diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..0e847a6
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,19 @@
+declare namespace keypair {
+    export interface Options {
+        bits?: number,
+        e?: number
+    }
+    
+    export interface Results {
+        public: string,
+        private: string
+    }    
+}
+
+/**
+ * Get an RSA PEM key pair.
+ * @param opts
+ */
+declare function keypair (opts?: keypair.Options): keypair.Results;
+
+export = keypair;
\ No newline at end of file