diff --git a/package.json b/package.json
index ddf4b106166f49c4c3579be3df11d91ce8022eba..d3c2ad8170e5f43d2e309a3a83543ed3ef76471f 100644
--- a/package.json
+++ b/package.json
@@ -88,7 +88,7 @@
 		"autwh": "0.1.0",
 		"bcryptjs": "2.4.3",
 		"bootstrap-vue": "2.0.0-rc.6",
-		"cafy": "7.0.1",
+		"cafy": "8.0.0",
 		"chai": "4.1.2",
 		"chai-http": "4.0.0",
 		"chalk": "2.4.1",
diff --git a/src/cafy-id.ts b/src/cafy-id.ts
index 3faf5cd996c59979533931d1427ac7bdaa880937..310b1eb20b0c8609a5d5077e3bb3b7055aa21422 100644
--- a/src/cafy-id.ts
+++ b/src/cafy-id.ts
@@ -8,8 +8,8 @@ export const isNotAnId = x => !isAnId(x);
  * ID
  */
 export default class ID extends Query<mongo.ObjectID> {
-	constructor(...args) {
-		super(...args);
+	constructor() {
+		super();
 
 		this.transform = v => {
 			if (isAnId(v) && !mongo.ObjectID.prototype.isPrototypeOf(v)) {
@@ -19,7 +19,7 @@ export default class ID extends Query<mongo.ObjectID> {
 			}
 		};
 
-		this.pushValidator(v => {
+		this.push(v => {
 			if (!mongo.ObjectID.prototype.isPrototypeOf(v) && isNotAnId(v)) {
 				return new Error('must-be-an-id');
 			}
diff --git a/src/models/note-reaction.ts b/src/models/note-reaction.ts
index 7891ebdf1719b61fb636472d8dba536f37b188fa..706ae54c168fc51ef9323a24d7d5405471115e90 100644
--- a/src/models/note-reaction.ts
+++ b/src/models/note-reaction.ts
@@ -17,7 +17,7 @@ export interface INoteReaction {
 	reaction: string;
 }
 
-export const validateReaction = $().string().or([
+export const validateReaction = $.str.or([
 	'like',
 	'love',
 	'laugh',
diff --git a/src/server/api/endpoints/aggregation/posts.ts b/src/server/api/endpoints/aggregation/posts.ts
index 87e9af3a564940f181b349573fe25f218fe6db78..d348cadae9b8c6e252f5dcb79d050183dff839a1 100644
--- a/src/server/api/endpoints/aggregation/posts.ts
+++ b/src/server/api/endpoints/aggregation/posts.ts
@@ -9,7 +9,7 @@ import Note from '../../../../models/note';
  */
 module.exports = params => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 365, limitErr] = $(params.limit).optional.number().range(1, 365).get();
+	const [limit = 365, limitErr] = $.num.optional().range(1, 365).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	const datas = await Note
diff --git a/src/server/api/endpoints/aggregation/users.ts b/src/server/api/endpoints/aggregation/users.ts
index 831d771333f93285564798e7e5e09402d5e8807b..b116c1454bc77f43db5cf02f71c6d5dadfdef570 100644
--- a/src/server/api/endpoints/aggregation/users.ts
+++ b/src/server/api/endpoints/aggregation/users.ts
@@ -9,7 +9,7 @@ import User from '../../../../models/user';
  */
 module.exports = params => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 365, limitErr] = $(params.limit).optional.number().range(1, 365).get();
+	const [limit = 365, limitErr] = $.num.optional().range(1, 365).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	const users = await User
diff --git a/src/server/api/endpoints/aggregation/users/activity.ts b/src/server/api/endpoints/aggregation/users/activity.ts
index 4a982ac3babc89d7865367fcc837280b6d8f4dd9..9109487ac6f8868e9c6dd64d40ba1688d65ec810 100644
--- a/src/server/api/endpoints/aggregation/users/activity.ts
+++ b/src/server/api/endpoints/aggregation/users/activity.ts
@@ -12,11 +12,11 @@ import Note from '../../../../../models/note';
  */
 module.exports = (params) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 365, limitErr] = $(params.limit).optional.number().range(1, 365).get();
+	const [limit = 365, limitErr] = $.num.optional().range(1, 365).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Lookup user
diff --git a/src/server/api/endpoints/aggregation/users/followers.ts b/src/server/api/endpoints/aggregation/users/followers.ts
index 3079542c6797f9d66add309ed777e00eba042cc5..dfcaf8462fa33c4849c2add769aea232dba9b9da 100644
--- a/src/server/api/endpoints/aggregation/users/followers.ts
+++ b/src/server/api/endpoints/aggregation/users/followers.ts
@@ -10,7 +10,7 @@ import FollowedLog from '../../../../../models/followed-log';
  */
 module.exports = (params) => new Promise(async (res, rej) => {
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Lookup user
diff --git a/src/server/api/endpoints/aggregation/users/following.ts b/src/server/api/endpoints/aggregation/users/following.ts
index 4efe20230d2224b72b45424d7515509c43db17ed..5f826fd71c20e7d0770b7af777543937f0cd8378 100644
--- a/src/server/api/endpoints/aggregation/users/following.ts
+++ b/src/server/api/endpoints/aggregation/users/following.ts
@@ -10,7 +10,7 @@ import FollowingLog from '../../../../../models/following-log';
  */
 module.exports = (params) => new Promise(async (res, rej) => {
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Lookup user
diff --git a/src/server/api/endpoints/aggregation/users/post.ts b/src/server/api/endpoints/aggregation/users/post.ts
index fc6541065b7e5d26329d936705844512f163af67..11f9ef14cd6f083235d7c42a26bbfe9b44005cf2 100644
--- a/src/server/api/endpoints/aggregation/users/post.ts
+++ b/src/server/api/endpoints/aggregation/users/post.ts
@@ -10,7 +10,7 @@ import Note from '../../../../../models/note';
  */
 module.exports = (params) => new Promise(async (res, rej) => {
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Lookup user
diff --git a/src/server/api/endpoints/aggregation/users/reaction.ts b/src/server/api/endpoints/aggregation/users/reaction.ts
index ea3363e1aa40a1861a14b35c480bfac4d0e40dfd..2de28402589f4a0d3c43b98ffdf7544facf61de0 100644
--- a/src/server/api/endpoints/aggregation/users/reaction.ts
+++ b/src/server/api/endpoints/aggregation/users/reaction.ts
@@ -13,7 +13,7 @@ import Reaction from '../../../../../models/note-reaction';
  */
 module.exports = (params) => new Promise(async (res, rej) => {
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Lookup user
diff --git a/src/server/api/endpoints/app/create.ts b/src/server/api/endpoints/app/create.ts
index 97154690fa774f6595bde760971ecca210662514..553bd2381ad3bc8ff9f28d29544b8592904100a7 100644
--- a/src/server/api/endpoints/app/create.ts
+++ b/src/server/api/endpoints/app/create.ts
@@ -67,24 +67,24 @@ import App, { isValidNameId, pack } from '../../../../models/app';
  */
 module.exports = async (params, user) => new Promise(async (res, rej) => {
 	// Get 'nameId' parameter
-	const [nameId, nameIdErr] = $(params.nameId).string().pipe(isValidNameId).get();
+	const [nameId, nameIdErr] = $.str.pipe(isValidNameId).get(params.nameId);
 	if (nameIdErr) return rej('invalid nameId param');
 
 	// Get 'name' parameter
-	const [name, nameErr] = $(params.name).string().get();
+	const [name, nameErr] = $.str.get(params.name);
 	if (nameErr) return rej('invalid name param');
 
 	// Get 'description' parameter
-	const [description, descriptionErr] = $(params.description).string().get();
+	const [description, descriptionErr] = $.str.get(params.description);
 	if (descriptionErr) return rej('invalid description param');
 
 	// Get 'permission' parameter
-	const [permission, permissionErr] = $(params.permission).array($().string()).unique().get();
+	const [permission, permissionErr] = $.arr($.str).unique().get(params.permission);
 	if (permissionErr) return rej('invalid permission param');
 
 	// Get 'callbackUrl' parameter
 	// TODO: Check it is valid url
-	const [callbackUrl = null, callbackUrlErr] = $(params.callbackUrl).optional.nullable.string().get();
+	const [callbackUrl = null, callbackUrlErr] = $.str.optional().nullable().get(params.callbackUrl);
 	if (callbackUrlErr) return rej('invalid callbackUrl param');
 
 	// Generate secret
diff --git a/src/server/api/endpoints/app/name_id/available.ts b/src/server/api/endpoints/app/name_id/available.ts
index 8c32a780ec74054fd9f017f2605ab02a3486a3a7..135bb7d2b4d81148a2ee1ba5083a612bf2fc0c11 100644
--- a/src/server/api/endpoints/app/name_id/available.ts
+++ b/src/server/api/endpoints/app/name_id/available.ts
@@ -42,7 +42,7 @@ import { isValidNameId } from '../../../../../models/app';
  */
 module.exports = async (params) => new Promise(async (res, rej) => {
 	// Get 'nameId' parameter
-	const [nameId, nameIdErr] = $(params.nameId).string().pipe(isValidNameId).get();
+	const [nameId, nameIdErr] = $.str.pipe(isValidNameId).get(params.nameId);
 	if (nameIdErr) return rej('invalid nameId param');
 
 	// Get exist
diff --git a/src/server/api/endpoints/app/show.ts b/src/server/api/endpoints/app/show.ts
index 84088502854bb4821be2ef662a4e5ba0cba08679..8d742ab1827d68a53914723509b82294d96286c3 100644
--- a/src/server/api/endpoints/app/show.ts
+++ b/src/server/api/endpoints/app/show.ts
@@ -41,11 +41,11 @@ module.exports = (params, user, app) => new Promise(async (res, rej) => {
 	const isSecure = user != null && app == null;
 
 	// Get 'appId' parameter
-	const [appId, appIdErr] = $(params.appId).optional.type(ID).get();
+	const [appId, appIdErr] = $.type(ID).optional().get(params.appId);
 	if (appIdErr) return rej('invalid appId param');
 
 	// Get 'nameId' parameter
-	const [nameId, nameIdErr] = $(params.nameId).optional.string().get();
+	const [nameId, nameIdErr] = $.str.optional().get(params.nameId);
 	if (nameIdErr) return rej('invalid nameId param');
 
 	if (appId === undefined && nameId === undefined) {
diff --git a/src/server/api/endpoints/auth/accept.ts b/src/server/api/endpoints/auth/accept.ts
index cb271f9d67314d98c045241e58f4e86414c18d45..695fbb08031f9bd7f4a8b7c4f135a2e69bb31cfb 100644
--- a/src/server/api/endpoints/auth/accept.ts
+++ b/src/server/api/endpoints/auth/accept.ts
@@ -40,7 +40,7 @@ import AccessToken from '../../../../models/access-token';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'token' parameter
-	const [token, tokenErr] = $(params.token).string().get();
+	const [token, tokenErr] = $.str.get(params.token);
 	if (tokenErr) return rej('invalid token param');
 
 	// Fetch token
diff --git a/src/server/api/endpoints/auth/session/generate.ts b/src/server/api/endpoints/auth/session/generate.ts
index 8d243b85cf4e26f2cbb5411be06e736ef63da468..d649a8d9024ce53e59cc811551976fd093182a91 100644
--- a/src/server/api/endpoints/auth/session/generate.ts
+++ b/src/server/api/endpoints/auth/session/generate.ts
@@ -46,7 +46,7 @@ import config from '../../../../../config';
  */
 module.exports = (params) => new Promise(async (res, rej) => {
 	// Get 'appSecret' parameter
-	const [appSecret, appSecretErr] = $(params.appSecret).string().get();
+	const [appSecret, appSecretErr] = $.str.get(params.appSecret);
 	if (appSecretErr) return rej('invalid appSecret param');
 
 	// Lookup app
diff --git a/src/server/api/endpoints/auth/session/show.ts b/src/server/api/endpoints/auth/session/show.ts
index 87a43c94b99b8bb1fd835a1a44da82f0064c3942..434cc264a03450176febee73ef3fd56d0b0ab085 100644
--- a/src/server/api/endpoints/auth/session/show.ts
+++ b/src/server/api/endpoints/auth/session/show.ts
@@ -53,7 +53,7 @@ import AuthSess, { pack } from '../../../../../models/auth-session';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'token' parameter
-	const [token, tokenErr] = $(params.token).string().get();
+	const [token, tokenErr] = $.str.get(params.token);
 	if (tokenErr) return rej('invalid token param');
 
 	// Lookup session
diff --git a/src/server/api/endpoints/auth/session/userkey.ts b/src/server/api/endpoints/auth/session/userkey.ts
index 29642e6327e4ed7f676b1cad8bec09e9813c1f8f..3026b477f12c4c752d5061dc95a30a8c14bc1bf5 100644
--- a/src/server/api/endpoints/auth/session/userkey.ts
+++ b/src/server/api/endpoints/auth/session/userkey.ts
@@ -51,7 +51,7 @@ import { pack } from '../../../../../models/user';
  */
 module.exports = (params) => new Promise(async (res, rej) => {
 	// Get 'appSecret' parameter
-	const [appSecret, appSecretErr] = $(params.appSecret).string().get();
+	const [appSecret, appSecretErr] = $.str.get(params.appSecret);
 	if (appSecretErr) return rej('invalid appSecret param');
 
