open-gstack-browser

An agent skill by garrytan, from garrytan/gstack. Tags: automation, browser, web.

What it does

Launch GStack Browser — AI-controlled Chromium with the sidebar extension baked in.

Install

With the skills CLI, which installs into Claude Code, Codex, Cursor and other agents:

npx skills add garrytan/gstack --skill open-gstack-browser

Or copy the skill folder into Claude Code's skills directory by hand (~/.claude/skills for every project, or .claude/skills inside one):

git clone --depth 1 https://github.com/garrytan/gstack
cp -r gstack/open-gstack-browser ~/.claude/skills/open-gstack-browser

Safety box score

Grade D, elevated risk: 65 of 100 risk points, rated 2026-10-20. The grade rates what the skill and its scripts can reach on the machine of whoever installs it, across eight categories from shell execution to secrets access. How the score works.

This skill launches and controls a dedicated Chromium/GStack browser and runs helper scripts from `~/.claude/skills/gstack/bin`. The main risks are executing local scripts and an external installer, plus modifying browser state, cookies, and session data while driving pages on the user’s behalf.

Category levels, from 0 (none) to 3 (high)
Category	Level	Why
Code & shell execution	3 (high)	It runs multiple shell commands and shipped binaries, including `~/.claude/skills/gstack/bin/gstack-skill-start`, `./setup`, `$B connect`, and `bash "$tmpfile" "bun-v$BUN_VERSION"`.
Network access	2 (moderate)	It downloads code from the network with `curl -fsSL "https://bun.sh/install" -o "$tmpfile"` and then uses the browser to reach arbitrary websites.
Filesystem reach	2 (moderate)	It reads and writes home dot-directories and browser state, including `~/.claude/skills/gstack/...`, `.gstack/browse.json`, `$GSTACK_STATE_ROOT/chromium-profile`, and `$GSTACK_STATE_ROOT/analytics/`.
Secrets & credentials	2 (moderate)	It explicitly handles browser sessions and cookies: `A running browse daemon may hold open tabs, cookies and logged-in sessions`, and it can replace that live session.
Privilege & persistence	1 (low)	It does not require sudo or register services, but it can run setup/installer commands under the user account and may change local environment state.
Instruction hijack surface	2 (moderate)	It creates a dynamic instruction channel by telling the agent to follow `GSTACK_INSTRUCTION_BEGIN ... GSTACK_INSTRUCTION_END` blocks from command output, which is an external instruction source.
Irreversible actions	2 (moderate)	Its purpose is to launch and drive a visible Chromium instance, and later it can navigate, click, fill, snapshot, and run a sidebar agent on the user’s behalf.
Transparency	2 (moderate)	Behavior depends on unread helper scripts and executables such as `~/.claude/skills/gstack/bin/gstack-skill-start`, `gstack-browser-ensure`, and `browse/dist/browse`, plus a downloaded installer.

Before installing

Read the `curl ... https://bun.sh/install` block and confirm you accept running a downloaded installer.
Inspect `~/.claude/skills/gstack/bin/gstack-skill-start` and `.../gstack-browser-ensure` before trusting the browser workflow.
Try it first in a scratch account or profile, because it can reuse or replace Chromium sessions and cookies.
Make sure you are okay with edits under `~/.claude/skills/gstack/` and `$GSTACK_STATE_ROOT` before enabling it.

Rated 2026-10-20 by an automated review of 1 file from the skill's repository.

Source

Repository: garrytan/gstack (all skills from this repository)
Path: open-gstack-browser/SKILL.md
Branch: main
Updated: 2026-10-05

aws-blocks — Guides building full-stack applications with AWS Blocks — an Infrastructure-from-Code framework.
chrome-mcp-troubleshooting — Diagnose and fix Claude in Chrome MCP extension connectivity issues.
free-tools — When the user wants to plan, evaluate, or build a free tool for marketing purposes — lead generation, SEO value, or brand awareness.
gh-cli — Enforces authenticated gh CLI workflows over unauthenticated curl, WebFetch, and MCP fetch patterns.
Make Bot UI — Use when building a custom UI (page, dashboard, buttons) that should wake a Grok Bot over a webhook, when the user must provide a webhook sender key.
programmatic-seo — When the user wants to create SEO-driven pages at scale using templates and data.