Cloud dev environments that feel like localhost

Claude Code or Codex run on your laptop, and use the Tesser CLI to give each worktree its own VM and run the dev server and the tests up there. To interact, open localhost:3000, and select which server you're connected to.

curl -fsSL https://tesser.sh/install | sh

Run ten agents at once without changing how you work

Your dev server and your tests run on the VM

  • Each worktree gets a VM of its own, and one is ready in a few seconds
  • Output streams back as it happens, with the real exit code, so the agent carries on the way it would locally
  • node_modules and anything else you install are still there next time

Your laptop stays the source of truth

Your working tree goes to the VM before each command, committed or notNothing on the VM ever writes back to your files

Point localhost:3000 at any worktree in one click

  • Every worktree is on port 3000, however many you have running
  • Open two branches side by side at <box_id>.localhost:3000

Walk away and the VM puts itself to sleep

It costs cents a day asleep and nothing once removedIt wakes in about 40 seconds with everything still installed

Start with one worktree

Install the CLI and add the skill. The next time your agent needs to run something, it makes a VM and runs it there. Every org starts with $50 of credit.

curl -fsSL https://tesser.sh/install | sh