Lumen — production-ready Crystal social network app starter

Lumen is a production-grade social network app written in Crystal — generated by cenius.ai, Apache-2.0-licensed. Lumen is a tech news link aggregator built with Kemal (Crystal) that features full social functionality: user submissions with user-defined tags, upvoting/downvoting, threaded comments, and user accounts with email/pa…. Clone Lumen, run the installer, done — you have a working product in minutes. Want to change something? Open Lumen on cenius.ai and say what you need — a revised build ships back, ready to deploy.

▶ Open & edit in cenius.ai — one click to an editable workspace: describe changes in plain English, get an instant preview, one-click deploy and host. Modifications made on the platform come with full rebrand & relicense rights.

Local clone? See Quick start below. cenius.ai is the zero-setup path.

Demo

▶ Full demo walkthrough — watch it on the project page ·

Screenshots

Quick start

./install.sh   # installs dependencies + seeds demo data

See INSTALL.md for full setup and usage instructions.

Features

• User Authentication
• Link Submission with Tags
• Voting
• Tagging System
• Commenting
• User Profiles
• Light/Dark Theme Toggle
• Search
• Responsive Design
• Browse by Tag and Sort

Architecture

The repository contains 248 files of Crystal source, organised under bin/, lib/, public/, src/, views/. Run ./install.sh once to install packages and populate demo data — the app is ready to use immediately after. Installation walkthrough: INSTALL.md.

Usage guide

Once Lumen is running (see INSTALL.md), open your browser at http://localhost:3000. Below is a guide to the main features and how to interact with them.

Home Page

The home page (/) displays a list of submitted links, ordered by recency (or votes, depending on the implementation). Each link shows its title, URL, tags, and submission metadata.

Example request:

curl http://localhost:3000/

Submitting a Link

Navigate to /links/submit or click the “Submit” button in the navigation bar. Fill in the form with a title, URL, and a comma-separated list of tags. After submission, you will be redirected to the newly created link’s page.

Example submission (if the form uses POST):

curl -X POST http://localhost:3000/links \
  -d "title=My Title&url=https://example.com&tags=tech,news"

(Note: exact parameter names depend on the implementation; adjust accordingly.)

Viewing a Link

Each link has a detail page at /links/:id where you can see the full information and possibly comments or actions.

curl http://localhost:3000/links/1

Browsing by Tag

Click on any tag (e.g., “tech”) to see all links associated with that tag at /tags/:tag.

curl http://localhost:3000/tags/tech

Searching

Use the search box to perform a keyword search. Results appear at /search?q=your+keywords.

curl "http://localhost:3000/search?q=crystal"

User Account

Full guide: USAGE.md

FAQ

What does it take to self-host Lumen?

Pull the repo, run ./install.sh, and you are up — the script installs packages and pre-seeds the database. INSTALL.md covers any platform-specific tweaks.

How is Lumen built technically?

Crystal. The full source in this repository is exactly what the app runs. Highlights include light/Dark Theme Toggle.

Is Lumen free for commercial use?

Confirmed free for commercial use — MIT terms let you incorporate, resell, or ship it in any product. LICENSE.

Can I rebrand or white-label Lumen?

Yes. You can edit the source directly under the MIT license, or remix it on cenius.ai — the platform route grants full rebrand and relicense rights over your derivative.

How can I customize Lumen without editing code?

cenius.ai handles the implementation. Tell it what you want in everyday words, pick up the updated build. No coding needed.

License & rebranding

Released under the Apache License 2.0 (© 2026 Cenius AI) — free for personal and commercial use. The Cenius name/logo are trademarks (see NOTICE).

Need a customized version? Remix this app on cenius.ai — modifications made on the platform come with full rebrand & relicense rights over your derivative.

Built with cenius.ai

This entire application — code, design, seeded demo data — was generated on cenius.ai from a plain-English description.

• 🚀 Build your own app on cenius.ai
• 🎛️ Remix Lumen on the marketplace — open it in a workspace, prompt for changes, and ship your own version.

More open-source apps: the Cenius-ai catalog · showcase index