diff --git a/.eslintignore b/.eslintignore
new file mode 100644
index 0000000..b3f0d2f
--- /dev/null
+++ b/.eslintignore
@@ -0,0 +1,2 @@
+*.d.ts
+
diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..c3607e0
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,15 @@
+/**
+ * create an argon2 hash
+ *
+ * @param {string} plain plain text
+ * @returns {Promise<string>} hash
+ */
+export function hash(plain: string): Promise<string>;
+/**
+ * verify a plain text against an argon2 hash
+ *
+ * @param {string} hash_str hash
+ * @param {string} plain plain text
+ * @returns {Promise<boolean>} true if valid
+ */
+export function verify(hash_str: string, plain: string): Promise<boolean>;