NYC Lean

The website for NYC Lean, a community for the Lean theorem prover and formal methods in New York City.

Live at lean.nyc.

Overview

A static site built with plain HTML, CSS, and vanilla JavaScript. There is no build step and no framework. Page motion is provided by GSAP, vendored locally. The site is deployed to GitHub Pages by a GitHub Actions workflow.

Repository structure

.
├── .github/workflows/deploy.yml   GitHub Pages deployment
├── .editorconfig
├── .gitignore
├── LICENSE
├── README.md
└── site/                          everything served at lean.nyc
    ├── index.html                 home page
    ├── calendar.html              served at /calendar
    ├── members.html               served at /members
    ├── 404.html
    ├── CNAME                      custom domain (do not delete)
    └── assets/
        ├── css/style.css          all styles
        ├── js/app.js              event rendering and GSAP motion
        ├── js/events.js           meetup data (edit this to add meetups)
        ├── img/                   favicon.svg, logo.svg
        └── vendor/gsap/           GSAP (gsap.min.js, ScrollTrigger.min.js)

Local development

The site is just static files. Serve the site directory with any static file server, for example:

python3 -m http.server 8000 --directory site

Then open http://localhost:8000.

Editing content

Meetups

All events live in site/assets/js/events.js as a single list. Each entry looks like:

{
  date: "2026-06-07",   // YYYY-MM-DD, required
  time: "2:00 PM",       // free text, "" if unknown
  location: "Mori",      // free text, "" if none or private
  title: "Weekend meetup",
  description: "..."     // optional, shown on the calendar page
}

Add the next meetup at the top of the list. Order does not matter, since entries are sorted by date. Events with a future date appear under "Upcoming"; once a date passes, they move to "Past" automatically. The home page shows the next three upcoming events.

Members

Edit site/members.html. Copy a .member block, set the name, optional role, and a link to a personal site (show the domain without the https:// prefix as the link text).

Deployment

Every push to main runs .github/workflows/deploy.yml, which publishes the site/ directory to GitHub Pages. The custom domain is configured in the repository's Pages settings and pinned by site/CNAME; HTTPS is enforced.

Contributing

Pull requests are welcome. To add yourself to the members list or add a meetup, edit the relevant file described above and open a PR.

License

Released under the MIT License.