QR Redirect Server

Lightweight Flask server intended for deployment on Render. It accepts POST requests from a Power Automate flow, maintains an in-memory map of redirect links, and returns QR codes that point at server-managed redirect URLs.

Features

• /webhook accepts a JSON payload containing a unique_id and final_url
• Generates a server-hosted redirect URL and corresponding QR code (base64 PNG)
• Updates existing entries when the same unique_id is posted again
• /redirect/<slug> and /<slug> redirect to the stored final_url (302 redirect)
• /health endpoint for uptime checks
• /admin/form simple HTML form to create/update redirects during testing
• /admin/entries table view of the in-memory map plus links to /qr/<unique_id> and inline delete confirmation
• Import/export helpers for JSON or CSV backups

Project Structure

• app.py – Flask application entry point
• requirements.txt – Python dependencies

Running Locally

python -m venv .venv
source .venv/bin/activate  # On Windows use: .venv\Scripts\activate
pip install -r requirements.txt
export FLASK_APP=app.py
flask run --reload

When running locally, the server will infer the base URL from the incoming request. For production (Render), set the BASE_URL environment variable to the public origin of your service (for example https://your-service.onrender.com).

Quick Test Helper

Run the server locally, then in a separate terminal execute:

python scripts/send_test_request.py YOUR-UNIQUE-ID https://example.com

• Creates/updates a redirect available at http://127.0.0.1:5000/YOUR-UNIQUE-ID
• Saves a qr_code.png file pointing to that redirect
• Prints the JSON response, including the ready-to-share QR code (base64)

Use --qr-output to pick a different filename or --host to target another deployment (e.g., your Render URL).

Browser-Based Testing

• Visit http://localhost:5000/admin/form to submit a unique_id and final_url via a web form.
• After submission, the page displays the redirect URL and embedded QR image.
• Visit http://localhost:5000/admin/entries to view all stored redirects, download QR links, and delete entries with confirmation.
• Scanning a QR (or visiting /<slug>) immediately redirects to the destination URL (302 redirect).
• Use the Import / Export section on admin/form to download JSON/CSV snapshots or import saved data (useful after redeploys).

Deploying to Render

1. Push this project to GitHub (for example, create a repo named qr-redirect-server and push the files).
2. Visit Render, create a new Web Service, and point it at your GitHub repo.
3. Render auto-detects render.yaml; otherwise configure manually:
   • Runtime: Python
   • Build command: pip install -r requirements.txt
   • Start command: gunicorn app:app
4. Add the environment variable BASE_URL with your Render service URL (Render shows it after the first deploy, e.g. https://your-app.onrender.com).
5. Deploy. Once live, test via:
   • POST to /webhook
   • Visit /admin/form for manual submissions
   • Fetch QR images from /qr/<unique_id>

Render stores no state between deploys or restarts, so redirects reset unless you connect a persistent store.

Example Request

curl -X POST http://localhost:5000/webhook \
     -H "Content-Type: application/json" \
     -d '{"unique_id": "ABC-123", "final_url": "https://example.com"}'

Response includes:

• redirect_url: server-hosted link to embed in QR codes
• qr_code_base64: base64-encoded PNG image of the QR code (no logo yet)
• status: created for new entries, updated for existing ones

Deployment Notes

• Render typically runs Python services with gunicorn. A sample start command: gunicorn app:app
• The current implementation uses in-memory storage. For persistence across restarts, integrate a database or cache service (e.g., Redis, PostgreSQL).
• QR customization (logo overlays, styling) can be added later by extending the _encode_qr_code helper.