Claude Code Across a Laptop and an HPC Cluster
What travels, what doesn't, and how to build permissions you can actually trust.
Verified against Claude Code v2.1.222, August 2026. Permission and sandbox behaviour changes fast; check the version before trusting the specifics.
Our group's compute loop looks like this. Write and test code on a laptop, where iteration is cheap. Push to the cluster through GitHub or rsync. Run there, because that is where the cores, the memory, and the multi-terabyte project storage live. Then stay on the cluster to diagnose: read the logs, inspect the outputs, work out why run 14 disagrees with run 13.
Claude Code is useful at both ends of that loop, and the diagnosis end is where it earns the most. But when you install it on the cluster it arrives knowing nothing. No project context, no permission guardrails, none of the accumulated understanding from months of sessions on the laptop.
This is not a bug, and the fix is not to copy your home directory across. The fix is to understand that Claude Code keeps state in three separate systems, each with a different answer to the question does this cross machine boundaries?
Get it wrong and you either work blind on the cluster, or, worse, run an agent there with no guardrails on hardware you share with everyone else at your institution.