act-sdk-js: Skill for Codex

.agents/skills/gstack-canary/SKILL.md

canary is a skill for Codex from act-sdk/act-sdk-js. It costs 90 tokens per session (5,254 once invoked), scanned C, a copy of canary, MIT.

A manually triggered guide for monitoring a deployed application after release. It uses periodic screenshots and browser checks to look for console errors, slowdowns, and failed pages.

In plain words
What is it for?
Use it after a deployment when you explicitly run /canary and want ongoing checks for visual changes, browser errors, performance regressions, or page failures.
Why use it?
It helps detect problems that appear only in the live application after deployment. It can compare the live site with screenshots captured before the release.

Skill for Codex

Written for Codex: agents/openai.yaml present. Also seen: names the AskUserQuestion tool; installed under .agents/ (shared by several agents); mentions Codex.

This is act-sdk/act-sdk-js's own configuration. It tells Codex how to work on act-sdk-js itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything act-sdk-js configures →

Reuse

Borrowing it

Nothing to install: this file belongs to act-sdk/act-sdk-js. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/act-sdk/act-sdk-js/main/.agents/skills/gstack-canary/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/act-sdk/act-sdk-js

Made for: Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for canary

README.md
[![agentmods](https://agentmods.dev/badge/skills/act-sdk/act-sdk-js/gstack-canary/github.svg)](https://agentmods.dev/skills/act-sdk/act-sdk-js/gstack-canary)
Your own site
<a href="https://agentmods.dev/skills/act-sdk/act-sdk-js/gstack-canary"><img src="https://agentmods.dev/badge/skills/act-sdk/act-sdk-js/gstack-canary/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for canary

Your own site · 80×15
<a href="https://agentmods.dev/skills/act-sdk/act-sdk-js/gstack-canary"><img src="https://agentmods.dev/badge/skills/act-sdk/act-sdk-js/gstack-canary.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 90 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,254 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 2 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 97% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00090 $0.05254
Opus 5.5 $0.00036 $0.02102
Sonnet 5.5 $0.00018 $0.01051
Haiku 4.5 $0.00009 $0.00525

Measured 1mo ago against content hash 79a49843f880, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade C, and why

canary scanned grade C with 2 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Downloads and executes remote codehighSupply chain

curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.

3. If `bun` is not installed: `curl -fsSL https://bun.sh/install | bash`

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

3. If `bun` is not installed: `curl -fsSL https://bun.sh/install | bash`
Origin

This is a copy

97% identical to canary — 49 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/gstack-canary/SKILL.md · 469 lines

How it starts

The opening of the file, as written. The whole thing — 469 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Preamble (run first)

_ROOT=$(git rev-parse --show-toplevel 2>/dev/null)
GSTACK_ROOT="$HOME/.codex/skills/gstack"
[ -n "$_ROOT" ] && [ -d "$_ROOT/.agents/skills/gstack" ] && GSTACK_ROOT="$_ROOT/.agents/skills/gstack"
GSTACK_BIN="$GSTACK_ROOT/bin"
GSTACK_BROWSE="$GSTACK_ROOT/browse/dist"
_UPD=$($GSTACK_BIN/gstack-update-check 2>/dev/null || .agents/skills/gstack/bin/gstack-update-check 2>/dev/null || true)
[ -n "$_UPD" ] && echo "$_UPD" || true
mkdir -p ~/.gstack/sessions
touch ~/.gstack/sessions/"$PPID"
_SESSIONS=$(find ~/.gstack/sessions -mmin -120 -type f 2>/dev/null | wc -l | tr -d ' ')
find ~/.gstack/sessions -mmin +120 -type f -delete 2>/dev/null || true
_CONTRIB=$($GSTACK_BIN/gstack-config get gstack_contributor 2>/dev/null || true)
_PROACTIVE=$($GSTACK_BIN/gstack-config get proactive 2>/dev/null || echo "true")
_BRANCH=$(git branch --show-current 2>/dev/null || echo "unknown")
echo "BRANCH: $_BRANCH"
echo "PROACTIVE: $_PROACTIVE"
source <($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: $_LAKE_SEEN"
_TEL=$($GSTACK_BIN/gstack-config get telemetry 2>/dev/null || true)
_TEL_PROMPTED=$([ -f ~/.gstack/.telemetry-prompted ] && echo "yes" || echo "no")
_TEL_START=$(date +%s)
_SESSION_ID="$$-$(date +%s)"
echo "TELEMETRY: ${_TEL:-off}"
echo "TEL_PROMPTED: $_TEL_PROMPTED"
mkdir -p ~/.gstack/analytics
echo '{"skill":"canary","ts":"'$(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
# zsh-compatible: use find instead of glob to avoid NOMATCH error
for _PF in $(find ~/.gstack/analytics -maxdepth 1 -name '.pending-*' 2>/dev/null); do [ -f "$_PF" ] && $GSTACK_BIN/gstack-telemetry-log --event-type skill_run --skill _pending_finalize --outcome unknown --session-id "$_SESSION_ID" 2>/dev/null || true; break; done

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

If output shows UPGRADE_AVAILABLE <old> <new>: read $GSTACK_ROOT/gstack-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 gstack v{to} (just updated!)" and continue.

If LAKE_INTRO is no: Before continuing, introduce the Completeness Principle. Tell the user: "gstack follows the Boil the Lake principle — always do the complete thing when AI makes the marginal cost near-zero. Read more: https://garryslist.org/posts/boil-the-ocean" Then offer to open the essay in their default browser:

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

Only run open if the user says yes. Always run touch to mark as seen. This only happens once.

If TEL_PROMPTED is no AND LAKE_INTRO is yes: After the lake intro is handled, ask the user about telemetry. Use AskUserQuestion:

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 $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

Read the full file on GitHub · 469 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 1mo ago First seen · 469 lines · 90 tokens per session scan C 79a49843f880

Subscribe to this mod's changes

canary is a skill published in the GitHub repository act-sdk/act-sdk-js (3 stars, last pushed 4mo ago), licensed MIT. It adds 90 tokens to every session and 5,254 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it C with 2 findings (downloads and executes remote code, makes network calls). It is 97% identical to canary, differing in 49 lines, and is treated as a copy.

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