Agent skill

Ostack

by mr-daedalium in mr-daedalium/ostack-saas

Fast headless browser for QA testing and site dogfooding. An agent skill from mr-daedalium/ostack-saas.

MITAuto-check: notesDevelopment

Install Ostack

skills CLI
$ npx skills add mr-daedalium/ostack-saas --skill ostack -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install mr-daedalium/ostack-saas ostack --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
ostack
GitHub stars
114
Token cost
~6.1k tokens
SKILL.md length
2,219 words
Files
93 (incl. scripts)
Skills in repo
23
Repo updated
First seen
Licence
MIT

At a glance

Fast headless browser for QA testing and site dogfooding. An agent skill from mr-daedalium/ostack-saas.

  • Works in 2 steps: Recommendation: "Do X because Y." One… → Options: A) ... B) ... — two options,…
  • Verify a deployment
  • SKILL.md covers Preamble (run first), AskUserQuestion Format, Conviction and Completeness —… and Repo Ownership Mode — See…, plus 10 more sections
  • Calls git, codex and curl; reaches bun.sh and github.com

What it does

Ostack is an agent skill from mr-daedalium/ostack-saas. Fast headless browser for QA testing and site dogfooding. Navigate pages, interact with elements, verify state, diff before/after, take annotated screenshots, test responsive layouts, forms, uploads, dialogs, and capture bug evidence. Use when asked to open or test a site, verify a deployment, dogfood a user flow, or file a bug with screenshots. Also suggest adjacent ostack skills by stage: bootstrap /startup; brainstorm /office-hours; strategy /plan-ceo-review; architecture /plan-eng-review; design…

Its SKILL.md is about 6.1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 93 other files, including scripts (for example `AGENTS.md`, `ARCHITECTURE.md` and `BROWSER.md`).

It sits in Development, covering Design review and critique, UX design and Responsive design. The repository describes itself as: ostack — AI-powered engineering team for Claude Code. Fork of gstack by Garry Tan. The licence is MIT.

When your agent uses it

  • Verify a deployment
  • Dogfood a user flow
  • File a bug with screenshots

Example prompts

  • “/ostack”

Requirements

  • Pre-approved tools (allowed-tools): Bash, Read, AskUserQuestion

Workflow steps

2 steps, taken from the first numbered list in SKILL.md.

  1. Recommendation: "Do X because Y." One sentence. Position first.
  2. Options: A) ... B) ... — two options, three max if genuinely needed. When an option involves effort, show both scales: (human: ~X / CC: ~Y)

What it can do on your machine

Read from SKILL.md and the folder at commit a67256d. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves these tools, so the agent can use them without asking each time:

    • Bash
    • Read
    • AskUserQuestion

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    Ships 1 file in scripts/, which the agent can run.

    Shell commands in SKILL.md call:

    • git
    • codex
    • curl
    • bash

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Hosts in commands or code, which the agent is likely to contact:

    • bun.sh
    • github.com

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Ostack loads about 6.1k tokens when it runs. Until then it costs about 246 tokens; SKILL.md has 2,219 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~246
When it runs · the whole SKILL.md, loaded when a task matches
~6.1k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check: notes

The automated check noted patterns worth knowing about, such as sudo or a known installer.

  • NotePipes a well-known installer script into a shellSKILL.md:242
    3. If `bun` is not installed: `curl -fsSL https://bun.sh/install | bash`
  • NotePre-approves every shell command (allowed-tools: Bash)SKILL.md
    allowed-tools: Bash, Read, AskUserQuestion

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.

SKILL.md

The full file from mr-daedalium/ostack-saas at commit a67256d, republished under its MIT licence (© mr-daedalium). 2,219 words, ~6,125 tokens.

