) {
     "patch",
     endpoints.GUILDS_BASE(guildId),
     options,
-  );
+  ) as DiscordGuild;
 
-  return result;
+  return structures.createGuildStruct(result, -1);
 }
diff --git a/src/helpers/guilds/edit_widget.ts b/src/helpers/guilds/edit_widget.ts
index f36511cc7..42eaefd1b 100644
--- a/src/helpers/guilds/edit_widget.ts
+++ b/src/helpers/guilds/edit_widget.ts
@@ -1,6 +1,8 @@
 import { rest } from "../../rest/rest.ts";
+import { GuildWidget } from "../../types/guilds/guild_widget.ts";
 import { endpoints } from "../../util/constants.ts";
 import { requireBotGuildPermissions } from "../../util/permissions.ts";
+import { snakeKeysToCamelCase } from "../../util/utils.ts";
 
 /** Modify a guild widget object for the guild. Requires the MANAGE_GUILD permission. */
 export async function editWidget(
@@ -19,5 +21,5 @@ export async function editWidget(
     },
   );
 
-  return result;
+  return snakeKeysToCamelCase(result) as GuildWidget;
 }
diff --git a/src/helpers/messages/send_message.ts b/src/helpers/messages/send_message.ts
index b7c628917..e80f5ff72 100644
--- a/src/helpers/messages/send_message.ts
+++ b/src/helpers/messages/send_message.ts
@@ -2,15 +2,19 @@ import { cacheHandlers } from "../../cache.ts";
 import { rest } from "../../rest/rest.ts";
 import { structures } from "../../structures/mod.ts";
 import { DiscordChannelTypes } from "../../types/channels/channel_types.ts";
+import { DiscordenoCreateMessage } from "../../types/discordeno/create_message.ts";
+import { DiscordAllowedMentionsTypes } from "../../types/messages/allowed_mentions_types.ts";
+import { DiscordMessage } from "../../types/messages/message.ts";
 import { Errors } from "../../types/misc/errors.ts";
 import { PermissionStrings } from "../../types/permissions/permission_strings.ts";
 import { endpoints } from "../../util/constants.ts";
 import { requireBotChannelPermissions } from "../../util/permissions.ts";
+import { camelKeysToSnakeCase } from "../../util/utils.ts";
 
 /** Send a message to the channel. Requires SEND_MESSAGES permission. */
 export async function sendMessage(
   channelId: string,
-  content: string | MessageContent,
+  content: string | DiscordenoCreateMessage,
 ) {
   if (typeof content === "string") content = { content };
 
@@ -33,7 +37,10 @@ export async function sendMessage(
 
     if (content.tts) requiredPerms.add("SEND_TTS_MESSAGES");
     if (content.embed) requiredPerms.add("EMBED_LINKS");
-    if (content.replyMessageId || content.mentions?.repliedUser) {
+    if (
+      content.messageReference?.messageId ||
+      content.allowedMentions?.repliedUser
+    ) {
       requiredPerms.add("READ_MESSAGE_HISTORY");
     }
 
@@ -45,50 +52,63 @@ export async function sendMessage(
     throw new Error(Errors.MESSAGE_MAX_LENGTH);
   }
 
-  if (content.mentions) {
-    if (content.mentions.users?.length) {
-      if (content.mentions.parse?.includes("users")) {
-        content.mentions.parse = content.mentions.parse.filter(
+  if (content.allowedMentions) {
+    if (content.allowedMentions.users?.length) {
+      if (
+        content.allowedMentions.parse?.includes(
+          DiscordAllowedMentionsTypes.UserMentions,
+        )
+      ) {
+        content.allowedMentions.parse = content.allowedMentions.parse.filter(
           (p) => p !== "users",
         );
       }
 
-      if (content.mentions.users.length > 100) {
-        content.mentions.users = content.mentions.users.slice(0, 100);
+      if (content.allowedMentions.users.length > 100) {
+        content.allowedMentions.users = content.allowedMentions.users.slice(
+          0,
+          100,
+        );
       }
     }
 
-    if (content.mentions.roles?.length) {
-      if (content.mentions.parse?.includes("roles")) {
-        content.mentions.parse = content.mentions.parse.filter(
+    if (content.allowedMentions.roles?.length) {
+      if (
+        content.allowedMentions.parse?.includes(
+          DiscordAllowedMentionsTypes.RoleMentions,
+        )
+      ) {
+        content.allowedMentions.parse = content.allowedMentions.parse.filter(
           (p) => p !== "roles",
         );
       }
 
-      if (content.mentions.roles.length > 100) {
-        content.mentions.roles = content.mentions.roles.slice(0, 100);
+      if (content.allowedMentions.roles.length > 100) {
+        content.allowedMentions.roles = content.allowedMentions.roles.slice(
+          0,
+          100,
+        );
       }
     }
   }
 
   const result =
-    (await rest.runMethod("post", endpoints.CHANNEL_MESSAGES(channelId), {
-      ...content,
-      allowed_mentions: content.mentions
-        ? {
-          ...content.mentions,
-          replied_user: content.mentions.repliedUser,
-        }
-        : undefined,
-      ...(content.replyMessageId
-        ? {
-          message_reference: {
-            message_id: content.replyMessageId,
-            fail_if_not_exists: content.failReplyIfNotExists === true,
-          },
-        }
-        : {}),
-    })) as MessageCreateOptions;
+    (await rest.runMethod(
+      "post",
+      endpoints.CHANNEL_MESSAGES(channelId),
+      camelKeysToSnakeCase({
+        ...content,
+        ...(content.messageReference?.messageId
+          ? {
+            messageReference: {
+              ...content.messageReference,
+              failIfNotExists:
+                content.messageReference.failIfNotExists === true,
+            },
+          }
+          : {}),
+      }),
+    )) as DiscordMessage;
 
   return structures.createMessageStruct(result);
 }
diff --git a/src/helpers/messages/unpin_message.ts b/src/helpers/messages/unpin_message.ts
index db19544ef..c2a5630bf 100644
--- a/src/helpers/messages/unpin_message.ts
+++ b/src/helpers/messages/unpin_message.ts
@@ -3,7 +3,10 @@ import { endpoints } from "../../util/constants.ts";
 import { requireBotChannelPermissions } from "../../util/permissions.ts";
 
 /** Unpin a message in a channel. Requires MANAGE_MESSAGES. */
-export async function unpin(channelId: string, messageId: string) {
+export async function unpin(
+  channelId: string,
+  messageId: string,
+): Promise<undefined> {
   await requireBotChannelPermissions(channelId, ["MANAGE_MESSAGES"]);
 
   const result = await rest.runMethod(