4ev.link/functions/api/signup.js

const ntfy = (env,title,msg,p=3) =>
  env.NTFY_TOPIC
    ? fetch(`https://ntfy.sh/${env.NTFY_TOPIC}`,{
        method:"POST",
        headers:{
          "Title":`🆕 ${title}`,
          "Priority":String(p),
          "Content-Type":"text/plain"
        },
        body:msg
      }).catch(()=>{})
    : Promise.resolve();

export async function onRequestPost({ request, env }) {
  try {
    const { "cf-turnstile-response":token, ...body } = await request.json();
    const vR = await fetch(
      "https://challenges.cloudflare.com/turnstile/v0/siteverify",
      {
        method:"POST",
        headers:{ "Content-Type":"application/json" },
        body:JSON.stringify({ secret:env.TURNSTILE_KEY, response:token })
      }
    );
    if (!(await vR.json()).success)
      return new Response("CAPTCHA verification failed.",{ status:403 });

    const { username, pass_hash } = body;
    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();

    const { country, region, city } = request.cf || {};
    const loc = [city, region, country].filter(Boolean).join(", ") || "Unknown";

    await ntfy(
      env,
      "auth-signup",
      `event=signup\nuser=${username}\nloc=${loc}`,
      3
    );

    return Response.json({ success:true, username },{ status:201 });
  } catch (e) {
    return new Response(e.message,{ status:500 });
  }
}