Pulse - Feel the Pulse

Pulse is a 100% free, lightweight, and self-hosted web application for running interactive live sessions like polls, Q&A, rankings, ratings, and wordclouds. It is built for speed, real-time interactivity, and strict GDPR compliance without any user limits or hidden costs.

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Architecture Overview

graph TD
    subgraph Clients
        P[Smartphone Participants<br>/ABC123]
        Host[Presenter Screen / Beamer<br>/live/ABC123]
        Remote[Smartphone Remote Control<br>/remote/ABC123]
        Dash[Host Dashboard<br>/dashboard]
    end

    subgraph Infrastructure [Docker Container]
        Nginx[Nginx Reverse Proxy & Static Host<br>:80]
        Frontend[React 19 SPA<br>Vite + Tailwind v4 + Framer Motion]
        Backend[Node.js + Express 5 Server<br>Socket.io + JWT Auth<br>:3001]
        DB[(SQLite WAL Mode<br>Prisma ORM)]
    end

    P <-->|Socket.io & REST| Nginx
    Host <-->|Socket.io & REST| Nginx
    Remote <-->|Socket.io| Nginx
    Dash <-->|REST API| Nginx

    Nginx -->|Serve SPA| Frontend
    Nginx -->|Proxy API & WS| Backend
    Backend <-->|Read / Write| DB

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Features

• Free & Unlimited: No subscription fees, no limits on participants or sessions.
• Privacy First & GDPR Compliant: Self-hosted on your own infrastructure. No third-party tracking, no advertising cookies, no external analytics.
• Multi-Language Support (i18n): Native bilingual support in English and German with automatic browser language detection and instant in-app switching.
• Built-in Compliance & Legal Notice: Integrated accessible modals for Imprint (§ 5 DDG) and Privacy Policy (GDPR / DSGVO), fully customizable or overridable via .env.
• Real-Time Synchronization: Uses Socket.io to push results instantly to all connected screens with automatic client reconnects.
• Multiple Session Types:
  • Wordcloud: Dynamic sizing based on frequency with Archimedean spiral positioning, sentence-splitting, and stop-word filtering.
  • Poll: Classic single-choice live poll with animated percentage distributions.
  • Ranking: Prioritization and drag-and-drop sorting by participants.
  • Rating: 5-Star scale evaluation for multiple criteria.
  • Q&A: Audience questions with real-time upvotes, moderator deletion, and moderation schema readiness.
  • Open Ended: Free-text brainstorming with real-time tile layout.
• Presenter Remote Control: Control the presentation view directly from your smartphone via secure QR-code pairing (/remote/:code) — pause sessions, toggle timers, show/hide results, and trigger floating emojis.
• Live Reactions (Emoji Rain): Allow participants to send live reactions (👍, ❤️, 🎉, 🔥, 👏) that float dynamically across the presenter's screen.
• PDF Report Export: Print-optimized report page (/live/:code/report) with clean CSS print styles to export session summaries directly to PDF.
• Session Timer: Hosts can set a live countdown that automatically locks the session when time expires.
• Data Export: Download session results instantly as CSV files.
• Interactive Onboarding: Built-in product tours guide new hosts through the dashboard and live views.
• High-Performance Architecture: SQLite in Write-Ahead Logging (WAL) mode with sliding-window rate limiters on WebSockets and REST endpoints.

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Tech Stack

• Frontend: React 19, Vite, Tailwind CSS v4, Framer Motion, Recharts, react-i18next, Lucide Icons
• Backend: Node.js, Express 5, Socket.io, Prisma 6 (SQLite with WAL), JWT Authentication, Helmet
• Infrastructure: Docker & Docker Compose (Multi-stage build with alpine Nginx)

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Quick Start (Docker Compose)

1. Clone the repository

git clone https://github.com/thefraggle/pulse.git
cd pulse

2. Configure Environment Variables

Pulse includes sensible defaults, but in production you should set your own ADMIN_PASSWORD and JWT_SECRET:

# Backend variables
cp backend/.env.example backend/.env

# Frontend variables
cp frontend/.env.example frontend/.env

3. Start the Application

docker compose up -d --build

4. Access Pulse

• Participant View: http://localhost/
• Host Dashboard: http://localhost/dashboard (Default login: admin / your configured ADMIN_PASSWORD)

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Legal & Privacy Notice Customization (White-Labeling)

Pulse includes built-in, DSGVO-compliant legal and privacy modals. If you operate an official organization and prefer linking your external legal pages, simply define:

# In frontend/.env:
VITE_IMPRESSUM_URL=https://yourcompany.com/imprint
VITE_PRIVACY_POLICY_URL=https://yourcompany.com/privacy

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Contributing & Security

• For code guidelines and pull request instructions, see CONTRIBUTING.md.
• For reporting security vulnerabilities, please refer to SECURITY.md.

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License

MIT License - Copyright (c) 2026 Daniel Notthoff