Stargazer Wall

Generate a short Remotion animation of a GitHub repository’s stargazers, then export it as MP4.

Stack

• Next.js (App Router) + React 19
• Better Auth — GitHub OAuth (token used for the GitHub API)
• Neon Postgres — auth tables
• Remotion — preview player + in-browser MP4 export (@remotion/web-renderer)
• shadcn/ui + Tailwind CSS

Setup

npm install
cp .env.example .env   # fill in secrets
npm run auth:migrate   # creates Better Auth tables on Neon
npm run dev

Open http://localhost:3000.

Required env

Variable	Purpose
BETTER_AUTH_SECRET	Auth encryption secret (openssl rand -base64 32)
BETTER_AUTH_URL / NEXT_PUBLIC_BASE_URL	App URL (http://localhost:3000 locally)
DATABASE_URL	Neon Postgres connection string
GITHUB_CLIENT_ID / GITHUB_CLIENT_SECRET	GitHub OAuth App (callback: {BASE}/api/auth/callback/github)

No AWS or FFmpeg setup is required. Export uses the browser’s WebCodecs API.

Browser support (export)

Browser	Minimum
Chrome	94+
Firefox	130+
Safari	26+

Scripts

Command	Description
npm run dev	Next.js dev server
npm run build	Production build
npm run remotion-studio	Remotion Studio for the composition
npm run auth:migrate	Apply Better Auth schema to Postgres

Flow

1. Sign in with GitHub (OAuth scopes include repo for private repos you can access).
2. Enter owner/repo and generate a preview.
3. Download MP4 — rendered on your device in the browser (keep the tab open).