 	// Lookup app
@@ -64,7 +64,7 @@ module.exports = (params) => new Promise(async (res, rej) => {
 	}
 
 	// Get 'token' parameter
-	const [token, tokenErr] = $(params.token).string().get();
+	const [token, tokenErr] = $.str.get(params.token);
 	if (tokenErr) return rej('invalid token param');
 
 	// Fetch token
diff --git a/src/server/api/endpoints/channels.ts b/src/server/api/endpoints/channels.ts
index 9fd0fcb89c4ca662c2dd66b8e2f44a84b14e8dff..ceef4b9cb91d4f2b5ccb4c524ee66d99b2946de9 100644
--- a/src/server/api/endpoints/channels.ts
+++ b/src/server/api/endpoints/channels.ts
@@ -13,15 +13,15 @@ import Channel, { pack } from '../../../models/channel';
  */
 module.exports = (params, me) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Check if both of sinceId and untilId is specified
diff --git a/src/server/api/endpoints/channels/create.ts b/src/server/api/endpoints/channels/create.ts
index 2574e0923d2d7b3582aceadff11fa4f89ad171d2..0e3c9dc5ac11cb258863c96b35819dc4853d5d56 100644
--- a/src/server/api/endpoints/channels/create.ts
+++ b/src/server/api/endpoints/channels/create.ts
@@ -11,7 +11,7 @@ import { pack } from '../../../../models/channel';
  */
 module.exports = async (params, user) => new Promise(async (res, rej) => {
 	// Get 'title' parameter
-	const [title, titleErr] = $(params.title).string().range(1, 100).get();
+	const [title, titleErr] = $.str.range(1, 100).get(params.title);
 	if (titleErr) return rej('invalid title param');
 
 	// Create a channel
diff --git a/src/server/api/endpoints/channels/notes.ts b/src/server/api/endpoints/channels/notes.ts
index a83cdb34c4d701ab967ad99e0d0eba323c660776..463152e74acc634c1183a7cae487c20ba86f4bef 100644
--- a/src/server/api/endpoints/channels/notes.ts
+++ b/src/server/api/endpoints/channels/notes.ts
@@ -10,15 +10,15 @@ import Note, { pack } from '../../../../models/note';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 1000, limitErr] = $(params.limit).optional.number().range(1, 1000).get();
+	const [limit = 1000, limitErr] = $.num.optional().range(1, 1000).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Check if both of sinceId and untilId is specified
@@ -27,7 +27,7 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	}
 
 	// Get 'channelId' parameter
-	const [channelId, channelIdErr] = $(params.channelId).type(ID).get();
+	const [channelId, channelIdErr] = $.type(ID).get(params.channelId);
 	if (channelIdErr) return rej('invalid channelId param');
 
 	// Fetch channel
diff --git a/src/server/api/endpoints/channels/show.ts b/src/server/api/endpoints/channels/show.ts
index d5ca4ba3b7dfff4a0ac74c35c38d763e852908c8..1bba63d490930199d22457fb4359b6bc4d866aa4 100644
--- a/src/server/api/endpoints/channels/show.ts
+++ b/src/server/api/endpoints/channels/show.ts
@@ -9,7 +9,7 @@ import Channel, { IChannel, pack } from '../../../../models/channel';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'channelId' parameter
-	const [channelId, channelIdErr] = $(params.channelId).type(ID).get();
+	const [channelId, channelIdErr] = $.type(ID).get(params.channelId);
 	if (channelIdErr) return rej('invalid channelId param');
 
 	// Fetch channel
diff --git a/src/server/api/endpoints/channels/unwatch.ts b/src/server/api/endpoints/channels/unwatch.ts
index 9385e209dfefe52a2c096382925ab5173c342a05..f7dddff461458e6e81b44c700b87a9961bdf3865 100644
--- a/src/server/api/endpoints/channels/unwatch.ts
+++ b/src/server/api/endpoints/channels/unwatch.ts
@@ -10,7 +10,7 @@ import Watching from '../../../../models/channel-watching';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'channelId' parameter
-	const [channelId, channelIdErr] = $(params.channelId).type(ID).get();
+	const [channelId, channelIdErr] = $.type(ID).get(params.channelId);
 	if (channelIdErr) return rej('invalid channelId param');
 
 	//#region Fetch channel
diff --git a/src/server/api/endpoints/channels/watch.ts b/src/server/api/endpoints/channels/watch.ts
index ceda3b130a10027139639d5cb2df32db2e9e77fd..34243ff68be3dacabdaa5f97b134af420b4e9089 100644
--- a/src/server/api/endpoints/channels/watch.ts
+++ b/src/server/api/endpoints/channels/watch.ts
@@ -10,7 +10,7 @@ import Watching from '../../../../models/channel-watching';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'channelId' parameter
-	const [channelId, channelIdErr] = $(params.channelId).type(ID).get();
+	const [channelId, channelIdErr] = $.type(ID).get(params.channelId);
 	if (channelIdErr) return rej('invalid channelId param');
 
 	//#region Fetch channel
diff --git a/src/server/api/endpoints/drive/files.ts b/src/server/api/endpoints/drive/files.ts
index 52dfe60fafbec07753e9390a41da0f9be5f9d627..ab4b18cef4db86b0f2cb0f45bfeae33edac65893 100644
--- a/src/server/api/endpoints/drive/files.ts
+++ b/src/server/api/endpoints/drive/files.ts
@@ -9,15 +9,15 @@ import DriveFile, { pack } from '../../../../models/drive-file';
  */
 module.exports = async (params, user, app) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) throw 'invalid limit param';
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) throw 'invalid sinceId param';
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) throw 'invalid untilId param';
 
 	// Check if both of sinceId and untilId is specified
@@ -26,11 +26,11 @@ module.exports = async (params, user, app) => {
 	}
 
 	// Get 'folderId' parameter
-	const [folderId = null, folderIdErr] = $(params.folderId).optional.nullable.type(ID).get();
+	const [folderId = null, folderIdErr] = $.type(ID).optional().nullable().get(params.folderId);
 	if (folderIdErr) throw 'invalid folderId param';
 
 	// Get 'type' parameter
-	const [type, typeErr] = $(params.type).optional.string().match(/^[a-zA-Z\/\-\*]+$/).get();
+	const [type, typeErr] = $.str.optional().match(/^[a-zA-Z\/\-\*]+$/).get(params.type);
 	if (typeErr) throw 'invalid type param';
 
 	// Construct query
diff --git a/src/server/api/endpoints/drive/files/create.ts b/src/server/api/endpoints/drive/files/create.ts
index b1a4bc9c521ea50c8b76b1d8dd6354f01be4787e..e9348e4e2f35642ffd1664392f3428bdfffc1a61 100644
--- a/src/server/api/endpoints/drive/files/create.ts
+++ b/src/server/api/endpoints/drive/files/create.ts
@@ -29,7 +29,7 @@ module.exports = async (file, params, user): Promise<any> => {
 	}
 
 	// Get 'folderId' parameter
-	const [folderId = null, folderIdErr] = $(params.folderId).optional.nullable.type(ID).get();
+	const [folderId = null, folderIdErr] = $.type(ID).optional().nullable().get(params.folderId);
 	if (folderIdErr) throw 'invalid folderId param';
 
 	try {
diff --git a/src/server/api/endpoints/drive/files/find.ts b/src/server/api/endpoints/drive/files/find.ts
index 4636d850509cfcda0d54a97fb3b38b906fc9dcdf..98165990fe5d25ad0f30f5db236466366af9dfe0 100644
--- a/src/server/api/endpoints/drive/files/find.ts
+++ b/src/server/api/endpoints/drive/files/find.ts
@@ -9,11 +9,11 @@ import DriveFile, { pack } from '../../../../../models/drive-file';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'name' parameter
-	const [name, nameErr] = $(params.name).string().get();
+	const [name, nameErr] = $.str.get(params.name);
 	if (nameErr) return rej('invalid name param');
 
 	// Get 'folderId' parameter
-	const [folderId = null, folderIdErr] = $(params.folderId).optional.nullable.type(ID).get();
+	const [folderId = null, folderIdErr] = $.type(ID).optional().nullable().get(params.folderId);
 	if (folderIdErr) return rej('invalid folderId param');
 
 	// Issue query
diff --git a/src/server/api/endpoints/drive/files/show.ts b/src/server/api/endpoints/drive/files/show.ts
index 7e62e12fad8d7b8a0e35052473c1c339300df8e9..c7efda7ab0b8ca6fd38655b09648141cb1854ed6 100644
--- a/src/server/api/endpoints/drive/files/show.ts
+++ b/src/server/api/endpoints/drive/files/show.ts
@@ -9,7 +9,7 @@ import DriveFile, { pack } from '../../../../../models/drive-file';
  */
 module.exports = async (params, user) => {
 	// Get 'fileId' parameter
-	const [fileId, fileIdErr] = $(params.fileId).type(ID).get();
+	const [fileId, fileIdErr] = $.type(ID).get(params.fileId);
 	if (fileIdErr) throw 'invalid fileId param';
 
 	// Fetch file
diff --git a/src/server/api/endpoints/drive/files/update.ts b/src/server/api/endpoints/drive/files/update.ts
index c80e26771c95933060491aebec8e1b4f44db07c4..12fa8e025def1f6305fe99a5a26a694836690841 100644
--- a/src/server/api/endpoints/drive/files/update.ts
+++ b/src/server/api/endpoints/drive/files/update.ts
@@ -11,7 +11,7 @@ import { publishDriveStream } from '../../../../../publishers/stream';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'fileId' parameter
-	const [fileId, fileIdErr] = $(params.fileId).type(ID).get();
+	const [fileId, fileIdErr] = $.type(ID).get(params.fileId);
 	if (fileIdErr) return rej('invalid fileId param');
 
 	// Fetch file
@@ -26,12 +26,12 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	}
 
 	// Get 'name' parameter
-	const [name, nameErr] = $(params.name).optional.string().pipe(validateFileName).get();
+	const [name, nameErr] = $.str.optional().pipe(validateFileName).get(params.name);
 	if (nameErr) return rej('invalid name param');
 	if (name) file.filename = name;
 
 	// Get 'folderId' parameter
-	const [folderId, folderIdErr] = $(params.folderId).optional.nullable.type(ID).get();
+	const [folderId, folderIdErr] = $.type(ID).optional().nullable().get(params.folderId);
 	if (folderIdErr) return rej('invalid folderId param');
 
 	if (folderId !== undefined) {
diff --git a/src/server/api/endpoints/drive/files/upload_from_url.ts b/src/server/api/endpoints/drive/files/upload_from_url.ts
index 540c317bee41f852111ddf95c740768bd3af550c..c012f0d3c96023237f352f86b1d40b19b0fad95a 100644
--- a/src/server/api/endpoints/drive/files/upload_from_url.ts
+++ b/src/server/api/endpoints/drive/files/upload_from_url.ts
@@ -11,11 +11,11 @@ import uploadFromUrl from '../../../../../services/drive/upload-from-url';
 module.exports = async (params, user): Promise<any> => {
 	// Get 'url' parameter
 	// TODO: Validate this url
-	const [url, urlErr] = $(params.url).string().get();
+	const [url, urlErr] = $.str.get(params.url);
 	if (urlErr) throw 'invalid url param';
 
 	// Get 'folderId' parameter
-	const [folderId = null, folderIdErr] = $(params.folderId).optional.nullable.type(ID).get();
+	const [folderId = null, folderIdErr] = $.type(ID).optional().nullable().get(params.folderId);
 	if (folderIdErr) throw 'invalid folderId param';
 
 	return pack(await uploadFromUrl(url, user, folderId));
diff --git a/src/server/api/endpoints/drive/folders.ts b/src/server/api/endpoints/drive/folders.ts
index 8193a8317a9cd524e28e0f89e53c579aebf27e1e..bc6c50eb99c458adde62ec6131a04e491edd3b3f 100644
--- a/src/server/api/endpoints/drive/folders.ts
+++ b/src/server/api/endpoints/drive/folders.ts
@@ -9,15 +9,15 @@ import DriveFolder, { pack } from '../../../../models/drive-folder';
  */
 module.exports = (params, user, app) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Check if both of sinceId and untilId is specified
@@ -26,7 +26,7 @@ module.exports = (params, user, app) => new Promise(async (res, rej) => {
 	}
 
 	// Get 'folderId' parameter
-	const [folderId = null, folderIdErr] = $(params.folderId).optional.nullable.type(ID).get();
+	const [folderId = null, folderIdErr] = $.type(ID).optional().nullable().get(params.folderId);
 	if (folderIdErr) return rej('invalid folderId param');
 
 	// Construct query
diff --git a/src/server/api/endpoints/drive/folders/create.ts b/src/server/api/endpoints/drive/folders/create.ts
index 487c1b2205a011f12f59dce17c39497a36d6589f..62e3b6f6e85b112305c9391b80dafa8e77fea28a 100644
--- a/src/server/api/endpoints/drive/folders/create.ts
+++ b/src/server/api/endpoints/drive/folders/create.ts
@@ -10,11 +10,11 @@ import { publishDriveStream } from '../../../../../publishers/stream';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'name' parameter
-	const [name = '無題のフォルダー', nameErr] = $(params.name).optional.string().pipe(isValidFolderName).get();
+	const [name = '無題のフォルダー', nameErr] = $.str.optional().pipe(isValidFolderName).get(params.name);
 	if (nameErr) return rej('invalid name param');
 