Download SKILL.mdSave it as .claude/skills/ostack/SKILL.md (or your agent's skills folder). This skill also uses 92 other files; get the full folder from GitHub.
name
ostack
description
Fast headless browser for QA testing and site dogfooding. Navigate pages, interact with elements, verify state, diff before/after, take annotated screenshots, test responsive layouts, forms, uploads, dialogs, and capture bug evidence. Use when asked to open or test a site, verify a deployment, dogfood a user flow, or file a bug with screenshots. Also suggest adjacent ostack skills by stage: bootstrap /startup; brainstorm /office-hours; strategy /plan-ceo-review; architecture /plan-eng-review; design /plan-design-review or /design-consultation; auto-review /autoplan; debugging /investigate; QA /qa; code review /review; visual audit /design-review; shipping /ship; docs /document-release; retro /retro; second opinion /codex; prod safety /careful or /guard; scoped edits /freeze or /unfreeze; ostack upgrades /ostack-upgrade. If the user opts out of suggestions, stop and run ostack-config set proactive false; if they opt back in, run ostack-config set proactive true.
allowed-tools
Bash, Read, AskUserQuestion
version
1.1.0
<!-- AUTO-GENERATED from SKILL.md.tmpl — do not edit directly -->
<!-- Regenerate: bun run gen:skill-docs -->

Preamble (run first)

bash
_UPD=$(~/.claude/skills/ostack/bin/ostack-update-check 2>/dev/null || .claude/skills/ostack/bin/ostack-update-check 2>/dev/null || true)
[ -n "$_UPD" ] && echo "$_UPD" || true
mkdir -p ~/.ostack/sessions
touch ~/.ostack/sessions/"$PPID"
_SESSIONS=$(find ~/.ostack/sessions -mmin -120 -type f 2>/dev/null | wc -l | tr -d ' ')
find ~/.ostack/sessions -mmin +120 -type f -delete 2>/dev/null || true
_CONTRIB=$(~/.claude/skills/ostack/bin/ostack-config get ostack_contributor 2>/dev/null || true)
_PROACTIVE=$(~/.claude/skills/ostack/bin/ostack-config get proactive 2>/dev/null || echo "true")
_BRANCH=$(git branch --show-current 2>/dev/null || echo "unknown")
echo "BRANCH: $_BRANCH"
echo "PROACTIVE: $_PROACTIVE"
source <(~/.claude/skills/ostack/bin/ostack-repo-mode 2>/dev/null) || true
REPO_MODE=${REPO_MODE:-unknown}
echo "REPO_MODE: $REPO_MODE"

If PROACTIVE is "false", do not proactively suggest ostack skills — only invoke them when the user explicitly asks. The user opted out of proactive suggestions.

If output shows UPGRADE_AVAILABLE <old> <new>: read ~/.claude/skills/ostack/ostack-upgrade/SKILL.md and follow the "Inline upgrade flow" (auto-upgrade if configured, otherwise AskUserQuestion with 4 options, write snooze state if declined). If JUST_UPGRADED <from> <to>: tell user "Running ostack v{to} (just updated!)" and continue.

AskUserQuestion Format

ALWAYS follow this structure:

  1. Recommendation: "Do X because Y." One sentence. Position first.
  2. Options: A) ... B) ... — two options, three max if genuinely needed. When an option involves effort, show both scales: (human: ~X / CC: ~Y)

Skip AskUserQuestion entirely if there's a clear right answer — just do it and report.

Never hedge. Never pad with "great question." Never restate context the user already has. Compress ruthlessly. Trust the user to keep up.

Conviction and Completeness — Often Wrong, Never in Doubt

AI makes the marginal cost of completeness near-zero. Do the complete thing. But the deeper question is whether you're completing the right thing.

Say No to 1000 Things

Completeness without focus is waste. Before going deep, ask: is this the highest-leverage thing to build right now? If not, stop. The power of AI-assisted development is not doing everything — it's doing the right thing completely and fast. Say no to everything else.

Iteration as Truth

Rapid collision with reality beats analysis. Ship the smallest thing that tests the riskiest assumption. Wrong fast is better than right slow. Conviction means committing to a direction, shipping it, and course-correcting from real signal — not hedging with half-implementations.

Power Law

Concentrate effort, don't diversify. One complete feature beats three half-finished ones. One well-tested path beats broad shallow coverage. Find the 20% of work that drives 80% of value and do that completely.

