diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..bc56d77
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,89 @@
+// String prototype extensions
+interface String {
+  splice(start: number, len: number, fill?: string): string
+  htmlspecialchars(sign?: 'ENT_QUOTES' | 'ENT_NOQUOTES'): string
+  tohtml(): string
+  xss(): string
+  escape(): string
+  at(num: number): string
+  toJson(): Record<string, string>
+  lt(v: string): boolean
+  lte(v: string): boolean
+  gt(v: string): boolean
+  gte(v: string): boolean
+  eq(v: string): boolean
+}
+
+// Set prototype extensions
+interface Set<T> {
+  union(other: Set<T>): Set<T>
+  difference(other: Set<T>): Set<T>
+  symmetricDifference(other: Set<T>): Set<T>
+  intersection(other: Set<T>): Set<T>
+  isSubsetOf(other: Set<T>): boolean
+  isSupersetOf(other: Set<T>): boolean
+  isDisjointFrom(other: Set<T>): boolean
+  equals(other: Set<T>): boolean
+}
+
+// Promise extensions
+interface PromiseConstructor {
+  defer<T>(): {
+    promise: Promise<T>
+    resolve: (value: T | PromiseLike<T>) => void
+    reject: (reason?: any) => void
+  }
+  withResolvers<T>(): {
+    promise: Promise<T>
+    resolve: (value: T | PromiseLike<T>) => void
+    reject: (reason?: any) => void
+  }
+}
+
+// Object extensions
+interface ObjectConstructor {
+  empty(obj: any): boolean
+  groupBy<T>(arr: T[], fn: (item: T) => string): Record<string, T[]>
+  hasOwn(obj: any, key: string): boolean
+}
+
+interface Object {
+  toParams(): string
+}
+
+// Number extensions
+interface NumberConstructor {
+  parse(val: string | number): string | number
+  fromString(val: string): number
+}
+
+// Map extensions
+interface MapConstructor {
+  groupBy<T, K>(arr: T[], fn: (item: T) => K): Map<K, T[]>
+}
+
+// Date prototype extensions
+interface Date {
+  getFullWeek(): number
+  getWeek(): number
+  format(str?: string): string
+}
+
+// Array prototype extensions
+interface Array<T> {
+  flat(deep?: number, arr?: T[]): T[]
+  flatMap<U>(callback: (value: T, index: number, array: T[]) => U | U[]): U[]
+  at(num: number): T
+  findLast(
+    predicate: (value: T, index: number, obj: T[]) => boolean
+  ): T | undefined
+  findLastIndex(
+    predicate: (value: T, index: number, obj: T[]) => boolean
+  ): number
+  toSorted(compareFn?: (a: T, b: T) => number): T[]
+  toReversed(): T[]
+  toSpliced(start: number, deleteCount?: number, ...items: T[]): T[]
+  with(index: number, value: T): T[]
+  group(callback: (value: T) => string): Record<string, T[]>
+  groupToMap<K>(callback: (value: T) => K): Map<K, T[]>
+}
diff --git a/package.json b/package.json
index 61cbff3..35f526c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "es.shim",
-  "version": "2.4.3",
+  "version": "2.5.0",
   "description": "实现部分新API, 以及一些常用的扩展方法",
   "keyworks": [
     "es5",
@@ -13,8 +13,10 @@
     "shim"
   ],
   "main": "dist/index.js",
+  "types": "index.d.ts",
   "files": [
-    "dist/*"
+    "dist/*",
+    "index.d.ts"
   ],
   "scripts": {
     "start": "node ./build.js"