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Documentation Index

Fetch the complete documentation index at: https://docs.celesto.ai/llms.txt

Use this file to discover all available pages before exploring further.

SmolVM lets you run coding agents like Claude, Codex, and Pi inside an isolated sandbox. The agent gets a full development environment — git credentials, dev tools, terminal access — but nothing it does can affect your host machine. No more pressing “accept changes” every few seconds. Let the agent work freely in its own computer.

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Start a coding agent

smolvm claude start
Each command launches a sandbox with the respective coding agent pre-installed and configured. Your existing credentials (from claude login, codex login, etc.) are forwarded into the sandbox automatically — no re-authentication needed.

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What you get

Each coding agent sandbox comes with:
  • Isolated environment — the agent runs in its own VM, separate from your host
  • Git credentials — pre-configured so the agent can clone, commit, and push
  • Dev tools — common development tooling ready to use
  • Terminal access — full shell access for multi-step workflows

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Share folders with the sandbox

You can share folders from your machine so the coding agent can see your existing code. By default, shared folders are read-only — the agent can read your files but cannot modify the originals. 
smolvm claude start --mount ~/Projects/my-app
The agent sees your project files inside the sandbox at /workspace. To let the agent write changes back to your machine, add --writable-mounts: 
smolvm claude start --mount ~/Projects/my-app --writable-mounts
With --writable-mounts, the agent can modify and delete files in the shared folder. Only enable this when you trust the code the agent will run.
See the host mounts guide for more options like sharing multiple folders and custom mount paths.
Last modified on April 29, 2026