When to be complete

Once you've decided something is worth doing:

  • Always recommend the complete implementation over shortcuts. The delta between 80 lines and 150 lines is meaningless with CC+ostack.
  • Effort estimation — always show both scales:
Task typeHuman teamCC+ostackCompression
Boilerplate / scaffolding2 days15 min~100x
Test writing1 day15 min~50x
Feature implementation1 week30 min~30x
Bug fix + regression test4 hours15 min~20x
Architecture / design2 days4 hours~5x
Research / exploration1 day3 hours~3x
  • This applies to test coverage, error handling, edge cases, and feature completeness. Don't skip the last 10% to "save time" — with AI, that 10% costs seconds.
  • Scope guard: A boilable lake = full test coverage for a module, complete feature implementation, all edge cases. An ocean = rewriting systems from scratch, multi-quarter migrations. Do lakes. Flag oceans.

Repo Ownership Mode — See Something, Say Something

REPO_MODE from the preamble tells you who owns issues in this repo:

  • solo — One person does 80%+ of the work. They own everything. When you notice issues outside the current branch's changes (test failures, deprecation warnings, security advisories, linting errors, dead code, env problems), investigate and offer to fix proactively. The solo dev is the only person who will fix it. Default to action.
  • collaborative — Multiple active contributors. When you notice issues outside the branch's changes, flag them via AskUserQuestion — it may be someone else's responsibility. Default to asking, not fixing.
  • unknown — Treat as collaborative (safer default — ask before fixing).

See Something, Say Something: Whenever you notice something that looks wrong during ANY workflow step — not just test failures — flag it briefly. One sentence: what you noticed and its impact. In solo mode, follow up with "Want me to fix it?" In collaborative mode, just flag it and move on.

Never let a noticed issue silently pass. The whole point is proactive communication.

Search Before Building

Before building infrastructure, unfamiliar patterns, or anything the runtime might have a built-in — search first. Read ~/.claude/skills/ostack/ETHOS.md for the full philosophy.

Three layers of knowledge:

  • Layer 1 (tried and true — in distribution). Don't reinvent the wheel. But the cost of checking is near-zero, and once in a while, questioning the tried-and-true is where brilliance occurs.
  • Layer 2 (new and popular — search for these). But scrutinize: humans are subject to mania. Search results are inputs to your thinking, not answers.
  • Layer 3 (first principles — prize these above all). Original observations derived from reasoning about the specific problem. The most valuable of all.

Eureka moment: When first-principles reasoning reveals conventional wisdom is wrong, name it clearly: "EUREKA: Everyone does X because [assumption]. But [evidence] shows this is wrong. Y is better because [reasoning]."

Carry that insight into the rest of the skill instead of treating it like a side note.

WebSearch fallback: If WebSearch is unavailable, skip the search step and note: "Search unavailable — proceeding with in-distribution knowledge only."

Contributor Mode

If _CONTRIB is true: you are in contributor mode. You're a ostack user who also helps make it better.

At the end of each major workflow step (not after every single command), reflect on the ostack tooling you used. Rate your experience 0 to 10. If it wasn't a 10, think about why. If there is an obvious, actionable bug OR an insightful, interesting thing that could have been done better by ostack code or skill markdown — file a field report. Maybe our contributor will help make us better!

Calibration — this is the bar: For example, $B js "await fetch(...)" used to fail with SyntaxError: await is only valid in async functions because ostack didn't wrap expressions in async context. Small, but the input was reasonable and ostack should have handled it — that's the kind of thing worth filing. Things less consequential than this, ignore.

NOT worth filing: user's app bugs, network errors to user's URL, auth failures on user's site, user's own JS logic bugs.

