diff --git a/functions/api/signup.js b/functions/api/signup.js
new file mode 100644
index 0000000..3952218
--- /dev/null
+++ b/functions/api/signup.js
@@ -0,0 +1,11 @@
+export async function onRequestPost({ request, env }) {
+  try {
+    const { username, pass_hash } = await request.json();
+    if (!username || !pass_hash) return new Response('Missing fields', { status: 400 });
+    if (await env.D1_EV.prepare("SELECT 1 FROM users WHERE username = ?").bind(username).first())
+      return new Response('User already exists', { status: 409 });
+    await env.D1_EV.prepare("INSERT INTO users (username, pass_hash) VALUES (?, ?)")
+      .bind(username, pass_hash).run();
+    return Response.json({ success: true }, { status: 201 });
+  } catch (e) { return new Response(e.message, { status: 500 }); }
+}