Preamble (run first)

_UPD=$(~/.codex/skills/gstack/bin/gstack-update-check 2>/dev/null || .agents/skills/gstack/bin/gstack-update-check 2>/dev/null || true)
[ -n "$_UPD" ] && echo "$_UPD" || true
mkdir -p ~/.gstack/sessions
touch ~/.gstack/sessions/"$PPID"
_SESSIONS=$(find ~/.gstack/sessions -mmin -120 -type f 2>/dev/null | wc -l | tr -d ' ')
find ~/.gstack/sessions -mmin +120 -type f -delete 2>/dev/null || true
_CONTRIB=$(~/.codex/skills/gstack/bin/gstack-config get gstack_contributor 2>/dev/null || true)
_PROACTIVE=$(~/.codex/skills/gstack/bin/gstack-config get proactive 2>/dev/null || echo "true")
_BRANCH=$(git branch --show-current 2>/dev/null || echo "unknown")
echo "BRANCH: $_BRANCH"
echo "PROACTIVE: $_PROACTIVE"
source <(~/.codex/skills/gstack/bin/gstack-repo-mode 2>/dev/null) || true
REPO_MODE=${REPO_MODE:-unknown}
echo "REPO_MODE: $REPO_MODE"
_LAKE_SEEN=$([ -f ~/.gstack/.completeness-intro-seen ] && echo "yes" || echo "no")
echo "LAKE_INTRO: $_LAKE_SEEN"
_TEL=$(~/.codex/skills/gstack/bin/gstack-config get telemetry 2>/dev/null || true)
_TEL_PROMPTED=$([ -f ~/.gstack/.telemetry-prompted ] && echo "yes" || echo "no")
_TEL_START=$(date +%s)
_SESSION_ID="$$-$(date +%s)"
echo "TELEMETRY: ${_TEL:-off}"
echo "TEL_PROMPTED: $_TEL_PROMPTED"
mkdir -p ~/.gstack/analytics
echo '{"skill":"gstack","ts":"'$(date -u +%Y-%m-%dT%H:%M:%SZ)'","repo":"'$(basename "$(git rev-parse --show-toplevel 2>/dev/null)" 2>/dev/null || echo "unknown")'"}'  >> ~/.gstack/analytics/skill-usage.jsonl 2>/dev/null || true
for _PF in ~/.gstack/analytics/.pending-*; do [ -f "$_PF" ] && ~/.codex/skills/gstack/bin/gstack-telemetry-log --event-type skill_run --skill _pending_finalize --outcome unknown --session-id "$_SESSION_ID" 2>/dev/null || true; break; done

If

PROACTIVE

"false"

If output shows

UPGRADE_AVAILABLE <old> <new>

~/.codex/skills/gstack/gstack-upgrade/SKILL.md

JUST_UPGRADED <from> <to>

If

LAKE_INTRO

no

open https://garryslist.org/posts/boil-the-ocean
touch ~/.gstack/.completeness-intro-seen

Only run

open

touch

If

TEL_PROMPTED

no

LAKE_INTRO

yes

Help gstack get better! Community mode shares usage data (which skills you use, how long they take, crash info) with a stable device ID so we can track trends and fix bugs faster. No code, file paths, or repo names are ever sent. Change anytime with

gstack-config set telemetry off

.

Options:

• A) Help gstack get better! (recommended)
• B) No thanks

If A: run

~/.codex/skills/gstack/bin/gstack-config set telemetry community

If B: ask a follow-up AskUserQuestion:

How about anonymous mode? We just learn that someone used gstack — no unique ID, no way to connect sessions. Just a counter that helps us know if anyone's out there.

Options:

• A) Sure, anonymous is fine
• B) No thanks, fully off

If B→A: run

~/.codex/skills/gstack/bin/gstack-config set telemetry anonymous

~/.codex/skills/gstack/bin/gstack-config set telemetry off

Always run:

touch ~/.gstack/.telemetry-prompted

This only happens once. If

TEL_PROMPTED

yes

AskUserQuestion Format

ALWAYS follow this structure for every AskUserQuestion call:

1. Re-ground: State the project, the current branch (use the

   _BRANCH

   value printed by the preamble — NOT any branch from conversation history or gitStatus), and the current plan/task. (1-2 sentences)
2. Simplify: Explain the problem in plain English a smart 16-year-old could follow. No raw function names, no internal jargon, no implementation details. Use concrete examples and analogies. Say what it DOES, not what it's called.
3. Recommend:

   RECOMMENDATION: Choose [X] because [one-line reason]

   — always prefer the complete option over shortcuts (see Completeness Principle). Include

   Completeness: X/10

   for each option. Calibration: 10 = complete implementation (all edge cases, full coverage), 7 = covers happy path but skips some edges, 3 = shortcut that defers significant work. If both options are 8+, pick the higher; if one is ≤5, flag it.
4. Options: Lettered options:

   A) ... B) ... C) ...

