agent-next sandbox

Disposable cloud Linux sandboxes for your coding agent. Run long jobs, untrusted code and heavy dependencies in the cloud instead of on your machine, and share a public preview URL for anything that serves a port.

This repo holds three things that share one name, sandbox:

piece	what it is	where
Claude Code and Codex plugin	the sandbox MCP server plus the sandbox skill	plugins/sandbox
sbx command-line tool	create, exec, list, kill from the shell	cli
Cookbook	prompts to try with the plugin	cookbook

Install the plugin

claude plugin marketplace add agent-next/sandbox

Then enable it and give it your API key:

claude plugin install sandbox@agent-next
export SBX_API_KEY=<your key>     # create one at https://sbx.agent-next.com/console

Start Claude Code from a shell where SBX_API_KEY is exported. Check with claude mcp list: you should see the sandbox server.

Codex:

codex plugin marketplace add agent-next/sandbox
codex plugin add sandbox@agent-next
export SBX_API_KEY=<your key>     # Codex sends it as a bearer token

Install the CLI

pip install "git+https://github.com/agent-next/sandbox#subdirectory=cli"

Quickstart: create, exec, kill

There is no sbx login: the key comes only from the environment. Agents and CI have no browser for the console — load an existing key from your secret store and export it.

export E2B_API_KEY=<your key>     # SBX_API_KEY also works

id=$(sbx create)                  # a fresh sandbox; prints its id
sbx exec "$id" 'echo hello'       # prints: hello
sbx kill "$id"                    # always kill what you create

sbx exec passes stdout and stderr through and exits with the command's own exit code. sbx create --timeout-min N sets an idle keep-alive (default 5 minutes); activity restarts the clock. The CLI opts into deletion at idle expiry, so copy durable results out. CPU sandboxes created by the MCP plugin instead pause at idle expiry and resume on the next exec or files call.

The same three steps from your agent: the plugin's tools are sandbox_create, sandbox_exec and sandbox_kill, and the sandbox skill tells the agent when to use them and to kill what it creates.

GPU from the shell: sbx gpu create --vram 4, then sbx gpu exec ID -c '...', pause, resume and kill (see cli/README.md). For CUDA work, also try the 1 GiB small-GPU quickstart. It includes a Python client that checks a tiny GPU computation and destroys the lease. GPU-enabled keys and available capacity are required. This MIT repository contains the client kit; the hosted service's backend is separate.

License

MIT — see LICENSE.

Security

See SECURITY.md.