One coding agent on a laptop is easy to live with. Three or four at once, each in its own repository or worktree, is a different load. The fans start, the editor lags and a test run that used to be quick now waits for memory.

Why the laptop slows down

The agent itself is rarely the heavy part. The work it starts is. Each agent session can run:

  • a package install, a build and a test suite;
  • a language server and a file watcher for its project;
  • a development server, a database container or a browser;
  • its own copy of dependencies in each worktree.

Run that several times in parallel and the agents compete for the same CPU cores, memory and disk. When memory runs out, the system starts swapping to disk, and everything on the machine waits, including you.

Check what is using it

Look before you change anything. On a Mac, open Activity Monitor, sort by Memory and watch the Memory Pressure graph. On Linux, run top or htop, sorted by memory, and free -h to see swap use. Group what you find by agent session: builds, tests, servers and containers usually stand out.

Fix it locally first

  • Run fewer agents at once. Queue the next task instead of starting another session.
  • Stop what you are not using. Close finished development servers, containers and browser tabs an agent opened.
  • Cap test and build parallelism. Most test runners and build tools accept a worker count. Lower it for agent sessions.
  • Keep worktrees few. Remove worktrees for merged branches so their dependencies and watchers go with them.

If the laptop is still the bottleneck after that, the remaining option is to run some of the agents somewhere else.

Move agents to a sandbox

A Runzivo Agent Sandbox is an isolated Linux microVM in Montréal (YUL). Give each agent task its own sandbox and connect over SSH, from your editor or from Orca. The builds, tests and servers that agent starts then use the sandbox’s CPU and memory, not your laptop’s.

Claude Code and Codex are included in the sandbox developer image, signed out. Sign in with your own account or provider key. Your provider bills model usage directly; Runzivo bills infrastructure only. Herdr keeps agent panes running while you disconnect from a running sandbox.

The Orca, editors and coding agents guide covers connecting and signing in.

What to know before you move

  • A workspace can run 2 sandboxes at once by default. Keep the rest of your agents local or queue them.
  • A sandbox lives 8 hours by default, or 12 or 24 hours where host capacity permits. Stopping does not pause the clock. Copy or push the work you want to keep before it expires.
  • Running sandboxes use your workspace allowance or prepaid credit at the rate for their size. See pricing.
  • Review what an agent changed and run your tests before you push.