   — when an option involves effort, show both scales:

   (human: ~X / CC: ~Y)

Assume the user hasn't looked at this window in 20 minutes and doesn't have the code open. If you'd need to read the source to understand your own explanation, it's too complex.

Per-skill instructions may add additional formatting rules on top of this baseline.

Completeness Principle — Boil the Lake

AI-assisted coding makes the marginal cost of completeness near-zero. When you present options:

• If Option A is the complete implementation (full parity, all edge cases, 100% coverage) and Option B is a shortcut that saves modest effort — always recommend A. The delta between 80 lines and 150 lines is meaningless with CC+gstack. "Good enough" is the wrong instinct when "complete" costs minutes more.
• Lake vs. ocean: A "lake" is boilable — 100% test coverage for a module, full feature implementation, handling all edge cases, complete error paths. An "ocean" is not — rewriting an entire system from scratch, adding features to dependencies you don't control, multi-quarter platform migrations. Recommend boiling lakes. Flag oceans as out of scope.
• When estimating effort, always show both scales: human team time and CC+gstack time. The compression ratio varies by task type — use this reference:

• This principle applies to test coverage, error handling, documentation, edge cases, and feature completeness. Don't skip the last 10% to "save time" — with AI, that 10% costs seconds.

Anti-patterns — DON'T do this:

• BAD: "Choose B — it covers 90% of the value with less code." (If A is only 70 lines more, choose A.)
• BAD: "We can skip edge case handling to save time." (Edge case handling costs minutes with CC.)
• BAD: "Let's defer test coverage to a follow-up PR." (Tests are the cheapest lake to boil.)
• BAD: Quoting only human-team effort: "This would take 2 weeks." (Say: "2 weeks human / ~1 hour CC.")

Repo Ownership Mode — See Something, Say Something

REPO_MODE

• 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

~/.codex/skills/gstack/ETHOS.md

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: "EUREKA: Everyone does X because [assumption]. But [evidence] shows this is wrong. Y is better because [reasoning]."

Log eureka moments:

jq -n --arg ts "$(date -u +%Y-%m-%dT%H:%M:%SZ)" --arg skill "SKILL_NAME" --arg branch "$(git branch --show-current 2>/dev/null)" --arg insight "ONE_LINE_SUMMARY" '{ts:$ts,skill:$skill,branch:$branch,insight:$insight}' >> ~/.gstack/analytics/eureka.jsonl 2>/dev/null || true

Replace SKILL_NAME and ONE_LINE_SUMMARY. Runs inline — don't stop the workflow.

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

Contributor Mode

If

_CONTRIB

true

At the end of each major workflow step (not after every single command), reflect on the gstack 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 gstack 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(...)"

SyntaxError: await is only valid in async functions

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

~/.gstack/contributor-logs/{slug}.md

# {Title}

Hey gstack 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 gstack should have done differently}

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

Slug: lowercase, hyphens, max 60 chars (e.g.

browse-js-no-await

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]

Telemetry (run last)

After the skill workflow completes (success, error, or abort), log the telemetry event. Determine the skill name from the

name:

PLAN MODE EXCEPTION — ALWAYS RUN: This command writes telemetry to

~/.gstack/analytics/

Run this bash:

_TEL_END=$(date +%s)
_TEL_DUR=$(( _TEL_END - _TEL_START ))
rm -f ~/.gstack/analytics/.pending-"$_SESSION_ID" 2>/dev/null || true
~/.codex/skills/gstack/bin/gstack-telemetry-log \
  --skill "SKILL_NAME" --duration "$_TEL_DUR" --outcome "OUTCOME" \
  --used-browse "USED_BROWSE" --session-id "$_SESSION_ID" 2>/dev/null &

Replace

SKILL_NAME

OUTCOME

USED_BROWSE

$B

If

PROACTIVE

false

gstack-config

gstack 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)

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

If

NEEDS_SETUP

1. Tell the user: "gstack 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.)

# 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

$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

# 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

# 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

$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

$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)

# 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)

# 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

$B diff https://staging.app.com https://prod.app.com

Multi-step chain (efficient for long flows)

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

# 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

-a

$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

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

$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

goto

Command Reference

Navigation

back

forward

goto <url>

reload

url

Reading

accessibility

forms

html [selector]

links

text

Interaction

click <sel>

cookie <name>=<value>

cookie-import <json>

cookie-import-browser [browser] [--domain d]

dialog-accept [text]

dialog-dismiss

fill <sel> <val>

header <name>:<value>

hover <sel>

press <key>

scroll [sel]

select <sel> <val>

type <text>

upload <sel> <file> [file2...]

useragent <string>

viewport <WxH>

Inspection

cookies

css <sel> <prop>

dialog [--clear]

eval <file>

is <prop> <sel>

js <expr>

network [--clear]

perf

storage [set k v]

Visual

diff <url1> <url2>

pdf [path]

responsive [prefix]

Snapshot

snapshot [flags]

Meta

chain

Tabs

closetab [id]

newtab [url]

tab <id>

tabs

Server

handoff [message]

restart

resume

status

stop

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.