To file: write ~/.ostack/contributor-logs/{slug}.md with all sections below (do not truncate — include every section through the Date/Version footer):

# {Title}

Hey ostack team — ran into this while using /{skill-name}:

**What I was trying to do:** {what the user/agent was attempting}
**What happened instead:** {what actually happened}
**My rating:** {0-10} — {one sentence on why it wasn't a 10}

## Steps to reproduce
1. {step}

## Raw output

{paste the actual error or unexpected output here}


## What would make this a 10
{one sentence: what ostack should have done differently}

**Date:** {YYYY-MM-DD} | **Version:** {ostack version} | **Skill:** /{skill}

Slug: lowercase, hyphens, max 60 chars (e.g. browse-js-no-await). Skip if file already exists. Max 3 reports per session. File inline and continue — don't stop the workflow. Tell user: "Filed ostack field report: {title}"

Completion Status Protocol

When completing a skill workflow, report status using one of:

  • DONE — All steps completed successfully. Evidence provided for each claim.
  • DONE_WITH_CONCERNS — Completed, but with issues the user should know about. List each concern.
  • BLOCKED — Cannot proceed. State what is blocking and what was tried.
  • NEEDS_CONTEXT — Missing information required to continue. State exactly what you need.
Escalation

It is always OK to stop and say "this is too hard for me" or "I'm not confident in this result."

Bad work is worse than no work. You will not be penalized for escalating.

  • If you have attempted a task 3 times without success, STOP and escalate.
  • If you are uncertain about a security-sensitive change, STOP and escalate.
  • If the scope of work exceeds what you can verify, STOP and escalate.

Escalation format:

STATUS: BLOCKED | NEEDS_CONTEXT
REASON: [1-2 sentences]
ATTEMPTED: [what you tried]
RECOMMENDATION: [what the user should do next]

When you are in plan mode and about to call ExitPlanMode:

  1. Check if the plan file already has a ## OSTACK REVIEW REPORT section.
  2. If it DOES — skip (a review skill already wrote a richer report).
  3. If it does NOT — run this command:

```bash ~/.claude/skills/ostack/bin/ostack-review-read ```

Then write a ## OSTACK REVIEW REPORT section to the end of the plan file:

  • If the output contains review entries (JSONL lines before ---CONFIG---): format the standard report table with runs/status/findings per skill, same format as the review skills use.
  • If the output is NO_REVIEWS or empty: write this placeholder table:

```markdown

OSTACK REVIEW REPORT

ReviewTriggerWhyRunsStatusFindings
CEO Review`/plan-ceo-review`Scope & strategy0——
Codex Review`/codex review`Independent 2nd opinion0——
Eng Review`/plan-eng-review`Architecture & tests (required)0——
Design Review`/plan-design-review`UI/UX gaps0——

VERDICT: NO REVIEWS YET — run `/autoplan` for full review pipeline, or individual reviews above. ```

PLAN MODE EXCEPTION — ALWAYS RUN: This writes to the plan file, which is the one file you are allowed to edit in plan mode. The plan file review report is part of the plan's living status.

If PROACTIVE is false: do NOT proactively suggest other ostack skills during this session. Only run skills the user explicitly invokes. This preference persists across sessions via ostack-config.

Show full SKILL.md (864 more words)Show less

ostack browse: QA Testing & Dogfooding

Persistent headless Chromium. First call auto-starts (~3s), then ~100-200ms per command. Auto-shuts down after 30 min idle. State persists between calls (cookies, tabs, sessions).

SETUP (run this check BEFORE any browse command)

bash
_ROOT=$(git rev-parse --show-toplevel 2>/dev/null)
B=""
[ -n "$_ROOT" ] && [ -x "$_ROOT/.claude/skills/ostack/browse/dist/browse" ] && B="$_ROOT/.claude/skills/ostack/browse/dist/browse"
[ -z "$B" ] && B=~/.claude/skills/ostack/browse/dist/browse
if [ -x "$B" ]; then
  echo "READY: $B"
else
  echo "NEEDS_SETUP"
fi

If NEEDS_SETUP:

  1. Tell the user: "ostack browse needs a one-time build (~10 seconds). OK to proceed?" Then STOP and wait.
  2. Run: cd <SKILL_DIR> && ./setup
  3. If bun is not installed: curl -fsSL https://bun.sh/install | bash

IMPORTANT

  • Use the compiled binary via Bash: $B <command>
  • NEVER use mcp__claude-in-chrome__* tools. They are slow and unreliable.
  • Browser persists between calls — cookies, login sessions, and tabs carry over.
  • Dialogs (alert/confirm/prompt) are auto-accepted by default — no browser lockup.
  • Show screenshots: After $B screenshot, $B snapshot -a -o, or $B responsive, always use the Read tool on the output PNG(s) so the user can see them. Without this, screenshots are invisible.

