639 Shell: a cloud for AI agents (alpha)

We built 639 Shell as a cloud compute home for agents and the people who run them: Linux
machines that are ready in seconds, made and driven by agents over SSH, MCP or an
HTTPS API. Run untrusted code in a throwaway sandbox, keep a long-running agent's
workspace that sleeps when idle and wakes on call; snapshot a machine and fork it into
many (beta).

Who we are: 639 Shell is made by 639cloud, a small independent cloud company running its
own servers in the US. It's an alpha: it works, it changes fast, and we're looking for
testers: agents and the people they work for. Tell us what's missing.

Speed, honestly: our servers aren't the fastest cloud, and we don't claim to be. We're
aiming for value. Measured 2026-11-13 on 639 Shell, size s1, from outside our data center
(network round trip included), median (95th percentile), 10 runs each:
  create a machine, its first command has run     1.52 s  (2.47 s)
  fork a running machine, its first command run   4.12 s  (4.42 s)
  wake a sleeping machine, its first command run  1.25 s  (1.27 s)
  run a command on an awake machine               0.08 s  (0.11 s)
  How we measured: https://shell.639cloud.com/docs/benchmarks.md

Free test drive, no sign-up: a machine for 1 hour.
  ssh try@shell.639cloud.com github:<your-github-username>
    (connect with an SSH key that's on that GitHub account; account 30+ days old)
  ssh try@shell.639cloud.com github:<user> 'python3 -c "print(6*7)"'   run a command
  ssh try@shell.639cloud.com github:<user> 'cat > app.py' < app.py     send a file
  ssh try@shell.639cloud.com github:<user> feedback 'what you think'   tell us: questions, hello,
    what's missing. It goes straight to the people who build 639 Shell; add an email
    if you'd like an answer.
  The trial machine: 1 core, 1 GiB RAM; reaches GitHub and package registries only;
  no inbound traffic; one trial per GitHub account per day.

Keep going, free during the alpha: ssh try@shell.639cloud.com signup
  a link for your human to sign up. The trial machine carries over, and compute stays
  free for testers while we're in alpha. Signed up, your human can say hello or ask us
  anything in the app's chat (ssh shell.639cloud.com, then Help → Chat): the people who build
  639 Shell are there.

Docs for agents: https://shell.639cloud.com/llms.txt
We record: your GitHub username, your SSH key's fingerprint, your network, and what runs
on the machine (as for every machine). Nothing else.