 	// Get 'parentId' parameter
-	const [parentId = null, parentIdErr] = $(params.parentId).optional.nullable.type(ID).get();
+	const [parentId = null, parentIdErr] = $.type(ID).optional().nullable().get(params.parentId);
 	if (parentIdErr) return rej('invalid parentId param');
 
 	// If the parent folder is specified
diff --git a/src/server/api/endpoints/drive/folders/find.ts b/src/server/api/endpoints/drive/folders/find.ts
index b8579219f98e7a5ef245df4c0d2952c1f019d406..9703d9e99d357dc387b095fd30b941f40f1f48f9 100644
--- a/src/server/api/endpoints/drive/folders/find.ts
+++ b/src/server/api/endpoints/drive/folders/find.ts
@@ -9,11 +9,11 @@ import DriveFolder, { pack } from '../../../../../models/drive-folder';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'name' parameter
-	const [name, nameErr] = $(params.name).string().get();
+	const [name, nameErr] = $.str.get(params.name);
 	if (nameErr) return rej('invalid name param');
 
 	// Get 'parentId' parameter
-	const [parentId = null, parentIdErr] = $(params.parentId).optional.nullable.type(ID).get();
+	const [parentId = null, parentIdErr] = $.type(ID).optional().nullable().get(params.parentId);
 	if (parentIdErr) return rej('invalid parentId param');
 
 	// Issue query
diff --git a/src/server/api/endpoints/drive/folders/show.ts b/src/server/api/endpoints/drive/folders/show.ts
index 36d7f1c69f5a93f5d985484240c151380827e571..44f1889001daf3e2909ff861b5b6bfaccadd1153 100644
--- a/src/server/api/endpoints/drive/folders/show.ts
+++ b/src/server/api/endpoints/drive/folders/show.ts
@@ -9,7 +9,7 @@ import DriveFolder, { pack } from '../../../../../models/drive-folder';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'folderId' parameter
-	const [folderId, folderIdErr] = $(params.folderId).type(ID).get();
+	const [folderId, folderIdErr] = $.type(ID).get(params.folderId);
 	if (folderIdErr) return rej('invalid folderId param');
 
 	// Get folder
diff --git a/src/server/api/endpoints/drive/folders/update.ts b/src/server/api/endpoints/drive/folders/update.ts
index 64a6cd293af6e5058b6d637bd92e3aabea9a3f24..e24d8a14cd27ec8a206a0e7613bfd75be974b207 100644
--- a/src/server/api/endpoints/drive/folders/update.ts
+++ b/src/server/api/endpoints/drive/folders/update.ts
@@ -10,7 +10,7 @@ import { publishDriveStream } from '../../../../../publishers/stream';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'folderId' parameter
-	const [folderId, folderIdErr] = $(params.folderId).type(ID).get();
+	const [folderId, folderIdErr] = $.type(ID).get(params.folderId);
 	if (folderIdErr) return rej('invalid folderId param');
 
 	// Fetch folder
@@ -25,12 +25,12 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	}
 
 	// Get 'name' parameter
-	const [name, nameErr] = $(params.name).optional.string().pipe(isValidFolderName).get();
+	const [name, nameErr] = $.str.optional().pipe(isValidFolderName).get(params.name);
 	if (nameErr) return rej('invalid name param');
 	if (name) folder.name = name;
 
 	// Get 'parentId' parameter
-	const [parentId, parentIdErr] = $(params.parentId).optional.nullable.type(ID).get();
+	const [parentId, parentIdErr] = $.type(ID).optional().nullable().get(params.parentId);
 	if (parentIdErr) return rej('invalid parentId param');
 	if (parentId !== undefined) {
 		if (parentId === null) {
diff --git a/src/server/api/endpoints/drive/stream.ts b/src/server/api/endpoints/drive/stream.ts
index b148f2ce51cdf0d979cda76cd3b1f3ead00ffad7..8cb3a99b42bf6bdc424e6592a7589d8b5a7c5480 100644
--- a/src/server/api/endpoints/drive/stream.ts
+++ b/src/server/api/endpoints/drive/stream.ts
@@ -9,15 +9,15 @@ import DriveFile, { pack } from '../../../../models/drive-file';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Check if both of sinceId and untilId is specified
@@ -26,7 +26,7 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	}
 
 	// Get 'type' parameter
-	const [type, typeErr] = $(params.type).optional.string().match(/^[a-zA-Z\/\-\*]+$/).get();
+	const [type, typeErr] = $.str.optional().match(/^[a-zA-Z\/\-\*]+$/).get(params.type);
 	if (typeErr) return rej('invalid type param');
 
 	// Construct query
diff --git a/src/server/api/endpoints/following/create.ts b/src/server/api/endpoints/following/create.ts
index 42a7b79b006b0d22adcd1ad34ebde15d4e4426e4..766a8c03d0aa1946c4c45ac9ef97abf698d95229 100644
--- a/src/server/api/endpoints/following/create.ts
+++ b/src/server/api/endpoints/following/create.ts
@@ -13,7 +13,7 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	const follower = user;
 
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// 自分自身
diff --git a/src/server/api/endpoints/following/delete.ts b/src/server/api/endpoints/following/delete.ts
index 3aef6523de0b955a72b3744bca1533e4a40506c6..396b19a6f60b00cfe19ed71f1c67dc0f9aec6b09 100644
--- a/src/server/api/endpoints/following/delete.ts
+++ b/src/server/api/endpoints/following/delete.ts
@@ -13,7 +13,7 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	const follower = user;
 
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Check if the followee is yourself
diff --git a/src/server/api/endpoints/following/stalk.ts b/src/server/api/endpoints/following/stalk.ts
index 34e3f80f8ac1eb8d2eaf71d5d5948bc9995740f1..f0bc8cbdfcaa926528e5a7fbeeefd815acb3812a 100644
--- a/src/server/api/endpoints/following/stalk.ts
+++ b/src/server/api/endpoints/following/stalk.ts
@@ -8,7 +8,7 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	const follower = user;
 
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Fetch following
diff --git a/src/server/api/endpoints/following/unstalk.ts b/src/server/api/endpoints/following/unstalk.ts
index f8ca39ef7d9c20f3548fba800a5903e471626b35..0d0a018c3486b9c32e002a73d40840ac1df762ae 100644
--- a/src/server/api/endpoints/following/unstalk.ts
+++ b/src/server/api/endpoints/following/unstalk.ts
@@ -8,7 +8,7 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	const follower = user;
 
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Fetch following
diff --git a/src/server/api/endpoints/i/2fa/done.ts b/src/server/api/endpoints/i/2fa/done.ts
index 310e5c574ebfeacea794dbda4ff667079a028910..1a2706aa8405bfcfce08defdb6d738660eb1a107 100644
--- a/src/server/api/endpoints/i/2fa/done.ts
+++ b/src/server/api/endpoints/i/2fa/done.ts
@@ -7,7 +7,7 @@ import User from '../../../../../models/user';
 
 module.exports = async (params, user) => new Promise(async (res, rej) => {
 	// Get 'token' parameter
-	const [token, tokenErr] = $(params.token).string().get();
+	const [token, tokenErr] = $.str.get(params.token);
 	if (tokenErr) return rej('invalid token param');
 
 	const _token = token.replace(/\s/g, '');
diff --git a/src/server/api/endpoints/i/2fa/register.ts b/src/server/api/endpoints/i/2fa/register.ts
index 51f66dc2fe7a99035364fc89609735f1525664a6..d314e1a2803b152eb4dba28a694fee98c0ec0748 100644
--- a/src/server/api/endpoints/i/2fa/register.ts
+++ b/src/server/api/endpoints/i/2fa/register.ts
@@ -10,7 +10,7 @@ import config from '../../../../../config';
 
 module.exports = async (params, user) => new Promise(async (res, rej) => {
 	// Get 'password' parameter
-	const [password, passwordErr] = $(params.password).string().get();
+	const [password, passwordErr] = $.str.get(params.password);
 	if (passwordErr) return rej('invalid password param');
 
 	// Compare password
diff --git a/src/server/api/endpoints/i/2fa/unregister.ts b/src/server/api/endpoints/i/2fa/unregister.ts
index 9fd940dcafc6d9814874616731a85cdb0edc4993..336a3564ab802fc72c0464f79fed964b61bb6da1 100644
--- a/src/server/api/endpoints/i/2fa/unregister.ts
+++ b/src/server/api/endpoints/i/2fa/unregister.ts
@@ -7,7 +7,7 @@ import User from '../../../../../models/user';
 
 module.exports = async (params, user) => new Promise(async (res, rej) => {
 	// Get 'password' parameter
-	const [password, passwordErr] = $(params.password).string().get();
+	const [password, passwordErr] = $.str.get(params.password);
 	if (passwordErr) return rej('invalid password param');
 
 	// Compare password
diff --git a/src/server/api/endpoints/i/authorized_apps.ts b/src/server/api/endpoints/i/authorized_apps.ts
index 9635091465e8288482ab3db711b1cedf5ce75162..d15bd67bf2637ef4aa1e2b04619c0bbf106f31d1 100644
--- a/src/server/api/endpoints/i/authorized_apps.ts
+++ b/src/server/api/endpoints/i/authorized_apps.ts
@@ -10,15 +10,15 @@ import { pack } from '../../../../models/app';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'offset' parameter
-	const [offset = 0, offsetErr] = $(params.offset).optional.number().min(0).get();
+	const [offset = 0, offsetErr] = $.num.optional().min(0).get(params.offset);
 	if (offsetErr) return rej('invalid offset param');
 
 	// Get 'sort' parameter
-	const [sort = 'desc', sortError] = $(params.sort).optional.string().or('desc asc').get();
+	const [sort = 'desc', sortError] = $.str.optional().or('desc asc').get(params.sort);
 	if (sortError) return rej('invalid sort param');
 
 	// Get tokens
diff --git a/src/server/api/endpoints/i/change_password.ts b/src/server/api/endpoints/i/change_password.ts
index 5c8c71d1400653b08ee0a16371ccccf0201d0db9..a1a1a43406c76418696c1a7c7fd0256b86139fa9 100644
--- a/src/server/api/endpoints/i/change_password.ts
+++ b/src/server/api/endpoints/i/change_password.ts
@@ -10,11 +10,11 @@ import User from '../../../../models/user';
  */
 module.exports = async (params, user) => new Promise(async (res, rej) => {
 	// Get 'currentPasword' parameter
-	const [currentPassword, currentPasswordErr] = $(params.currentPasword).string().get();
+	const [currentPassword, currentPasswordErr] = $.str.get(params.currentPasword);
 	if (currentPasswordErr) return rej('invalid currentPasword param');
 
 	// Get 'newPassword' parameter
-	const [newPassword, newPasswordErr] = $(params.newPassword).string().get();
+	const [newPassword, newPasswordErr] = $.str.get(params.newPassword);
 	if (newPasswordErr) return rej('invalid newPassword param');
 
 	// Compare password
diff --git a/src/server/api/endpoints/i/favorites.ts b/src/server/api/endpoints/i/favorites.ts
index a65f673a7dad42b44c7f1090740891bbacb84382..23517baaff4ec66081f789801c3e29f6019e8448 100644
--- a/src/server/api/endpoints/i/favorites.ts
+++ b/src/server/api/endpoints/i/favorites.ts
@@ -9,15 +9,15 @@ import Favorite, { pack } from '../../../../models/favorite';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Check if both of sinceId and untilId is specified
diff --git a/src/server/api/endpoints/i/notifications.ts b/src/server/api/endpoints/i/notifications.ts
index a0bf2338a6b6d0453ba05854f7c109a8e6c2088c..50ed9b27e876b0535b0e230de5c8e5f50977615e 100644
--- a/src/server/api/endpoints/i/notifications.ts
+++ b/src/server/api/endpoints/i/notifications.ts
@@ -14,27 +14,27 @@ import read from '../../common/read-notification';
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'following' parameter
 	const [following = false, followingError] =
-		$(params.following).optional.boolean().get();
+		$.bool.optional().get(params.following);
 	if (followingError) return rej('invalid following param');
 
 	// Get 'markAsRead' parameter
-	const [markAsRead = true, markAsReadErr] = $(params.markAsRead).optional.boolean().get();
+	const [markAsRead = true, markAsReadErr] = $.bool.optional().get(params.markAsRead);
 	if (markAsReadErr) return rej('invalid markAsRead param');
 
 	// Get 'type' parameter
-	const [type, typeErr] = $(params.type).optional.array($().string()).unique().get();
+	const [type, typeErr] = $.arr($.str).optional().unique().get(params.type);
 	if (typeErr) return rej('invalid type param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Check if both of sinceId and untilId is specified
diff --git a/src/server/api/endpoints/i/pin.ts b/src/server/api/endpoints/i/pin.ts
index 1d995746dce052297f8a61cf02f8766a7c8a19cb..423f0ac4ae66a225b5e2d100564e217ab396d495 100644
--- a/src/server/api/endpoints/i/pin.ts
+++ b/src/server/api/endpoints/i/pin.ts
@@ -11,7 +11,7 @@ import { pack } from '../../../../models/user';
  */
 module.exports = async (params, user) => new Promise(async (res, rej) => {
 	// Get 'noteId' parameter
-	const [noteId, noteIdErr] = $(params.noteId).type(ID).get();
+	const [noteId, noteIdErr] = $.type(ID).get(params.noteId);
 	if (noteIdErr) return rej('invalid noteId param');
 
