kaplanelad/shellfirm

What is it?

Key features

• 01Detects 100+ risky command patterns across filesystem, git, Kubernetes, Terraform, Docker, AWS, GCP/Azure, Heroku, and databases.
• 02Supports eight shells, including Zsh, Bash, Fish, Nushell, and PowerShell.
• 03Raises challenge difficulty in SSH, root, protected-branch, and production Kubernetes contexts.
• 04Shows safer alternative commands alongside each warning.
• 05Shares team safety rules through a .shellfirm.yaml project policy that can only add restrictions.
• 06Logs every intercepted command and decision as JSON lines.

Use cases

• Protecting your own terminal from accidental destructive commands like rm -rf or force pushes.
• Letting Claude Code or other AI agents run shell commands with a safety check on each Bash call.
• Enforcing shared safety rules for a team's production infrastructure work.
• Reviewing an audit trail of risky commands run in a shared environment.

Quick start

1. 1

   Install via npm

   npm install -g @shellfirm/cli
2. 2

   Install the shell hook (auto-detects your shell)

   shellfirm init
3. 3

   Restart your shell or source your rc file

4. 4

   Test it: the command should trigger shellfirm

   git reset --hard

Things to know

• !It only guards shells where the hook is installed, and each shell needs its own setup.

Topics

FAQ

What is shellfirm?

A shell guardrail that intercepts dangerous terminal commands from humans and AI coding agents and requires confirmation before running them. shellfirm sits between you and your shell and checks commands before they run. When a command matches one of its built-in patterns, such as recursive deletes, force pushes, or destructive Kubernetes, Terraform, Docker, or database operations, it shows the severity, the affected scope, and a safer alternative, then asks you to solve a small challenge before continuing.

Is shellfirm free to use? What license does it have?

shellfirm is open source under the Apache-2.0 license. Check the license terms before using it in commercial products.

Is shellfirm still maintained?

Updated within 6 months. The last commit to shellfirm was on May 15, 2026.

What can I use shellfirm for?

Protecting your own terminal from accidental destructive commands like rm -rf or force pushes. Letting Claude Code or other AI agents run shell commands with a safety check on each Bash call. Enforcing shared safety rules for a team's production infrastructure work. Reviewing an audit trail of risky commands run in a shared environment.

How do I install shellfirm?

Install via npm: npm install -g @shellfirm/cli Install the shell hook (auto-detects your shell): shellfirm init Restart your shell or source your rc file Test it: the command should trigger shellfirm: git reset --hard

Where can I get shellfirm?

The source code and installation instructions are on GitHub: https://github.com/kaplanelad/shellfirm