The open-source skill pack from Y Combinator's CEO (55 skills by the official recount, Aug 2026), installed with one command
gstack = a skill pack for Claude Code
gstack is an open-source project from Garry Tan , the current CEO of Y Combinator. It fits Claude Code with 23 specialist skills and 8 tools, from automated QA to AI code review to opening a PR in one step, all from a single command.
Think of Claude Code as a new phone, and gstack as installing the 23 most useful apps in one go.
When it finishes, run bun --version and if a version number shows up, you are good.
Open Terminal and paste this:
Open Claude Code and type:
If Claude Code recognizes the command instead of saying it cannot find it, gstack installed fine.
Give it a URL and it opens a browser, hunts for bugs, and fixes what it finds. No clicking through every button and form yourself. The AI runs the pass and repairs what breaks.
Lets the AI see the page. Screenshots, clicks, filling forms. It used to read code without ever seeing the screen. Now it drives the browser like a person and sees what your users see.
Run the tests, review the code, open the PR, all in one command. It used to mean running tests by hand, writing the PR description, waiting for review. Now one /ship handles all of it.
Reviews your code the way a senior engineer would. It looks at architecture, logic and security, and gives concrete suggestions. Code review is what you miss most when you build alone, and this skill fills the gap.
Hand it an error message and it chases the cause down. Not "here is what it might be", but actually reading the code, finding the reason, and handing you the fix.
| Skill | What it does |
|---|---|
/office-hours | Simulated office hours to sharpen an idea |
/plan-ceo-review | Reviews your plan from a CEO's seat |
/plan-eng-review | Reviews the technical plan from an engineering lead's seat |
/plan-design-review | Reviews UX and UI from a design lead's seat |
| Skill | What it does |
|---|---|
/design-consultation | Design consultation, talking through direction and style |
/design-review | Reviews a design and suggests improvements |
| Skill | What it does |
|---|---|
/review | AI code review, checking code quality |
/investigate | Tracks a bug to its root cause |
/ship | Tests + code review + PR in one step |
| Skill | What it does |
|---|---|
/qa | Automated QA, opens a browser to find bugs and fix them |
/qa-only | Tests only, no fixes, produces a report |
/cso | Security review, hunts for vulnerabilities |
/benchmark | Performance testing, finds the bottleneck |
/canary | Canary testing, verifies on a small slice |
| Skill | What it does |
|---|---|
/land-and-deploy | Merges the PR and deploys |
/document-release | Generates release notes |
/retro | Retrospective, records what you learned |
| Skill | What it does |
|---|---|
/browse | Opens a browser to visit pages, screenshot and interact |
/connect-chrome | Connects to a Chrome window you already have open |
/setup-browser-cookies | Sets up browser cookies |
| Skill | What it does |
|---|---|
/careful | Careful mode, confirms every step |
/freeze | Freezes files so the AI cannot change them by mistake |
/guard | Guard mode, watches for changes |
/unfreeze | Unfreezes |
Completely free, under the MIT open-source license. Anyone can use it, change it and share it. gstack itself is free, but you still need access to Claude Code (an Anthropic API key or a Claude Max subscription).
Yes. Run the install command in Git Bash or WSL (Windows Subsystem for Linux). WSL2 runs smoothest and feels the same as Mac or Linux.
gstack is anadd-on pack for Claude Code, like installing an app on your phone. Claude Code is the base system, and gstack adds 23 specialist skills on top. Without Claude Code you cannot run gstack, and Claude Code works fine on its own if you skip gstack.
Type this inside Claude Code to move to the latest version:
No. gstack installs into ~/.claude/skills/gstack/ and never touches your project files. It only adds skills inside Claude Code, and changes no existing settings or code.
gstack keeps a local record of which skills you use, at ~/.gstack/analytics/skill-usage.jsonl.
Nothing is uploaded by default.Unless you opt into telemetry during install, the data stays on your own machine.
How to check your own state:
Content in there means there is a local record, still going nowhere.
If that bothers you, delete the log:
The skills themselves are fine. The telemetry is just something users should know about.
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