up

up . runs your local project in a persistent Vercel Sandbox and gives you a public *.vercel.run URL. Edit locally and changes sync up; stop it and a later up . resumes from a snapshot. It is an experimental demo of persistent Vercel Sandboxes, distributed only via curl | sh (not npm).

Experimental. Try up on experimental workloads, not production projects or real data. The *.vercel.run URL is public and unauthenticated: anyone with the link can reach your dev server while the sandbox is alive. Secrets are excluded by filename, not by content, so a secret hardcoded in source or in a non-.env* file is uploaded. See SECURITY.md.

Install

curl -fsSL https://cdn.upcli.dev/install.sh | sh
cd ~/projects/my-app
up .

Requires Node.js >=20.19.0. The installer verifies a SHA-256 checksum and drops up in ~/.local/bin; installing needs no login. To run, up reuses your Vercel CLI login (or VERCEL_TOKEN) and must run inside a project, not your home directory.

Usage

up .                        # sync, install, run; prints the public URL
up . --open                 # also open the URL in your browser
up . --port 8080            # override the dev server port
up . --command '<cmd>'      # set the start command ($PORT is provided)
up . --env-file .env.local  # inject a local dotenv into the app process only
up . --save-config          # write the resolved setup to up.config.json
up stop                     # stop the sandbox and save a snapshot
up ls                       # list your sandboxes

up auto-detects most frameworks (Next, Vite, Astro, SvelteKit, ...) and the package manager (npm, pnpm, Yarn, Bun, provisioned in the sandbox). Python and custom apps take a command once via --command or a checked-in up.config.json, which up shows and asks you to trust before running.

Sync and persistence

• One-way sync from your project directory. .env*, key material (.ssh, *.pem, id_rsa*, ...), credential config (.npmrc, .netrc, ...), VCS metadata and build outputs are never uploaded (credential config can be opted in with --include-sensitive-config). Exclusion is by filename, not content, and files over 20 MB are skipped.
• Ctrl-C detaches and leaves the sandbox running. up stop snapshots it; a later up . reconnects if it is still up, or restores from the snapshot. Sandbox names are stable per local install and project path.

Development

pnpm install
pnpm lint && pnpm typecheck && pnpm test && pnpm build

The landing page lives in landing/ and the installer host in apps/downloads/ (served at cdn.upcli.dev).