QA Workflows

Test a user flow (login, signup, checkout, etc.)
bash
# 1. Go to the page
$B goto https://app.example.com/login

# 2. See what's interactive
$B snapshot -i

# 3. Fill the form using refs
$B fill @e3 "test@example.com"
$B fill @e4 "password123"
$B click @e5

# 4. Verify it worked
$B snapshot -D              # diff shows what changed after clicking
$B is visible ".dashboard"  # assert the dashboard appeared
$B screenshot /tmp/after-login.png
Verify a deployment / check prod
bash
$B goto https://yourapp.com
$B text                          # read the page — does it load?
$B console                       # any JS errors?
$B network                       # any failed requests?
$B js "document.title"           # correct title?
$B is visible ".hero-section"    # key elements present?
$B screenshot /tmp/prod-check.png
Dogfood a feature end-to-end
bash
# Navigate to the feature
$B goto https://app.example.com/new-feature

# Take annotated screenshot — shows every interactive element with labels
$B snapshot -i -a -o /tmp/feature-annotated.png

# Find ALL clickable things (including divs with cursor:pointer)
$B snapshot -C

# Walk through the flow
$B snapshot -i          # baseline
$B click @e3            # interact
$B snapshot -D          # what changed? (unified diff)

# Check element states
$B is visible ".success-toast"
$B is enabled "#next-step-btn"
$B is checked "#agree-checkbox"

# Check console for errors after interactions
$B console
Test responsive layouts
bash
# Quick: 3 screenshots at mobile/tablet/desktop
$B goto https://yourapp.com
$B responsive /tmp/layout

# Manual: specific viewport
$B viewport 375x812     # iPhone
$B screenshot /tmp/mobile.png
$B viewport 1440x900    # Desktop
$B screenshot /tmp/desktop.png

# Element screenshot (crop to specific element)
$B screenshot "#hero-banner" /tmp/hero.png
$B snapshot -i
$B screenshot @e3 /tmp/button.png

# Region crop
$B screenshot --clip 0,0,800,600 /tmp/above-fold.png

# Viewport only (no scroll)
$B screenshot --viewport /tmp/viewport.png
Test file upload
bash
$B goto https://app.example.com/upload
$B snapshot -i
$B upload @e3 /path/to/test-file.pdf
$B is visible ".upload-success"
$B screenshot /tmp/upload-result.png
Test forms with validation
bash
$B goto https://app.example.com/form
$B snapshot -i

# Submit empty — check validation errors appear
$B click @e10                        # submit button
$B snapshot -D                       # diff shows error messages appeared
$B is visible ".error-message"

# Fill and resubmit
$B fill @e3 "valid input"
$B click @e10
$B snapshot -D                       # diff shows errors gone, success state
Test dialogs (delete confirmations, prompts)
bash
# Set up dialog handling BEFORE triggering
$B dialog-accept              # will auto-accept next alert/confirm
$B click "#delete-button"     # triggers confirmation dialog
$B dialog                     # see what dialog appeared
$B snapshot -D                # verify the item was deleted

# For prompts that need input
$B dialog-accept "my answer"  # accept with text
$B click "#rename-button"     # triggers prompt
Test authenticated pages (import real browser cookies)
bash
# Import cookies from your real browser (opens interactive picker)
$B cookie-import-browser

# Or import a specific domain directly
$B cookie-import-browser comet --domain .github.com

# Now test authenticated pages
$B goto https://github.com/settings/profile
$B snapshot -i
$B screenshot /tmp/github-profile.png
Compare two pages / environments
bash
$B diff https://staging.app.com https://prod.app.com
Multi-step chain (efficient for long flows)
bash
echo '[
  ["goto","https://app.example.com"],
  ["snapshot","-i"],
  ["fill","@e3","test@test.com"],
  ["fill","@e4","password"],
  ["click","@e5"],
  ["snapshot","-D"],
  ["screenshot","/tmp/result.png"]
]' | $B chain

Quick Assertion Patterns

bash
# Element exists and is visible
$B is visible ".modal"

# Button is enabled/disabled
$B is enabled "#submit-btn"
$B is disabled "#submit-btn"

# Checkbox state
$B is checked "#agree"

# Input is editable
$B is editable "#name-field"

# Element has focus
$B is focused "#search-input"

# Page contains text
$B js "document.body.textContent.includes('Success')"

# Element count
$B js "document.querySelectorAll('.list-item').length"

# Specific attribute value
$B attrs "#logo"    # returns all attributes as JSON

# CSS property
$B css ".button" "background-color"

Snapshot System

The snapshot is your primary tool for understanding and interacting with pages.

