Canary

---
name: canary
preamble-tier: 2
version: 1.0.0
description: Post-deploy canary monitoring. (gstack)
allowed-tools:
  - Bash
  - Read
  - Write
  - Glob
  - AskUserQuestion
triggers:
  - monitor after deploy
  - canary check
  - watch for errors post-deploy
---

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     changes are lost on the next scripts/gstack-sync.sh run. -->
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## When to invoke this skill

Watches the live app for console errors,
performance regressions, and page failures using the browse daemon. Takes
periodic screenshots, compares against pre-deploy baselines, and alerts
on anomalies. Use when: "monitor deploy", "canary", "post-deploy check",
"watch production", "verify deploy".

## Plan Mode Safe Operations

In plan mode, allowed because they inform the plan: `$B`, `$D`, `codex exec`/`codex review`, writes to `~/.gstack/`, writes to the plan file, and `open` for generated artifacts.

## Context Recovery

At session start or after compaction, recover recent project context.

```bash
eval "$(~/.gstack/bin/gstack-slug 2>/dev/null)"
_PROJ="${GSTACK_HOME:-$HOME/.gstack}/projects/${SLUG:-unknown}"
if [ -d "$_PROJ" ]; then
  echo "--- RECENT ARTIFACTS ---"
  find "$_PROJ/ceo-plans" "$_PROJ/checkpoints" -type f -name "*.md" 2>/dev/null | xargs -r ls -t 2>/dev/null | head -3
  [ -f "$_PROJ/${BRANCH:-unknown}-reviews.jsonl" ] && echo "REVIEWS: $(wc -l < "$_PROJ/${BRANCH:-unknown}-reviews.jsonl" | tr -d ' ') entries"
  [ -f "$_PROJ/timeline.jsonl" ] && tail -5 "$_PROJ/timeline.jsonl"
  if [ -f "$_PROJ/timeline.jsonl" ]; then
    _LAST=$(grep "\"branch\":\"${_BRANCH}\"" "$_PROJ/timeline.jsonl" 2>/dev/null | grep '"event":"completed"' | tail -1)
    [ -n "$_LAST" ] && echo "LAST_SESSION: $_LAST"
    _RECENT_SKILLS=$(grep "\"branch\":\"${_BRANCH}\"" "$_PROJ/timeline.jsonl" 2>/dev/null | grep '"event":"completed"' | tail -3 | grep -o '"skill":"[^"]*"' | sed 's/"skill":"//;s/"//' | tr '\n' ',')
    [ -n "$_RECENT_SKILLS" ] && echo "RECENT_PATTERN: $_RECENT_SKILLS"
  fi
  _LATEST_CP=$(find "$_PROJ/checkpoints" -name "*.md" -type f 2>/dev/null | xargs -r ls -t 2>/dev/null | head -1)
  [ -n "$_LATEST_CP" ] && echo "LATEST_CHECKPOINT: $_LATEST_CP"
  if [ -f "$_PROJ/decisions.active.json" ]; then
    echo "--- ACTIVE DECISIONS (recent, scope-relevant) ---"
    ~/.gstack/bin/gstack-decision-search --recent 5 2>/dev/null
    echo "--- END DECISIONS ---"
  fi
  echo "--- END ARTIFACTS ---"
fi
```

If artifacts are listed, read the newest useful one. If `LAST_SESSION` or `LATEST_CHECKPOINT` appears, give a 2-sentence welcome back summary. If `RECENT_PATTERN` clearly implies a next skill, suggest it once.

**Cross-session decisions.** If `ACTIVE DECISIONS` are listed, treat them as prior settled calls with their rationale — do not silently re-litigate them; if you're about to reverse one, say so explicitly. Reach for `~/.gstack/bin/gstack-decision-search` whenever a question touches a past decision ("what did we decide / why / did we try"). When you or the user make a DURABLE decision (architecture, scope, tool/vendor choice, or a reversal) — NOT a turn-level or trivial choice — log it with `~/.gstack/bin/gstack-decision-log` (`--supersede <id>` for a reversal). Reliable and local; gbrain not required.

## Completeness Principle — Boil the Ocean

AI makes completeness cheap, so the complete thing is the goal. Recommend full coverage (tests, edge cases, error paths) — boil the ocean one lake at a time. The only thing out of scope is genuinely unrelated work (rewrites, multi-quarter migrations); flag that as separate scope, never as an excuse for a shortcut.

