Garry Tan's gstack: An Open Source AI Agent Framework for Claude Code

What gstack is

gstack is Garry Tan's open source software factory that transforms Claude Code into a managed virtual engineering team. It's MIT licensed and available on GitHub. According to Tan, he's written over 600,000 lines of production code in the last 60 days (35% tests) and does 10,000-20,000 usable lines of code per day as part of his CEO duties at Y Combinator.

How it works

The framework provides 13 specialist roles as slash commands, all using Markdown. These include:

• /plan-ceo-review - Rethinks the product direction (e.g., expands "photo upload" to auto-identify products, pull specs and comps from the web, and draft listings automatically)
• /plan-design-review - Catches AI slop patterns, provides design scores, exports DESIGN.md, flags patterns like gradient hero, icon grid, uniform radius
• /plan-eng-review - Locks architecture with ASCII diagrams for data flows, state machines, error paths, plus test matrices and security concerns
• /review - Finds production bugs, auto-fixes issues like orphan S3 cleanup, missing indexes, and flags race conditions

Other roles mentioned include QA lead (opens real browser and clicks through apps), release engineer (ships PR), and designer.

Example workflow

From the source: When requesting "photo upload for sellers," /plan-ceo-review responds with expansion proposals, /plan-design-review provides an 80-item audit and design system inference, /plan-eng-review creates ASCII diagrams and test matrices. After approval, Claude writes 2,400 lines across 11 files (models, services, controllers, views, migrations, tests) in about 8 minutes.

Technical details

The repository includes directories for workflows, bin, design-consultation, docs, document-release, gstack-upgrade, plan reviews, QA reviews, retro, review, scripts, setup-browser-cookies, ship, and test. Key files include ARCHITECTURE.md, BROWSER.md, CLAUDE.md, conductor.json, and package.json.