A Meta-Layer for Your Coding Agent Stack

A new project called use-zerostack dropped on Hacker News this weekend, and it's exactly the kind of tool that makes you wonder why nobody built it sooner. The concept is simple but powerful: a skill module that lets AI coding agents like Claude Code or Cursor delegate specific tasks to zerostack—a lightweight CLI-based coding assistant—using slash commands. Think of it as giving your agentic workflow access to specialized sub-agents without leaving the conversation.

What Is Zerostack?

Zerostack itself is a standalone CLI tool that functions as a lightweight coding agent. It can write code, answer questions, plan implementations, review diffs, and even handle parallel worktree tasks or complex multi-sub-agent orchestration. The use-zerostack skill essentially bridges the gap between larger agentic IDEs and this leaner alternative. When your primary agent hits a task better suited for focused execution—say, reviewing a tricky PR diff or spinning up a detailed implementation plan—it can hand it off with a simple command like /zs:review or /zs:code.

Available Commands

The skill exposes six core commands: /zs:code for implementing or fixing code; /zs:ask for queries that don't require file writes; /zs:plan to generate step-by-step implementation plans; /zs:review [focus] for reviewing code, diffs, or pull requests; /zs:parallel for isolated worktree coding tasks; and /zs:orchestrate for managing multi-sub-agent workflows. The skill activates on these slash commands as well as trigger phrases like "run zerostack" or "delegate to zs."

Installation Path

Getting started requires two steps: installing zerostack itself (via Homebrew, Cargo, or the install script) and dropping the use-zerostack/ directory into your coding agent's skills directory. Users also need at least one API key—ANTHROPIC_API_KEY or OPENAI_API_KEY—configured in their environment or zerostack's config file. The project is licensed under GPL-3.0.

Key Takeaways

  • Use-zerostack acts as a bridge between major coding agents (Claude Code, Cursor) and zerostack CLI
  • Six slash commands enable code writing, planning, reviewing, parallel worktrees, and orchestration
  • Installation requires zerostack plus your API key—no additional dependencies
  • Open-source under GPL-3.0, maintained by developer gi-dellav

The Bottom Line

This is a niche tool for power users running multi-agent workflows, but that's exactly where it shines. If you're already living in Claude Code or Cursor and want granular control over task delegation without context-switching, zerostack as a backend handler is worth exploring. Just don't expect hand-holding—the docs assume you know what you're doing.