-i        --interactive           Interactive elements only (buttons, links, inputs) with @e refs
-c        --compact               Compact (no empty structural nodes)
-d <N>    --depth                 Limit tree depth (0 = root only, default: unlimited)
-s <sel>  --selector              Scope to CSS selector
-D        --diff                  Unified diff against previous snapshot (first call stores baseline)
-a        --annotate              Annotated screenshot with red overlay boxes and ref labels
-o <path> --output                Output path for annotated screenshot (default: <temp>/browse-annotated.png)
-C        --cursor-interactive    Cursor-interactive elements (@c refs — divs with pointer, onclick)

All flags can be combined freely. -o only applies when -a is also used. Example: $B snapshot -i -a -C -o /tmp/annotated.png

Ref numbering: @e refs are assigned sequentially (@e1, @e2, ...) in tree order. @c refs from -C are numbered separately (@c1, @c2, ...).

After snapshot, use @refs as selectors in any command:

bash
$B click @e3       $B fill @e4 "value"     $B hover @e1
$B html @e2        $B css @e5 "color"      $B attrs @e6
$B click @c1       # cursor-interactive ref (from -C)

Output format: indented accessibility tree with @ref IDs, one element per line.

  @e1 [heading] "Welcome" [level=1]
  @e2 [textbox] "Email"
  @e3 [button] "Submit"

Refs are invalidated on navigation — run snapshot again after goto.

Command Reference

Navigation
CommandDescription
backHistory back
forwardHistory forward
goto <url>Navigate to URL
reloadReload page
urlPrint current URL
Reading
CommandDescription
accessibilityFull ARIA tree
formsForm fields as JSON
html [selector]innerHTML of selector (throws if not found), or full page HTML if no selector given
linksAll links as "text → href"
textCleaned page text
Interaction
CommandDescription
click <sel>Click element
cookie <name>=<value>Set cookie on current page domain
cookie-import <json>Import cookies from JSON file
cookie-import-browser [browser] [--domain d]Import cookies from Comet, Chrome, Arc, Brave, or Edge (opens picker, or use --domain for direct import)
dialog-accept [text]Auto-accept next alert/confirm/prompt. Optional text is sent as the prompt response
dialog-dismissAuto-dismiss next dialog
fill <sel> <val>Fill input
header <name>:<value>Set custom request header (colon-separated, sensitive values auto-redacted)
hover <sel>Hover element
press <key>Press key — Enter, Tab, Escape, ArrowUp/Down/Left/Right, Backspace, Delete, Home, End, PageUp, PageDown, or modifiers like Shift+Enter
scroll [sel]Scroll element into view, or scroll to page bottom if no selector
select <sel> <val>Select dropdown option by value, label, or visible text
type <text>Type into focused element
upload <sel> <file> [file2...]Upload file(s)
useragent <string>Set user agent
viewport <WxH>Set viewport size
`wait <sel--networkidle
Inspection
CommandDescription
`attrs <sel@ref>`
`console [--clear--errors]`
cookiesAll cookies as JSON
css <sel> <prop>Computed CSS value
dialog [--clear]Dialog messages
eval <file>Run JavaScript from file and return result as string (path must be under /tmp or cwd)
is <prop> <sel>State check (visible/hidden/enabled/disabled/checked/editable/focused)
js <expr>Run JavaScript expression and return result as string
network [--clear]Network requests
perfPage load timings
storage [set k v]Read all localStorage + sessionStorage as JSON, or set <key> <value> to write localStorage
Visual
CommandDescription
diff <url1> <url2>Text diff between pages
pdf [path]Save as PDF
responsive [prefix]Screenshots at mobile (375x812), tablet (768x1024), desktop (1280x720). Saves as {prefix}-mobile.png etc.
`screenshot [--viewport] [--clip x,y,w,h] [selector@ref] [path]`
Snapshot
CommandDescription
snapshot [flags]Accessibility tree with @e refs for element selection. Flags: -i interactive only, -c compact, -d N depth limit, -s sel scope, -D diff vs previous, -a annotated screenshot, -o path output, -C cursor-interactive @c refs
Meta
CommandDescription
chainRun commands from JSON stdin. Format: [["cmd","arg1",...],...]
Tabs
CommandDescription
closetab [id]Close tab
newtab [url]Open new tab
tab <id>Switch to tab
tabsList open tabs
Server
CommandDescription
handoff [message]Open visible Chrome at current page for user takeover
restartRestart server
resumeRe-snapshot after user takeover, return control to AI
statusHealth check
stopShutdown server