 	// Fetch pinee
diff --git a/src/server/api/endpoints/i/regenerate_token.ts b/src/server/api/endpoints/i/regenerate_token.ts
index df440c68abec1cbd66da4296a5f188990f315f13..6e1e571297451cfe6671a7598eca337afdf4cb7f 100644
--- a/src/server/api/endpoints/i/regenerate_token.ts
+++ b/src/server/api/endpoints/i/regenerate_token.ts
@@ -12,7 +12,7 @@ import generateUserToken from '../../common/generate-native-user-token';
  */
 module.exports = async (params, user) => new Promise(async (res, rej) => {
 	// Get 'password' parameter
-	const [password, passwordErr] = $(params.password).string().get();
+	const [password, passwordErr] = $.str.get(params.password);
 	if (passwordErr) return rej('invalid password param');
 
 	// Compare password
diff --git a/src/server/api/endpoints/i/signin_history.ts b/src/server/api/endpoints/i/signin_history.ts
index d505caad82c6ac50fa8f057e9cdb35804fbaefc0..63a74b41b17de015ac99578716450c3f857a18f5 100644
--- a/src/server/api/endpoints/i/signin_history.ts
+++ b/src/server/api/endpoints/i/signin_history.ts
@@ -9,15 +9,15 @@ import Signin, { pack } from '../../../../models/signin';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Check if both of sinceId and untilId is specified
diff --git a/src/server/api/endpoints/i/update.ts b/src/server/api/endpoints/i/update.ts
index 2b76497025ed1fea75a48ce25b408435ccb4a64e..6ba47299516c77adc79ee2e07f6d16be30b60380 100644
--- a/src/server/api/endpoints/i/update.ts
+++ b/src/server/api/endpoints/i/update.ts
@@ -12,42 +12,42 @@ module.exports = async (params, user, app) => new Promise(async (res, rej) => {
 	const isSecure = user != null && app == null;
 
 	// Get 'name' parameter
-	const [name, nameErr] = $(params.name).optional.nullable.string().pipe(isValidName).get();
+	const [name, nameErr] = $.str.optional().nullable().pipe(isValidName).get(params.name);
 	if (nameErr) return rej('invalid name param');
 	if (name) user.name = name;
 
 	// Get 'description' parameter
-	const [description, descriptionErr] = $(params.description).optional.nullable.string().pipe(isValidDescription).get();
+	const [description, descriptionErr] = $.str.optional().nullable().pipe(isValidDescription).get(params.description);
 	if (descriptionErr) return rej('invalid description param');
 	if (description !== undefined) user.description = description;
 
 	// Get 'location' parameter
-	const [location, locationErr] = $(params.location).optional.nullable.string().pipe(isValidLocation).get();
+	const [location, locationErr] = $.str.optional().nullable().pipe(isValidLocation).get(params.location);
 	if (locationErr) return rej('invalid location param');
 	if (location !== undefined) user.profile.location = location;
 
 	// Get 'birthday' parameter
-	const [birthday, birthdayErr] = $(params.birthday).optional.nullable.string().pipe(isValidBirthday).get();
+	const [birthday, birthdayErr] = $.str.optional().nullable().pipe(isValidBirthday).get(params.birthday);
 	if (birthdayErr) return rej('invalid birthday param');
 	if (birthday !== undefined) user.profile.birthday = birthday;
 
 	// Get 'avatarId' parameter
-	const [avatarId, avatarIdErr] = $(params.avatarId).optional.type(ID).get();
+	const [avatarId, avatarIdErr] = $.type(ID).optional().get(params.avatarId);
 	if (avatarIdErr) return rej('invalid avatarId param');
 	if (avatarId) user.avatarId = avatarId;
 
 	// Get 'bannerId' parameter
-	const [bannerId, bannerIdErr] = $(params.bannerId).optional.type(ID).get();
+	const [bannerId, bannerIdErr] = $.type(ID).optional().get(params.bannerId);
 	if (bannerIdErr) return rej('invalid bannerId param');
 	if (bannerId) user.bannerId = bannerId;
 
 	// Get 'isBot' parameter
-	const [isBot, isBotErr] = $(params.isBot).optional.boolean().get();
+	const [isBot, isBotErr] = $.bool.optional().get(params.isBot);
 	if (isBotErr) return rej('invalid isBot param');
 	if (isBot != null) user.isBot = isBot;
 
 	// Get 'autoWatch' parameter
-	const [autoWatch, autoWatchErr] = $(params.autoWatch).optional.boolean().get();
+	const [autoWatch, autoWatchErr] = $.bool.optional().get(params.autoWatch);
 	if (autoWatchErr) return rej('invalid autoWatch param');
 	if (autoWatch != null) user.settings.autoWatch = autoWatch;
 
diff --git a/src/server/api/endpoints/i/update_client_setting.ts b/src/server/api/endpoints/i/update_client_setting.ts
index 278eb1cbeb8b6c706531b0bea2cee411e94cb36f..e91d7565fdd5f6d11d00193e2e9e55c57b8d226b 100644
--- a/src/server/api/endpoints/i/update_client_setting.ts
+++ b/src/server/api/endpoints/i/update_client_setting.ts
@@ -2,7 +2,7 @@
  * Module dependencies
  */
 import $ from 'cafy';
-import User, { pack } from '../../../../models/user';
+import User from '../../../../models/user';
 import event from '../../../../publishers/stream';
 
 /**
@@ -10,11 +10,11 @@ import event from '../../../../publishers/stream';
  */
 module.exports = async (params, user) => new Promise(async (res, rej) => {
 	// Get 'name' parameter
-	const [name, nameErr] = $(params.name).string().get();
+	const [name, nameErr] = $.str.get(params.name);
 	if (nameErr) return rej('invalid name param');
 
 	// Get 'value' parameter
-	const [value, valueErr] = $(params.value).nullable.any().get();
+	const [value, valueErr] = $.any.nullable().get(params.value);
 	if (valueErr) return rej('invalid value param');
 
 	const x = {};
diff --git a/src/server/api/endpoints/i/update_home.ts b/src/server/api/endpoints/i/update_home.ts
index baf9b739ae5cbafbc942c460998f4ae83311dc85..8ce551957e66ff13b9c18e5281bfb06154f2a1ce 100644
--- a/src/server/api/endpoints/i/update_home.ts
+++ b/src/server/api/endpoints/i/update_home.ts
@@ -7,20 +7,22 @@ import event from '../../../../publishers/stream';
 
 module.exports = async (params, user) => new Promise(async (res, rej) => {
 	// Get 'home' parameter
-	const [home, homeErr] = $(params.home).optional.array().each(
-		$().object(true)
-			.have('name', $().string())
-			.have('id', $().string())
-			.have('place', $().string())
-			.have('data', $().object())).get();
+	const [home, homeErr] = $.arr(
+		$.obj.strict()
+			.have('name', $.str)
+			.have('id', $.str)
+			.have('place', $.str)
+			.have('data', $.obj))
+		.optional()
+		.get(params.home);
 	if (homeErr) return rej('invalid home param');
 
 	// Get 'id' parameter
-	const [id, idErr] = $(params.id).optional.string().get();
+	const [id, idErr] = $.str.optional().get(params.id);
 	if (idErr) return rej('invalid id param');
 
 	// Get 'data' parameter
-	const [data, dataErr] = $(params.data).optional.object().get();
+	const [data, dataErr] = $.obj.optional().get(params.data);
 	if (dataErr) return rej('invalid data param');
 
 	if (home) {
diff --git a/src/server/api/endpoints/i/update_mobile_home.ts b/src/server/api/endpoints/i/update_mobile_home.ts
index 21d94839b79870a340a3d0be8b97997627852f16..d79a77072b230c251990fb9afc148da449770944 100644
--- a/src/server/api/endpoints/i/update_mobile_home.ts
+++ b/src/server/api/endpoints/i/update_mobile_home.ts
@@ -7,19 +7,20 @@ import event from '../../../../publishers/stream';
 
 module.exports = async (params, user) => new Promise(async (res, rej) => {
 	// Get 'home' parameter
-	const [home, homeErr] = $(params.home).optional.array().each(
-		$().object(true)
-			.have('name', $().string())
-			.have('id', $().string())
-			.have('data', $().object())).get();
+	const [home, homeErr] = $.arr(
+		$.obj.strict()
+			.have('name', $.str)
+			.have('id', $.str)
+			.have('data', $.obj))
+		.optional().get(params.home);
 	if (homeErr) return rej('invalid home param');
 
 	// Get 'id' parameter
-	const [id, idErr] = $(params.id).optional.string().get();
+	const [id, idErr] = $.str.optional().get(params.id);
 	if (idErr) return rej('invalid id param');
 
 	// Get 'data' parameter
-	const [data, dataErr] = $(params.data).optional.object().get();
+	const [data, dataErr] = $.obj.optional().get(params.data);
 	if (dataErr) return rej('invalid data param');
 
 	if (home) {
diff --git a/src/server/api/endpoints/messaging/history.ts b/src/server/api/endpoints/messaging/history.ts
index 9fd1f80d7b0406791c614c3dc80367d7b744fa2b..ec97642f173b67f2cd9ac5720fe06e24fda7c0b0 100644
--- a/src/server/api/endpoints/messaging/history.ts
+++ b/src/server/api/endpoints/messaging/history.ts
@@ -11,7 +11,7 @@ import { pack } from '../../../../models/messaging-message';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	const mute = await Mute.find({
diff --git a/src/server/api/endpoints/messaging/messages.ts b/src/server/api/endpoints/messaging/messages.ts
index f154133a12d2cdd7efeb796087f7b4cccc215993..0338aba68a1fa7333a4c18841e76bca85e2ad4ea 100644
--- a/src/server/api/endpoints/messaging/messages.ts
+++ b/src/server/api/endpoints/messaging/messages.ts
@@ -16,7 +16,7 @@ import read from '../../common/read-messaging-message';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'userId' parameter
-	const [recipientId, recipientIdErr] = $(params.userId).type(ID).get();
+	const [recipientId, recipientIdErr] = $.type(ID).get(params.userId);
 	if (recipientIdErr) return rej('invalid userId param');
 
 	// Fetch recipient
@@ -33,19 +33,19 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	}
 
 	// Get 'markAsRead' parameter
-	const [markAsRead = true, markAsReadErr] = $(params.markAsRead).optional.boolean().get();
+	const [markAsRead = true, markAsReadErr] = $.bool.optional().get(params.markAsRead);
 	if (markAsReadErr) return rej('invalid markAsRead param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Check if both of sinceId and untilId is specified
diff --git a/src/server/api/endpoints/messaging/messages/create.ts b/src/server/api/endpoints/messaging/messages/create.ts
index 8b708eeaa9bfadffea0b435ad95bdd290bfecd65..db471839e75e23c5a6e51fd6b22eb66fe641be69 100644
--- a/src/server/api/endpoints/messaging/messages/create.ts
+++ b/src/server/api/endpoints/messaging/messages/create.ts
@@ -19,7 +19,7 @@ import config from '../../../../../config';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'userId' parameter
-	const [recipientId, recipientIdErr] = $(params.userId).type(ID).get();
+	const [recipientId, recipientIdErr] = $.type(ID).get(params.userId);
 	if (recipientIdErr) return rej('invalid userId param');
 
 	// Myself
@@ -41,11 +41,11 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	}
 
 	// Get 'text' parameter
-	const [text, textErr] = $(params.text).optional.string().pipe(isValidText).get();
+	const [text, textErr] = $.str.optional().pipe(isValidText).get(params.text);
 	if (textErr) return rej('invalid text');
 
 	// Get 'fileId' parameter
-	const [fileId, fileIdErr] = $(params.fileId).optional.type(ID).get();
+	const [fileId, fileIdErr] = $.type(ID).optional().get(params.fileId);
 	if (fileIdErr) return rej('invalid fileId param');
 
 	let file = null;
diff --git a/src/server/api/endpoints/mute/create.ts b/src/server/api/endpoints/mute/create.ts
index aa9f6eb7311a0527b54ad1143b028451f2d405cf..534020c671800e326b7ae308b660062ac57f1085 100644
--- a/src/server/api/endpoints/mute/create.ts
+++ b/src/server/api/endpoints/mute/create.ts
@@ -12,7 +12,7 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	const muter = user;
 
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// 自分自身
diff --git a/src/server/api/endpoints/mute/delete.ts b/src/server/api/endpoints/mute/delete.ts
index f24db6770d806b271326e126d1c51acaba353908..949aff64ba835c5af1e21585c98b7da5ce2a7940 100644
--- a/src/server/api/endpoints/mute/delete.ts
+++ b/src/server/api/endpoints/mute/delete.ts
@@ -12,7 +12,7 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 	const muter = user;
 
