opencode-shell-strategy

OpenCode instructions for running shell commands safely in a non-interactive environment.

OpenCode's shell is non-interactive: it has no TTY/PTY, so commands that wait for input, launch a pager, or open an editor will hang until timeout. These instructions teach an agent to use command-specific non-interactive forms, fail fast when authorization is missing, and avoid unsafe patterns that bypass security controls.

The rules are written for OpenCode and apply to any comparable headless agent host.

Installation

Add the remote instruction file to your OpenCode configuration:

{
  "instructions": [
    "https://raw.githubusercontent.com/JRedeker/opencode-shell-strategy/trunk/shell_strategy.md"
  ]
}

Restart OpenCode. The rules load automatically at the start of each session.

A local clone is optional. If you want to edit or contribute, clone the repository and point your config at the local shell_strategy.md path instead.

What it covers

Safe non-interactive forms

Always-banned commands

These hang or break autonomy in a non-interactive shell:

• vim, nano, vi, emacs (editors)
• less, more, man (pagers)
• git add -p, git rebase -i (interactive git modes)
• python, node, ipython, irb without a script or -c/-e argument (REPLs)
• bash -i, zsh -i (interactive shells)

Handling commands that must prompt

Do not use yes | … or heredocs to blanket-approve unknown prompts. If a command has no non-interactive flag, choose one of:

1. Use a documented non-interactive flag. Example: apt-get install -y pkg.
2. Fail fast with a non-interactive mode. Example: sudo -n command exits immediately if a password is required.
3. Stop visibly. Report that the operation needs credentials, user approval, or a trusted host, and do not proceed.

SSH and new hosts

For an explicitly trusted first contact, use StrictHostKeyChecking=accept-new with a short timeout:

ssh -o BatchMode=yes -o StrictHostKeyChecking=accept-new -o ConnectTimeout=10 user@host

If a host key changes, the command fails. Do not use StrictHostKeyChecking=no.

Privileged commands

Use sudo -n to run a command only when it needs no password:

sudo -n systemctl status nginx

If the command requires a password, sudo -n fails immediately. Do not pipe passwords into sudo -S.

License

MIT

Release notes

v1.1.0

• Safer guidance for commands that need authorization: prefer sudo -n so failures are visible instead of hanging, and do not pipe passwords into sudo -S.
• Safer SSH first-contact guidance: use StrictHostKeyChecking=accept-new with a short timeout and BatchMode=yes instead of disabling host-key checks.
• Added a dependency-free verification script (test.sh verify) so the rule set can be checked without installing extra tools.
• No new runtime dependencies were introduced.