diff --git a/src/managers/ApplicationCommandManager.js b/src/managers/ApplicationCommandManager.js
index dbc83dcb2c0b..c053382f3a9a 100644
--- a/src/managers/ApplicationCommandManager.js
+++ b/src/managers/ApplicationCommandManager.js
@@ -100,7 +100,7 @@ class ApplicationCommandManager extends CachedManager {
 
   /**
    * Creates an application command.
-   * @param {ApplicationCommandData} command The command
+   * @param {ApplicationCommandData|APIApplicationCommand} command The command
    * @param {Snowflake} [guildId] The guild's id to create this command in,
    * ignored when using a {@link GuildApplicationCommandManager}
    * @returns {Promise<ApplicationCommand>}
@@ -122,7 +122,7 @@ class ApplicationCommandManager extends CachedManager {
 
   /**
    * Sets all the commands for this application or guild.
-   * @param {ApplicationCommandData[]} commands The commands
+   * @param {ApplicationCommandData[]|APIApplicationCommand[]} commands The commands
    * @param {Snowflake} [guildId] The guild's id to create the commands in,
    * ignored when using a {@link GuildApplicationCommandManager}
    * @returns {Promise<Collection<Snowflake, ApplicationCommand>>}
@@ -155,7 +155,7 @@ class ApplicationCommandManager extends CachedManager {
   /**
    * Edits an application command.
    * @param {ApplicationCommandResolvable} command The command to edit
-   * @param {ApplicationCommandData} data The data to update the command with
+   * @param {ApplicationCommandData|APIApplicationCommand} data The data to update the command with
    * @param {Snowflake} [guildId] The guild's id where the command registered,
    * ignored when using a {@link GuildApplicationCommandManager}
    * @returns {Promise<ApplicationCommand>}
@@ -171,7 +171,9 @@ class ApplicationCommandManager extends CachedManager {
     const id = this.resolveId(command);
     if (!id) throw new TypeError('INVALID_TYPE', 'command', 'ApplicationCommandResolvable');
 
-    const patched = await this.commandPath({ id, guildId }).patch({ data: this.constructor.transformCommand(data) });
+    const patched = await this.commandPath({ id, guildId }).patch({
+      data: this.constructor.transformCommand(data),
+    });
     return this._add(patched, !guildId, guildId);
   }
 
@@ -200,7 +202,7 @@ class ApplicationCommandManager extends CachedManager {
 
   /**
    * Transforms an {@link ApplicationCommandData} object into something that can be used with the API.
-   * @param {ApplicationCommandData} command The command to transform
+   * @param {ApplicationCommandData|APIApplicationCommand} command The command to transform
    * @returns {APIApplicationCommand}
    * @private
    */
@@ -210,7 +212,7 @@ class ApplicationCommandManager extends CachedManager {
       description: command.description,
       type: typeof command.type === 'number' ? command.type : ApplicationCommandTypes[command.type],
       options: command.options?.map(o => ApplicationCommand.transformOption(o)),
-      default_permission: command.defaultPermission,
+      default_permission: command.defaultPermission ?? command.default_permission,
     };
   }
 }
diff --git a/typings/index.d.ts b/typings/index.d.ts
index e1f8bf8d4765..61251c5fa5ba 100644
--- a/typings/index.d.ts
+++ b/typings/index.d.ts
@@ -45,6 +45,7 @@ import {
   APIUser,
   GatewayVoiceServerUpdateDispatchData,
   GatewayVoiceStateUpdateDispatchData,
+  RESTPostAPIApplicationCommandsJSONBody,
   Snowflake,
 } from 'discord-api-types/v9';
 import { EventEmitter } from 'events';
@@ -237,6 +238,8 @@ export class ApplicationCommand<PermissionsFetchType = {}> extends Base {
     enforceOptionorder?: boolean,
   ): boolean;
   private static transformOption(option: ApplicationCommandOptionData, received?: boolean): unknown;
+  private static transformCommand(command: ApplicationCommandData): RESTPostAPIApplicationCommandsJSONBody;
+  private static isAPICommandData(command: object): command is RESTPostAPIApplicationCommandsJSONBody;
 }
 
 export type ApplicationResolvable = Application | Activity | Snowflake;
@@ -2400,6 +2403,8 @@ export abstract class CachedManager<K, Holds, R> extends DataManager<K, Holds, R
   private _add(data: unknown, cache?: boolean, { id, extras }?: { id: K; extras: unknown[] }): Holds;
 }
 