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Check if the mutee is yourself
diff --git a/src/server/api/endpoints/mute/list.ts b/src/server/api/endpoints/mute/list.ts
index f7199db64e1af6bf3cc33cdd3cf59d312b3b404b..cf89f7e959d9b866db153fd7db1a032ebb73f1cd 100644
--- a/src/server/api/endpoints/mute/list.ts
+++ b/src/server/api/endpoints/mute/list.ts
@@ -11,15 +11,15 @@ import { getFriendIds } from '../../common/get-friends';
  */
 module.exports = (params, me) => new Promise(async (res, rej) => {
 	// Get 'iknow' parameter
-	const [iknow = false, iknowErr] = $(params.iknow).optional.boolean().get();
+	const [iknow = false, iknowErr] = $.bool.optional().get(params.iknow);
 	if (iknowErr) return rej('invalid iknow param');
 
 	// Get 'limit' parameter
-	const [limit = 30, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 30, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'cursor' parameter
-	const [cursor = null, cursorErr] = $(params.cursor).optional.type(ID).get();
+	const [cursor = null, cursorErr] = $.type(ID).optional().get(params.cursor);
 	if (cursorErr) return rej('invalid cursor param');
 
 	// Construct query
diff --git a/src/server/api/endpoints/my/apps.ts b/src/server/api/endpoints/my/apps.ts
index 3b58b3024158b13db2035f37dca0ee3ca38c2bcc..086e0b8965e6b02325bd3be32eb21b49b9498e79 100644
--- a/src/server/api/endpoints/my/apps.ts
+++ b/src/server/api/endpoints/my/apps.ts
@@ -9,11 +9,11 @@ import App, { pack } from '../../../../models/app';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'offset' parameter
-	const [offset = 0, offsetErr] = $(params.offset).optional.number().min(0).get();
+	const [offset = 0, offsetErr] = $.num.optional().min(0).get(params.offset);
 	if (offsetErr) return rej('invalid offset param');
 
 	const query = {
diff --git a/src/server/api/endpoints/notes.ts b/src/server/api/endpoints/notes.ts
index 7be35961d27804ff1ec41272fce97dabb7c36a6a..4ce7613d709325dfdbc5d01dda2e0e09f9f04e8d 100644
--- a/src/server/api/endpoints/notes.ts
+++ b/src/server/api/endpoints/notes.ts
@@ -9,35 +9,35 @@ import Note, { pack } from '../../../models/note';
  */
 module.exports = (params) => new Promise(async (res, rej) => {
 	// Get 'reply' parameter
-	const [reply, replyErr] = $(params.reply).optional.boolean().get();
+	const [reply, replyErr] = $.bool.optional().get(params.reply);
 	if (replyErr) return rej('invalid reply param');
 
 	// Get 'renote' parameter
-	const [renote, renoteErr] = $(params.renote).optional.boolean().get();
+	const [renote, renoteErr] = $.bool.optional().get(params.renote);
 	if (renoteErr) return rej('invalid renote param');
 
 	// Get 'media' parameter
-	const [media, mediaErr] = $(params.media).optional.boolean().get();
+	const [media, mediaErr] = $.bool.optional().get(params.media);
 	if (mediaErr) return rej('invalid media param');
 
 	// Get 'poll' parameter
-	const [poll, pollErr] = $(params.poll).optional.boolean().get();
+	const [poll, pollErr] = $.bool.optional().get(params.poll);
 	if (pollErr) return rej('invalid poll param');
 
 	// Get 'bot' parameter
-	//const [bot, botErr] = $(params.bot).optional.boolean().get();
+	//const [bot, botErr] = $.bool.optional().get(params.bot);
 	//if (botErr) return rej('invalid bot param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Check if both of sinceId and untilId is specified
diff --git a/src/server/api/endpoints/notes/context.ts b/src/server/api/endpoints/notes/context.ts
index 7e3533cfd8351fff1f146801bd1e59b8f12c7d87..1cd27250e27d0545e3936d09410e2f4c7fb2d472 100644
--- a/src/server/api/endpoints/notes/context.ts
+++ b/src/server/api/endpoints/notes/context.ts
@@ -13,15 +13,15 @@ import Note, { pack } from '../../../../models/note';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'noteId' parameter
-	const [noteId, noteIdErr] = $(params.noteId).type(ID).get();
+	const [noteId, noteIdErr] = $.type(ID).get(params.noteId);
 	if (noteIdErr) return rej('invalid noteId param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'offset' parameter
-	const [offset = 0, offsetErr] = $(params.offset).optional.number().min(0).get();
+	const [offset = 0, offsetErr] = $.num.optional().min(0).get(params.offset);
 	if (offsetErr) return rej('invalid offset param');
 
 	// Lookup note
diff --git a/src/server/api/endpoints/notes/create.ts b/src/server/api/endpoints/notes/create.ts
index 52c6068fd0d9cb525ce93c5a45063d3de4372764..fe947174d10be282d409f62b063f2e297b84a95a 100644
--- a/src/server/api/endpoints/notes/create.ts
+++ b/src/server/api/endpoints/notes/create.ts
@@ -14,11 +14,11 @@ import { IApp } from '../../../../models/app';
  */
 module.exports = (params, user: ILocalUser, app: IApp) => new Promise(async (res, rej) => {
 	// Get 'visibility' parameter
-	const [visibility = 'public', visibilityErr] = $(params.visibility).optional.string().or(['public', 'home', 'followers', 'specified', 'private']).get();
+	const [visibility = 'public', visibilityErr] = $.str.optional().or(['public', 'home', 'followers', 'specified', 'private']).get(params.visibility);
 	if (visibilityErr) return rej('invalid visibility');
 
 	// Get 'visibleUserIds' parameter
-	const [visibleUserIds, visibleUserIdsErr] = $(params.visibleUserIds).optional.array($().type(ID)).unique().min(1).get();
+	const [visibleUserIds, visibleUserIdsErr] = $.arr($.type(ID)).optional().unique().min(1).get(params.visibleUserIds);
 	if (visibleUserIdsErr) return rej('invalid visibleUserIds');
 
 	let visibleUsers = [];
@@ -29,36 +29,36 @@ module.exports = (params, user: ILocalUser, app: IApp) => new Promise(async (res
 	}
 
 	// Get 'text' parameter
-	const [text = null, textErr] = $(params.text).optional.nullable.string().pipe(isValidText).get();
+	const [text = null, textErr] = $.str.optional().nullable().pipe(isValidText).get(params.text);
 	if (textErr) return rej('invalid text');
 
 	// Get 'cw' parameter
-	const [cw, cwErr] = $(params.cw).optional.nullable.string().pipe(isValidCw).get();
+	const [cw, cwErr] = $.str.optional().nullable().pipe(isValidCw).get(params.cw);
 	if (cwErr) return rej('invalid cw');
 
 	// Get 'viaMobile' parameter
-	const [viaMobile = false, viaMobileErr] = $(params.viaMobile).optional.boolean().get();
+	const [viaMobile = false, viaMobileErr] = $.bool.optional().get(params.viaMobile);
 	if (viaMobileErr) return rej('invalid viaMobile');
 
 	// Get 'tags' parameter
-	const [tags = [], tagsErr] = $(params.tags).optional.array($().string().range(1, 32)).unique().get();
+	const [tags = [], tagsErr] = $.arr($.str.optional().range(1, 32)).unique().get(params.tags);
 	if (tagsErr) return rej('invalid tags');
 
 	// Get 'geo' parameter
-	const [geo, geoErr] = $(params.geo).optional.nullable.object(true)
-		.have('coordinates', $().array().length(2)
-			.item(0, $().number().range(-180, 180))
-			.item(1, $().number().range(-90, 90)))
-		.have('altitude', $().nullable.number())
-		.have('accuracy', $().nullable.number())
-		.have('altitudeAccuracy', $().nullable.number())
-		.have('heading', $().nullable.number().range(0, 360))
-		.have('speed', $().nullable.number())
-		.get();
+	const [geo, geoErr] = $.obj.optional().nullable().strict()
+		.have('coordinates', $.arr().length(2)
+			.item(0, $.num.range(-180, 180))
+			.item(1, $.num.range(-90, 90)))
+		.have('altitude', $.num.nullable())
+		.have('accuracy', $.num.nullable())
+		.have('altitudeAccuracy', $.num.nullable())
+		.have('heading', $.num.nullable().range(0, 360))
+		.have('speed', $.num.nullable())
+		.get(params.geo);
 	if (geoErr) return rej('invalid geo');
 
 	// Get 'mediaIds' parameter
-	const [mediaIds, mediaIdsErr] = $(params.mediaIds).optional.array($().type(ID)).unique().range(1, 4).get();
+	const [mediaIds, mediaIdsErr] = $.arr($.type(ID)).optional().unique().range(1, 4).get(params.mediaIds);
 	if (mediaIdsErr) return rej('invalid mediaIds');
 
 	let files = [];
@@ -85,7 +85,7 @@ module.exports = (params, user: ILocalUser, app: IApp) => new Promise(async (res
 	}
 
 	// Get 'renoteId' parameter
-	const [renoteId, renoteIdErr] = $(params.renoteId).optional.type(ID).get();
+	const [renoteId, renoteIdErr] = $.type(ID).optional().get(params.renoteId);
 	if (renoteIdErr) return rej('invalid renoteId');
 
 	let renote: INote = null;
@@ -106,7 +106,7 @@ module.exports = (params, user: ILocalUser, app: IApp) => new Promise(async (res
 	}
 
 	// Get 'replyId' parameter
-	const [replyId, replyIdErr] = $(params.replyId).optional.type(ID).get();
+	const [replyId, replyIdErr] = $.type(ID).optional().get(params.replyId);
 	if (replyIdErr) return rej('invalid replyId');
 
 	let reply: INote = null;
@@ -127,7 +127,7 @@ module.exports = (params, user: ILocalUser, app: IApp) => new Promise(async (res
 	}
 
 	// Get 'channelId' parameter
-	const [channelId, channelIdErr] = $(params.channelId).optional.type(ID).get();
+	const [channelId, channelIdErr] = $.type(ID).optional().get(params.channelId);
 	if (channelIdErr) return rej('invalid channelId');
 
 	let channel: IChannel = null;
@@ -168,12 +168,12 @@ module.exports = (params, user: ILocalUser, app: IApp) => new Promise(async (res
 	}
 
 	// Get 'poll' parameter
-	const [poll, pollErr] = $(params.poll).optional.object(true)
-		.have('choices', $().array($().string())
+	const [poll, pollErr] = $.obj.optional().strict()
+		.have('choices', $.arr($.str)
 			.unique()
 			.range(2, 10)
 			.each(c => c.length > 0 && c.length < 50))
-		.get();
+		.get(params.poll);
 	if (pollErr) return rej('invalid poll');
 
 	if (poll) {
diff --git a/src/server/api/endpoints/notes/favorites/create.ts b/src/server/api/endpoints/notes/favorites/create.ts
index e6396b85cef84ce76a2cc244efd3cc0a9d934449..6832b52f75994d2a81da0f6fa1b5ec4ed7c63b7e 100644
--- a/src/server/api/endpoints/notes/favorites/create.ts
+++ b/src/server/api/endpoints/notes/favorites/create.ts
@@ -10,7 +10,7 @@ import Note from '../../../../../models/note';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'noteId' parameter
-	const [noteId, noteIdErr] = $(params.noteId).type(ID).get();
+	const [noteId, noteIdErr] = $.type(ID).get(params.noteId);
 	if (noteIdErr) return rej('invalid noteId param');
 
 	// Get favoritee
diff --git a/src/server/api/endpoints/notes/favorites/delete.ts b/src/server/api/endpoints/notes/favorites/delete.ts
index f1de4247251a9909d3e880dcb3ffc81e15906bf0..07112dae15007b638927e3c43cb4ff7c3f0f343a 100644
--- a/src/server/api/endpoints/notes/favorites/delete.ts
+++ b/src/server/api/endpoints/notes/favorites/delete.ts
@@ -10,7 +10,7 @@ import Note from '../../../../../models/note';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'noteId' parameter
-	const [noteId, noteIdErr] = $(params.noteId).type(ID).get();
+	const [noteId, noteIdErr] = $.type(ID).get(params.noteId);
 	if (noteIdErr) return rej('invalid noteId param');
 
 	// Get favoritee
diff --git a/src/server/api/endpoints/notes/global-timeline.ts b/src/server/api/endpoints/notes/global-timeline.ts
index 212345aac08a55947ba2bd98074c5caf50545882..d22a1763de4a8f1ed98ce4d226a42f739edd7933 100644
--- a/src/server/api/endpoints/notes/global-timeline.ts
+++ b/src/server/api/endpoints/notes/global-timeline.ts
@@ -11,23 +11,23 @@ import { pack } from '../../../../models/note';
  */
 module.exports = async (params, user, app) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) throw 'invalid limit param';
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) throw 'invalid sinceId param';
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) throw 'invalid untilId param';
 
 	// Get 'sinceDate' parameter
-	const [sinceDate, sinceDateErr] = $(params.sinceDate).optional.number().get();
+	const [sinceDate, sinceDateErr] = $.num.optional().get(params.sinceDate);
 	if (sinceDateErr) throw 'invalid sinceDate param';
 
 	// Get 'untilDate' parameter
-	const [untilDate, untilDateErr] = $(params.untilDate).optional.number().get();
+	const [untilDate, untilDateErr] = $.num.optional().get(params.untilDate);
 	if (untilDateErr) throw 'invalid untilDate param';
 
