If you search for “GStack,” you will see people describing it as a Claude Code setup, a workflow, or even an AI engineering team. All of those are partially correct, but they miss the core idea.

GStack is a structured development system built on top of Claude Code.

It does not replace Claude. It organizes how Claude works.

Instead of giving vague prompts like “build a login system,” GStack forces you into a sequence of roles and decisions. Each role is encoded as a skill, which is essentially a Markdown prompt template with strict expectations.

These skills are triggered using slash commands such as:

Each one transforms the AI’s behavior.

For example:

This is why GStack feels different from tools like Copilot or Cursor.

Those tools focus on:

GStack focuses on:

In simple terms:

If you want a base understanding of the underlying system, see [Claude Code guide]. For a broader comparison, refer to [AI coding tools comparison].

GStack was created by Garry Tan, CEO of Y Combinator.

His background explains why GStack exists:

Garry Tan is not just a manager. He is a builder who has repeatedly worked at high speed.

In 2026, he shared results that got attention:

Instead of keeping that workflow private, he turned it into GStack.

The core idea is simple:

This is why GStack is not just a tool. It is a codified mindset.

Before you install GStack, you need a working Claude Code environment.

This installs GStack globally for your user.

This is useful when working with teams. Everyone gets the same skills automatically.

Supported hosts include:

When you run the setup script, GStack installs:

Important:

After installation, you will be prompted to update your CLAUDE.md file.

Inside Claude Code:

GStack currently includes 23 core workflow skills plus utility commands. Each skill activates a different role.

This is the starting point.

It forces you to answer six critical questions about your idea. It challenges assumptions and reframes the problem.

Think of it as YC office hours with an AI partner.

This skill evaluates your idea like a founder.

It introduces four modes:

This prevents overbuilding or underbuilding.

This is where engineering rigor kicks in.

It forces:

Focuses on UI and UX.

It scores your design and explains what a perfect version would look like.

This chains all planning skills into one command.

It reduces friction and ensures consistency.

Creates a design system from scratch.

Outputs a DESIGN.md file that becomes your reference.

Generates multiple design directions.

You choose the best one. The system learns your taste over time.

Converts designs into production-ready HTML.

Works with frameworks like React, Vue, and Svelte.

Runs a detailed UI audit.

Fixes issues and improves visual consistency.

Acts like a senior engineer reviewing your code.

Finds:

For debugging.

It prevents random fixes and enforces structured debugging.

Uses a different AI model for a second opinion.

This reduces blind spots.

Uses a real browser to test your app.

Finds bugs and fixes them automatically.

Same as above but generates a report only.

Automates release steps:

Completes deployment and verifies production.

Monitors your app after deployment.

Keeps documentation aligned with code.

Runs security audits based on OWASP principles.

Measures performance and tracks improvements.

Headless browser automation.

Full browser with sidebar AI agent.

Allows multiple AI agents to collaborate in a shared browser.

Weekly performance review.

Stores long-term learnings and patterns.

Includes:

GStack works best when used as a full system.

A typical workflow:

This compresses an entire engineering team into a repeatable process.

Performance claims:

Best for:

Not ideal for:

GStack is a workflow system for Claude Code that organizes AI development into structured roles.

Yes. It is open source under the MIT license.

Use the Git clone command provided in this guide.

Yes. It supports multiple AI agents and environments.

It is a strategic planning skill that evaluates product scope and direction.

Copilot helps write code. GStack structures how software is built end to end.

Garry Tan, CEO of Y Combinator.

Claude Code, Git, Bun, and an API key.

Step 1: Install GStack

Step 2: Run /office-hours

Step 3: Run /autoplan

If you use GStack casually, it will feel like a better prompt system.

If you use it fully, it becomes something else entirely:

A system that turns one developer into a structured, high-output engineering team.