diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..b45cce9
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,24 @@
+type CPSFn<
+  Callbacks extends Array<(...args: unknown[]) => void>
+> = (...args: Callbacks) => void
+
+type ChainFns<
+  FromCallbacks extends Array<(...args: unknown[]) => void>,
+  ToCallbacks extends Array<(...args: unknown[]) => void>,
+> = {
+  [T in keyof FromCallbacks]?: ((...args: Parameters<FromCallbacks[T]>) => CPSFn<ToCallbacks>) | undefined
+}
+
+type CPS<
+  Callbacks extends Array<(...args: unknown[]) => void>
+> = CPSFn<Callbacks> & {
+  chain<
+    ToCallbacks extends Array<(...args: unknown[]) => void>
+  >(...fns: ChainFns<Callbacks, ToCallbacks>): CPS<ToCallbacks>
+}
+
+declare function CPS<
+  Callbacks extends Array<(...args: unknown[]) => void>
+>(fn: CPSFn<Callbacks>): CPS<Callbacks>
+
+export { CPS, CPSFn }
diff --git a/package.json b/package.json
index a4ded3b..a637d06 100644
--- a/package.json
+++ b/package.json
@@ -3,8 +3,10 @@
   "name": "cpsfy",
   "description": "Tiny goodies for Continuation-Passing-Style functions",
   "main": "index.js",
+  "types": "index.d.ts",
   "files": [
     "index.js",
+    "index.d.ts",
     "utils.js"
   ],
   "repository": "https://github.com/dmitriz/cpsfy.git",
diff --git a/type-test/chain.ts b/type-test/chain.ts
new file mode 100644
index 0000000..34c322d
--- /dev/null
+++ b/type-test/chain.ts
@@ -0,0 +1,35 @@
+import { CPS, type CPSFn } from "../index"
+
+const cpsFn: CPSFn<[
+  (a: number, b: number) => void,
+  (a: number, b: string) => void,
+]> = (cb1, cb2) => { cb1(2,3); cb2(7, "bar") }
+
+const f1 = (x: number, y: number): CPSFn<[
+  (x: number, y?: string) => void,
+  (x: number) => void,
+]> => (cb1, cb2) => { cb1(x+y); cb2(x-y) }
+
+const f2 = (x: number, y: string): CPSFn<[
+  (x: number, y?: string) => void,
+]> => (cb1) => { cb1(x, y) }
+
+const chainOneWay = CPS(cpsFn).chain(f1, f2)
+
+const chainSecondWay = CPS(cpsFn).chain<[
+  (x: number, y?: string) => void,
+  (x: number) => void,
+]>(
+  (x, y) => (cb1, cb2) => { cb1(x+y); cb2(x-y) },
+  (x, y) => (cb1) => { cb1(x, y) }
+)
+
+const chainThirdWay = CPS(cpsFn).chain(
+  (x: number, y: number) => (
+    cb1: (x: number, y?: string) => void,
+    cb2: (x: number) => void
+  ) => { cb1(x+y); cb2(x-y) },
+  (x: number, y: string) => (
+    cb1: (x: number, y?: string) => void,
+  ) => { cb1(x, y) }
+)