 	// Check if only one of sinceId, untilId, sinceDate, untilDate specified
diff --git a/src/server/api/endpoints/notes/local-timeline.ts b/src/server/api/endpoints/notes/local-timeline.ts
index 12dd2d5a85d4c8710872e1ef86aa364e391d8073..e7ebe5d960ee577fb16fe67b3160d91b103f31f1 100644
--- a/src/server/api/endpoints/notes/local-timeline.ts
+++ b/src/server/api/endpoints/notes/local-timeline.ts
@@ -11,23 +11,23 @@ import { pack } from '../../../../models/note';
  */
 module.exports = async (params, user, app) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) throw 'invalid limit param';
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) throw 'invalid sinceId param';
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) throw 'invalid untilId param';
 
 	// Get 'sinceDate' parameter
-	const [sinceDate, sinceDateErr] = $(params.sinceDate).optional.number().get();
+	const [sinceDate, sinceDateErr] = $.num.optional().get(params.sinceDate);
 	if (sinceDateErr) throw 'invalid sinceDate param';
 
 	// Get 'untilDate' parameter
-	const [untilDate, untilDateErr] = $(params.untilDate).optional.number().get();
+	const [untilDate, untilDateErr] = $.num.optional().get(params.untilDate);
 	if (untilDateErr) throw 'invalid untilDate param';
 
 	// Check if only one of sinceId, untilId, sinceDate, untilDate specified
diff --git a/src/server/api/endpoints/notes/mentions.ts b/src/server/api/endpoints/notes/mentions.ts
index db7c630897714ac928f2284c05a6e54e84c0ccb7..163a6b48666707f9854e025a2aa94f86a8061882 100644
--- a/src/server/api/endpoints/notes/mentions.ts
+++ b/src/server/api/endpoints/notes/mentions.ts
@@ -16,19 +16,19 @@ import { pack } from '../../../../models/note';
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'following' parameter
 	const [following = false, followingError] =
-		$(params.following).optional.boolean().get();
+		$.bool.optional().get(params.following);
 	if (followingError) return rej('invalid following param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Check if both of sinceId and untilId is specified
diff --git a/src/server/api/endpoints/notes/polls/recommendation.ts b/src/server/api/endpoints/notes/polls/recommendation.ts
index 1994c5ce7a1027d67d147e8afae8235f4e8286fa..a272378d19bdb02e31219800c6b4eeebaca4e7ae 100644
--- a/src/server/api/endpoints/notes/polls/recommendation.ts
+++ b/src/server/api/endpoints/notes/polls/recommendation.ts
@@ -10,11 +10,11 @@ import Note, { pack } from '../../../../../models/note';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'offset' parameter
-	const [offset = 0, offsetErr] = $(params.offset).optional.number().min(0).get();
+	const [offset = 0, offsetErr] = $.num.optional().min(0).get(params.offset);
 	if (offsetErr) return rej('invalid offset param');
 
 	// Get votes
diff --git a/src/server/api/endpoints/notes/polls/vote.ts b/src/server/api/endpoints/notes/polls/vote.ts
index 1915e0c79bc4aefd452c12d8ed7030258ffd4f97..f8f4515308f7607094ec1d84c2ed83919fab1725 100644
--- a/src/server/api/endpoints/notes/polls/vote.ts
+++ b/src/server/api/endpoints/notes/polls/vote.ts
@@ -14,7 +14,7 @@ import notify from '../../../../../publishers/notify';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'noteId' parameter
-	const [noteId, noteIdErr] = $(params.noteId).type(ID).get();
+	const [noteId, noteIdErr] = $.type(ID).get(params.noteId);
 	if (noteIdErr) return rej('invalid noteId param');
 
 	// Get votee
@@ -32,9 +32,9 @@ module.exports = (params, user) => new Promise(async (res, rej) => {
 
 	// Get 'choice' parameter
 	const [choice, choiceError] =
-		$(params.choice).number()
+		$.num
 			.pipe(c => note.poll.choices.some(x => x.id == c))
-			.get();
+			.get(params.choice);
 	if (choiceError) return rej('invalid choice param');
 
 	// if already voted
diff --git a/src/server/api/endpoints/notes/reactions.ts b/src/server/api/endpoints/notes/reactions.ts
index 75ed580de235f4b5a30e84a98ec4b0387331cf69..4ad952a7a196764be305a43763bb5ab0e646a56a 100644
--- a/src/server/api/endpoints/notes/reactions.ts
+++ b/src/server/api/endpoints/notes/reactions.ts
@@ -14,19 +14,19 @@ import Reaction, { pack } from '../../../../models/note-reaction';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'noteId' parameter
-	const [noteId, noteIdErr] = $(params.noteId).type(ID).get();
+	const [noteId, noteIdErr] = $.type(ID).get(params.noteId);
 	if (noteIdErr) return rej('invalid noteId param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'offset' parameter
-	const [offset = 0, offsetErr] = $(params.offset).optional.number().min(0).get();
+	const [offset = 0, offsetErr] = $.num.optional().min(0).get(params.offset);
 	if (offsetErr) return rej('invalid offset param');
 
 	// Get 'sort' parameter
-	const [sort = 'desc', sortError] = $(params.sort).optional.string().or('desc asc').get();
+	const [sort = 'desc', sortError] = $.str.optional().or('desc asc').get(params.sort);
 	if (sortError) return rej('invalid sort param');
 
 	// Lookup note
diff --git a/src/server/api/endpoints/notes/reactions/create.ts b/src/server/api/endpoints/notes/reactions/create.ts
index 9dc1b3c82af389bfa00b1b4778023e576b8c3194..21757cb4278927b41e57783b3e5f1a4399914a49 100644
--- a/src/server/api/endpoints/notes/reactions/create.ts
+++ b/src/server/api/endpoints/notes/reactions/create.ts
@@ -11,11 +11,11 @@ import { validateReaction } from '../../../../../models/note-reaction';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'noteId' parameter
-	const [noteId, noteIdErr] = $(params.noteId).type(ID).get();
+	const [noteId, noteIdErr] = $.type(ID).get(params.noteId);
 	if (noteIdErr) return rej('invalid noteId param');
 
 	// Get 'reaction' parameter
-	const [reaction, reactionErr] = $(params.reaction).string().pipe(validateReaction.ok).get();
+	const [reaction, reactionErr] = $.str.pipe(validateReaction.ok).get(params.reaction);
 	if (reactionErr) return rej('invalid reaction param');
 
 	// Fetch reactee
diff --git a/src/server/api/endpoints/notes/reactions/delete.ts b/src/server/api/endpoints/notes/reactions/delete.ts
index 6bd5edef423af689e03f6ea927aea7c6e3a78780..afb86291125f8e1dfc739d5e95d18b0a27953b3c 100644
--- a/src/server/api/endpoints/notes/reactions/delete.ts
+++ b/src/server/api/endpoints/notes/reactions/delete.ts
@@ -10,7 +10,7 @@ import Note from '../../../../../models/note';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'noteId' parameter
-	const [noteId, noteIdErr] = $(params.noteId).type(ID).get();
+	const [noteId, noteIdErr] = $.type(ID).get(params.noteId);
 	if (noteIdErr) return rej('invalid noteId param');
 
 	// Fetch unreactee
diff --git a/src/server/api/endpoints/notes/replies.ts b/src/server/api/endpoints/notes/replies.ts
index 47c9ae501f58289ba2d37587045edc7a6cdc73fa..11d221d8f77c9dfd86be721373ae95bf33d91df4 100644
--- a/src/server/api/endpoints/notes/replies.ts
+++ b/src/server/api/endpoints/notes/replies.ts
@@ -13,19 +13,19 @@ import Note, { pack } from '../../../../models/note';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'noteId' parameter
-	const [noteId, noteIdErr] = $(params.noteId).type(ID).get();
+	const [noteId, noteIdErr] = $.type(ID).get(params.noteId);
 	if (noteIdErr) return rej('invalid noteId param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'offset' parameter
-	const [offset = 0, offsetErr] = $(params.offset).optional.number().min(0).get();
+	const [offset = 0, offsetErr] = $.num.optional().min(0).get(params.offset);
 	if (offsetErr) return rej('invalid offset param');
 
 	// Get 'sort' parameter
-	const [sort = 'desc', sortError] = $(params.sort).optional.string().or('desc asc').get();
+	const [sort = 'desc', sortError] = $.str.optional().or('desc asc').get(params.sort);
 	if (sortError) return rej('invalid sort param');
 
 	// Lookup note
diff --git a/src/server/api/endpoints/notes/reposts.ts b/src/server/api/endpoints/notes/reposts.ts
index b388ee599f0a66d64a30a871c0cd4170b71fe6c2..3098211b617eb283b0defe7747bb9e8355989d66 100644
--- a/src/server/api/endpoints/notes/reposts.ts
+++ b/src/server/api/endpoints/notes/reposts.ts
@@ -13,19 +13,19 @@ import Note, { pack } from '../../../../models/note';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'noteId' parameter
-	const [noteId, noteIdErr] = $(params.noteId).type(ID).get();
+	const [noteId, noteIdErr] = $.type(ID).get(params.noteId);
 	if (noteIdErr) return rej('invalid noteId param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Check if both of sinceId and untilId is specified
diff --git a/src/server/api/endpoints/notes/search.ts b/src/server/api/endpoints/notes/search.ts
index 8b3c78145dc037f4db510bdd582bea0a80318cbf..9705dcfd6ec9da0da28ea3f4e4fdaa801cf8281d 100644
--- a/src/server/api/endpoints/notes/search.ts
+++ b/src/server/api/endpoints/notes/search.ts
@@ -18,63 +18,63 @@ import { pack } from '../../../../models/note';
  */
 module.exports = (params, me) => new Promise(async (res, rej) => {
 	// Get 'text' parameter
-	const [text, textError] = $(params.text).optional.string().get();
+	const [text, textError] = $.str.optional().get(params.text);
 	if (textError) return rej('invalid text param');
 
 	// Get 'includeUserIds' parameter
-	const [includeUserIds = [], includeUserIdsErr] = $(params.includeUserIds).optional.array($().type(ID)).get();
+	const [includeUserIds = [], includeUserIdsErr] = $.arr($.type(ID)).optional().get(params.includeUserIds);
 	if (includeUserIdsErr) return rej('invalid includeUserIds param');
 
 	// Get 'excludeUserIds' parameter
-	const [excludeUserIds = [], excludeUserIdsErr] = $(params.excludeUserIds).optional.array($().type(ID)).get();
+	const [excludeUserIds = [], excludeUserIdsErr] = $.arr($.type(ID)).optional().get(params.excludeUserIds);
 	if (excludeUserIdsErr) return rej('invalid excludeUserIds param');
 
 	// Get 'includeUserUsernames' parameter
-	const [includeUserUsernames = [], includeUserUsernamesErr] = $(params.includeUserUsernames).optional.array($().string()).get();
+	const [includeUserUsernames = [], includeUserUsernamesErr] = $.arr($.str).optional().get(params.includeUserUsernames);
 	if (includeUserUsernamesErr) return rej('invalid includeUserUsernames param');
 
 	// Get 'excludeUserUsernames' parameter
-	const [excludeUserUsernames = [], excludeUserUsernamesErr] = $(params.excludeUserUsernames).optional.array($().string()).get();
+	const [excludeUserUsernames = [], excludeUserUsernamesErr] = $.arr($.str).optional().get(params.excludeUserUsernames);
 	if (excludeUserUsernamesErr) return rej('invalid excludeUserUsernames param');
 
 	// Get 'following' parameter
-	const [following = null, followingErr] = $(params.following).optional.nullable.boolean().get();
+	const [following = null, followingErr] = $.bool.optional().nullable().get(params.following);
 	if (followingErr) return rej('invalid following param');
 
 	// Get 'mute' parameter
-	const [mute = 'mute_all', muteErr] = $(params.mute).optional.string().get();
+	const [mute = 'mute_all', muteErr] = $.str.optional().get(params.mute);
 	if (muteErr) return rej('invalid mute param');
 
 	// Get 'reply' parameter
-	const [reply = null, replyErr] = $(params.reply).optional.nullable.boolean().get();
+	const [reply = null, replyErr] = $.bool.optional().nullable().get(params.reply);
 	if (replyErr) return rej('invalid reply param');
 
 	// Get 'renote' parameter
-	const [renote = null, renoteErr] = $(params.renote).optional.nullable.boolean().get();
+	const [renote = null, renoteErr] = $.bool.optional().nullable().get(params.renote);
 	if (renoteErr) return rej('invalid renote param');
 
 	// Get 'media' parameter
-	const [media = null, mediaErr] = $(params.media).optional.nullable.boolean().get();
+	const [media = null, mediaErr] = $.bool.optional().nullable().get(params.media);
 	if (mediaErr) return rej('invalid media param');
 
 	// Get 'poll' parameter
-	const [poll = null, pollErr] = $(params.poll).optional.nullable.boolean().get();
+	const [poll = null, pollErr] = $.bool.optional().nullable().get(params.poll);
 	if (pollErr) return rej('invalid poll param');
 
 	// Get 'sinceDate' parameter
-	const [sinceDate, sinceDateErr] = $(params.sinceDate).optional.number().get();
+	const [sinceDate, sinceDateErr] = $.num.optional().get(params.sinceDate);
 	if (sinceDateErr) throw 'invalid sinceDate param';
 
