# Thunkable QR-based login approval (mobile scans desktop QR to sign in) — DnD vs Snap-to-Place?

**URL:** <https://community.thunkable.com/t/thunkable-qr-based-login-approval-mobile-scans-desktop-qr-to-sign-in-dnd-vs-snap-to-place/4107595>\
**Category:** Questions about Thunkable X\
**Tags:** beginner, help\
**Created:** [September 9, 2025, 6:30am UTC](https://community.thunkable.com/t/thunkable-qr-based-login-approval-mobile-scans-desktop-qr-to-sign-in-dnd-vs-snap-to-place/4107595 "2025-09-09T06:30:36Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![keenanabigailidnkjc](https://avatars.discourse-cdn.com/v4/letter/k/d26b3c/32.png) [@keenanabigailidnkjc](https://community.thunkable.com/u/keenanabigailidnkjc)\
**Post date:** [September 9, 2025, 6:30am UTC](https://community.thunkable.com/t/thunkable-qr-based-login-approval-mobile-scans-desktop-qr-to-sign-in-dnd-vs-snap-to-place/4107595/1 "2025-09-09T06:30:36Z")

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I’m building a Thunkable app that must scan many QR codes. The desktop web uses Laravel + JWT (email/password). I want a “Login with phone” flow: the desktop shows a QR; the mobile app scans it and approves the desktop session.

Constraints: I’m currently on **Drag-and-Drop (DnD)**; I can switch to **Snap-to-Place (StP)** if needed.

**Questions:**

1. Is a QR-based approval flow possible in DnD (without a native scanner), or should I use StP’s Barcode Scanner?

2. Recommended architecture for security (nonce, expiry, one-time use)?

3. In Thunkable, what’s the best practice to:

**What I’m thinking:**

- Desktop generates `{request_id, nonce}` → shows as QR → polls `/qr/status`.

- Mobile scans → POST `/qr/claim` with `{request_id, nonce, mobile_jwt}`.

- Server verifies and approves → desktop session logs in.

Any code/block examples or gotchas (especially for DnD/Web Viewer postMessage) would be appreciated!

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**Author:** ![system](https://us1.discourse-cdn.com/flex015/uploads/thunkable/original/3X/0/f/0f59f292712368bce16ff80133ae10de8a6f27e8.png) [@system](https://community.thunkable.com/u/system)\
**Post date:** [December 8, 2025, 6:31am UTC](https://community.thunkable.com/t/thunkable-qr-based-login-approval-mobile-scans-desktop-qr-to-sign-in-dnd-vs-snap-to-place/4107595/2 "2025-12-08T06:31:12Z")

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