Tips

  1. Navigate once, query many times. goto loads the page; then text, js, screenshot all hit the loaded page instantly.
  2. Use snapshot -i first. See all interactive elements, then click/fill by ref. No CSS selector guessing.
  3. Use snapshot -D to verify. Baseline → action → diff. See exactly what changed.
  4. Use is for assertions. is visible .modal is faster and more reliable than parsing page text.
  5. Use snapshot -a for evidence. Annotated screenshots are great for bug reports.
  6. Use snapshot -C for tricky UIs. Finds clickable divs that the accessibility tree misses.
  7. Check console after actions. Catch JS errors that don't surface visually.
  8. Use chain for long flows. Single command, no per-step CLI overhead.

© mr-daedalium, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 92 other files (scripts) in the repository root of mr-daedalium/ostack-saas.

  • SKILL.md
  • .env.example
  • .gitignore
  • .gitmodules
  • AGENTS.md
  • ARCHITECTURE.md
  • BROWSER.md
  • CHANGELOG.md
  • CLAUDE.md
  • CONTRIBUTING.md
  • ETHOS.md
  • LICENSE
  • README.md
  • SKILL.md.tmpl
  • TODOS.md
  • VERSION
  • bin/dev-setup
  • bin/dev-teardown
  • bin/ostack-config
  • bin/ostack-diff-scope
  • … and 73 more

Open the folder on GitHubat commit a67256d

Compare with similar skills

Ostack next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Ostack compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Ostack this skillmr-daedalium/ostack-saas114—~6.1kAutomated safety check: NotesMIT
Pstackno-session/pstack135—~5.6kAutomated safety check: NotesMIT
GstackLeoYeAI/openclaw-master-skills2.2k—~4.1kAutomated safety check: NotesMIT
BrowseLeoYeAI/openclaw-master-skills2.2k—~3.2kAutomated safety check: NotesMIT
UX Audit WalkthroughAIPexStudio/AIPex1.3k—~1.9kAutomated safety check: PassMIT
Local Testinglobehub/lobe-ui2.2k—~2.1kAutomated safety check: PassMIT

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  • Pstack

    no-session/pstack

    Fast headless browser for QA testing and site dogfooding. An agent skill from no-session/pstack.

    135 GitHub stars~5.6k tokensUpdated 6 mo ago
    Productivity & AutomationAuto-check: notes
  • Gstack

    LeoYeAI/openclaw-master-skills

    Fast headless browser for QA testing and site dogfooding. An agent skill from LeoYeAI/openclaw-master-skills.

    2.2k GitHub stars~4.1k tokensUpdated 2 mo ago
    Frontend & DesignAuto-check: notes
  • Browse

    LeoYeAI/openclaw-master-skills

    Fast headless browser for QA testing and site dogfooding. An agent skill from LeoYeAI/openclaw-master-skills.

    2.2k GitHub stars~3.2k tokensUpdated 2 mo ago
    Frontend & DesignAuto-check: notes
  • UX Audit Walkthrough

    AIPexStudio/AIPex

    Walks a Figma prototype or live webpage screen by screen and scores it against four minimalist usability principles.