+export type ApplicationCommandDataResolvable = ApplicationCommandData | RESTPostAPIApplicationCommandsJSONBody;
+
 export class ApplicationCommandManager<
   ApplicationCommandScope = ApplicationCommand<{ guild: GuildResolvable }>,
   PermissionsOptionsExtras = { guild: GuildResolvable },
@@ -2414,13 +2419,16 @@ export class ApplicationCommandManager<
     null
   >;
   private commandPath({ id, guildId }: { id?: Snowflake; guildId?: Snowflake }): unknown;
-  public create(command: ApplicationCommandData): Promise<ApplicationCommandScope>;
-  public create(command: ApplicationCommandData, guildId: Snowflake): Promise<ApplicationCommand>;
+  public create(command: ApplicationCommandDataResolvable): Promise<ApplicationCommandScope>;
+  public create(command: ApplicationCommandDataResolvable, guildId: Snowflake): Promise<ApplicationCommand>;
   public delete(command: ApplicationCommandResolvable, guildId?: Snowflake): Promise<ApplicationCommandScope | null>;
-  public edit(command: ApplicationCommandResolvable, data: ApplicationCommandData): Promise<ApplicationCommandScope>;
   public edit(
     command: ApplicationCommandResolvable,
-    data: ApplicationCommandData,
+    data: ApplicationCommandDataResolvable,
+  ): Promise<ApplicationCommandScope>;
+  public edit(
+    command: ApplicationCommandResolvable,
+    data: ApplicationCommandDataResolvable,
     guildId: Snowflake,
   ): Promise<ApplicationCommand>;
   public fetch(
@@ -2432,9 +2440,9 @@ export class ApplicationCommandManager<
     id?: Snowflake,
     options?: FetchApplicationCommandOptions,
   ): Promise<Collection<Snowflake, ApplicationCommandScope>>;
-  public set(commands: ApplicationCommandData[]): Promise<Collection<Snowflake, ApplicationCommandScope>>;
+  public set(commands: ApplicationCommandDataResolvable[]): Promise<Collection<Snowflake, ApplicationCommandScope>>;
   public set(
-    commands: ApplicationCommandData[],
+    commands: ApplicationCommandDataResolvable[],
     guildId: Snowflake,
   ): Promise<Collection<Snowflake, ApplicationCommand>>;
   private static transformCommand(
@@ -2502,12 +2510,15 @@ export class ChannelManager extends CachedManager<Snowflake, Channel, ChannelRes
 export class GuildApplicationCommandManager extends ApplicationCommandManager<ApplicationCommand, {}, Guild> {
   public constructor(guild: Guild, iterable?: Iterable<RawApplicationCommandData>);
   public guild: Guild;
-  public create(command: ApplicationCommandData): Promise<ApplicationCommand>;
+  public create(command: ApplicationCommandDataResolvable): Promise<ApplicationCommand>;
   public delete(command: ApplicationCommandResolvable): Promise<ApplicationCommand | null>;
-  public edit(command: ApplicationCommandResolvable, data: ApplicationCommandData): Promise<ApplicationCommand>;
+  public edit(
+    command: ApplicationCommandResolvable,
+    data: ApplicationCommandDataResolvable,
+  ): Promise<ApplicationCommand>;
   public fetch(id: Snowflake, options?: BaseFetchOptions): Promise<ApplicationCommand>;
   public fetch(id?: undefined, options?: BaseFetchOptions): Promise<Collection<Snowflake, ApplicationCommand>>;
-  public set(commands: ApplicationCommandData[]): Promise<Collection<Snowflake, ApplicationCommand>>;
+  public set(commands: ApplicationCommandDataResolvable[]): Promise<Collection<Snowflake, ApplicationCommand>>;
 }
 
 export class GuildChannelManager extends CachedManager<