diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..43934ec
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,23 @@
+import { Duplex } from 'bare-stream'
+
+declare class IPC extends Duplex {
+  constructor(port: IPCPort)
+}
+
+declare interface IPCPort {
+  incoming: string | number
+  outgoing: string | number
+  detached: boolean
+
+  connect(): IPC
+}
+
+declare class IPCPort {
+  constructor(incoming: string | number, outgoing: string | number)
+}
+
+declare namespace IPC {
+  export function open(): [IPCPort, IPCPort]
+}
+
+export = IPC
diff --git a/index.js b/index.js
index 87769e0..66b26ef 100644
--- a/index.js
+++ b/index.js
@@ -78,9 +78,9 @@ class IPCPort {
   }
 }
 
-exports.open = function open(opts) {
-  const a = Pipe.pipe(opts)
-  const b = Pipe.pipe(opts)
+exports.open = function open() {
+  const a = Pipe.pipe()
+  const b = Pipe.pipe()
 
-  return [new IPCPort(a[0], b[1], opts), new IPCPort(b[0], a[1], opts)]
+  return [new IPCPort(a[0], b[1]), new IPCPort(b[0], a[1])]
 }
diff --git a/lib/errors.d.ts b/lib/errors.d.ts
new file mode 100644
index 0000000..13d9a2a
--- /dev/null
+++ b/lib/errors.d.ts
@@ -0,0 +1,5 @@
+declare class IPCError extends Error {
+  static ALREADY_CONNECTED(msg: string): IPCError
+}
+
+export = IPCError
diff --git a/package.json b/package.json
index a1c3240..fdcfe1f 100644
--- a/package.json
+++ b/package.json
@@ -3,12 +3,19 @@
   "version": "1.0.1",
   "description": "Lightweight pipe-based IPC for Bare",
   "exports": {
-    ".": "./index.js",
+    ".": {
+      "types": "./index.d.ts",
+      "default": "./index.js"
+    },
     "./package": "./package.json",
-    "./errors": "./lib/errors.js"
+    "./errors": {
+      "types": "./lib/errors.d.ts",
+      "default": "./lib/errors.js"
+    }
   },
   "files": [
     "index.js",
+    "index.d.ts",
     "lib"
   ],
   "scripts": {