 	// Get 'untilDate' parameter
-	const [untilDate, untilDateErr] = $(params.untilDate).optional.number().get();
+	const [untilDate, untilDateErr] = $.num.optional().get(params.untilDate);
 	if (untilDateErr) throw 'invalid untilDate param';
 
 	// Get 'offset' parameter
-	const [offset = 0, offsetErr] = $(params.offset).optional.number().min(0).get();
+	const [offset = 0, offsetErr] = $.num.optional().min(0).get(params.offset);
 	if (offsetErr) return rej('invalid offset param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 30).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 30).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	let includeUsers = includeUserIds;
diff --git a/src/server/api/endpoints/notes/show.ts b/src/server/api/endpoints/notes/show.ts
index 2a4f8f97e14ea683498c61356b87fe2ebfe1f4a4..78dc55a7037a45061f7d0df34c7f1b2628e3ab56 100644
--- a/src/server/api/endpoints/notes/show.ts
+++ b/src/server/api/endpoints/notes/show.ts
@@ -13,7 +13,7 @@ import Note, { pack } from '../../../../models/note';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'noteId' parameter
-	const [noteId, noteIdErr] = $(params.noteId).type(ID).get();
+	const [noteId, noteIdErr] = $.type(ID).get(params.noteId);
 	if (noteIdErr) return rej('invalid noteId param');
 
 	// Get note
diff --git a/src/server/api/endpoints/notes/timeline.ts b/src/server/api/endpoints/notes/timeline.ts
index 222f0b795f4d9239ee5e71e351a8bbd761364eb5..78786d4a16a866bf6638a9f23c23dc46f8343354 100644
--- a/src/server/api/endpoints/notes/timeline.ts
+++ b/src/server/api/endpoints/notes/timeline.ts
@@ -13,23 +13,23 @@ import { pack } from '../../../../models/note';
  */
 module.exports = async (params, user, app) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) throw 'invalid limit param';
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) throw 'invalid sinceId param';
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) throw 'invalid untilId param';
 
 	// Get 'sinceDate' parameter
-	const [sinceDate, sinceDateErr] = $(params.sinceDate).optional.number().get();
+	const [sinceDate, sinceDateErr] = $.num.optional().get(params.sinceDate);
 	if (sinceDateErr) throw 'invalid sinceDate param';
 
 	// Get 'untilDate' parameter
-	const [untilDate, untilDateErr] = $(params.untilDate).optional.number().get();
+	const [untilDate, untilDateErr] = $.num.optional().get(params.untilDate);
 	if (untilDateErr) throw 'invalid untilDate param';
 
 	// Check if only one of sinceId, untilId, sinceDate, untilDate specified
@@ -38,11 +38,11 @@ module.exports = async (params, user, app) => {
 	}
 
 	// Get 'includeMyRenotes' parameter
-	const [includeMyRenotes = true, includeMyRenotesErr] = $(params.includeMyRenotes).optional.boolean().get();
+	const [includeMyRenotes = true, includeMyRenotesErr] = $.bool.optional().get(params.includeMyRenotes);
 	if (includeMyRenotesErr) throw 'invalid includeMyRenotes param';
 
 	// Get 'includeRenotedMyNotes' parameter
-	const [includeRenotedMyNotes = true, includeRenotedMyNotesErr] = $(params.includeRenotedMyNotes).optional.boolean().get();
+	const [includeRenotedMyNotes = true, includeRenotedMyNotesErr] = $.bool.optional().get(params.includeRenotedMyNotes);
 	if (includeRenotedMyNotesErr) throw 'invalid includeRenotedMyNotes param';
 
 	const [followings, watchingChannelIds, mutedUserIds] = await Promise.all([
diff --git a/src/server/api/endpoints/notes/trend.ts b/src/server/api/endpoints/notes/trend.ts
index 915d45ce9171da6920393c3339cd5227e21b0e74..9cb3debe635699f6c9c462ef7598f69e1229f8bf 100644
--- a/src/server/api/endpoints/notes/trend.ts
+++ b/src/server/api/endpoints/notes/trend.ts
@@ -14,27 +14,27 @@ import Note, { pack } from '../../../../models/note';
  */
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'offset' parameter
-	const [offset = 0, offsetErr] = $(params.offset).optional.number().min(0).get();
+	const [offset = 0, offsetErr] = $.num.optional().min(0).get(params.offset);
 	if (offsetErr) return rej('invalid offset param');
 
 	// Get 'reply' parameter
-	const [reply, replyErr] = $(params.reply).optional.boolean().get();
+	const [reply, replyErr] = $.bool.optional().get(params.reply);
 	if (replyErr) return rej('invalid reply param');
 
 	// Get 'renote' parameter
-	const [renote, renoteErr] = $(params.renote).optional.boolean().get();
+	const [renote, renoteErr] = $.bool.optional().get(params.renote);
 	if (renoteErr) return rej('invalid renote param');
 
 	// Get 'media' parameter
-	const [media, mediaErr] = $(params.media).optional.boolean().get();
+	const [media, mediaErr] = $.bool.optional().get(params.media);
 	if (mediaErr) return rej('invalid media param');
 
 	// Get 'poll' parameter
-	const [poll, pollErr] = $(params.poll).optional.boolean().get();
+	const [poll, pollErr] = $.bool.optional().get(params.poll);
 	if (pollErr) return rej('invalid poll param');
 
 	const query = {
diff --git a/src/server/api/endpoints/notes/user-list-timeline.ts b/src/server/api/endpoints/notes/user-list-timeline.ts
index 8d4eb590cbe98329f0693eb2815bd2d22ad0b1b5..9f8397d67971afad11be37e6a735cd8fd292d65c 100644
--- a/src/server/api/endpoints/notes/user-list-timeline.ts
+++ b/src/server/api/endpoints/notes/user-list-timeline.ts
@@ -12,23 +12,23 @@ import UserList from '../../../../models/user-list';
  */
 module.exports = async (params, user, app) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) throw 'invalid limit param';
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) throw 'invalid sinceId param';
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) throw 'invalid untilId param';
 
 	// Get 'sinceDate' parameter
-	const [sinceDate, sinceDateErr] = $(params.sinceDate).optional.number().get();
+	const [sinceDate, sinceDateErr] = $.num.optional().get(params.sinceDate);
 	if (sinceDateErr) throw 'invalid sinceDate param';
 
 	// Get 'untilDate' parameter
-	const [untilDate, untilDateErr] = $(params.untilDate).optional.number().get();
+	const [untilDate, untilDateErr] = $.num.optional().get(params.untilDate);
 	if (untilDateErr) throw 'invalid untilDate param';
 
 	// Check if only one of sinceId, untilId, sinceDate, untilDate specified
@@ -37,15 +37,15 @@ module.exports = async (params, user, app) => {
 	}
 
 	// Get 'includeMyRenotes' parameter
-	const [includeMyRenotes = true, includeMyRenotesErr] = $(params.includeMyRenotes).optional.boolean().get();
+	const [includeMyRenotes = true, includeMyRenotesErr] = $.bool.optional().get(params.includeMyRenotes);
 	if (includeMyRenotesErr) throw 'invalid includeMyRenotes param';
 
 	// Get 'includeRenotedMyNotes' parameter
-	const [includeRenotedMyNotes = true, includeRenotedMyNotesErr] = $(params.includeRenotedMyNotes).optional.boolean().get();
+	const [includeRenotedMyNotes = true, includeRenotedMyNotesErr] = $.bool.optional().get(params.includeRenotedMyNotes);
 	if (includeRenotedMyNotesErr) throw 'invalid includeRenotedMyNotes param';
 
 	// Get 'listId' parameter
-	const [listId, listIdErr] = $(params.listId).type(ID).get();
+	const [listId, listIdErr] = $.type(ID).get(params.listId);
 	if (listIdErr) throw 'invalid listId param';
 
 	const [list, mutedUserIds] = await Promise.all([
diff --git a/src/server/api/endpoints/othello/games.ts b/src/server/api/endpoints/othello/games.ts
index 05bff180c13d4439fcdb4c358f3dfae2455fc96a..2320a34b0471923e4cc3b30856ec472ba8ebbd8f 100644
--- a/src/server/api/endpoints/othello/games.ts
+++ b/src/server/api/endpoints/othello/games.ts
@@ -3,19 +3,19 @@ import OthelloGame, { pack } from '../../../../models/othello-game';
 
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'my' parameter
-	const [my = false, myErr] = $(params.my).optional.boolean().get();
+	const [my = false, myErr] = $.bool.optional().get(params.my);
 	if (myErr) return rej('invalid my param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Check if both of sinceId and untilId is specified
diff --git a/src/server/api/endpoints/othello/games/show.ts b/src/server/api/endpoints/othello/games/show.ts
index 991bb9622e0fa7c877c141739850d8c6ac48b13e..6b2f5ce137584f9961ef3f2f18eabc3979c2dad3 100644
--- a/src/server/api/endpoints/othello/games/show.ts
+++ b/src/server/api/endpoints/othello/games/show.ts
@@ -4,7 +4,7 @@ import Othello from '../../../../../othello/core';
 
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'gameId' parameter
-	const [gameId, gameIdErr] = $(params.gameId).type(ID).get();
+	const [gameId, gameIdErr] = $.type(ID).get(params.gameId);
 	if (gameIdErr) return rej('invalid gameId param');
 
 	const game = await OthelloGame.findOne({ _id: gameId });
diff --git a/src/server/api/endpoints/othello/match.ts b/src/server/api/endpoints/othello/match.ts
index 9769c94da302417cfd8b8ff5147d8b5afde9d3c3..e70e579755b82e8596a99552042ad56f8403c469 100644
--- a/src/server/api/endpoints/othello/match.ts
+++ b/src/server/api/endpoints/othello/match.ts
@@ -7,7 +7,7 @@ import { eighteight } from '../../../../othello/maps';
 
 module.exports = (params, user) => new Promise(async (res, rej) => {
 	// Get 'userId' parameter
-	const [childId, childIdErr] = $(params.userId).type(ID).get();
+	const [childId, childIdErr] = $.type(ID).get(params.userId);
 	if (childIdErr) return rej('invalid userId param');
 
 	// Myself
diff --git a/src/server/api/endpoints/sw/register.ts b/src/server/api/endpoints/sw/register.ts
index 222e6edc8e4c5ec635b95a43151762e4eb8e1618..b22a8b08efcd35e50f883c500ad66e401ea1c7b0 100644
--- a/src/server/api/endpoints/sw/register.ts
+++ b/src/server/api/endpoints/sw/register.ts
@@ -9,15 +9,15 @@ import Subscription from '../../../../models/sw-subscription';
  */
 module.exports = async (params, user, app) => new Promise(async (res, rej) => {
 	// Get 'endpoint' parameter
-	const [endpoint, endpointErr] = $(params.endpoint).string().get();
+	const [endpoint, endpointErr] = $.str.get(params.endpoint);
 	if (endpointErr) return rej('invalid endpoint param');
 
 	// Get 'auth' parameter
-	const [auth, authErr] = $(params.auth).string().get();
+	const [auth, authErr] = $.str.get(params.auth);
 	if (authErr) return rej('invalid auth param');
 
 	// Get 'publickey' parameter
-	const [publickey, publickeyErr] = $(params.publickey).string().get();
+	const [publickey, publickeyErr] = $.str.get(params.publickey);
 	if (publickeyErr) return rej('invalid publickey param');
 
 	// if already subscribed
diff --git a/src/server/api/endpoints/username/available.ts b/src/server/api/endpoints/username/available.ts
index 65b297683d62b1af44dbb5f2567fdd7ec4ad5edf..b11bec4e583008831f8e506d25fd7ad2df8fc655 100644
--- a/src/server/api/endpoints/username/available.ts
+++ b/src/server/api/endpoints/username/available.ts
@@ -13,7 +13,7 @@ import { validateUsername } from '../../../../models/user';
  */
 module.exports = async (params) => new Promise(async (res, rej) => {
 	// Get 'username' parameter
-	const [username, usernameError] = $(params.username).string().pipe(validateUsername).get();
+	const [username, usernameError] = $.str.pipe(validateUsername).get(params.username);
 	if (usernameError) return rej('invalid username param');
 
 	// Get exist
diff --git a/src/server/api/endpoints/users.ts b/src/server/api/endpoints/users.ts
index 2f7d00fa8486c8a13e2a8260fe502f03b9ab7e9f..eb581cb7e6251dc12be00cc38a4daffe32a49011 100644
--- a/src/server/api/endpoints/users.ts
+++ b/src/server/api/endpoints/users.ts
@@ -9,15 +9,15 @@ import User, { pack } from '../../../models/user';
  */
 module.exports = (params, me) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'offset' parameter
-	const [offset = 0, offsetErr] = $(params.offset).optional.number().min(0).get();
+	const [offset = 0, offsetErr] = $.num.optional().min(0).get(params.offset);
 	if (offsetErr) return rej('invalid offset param');
 
 	// Get 'sort' parameter
-	const [sort, sortError] = $(params.sort).optional.string().or('+follower|-follower').get();
+	const [sort, sortError] = $.str.optional().or('+follower|-follower').get(params.sort);
 	if (sortError) return rej('invalid sort param');
 