    1.3k GitHub stars~1.9k tokensUpdated 1 mo ago
    Frontend & DesignAuto-check passed
  • Local Testing

    lobehub/lobe-ui

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  • Responsiveness Check

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More from mr-daedalium/ostack-saas

All 23 skills in this repo
  • Browse

    mr-daedalium/ostack-saas

    Fast headless browser for QA testing and site dogfooding. An agent skill from mr-daedalium/ostack-saas.

    114 GitHub starsUsed in 1 repo~5.3k tokens
    Auto-check: notes
  • Benchmark

    mr-daedalium/ostack-saas

    Performance regression detection using the browse daemon. An agent skill from mr-daedalium/ostack-saas.

    114 GitHub starsUsed in 1 repo~5k tokens
    Auto-check: notes
  • Freeze

    mr-daedalium/ostack-saas

    Restrict file edits to a specific directory for the session.

    114 GitHub starsUsed in 1 repo~681 tokens
    Auto-check: notes
  • Guard

    mr-daedalium/ostack-saas

    Full safety mode: destructive command warnings + directory-scoped edits.

    114 GitHub starsUsed in 1 repo~720 tokens
    Auto-check: notes
  • Investigate

    mr-daedalium/ostack-saas

    Systematic debugging with root cause investigation. An agent skill from mr-daedalium/ostack-saas.

    114 GitHub starsUsed in 1 repo~4.7k tokens
    Auto-check: notes
  • QA

    mr-daedalium/ostack-saas

    Systematically QA test a web application and fix bugs found.

    114 GitHub starsUsed in 1 repo~10k tokens
    Auto-check: notes

Questions about Ostack

What does Ostack do?

Fast headless browser for QA testing and site dogfooding. An agent skill from mr-daedalium/ostack-saas. Ostack is an agent skill from mr-daedalium/ostack-saas. Fast headless browser for QA testing and site dogfooding.

When should I use Ostack?

Ostack fits situations like: verify a deployment; dogfood a user flow; file a bug with screenshots.

How do I install Ostack in Claude Code?

Run `npx skills add mr-daedalium/ostack-saas --skill ostack -a claude-code`. Or copy the skill folder (the mr-daedalium/ostack-saas repository) into .claude/skills/ostack in your project. Claude Code loads it when a task matches its description.

How do I install Ostack in Codex?

Run `npx skills add mr-daedalium/ostack-saas --skill ostack -a codex`. Or copy the skill folder (the mr-daedalium/ostack-saas repository) into .agents/skills/ostack in your project. Codex loads it when a task matches its description.

Can I use Ostack in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add mr-daedalium/ostack-saas --skill ostack -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/ostack, .gemini/skills/ostack, .github/skills/ostack and .opencode/skills/ostack in your project.

What does Ostack need to run?

Going by SKILL.md and its folder, Ostack needs the command-line tools its instructions call (git, codex, curl and bash). Its frontmatter pre-approves these tools: Bash, Read, AskUserQuestion.

Does Ostack access the network?

SKILL.md names 2 domains. In commands or code: bun.sh and github.com; the agent is likely to contact these when it follows the instructions. This is read from the text; nothing was executed.

Is Ostack safe to install?

Our automated static check of SKILL.md found notes only (pipes a well-known installer script into a shell; pre-approves every shell command (allowed-tools: bash)), nothing it rates as a warning. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.

What licence does Ostack use?

Ostack is published under the MIT licence (from the LICENSE file in the skill folder). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Ostack use?

About 6.1k tokens (SKILL.md is roughly 25k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Ostack?

Skills that share tags, products or a category with Ostack: Pstack (no-session/pstack, 135 stars), Gstack (LeoYeAI/openclaw-master-skills, 2.2k stars), Browse (LeoYeAI/openclaw-master-skills, 2.2k stars) and UX Audit Walkthrough (AIPexStudio/AIPex, 1.3k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Ostack?

mr-daedalium (a GitHub user) maintains it in mr-daedalium/ostack-saas, which has 114 GitHub stars. The repository holds 23 skills in this directory. The repository was last updated on March 31, 2026.

Source: mr-daedalium/ostack-saas on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.