Safe Coder

Safe Coder is a configuration package for the pi coding agent that adds safety guardrails and project-specific extensions to reduce risky operations while you code with an AI assistant.

This project is meant to be used as a dependency or a template: you point pi at this package, and it will load its extensions and skills automatically.

Installation

# install pi coding agent
npm install -g @mariozechner/pi-coding-agent

# install safe coder
pi install npm:safe-coder

Features

• Permission gate for dangerous shell commands
  • Intercepts bash tool calls that look dangerous, such as:
    • rm -rf, recursive remove
    • sudo commands
    • chmod / chown with 777
  • Prompts for explicit confirmation before allowing these commands to run.
• Workspace boundary enforcement
  • Blocks file tools (read, write, edit) when they target paths outside the current working directory where pi was started, unless you explicitly allow them.
  • Flags shell commands that appear to touch absolute paths, home-relative paths (~/), or ../-style traversal and asks for confirmation.
• Protected path guard
  • Fully protects any .env files (no read, write, or edit allowed via tools).
  • Blocks write/edit attempts into common sensitive locations like .git/ and node_modules/.
• Skill-based workflows
  • Ships with a skills/skills.txt reference that documents how pi discovers and uses Agent Skills.
  • Compatible with the Agent Skills specification.

Project Layout

• package.json
  • Declares this package as safe-coder.
  • Configures pi to load from:
    • ./extensions
    • ./skills
    • ./prompts
    • ./themes
• extensions/permission-gate.ts
  • A pi extension that listens to tool_call events and:
    • Detects dangerous shell commands via regex heuristics.
    • Detects file operations that leave the current working directory.
    • Uses ctx.ui.select to ask the user whether to allow or block the call.
• extensions/protected-paths.ts
  • A pi extension that:
    • Completely blocks all access to .env paths.
    • Blocks write and edit tool calls into .git/ and node_modules/.
    • Optionally notifies the user when an operation is blocked.
• skills/
  • Currently contains skills.txt, which documents how Agent Skills work and how pi discovers and validates them.

Requirements

• Node.js (version compatible with @mariozechner/pi-coding-agent).
• pnpm as package manager (see packageManager field in package.json).
• The pi coding agent installed and available on your system.

Installation

You can add this project to another workspace or clone it as a starting point.

git clone <this-repo-url> safe-coder
cd safe-coder
pnpm install    # if you add dependencies later

Because this package primarily provides configuration, there are no runtime scripts defined apart from the default test placeholder.

Using with pi

Point pi at this project so it can load its extensions and skills. For example, from the project root:

cd /path/to/safe-coder
pi .

When pi starts:

• It discovers extensions from the pi.extensions entry in package.json and loads:
  • extensions/permission-gate.ts
  • extensions/protected-paths.ts
• It discovers skills via the pi.skills entry and any SKILL.md/skill files under skills/.

You will then see:

• Confirmation prompts when the assistant attempts potentially dangerous or out-of-bounds commands.
• Warnings and blocks when the assistant tries to touch protected paths.

Customization

• Adjust dangerous patterns
  • Edit extensions/permission-gate.ts to add or refine regex patterns for dangerous commands or external paths.
• Change protected paths
  • Edit extensions/protected-paths.ts and update the protectedPaths array or the .env handling logic.
• Add skills
  • Create new skill directories under skills/ following the Agent Skills format (each with a SKILL.md file and optional scripts/docs).
  • Update descriptions so the assistant knows when to use each skill.

Development Notes

• The TypeScript extensions currently use // @ts-nocheck for simplicity. You can progressively add types and strictness as needed.
• Follow the Agent Skills and pi extension best practices to keep new skills and extensions small, focused, and easy to review for safety.