 	// Construct query
diff --git a/src/server/api/endpoints/users/followers.ts b/src/server/api/endpoints/users/followers.ts
index 7892f633d430e77c338be2c72030862c8f41928d..810cd7341bac34696323aca25c75cca302d0f193 100644
--- a/src/server/api/endpoints/users/followers.ts
+++ b/src/server/api/endpoints/users/followers.ts
@@ -12,19 +12,19 @@ import { getFriendIds } from '../../common/get-friends';
  */
 module.exports = (params, me) => new Promise(async (res, rej) => {
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Get 'iknow' parameter
-	const [iknow = false, iknowErr] = $(params.iknow).optional.boolean().get();
+	const [iknow = false, iknowErr] = $.bool.optional().get(params.iknow);
 	if (iknowErr) return rej('invalid iknow param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'cursor' parameter
-	const [cursor = null, cursorErr] = $(params.cursor).optional.type(ID).get();
+	const [cursor = null, cursorErr] = $.type(ID).optional().get(params.cursor);
 	if (cursorErr) return rej('invalid cursor param');
 
 	// Lookup user
diff --git a/src/server/api/endpoints/users/following.ts b/src/server/api/endpoints/users/following.ts
index e584e61f9c27e63b7e9cd2c7d8e29a6d10689a50..3373b9d632bfd7735c132a127ee22cb7d000c627 100644
--- a/src/server/api/endpoints/users/following.ts
+++ b/src/server/api/endpoints/users/following.ts
@@ -16,19 +16,19 @@ import { getFriendIds } from '../../common/get-friends';
  */
 module.exports = (params, me) => new Promise(async (res, rej) => {
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Get 'iknow' parameter
-	const [iknow = false, iknowErr] = $(params.iknow).optional.boolean().get();
+	const [iknow = false, iknowErr] = $.bool.optional().get(params.iknow);
 	if (iknowErr) return rej('invalid iknow param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'cursor' parameter
-	const [cursor = null, cursorErr] = $(params.cursor).optional.type(ID).get();
+	const [cursor = null, cursorErr] = $.type(ID).optional().get(params.cursor);
 	if (cursorErr) return rej('invalid cursor param');
 
 	// Lookup user
diff --git a/src/server/api/endpoints/users/get_frequently_replied_users.ts b/src/server/api/endpoints/users/get_frequently_replied_users.ts
index 034684260c37a3579b847cba5bb250a07f9fcc80..64d737a06ba675df063dd1725753f60549faf1f6 100644
--- a/src/server/api/endpoints/users/get_frequently_replied_users.ts
+++ b/src/server/api/endpoints/users/get_frequently_replied_users.ts
@@ -7,11 +7,11 @@ import User, { pack } from '../../../../models/user';
 
 module.exports = (params, me) => new Promise(async (res, rej) => {
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Lookup user
diff --git a/src/server/api/endpoints/users/lists/create.ts b/src/server/api/endpoints/users/lists/create.ts
index 79a680c736d06168daab7fb41ce3844f82a4de95..100a78b8725fd9a0801a6260a54c12fde3d5f243 100644
--- a/src/server/api/endpoints/users/lists/create.ts
+++ b/src/server/api/endpoints/users/lists/create.ts
@@ -9,7 +9,7 @@ import UserList, { pack } from '../../../../../models/user-list';
  */
 module.exports = async (params, user) => new Promise(async (res, rej) => {
 	// Get 'title' parameter
-	const [title, titleErr] = $(params.title).string().range(1, 100).get();
+	const [title, titleErr] = $.str.range(1, 100).get(params.title);
 	if (titleErr) return rej('invalid title param');
 
 	// insert
diff --git a/src/server/api/endpoints/users/lists/push.ts b/src/server/api/endpoints/users/lists/push.ts
index ceb5692c810e288f3f5b4971141b13956d6b9526..da5a9a134c1d1d35557a77c3c8d678f3b29e53a6 100644
--- a/src/server/api/endpoints/users/lists/push.ts
+++ b/src/server/api/endpoints/users/lists/push.ts
@@ -11,7 +11,7 @@ import { deliver } from '../../../../../queue';
  */
 module.exports = async (params, me) => new Promise(async (res, rej) => {
 	// Get 'listId' parameter
-	const [listId, listIdErr] = $(params.listId).type(ID).get();
+	const [listId, listIdErr] = $.type(ID).get(params.listId);
 	if (listIdErr) return rej('invalid listId param');
 
 	// Fetch the list
@@ -25,7 +25,7 @@ module.exports = async (params, me) => new Promise(async (res, rej) => {
 	}
 
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).type(ID).get();
+	const [userId, userIdErr] = $.type(ID).get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Fetch the user
diff --git a/src/server/api/endpoints/users/lists/show.ts b/src/server/api/endpoints/users/lists/show.ts
index 54e1df7b2ff1164ffdf23c13b485c7b7d182c155..16cb3382fda9bfbd7262df1d2fd73d79708f9265 100644
--- a/src/server/api/endpoints/users/lists/show.ts
+++ b/src/server/api/endpoints/users/lists/show.ts
@@ -6,7 +6,7 @@ import UserList, { pack } from '../../../../../models/user-list';
  */
 module.exports = async (params, me) => new Promise(async (res, rej) => {
 	// Get 'listId' parameter
-	const [listId, listIdErr] = $(params.listId).type(ID).get();
+	const [listId, listIdErr] = $.type(ID).get(params.listId);
 	if (listIdErr) return rej('invalid listId param');
 
 	// Fetch the list
diff --git a/src/server/api/endpoints/users/notes.ts b/src/server/api/endpoints/users/notes.ts
index 67b14b36a3624d99a18e3512221724d04a182e70..061c363d0ff17b5e9562c980e511d67ec3b2a5cb 100644
--- a/src/server/api/endpoints/users/notes.ts
+++ b/src/server/api/endpoints/users/notes.ts
@@ -11,11 +11,11 @@ import User from '../../../../models/user';
  */
 module.exports = (params, me) => new Promise(async (res, rej) => {
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).optional.type(ID).get();
+	const [userId, userIdErr] = $.type(ID).optional().get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Get 'username' parameter
-	const [username, usernameErr] = $(params.username).optional.string().get();
+	const [username, usernameErr] = $.str.optional().get(params.username);
 	if (usernameErr) return rej('invalid username param');
 
 	if (userId === undefined && username === undefined) {
@@ -23,7 +23,7 @@ module.exports = (params, me) => new Promise(async (res, rej) => {
 	}
 
 	// Get 'host' parameter
-	const [host, hostErr] = $(params.host).optional.string().get();
+	const [host, hostErr] = $.str.optional().get(params.host);
 	if (hostErr) return rej('invalid host param');
 
 	if (userId === undefined && host === undefined) {
@@ -31,31 +31,31 @@ module.exports = (params, me) => new Promise(async (res, rej) => {
 	}
 
 	// Get 'includeReplies' parameter
-	const [includeReplies = true, includeRepliesErr] = $(params.includeReplies).optional.boolean().get();
+	const [includeReplies = true, includeRepliesErr] = $.bool.optional().get(params.includeReplies);
 	if (includeRepliesErr) return rej('invalid includeReplies param');
 
 	// Get 'withMedia' parameter
-	const [withMedia = false, withMediaErr] = $(params.withMedia).optional.boolean().get();
+	const [withMedia = false, withMediaErr] = $.bool.optional().get(params.withMedia);
 	if (withMediaErr) return rej('invalid withMedia param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'sinceId' parameter
-	const [sinceId, sinceIdErr] = $(params.sinceId).optional.type(ID).get();
+	const [sinceId, sinceIdErr] = $.type(ID).optional().get(params.sinceId);
 	if (sinceIdErr) return rej('invalid sinceId param');
 
 	// Get 'untilId' parameter
-	const [untilId, untilIdErr] = $(params.untilId).optional.type(ID).get();
+	const [untilId, untilIdErr] = $.type(ID).optional().get(params.untilId);
 	if (untilIdErr) return rej('invalid untilId param');
 
 	// Get 'sinceDate' parameter
-	const [sinceDate, sinceDateErr] = $(params.sinceDate).optional.number().get();
+	const [sinceDate, sinceDateErr] = $.num.optional().get(params.sinceDate);
 	if (sinceDateErr) throw 'invalid sinceDate param';
 
 	// Get 'untilDate' parameter
-	const [untilDate, untilDateErr] = $(params.untilDate).optional.number().get();
+	const [untilDate, untilDateErr] = $.num.optional().get(params.untilDate);
 	if (untilDateErr) throw 'invalid untilDate param';
 
 	// Check if only one of sinceId, untilId, sinceDate, untilDate specified
diff --git a/src/server/api/endpoints/users/recommendation.ts b/src/server/api/endpoints/users/recommendation.ts
index f48ac7cb289c68e482d5bc34a336d9b59a0788a7..620ae17ca2ec85689a2f8240d32fc34dd97d9876 100644
--- a/src/server/api/endpoints/users/recommendation.ts
+++ b/src/server/api/endpoints/users/recommendation.ts
@@ -16,11 +16,11 @@ import Mute from '../../../../models/mute';
  */
 module.exports = (params, me) => new Promise(async (res, rej) => {
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	// Get 'offset' parameter
-	const [offset = 0, offsetErr] = $(params.offset).optional.number().min(0).get();
+	const [offset = 0, offsetErr] = $.num.optional().min(0).get(params.offset);
 	if (offsetErr) return rej('invalid offset param');
 
 	// ID list of the user itself and other users who the user follows
diff --git a/src/server/api/endpoints/users/search.ts b/src/server/api/endpoints/users/search.ts
index 48630c6fd33ad48efc2438fbe000a0715323e6e6..cfbdc337bff736e5e3bb626969cebcc025240298 100644
--- a/src/server/api/endpoints/users/search.ts
+++ b/src/server/api/endpoints/users/search.ts
@@ -16,15 +16,15 @@ const escapeRegexp = require('escape-regexp');
  */
 module.exports = (params, me) => new Promise(async (res, rej) => {
 	// Get 'query' parameter
-	const [query, queryError] = $(params.query).string().pipe(x => x != '').get();
+	const [query, queryError] = $.str.pipe(x => x != '').get(params.query);
 	if (queryError) return rej('invalid query param');
 
 	// Get 'offset' parameter
-	const [offset = 0, offsetErr] = $(params.offset).optional.number().min(0).get();
+	const [offset = 0, offsetErr] = $.num.optional().min(0).get(params.offset);
 	if (offsetErr) return rej('invalid offset param');
 
 	// Get 'max' parameter
-	const [max = 10, maxErr] = $(params.max).optional.number().range(1, 30).get();
+	const [max = 10, maxErr] = $.num.optional().range(1, 30).get(params.max);
 	if (maxErr) return rej('invalid max param');
 
 	// If Elasticsearch is available, search by $
diff --git a/src/server/api/endpoints/users/search_by_username.ts b/src/server/api/endpoints/users/search_by_username.ts
index da3834795609184683f5d33892c4ad9002820dac..5927d00faf7a443c6adccc7d4be83dd12ac7638d 100644
--- a/src/server/api/endpoints/users/search_by_username.ts
+++ b/src/server/api/endpoints/users/search_by_username.ts
@@ -9,15 +9,15 @@ import User, { pack } from '../../../../models/user';
  */
 module.exports = (params, me) => new Promise(async (res, rej) => {
 	// Get 'query' parameter
-	const [query, queryError] = $(params.query).string().get();
+	const [query, queryError] = $.str.get(params.query);
 	if (queryError) return rej('invalid query param');
 
 	// Get 'offset' parameter
-	const [offset = 0, offsetErr] = $(params.offset).optional.number().min(0).get();
+	const [offset = 0, offsetErr] = $.num.optional().min(0).get(params.offset);
 	if (offsetErr) return rej('invalid offset param');
 
 	// Get 'limit' parameter
-	const [limit = 10, limitErr] = $(params.limit).optional.number().range(1, 100).get();
+	const [limit = 10, limitErr] = $.num.optional().range(1, 100).get(params.limit);
 	if (limitErr) return rej('invalid limit param');
 
 	const users = await User
diff --git a/src/server/api/endpoints/users/show.ts b/src/server/api/endpoints/users/show.ts
index 89a8684538fd96428681c5d7360a42a792a127f8..b8c6ff25c4922c79db799a6acac9dec7c8026b11 100644
--- a/src/server/api/endpoints/users/show.ts
+++ b/src/server/api/endpoints/users/show.ts
@@ -14,19 +14,19 @@ module.exports = (params, me) => new Promise(async (res, rej) => {
 	let user;
 
 	// Get 'userId' parameter
-	const [userId, userIdErr] = $(params.userId).optional.type(ID).get();
+	const [userId, userIdErr] = $.type(ID).optional().get(params.userId);
 	if (userIdErr) return rej('invalid userId param');
 
 	// Get 'userIds' parameter
-	const [userIds, userIdsErr] = $(params.userIds).optional.array($().type(ID)).get();
+	const [userIds, userIdsErr] = $.arr($.type(ID)).optional().get(params.userIds);
 	if (userIdsErr) return rej('invalid userIds param');
 
 	// Get 'username' parameter
-	const [username, usernameErr] = $(params.username).optional.string().get();
+	const [username, usernameErr] = $.str.optional().get(params.username);
 	if (usernameErr) return rej('invalid username param');
 
 	// Get 'host' parameter
-	const [host, hostErr] = $(params.host).nullable.optional.string().get();
+	const [host, hostErr] = $.str.optional().nullable().get(params.host);
 	if (hostErr) return rej('invalid host param');
 
 	if (userIds) {