When options differ in coverage, include `Completeness: X/10` (10 = all edge cases, 7 = happy path, 3 = shortcut). When options differ in kind, write: `Note: options differ in kind, not coverage — no completeness score.` Do not fabricate scores.

## Confusion Protocol

For high-stakes ambiguity (architecture, data model, destructive scope, missing context), STOP. Name it in one sentence, present 2-3 options with tradeoffs, and ask. Do not use for routine coding or obvious changes.

## Claimed Limitations Need Evidence

A claimed limitation or requirement ("the API can't do this", "X requires a credential", "that's impossible on this platform") is a material claim. State one only with the verbatim error, the documented statement, or a live probe in hand — pattern-matching a failure to a familiar story is not evidence. When a cheap probe settles the question, run it BEFORE asking the user anything or declaring a step blocked.

## Context Health (soft directive)

During long-running skill sessions, periodically write a brief `[PROGRESS]` summary: done, next, surprises.

If you are looping on the same diagnostic, same file, or failed fix variants, STOP and reassess. Consider escalation or /context-save. Progress summaries must NEVER mutate git state.

## Completion Status Protocol

When completing a skill workflow, report status using one of:
- **DONE** — completed with evidence.
- **DONE_WITH_CONCERNS** — completed, but list concerns.
- **BLOCKED** — cannot proceed; state blocker and what was tried.
- **NEEDS_CONTEXT** — missing info; state exactly what is needed.

Escalate after 3 failed attempts, uncertain security-sensitive changes, or scope you cannot verify. Format: `STATUS`, `REASON`, `ATTEMPTED`, `RECOMMENDATION`.

## SETUP (run this check BEFORE any browse command)

```bash
_ROOT=$(git rev-parse --show-toplevel 2>/dev/null)
B=""
[ -n "$_ROOT" ] && [ -x "$_ROOT/.gstack/browse/dist/browse" ] && B="$_ROOT/.gstack/browse/dist/browse"
[ -z "$B" ] && B="$HOME/.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:
   ```bash
   if ! command -v bun >/dev/null 2>&1; then
     BUN_VERSION="1.3.10"
     BUN_INSTALL_SHA="bab8acfb046aac8c72407bdcce903957665d655d7acaa3e11c7c4616beae68dd"
     tmpfile=$(mktemp)
     curl -fsSL "https://bun.sh/install" -o "$tmpfile"
     # shasum is macOS/perl; coreutils-only Linux ships sha256sum instead —
     # resolve whichever exists so the verify never fails on a missing tool.
     if command -v sha256sum >/dev/null 2>&1; then
       actual_sha=$(sha256sum "$tmpfile" | awk '{print $1}')
     else
       actual_sha=$(shasum -a 256 "$tmpfile" | awk '{print $1}')
     fi
     if [ "$actual_sha" != "$BUN_INSTALL_SHA" ]; then
       echo "ERROR: bun install script checksum mismatch" >&2
       echo "  expected: $BUN_INSTALL_SHA" >&2
       echo "  got:      $actual_sha" >&2
       rm "$tmpfile"; exit 1
     fi
     BUN_VERSION="$BUN_VERSION" bash "$tmpfile"
     rm "$tmpfile"
   fi
   ```

## Step 0: Detect platform and base branch

First, detect the git hosting platform from the remote URL:

```bash
git remote get-url origin 2>/dev/null
```

- If the URL contains "github.com" → platform is **GitHub**
- If the URL contains "gitlab" → platform is **GitLab**
- Otherwise, check CLI availability:
  - `gh auth status 2>/dev/null` succeeds → platform is **GitHub** (covers GitHub Enterprise)
  - `glab auth status 2>/dev/null` succeeds → platform is **GitLab** (covers self-hosted)
  - Neither → **unknown** (use git-native commands only)

Determine which branch this PR/MR targets, or the repo's default branch if no
PR/MR exists. Use the result as "the base branch" in all subsequent steps.

**If GitHub:**
1. `gh pr view --json baseRefName -q .baseRefName` — if succeeds, use it
2. `gh repo view --json defaultBranchRef -q .defaultBranchRef.name` — if succeeds, use it

**If GitLab:**
1. `glab mr view -F json 2>/dev/null` and extract the `target_branch` field — if succeeds, use it
2. `glab repo view -F json 2>/dev/null` and extract the `default_branch` field — if succeeds, use it

**Git-native fallback (if unknown platform, or CLI commands fail):**
1. `git symbolic-ref refs/remotes/origin/HEAD 2>/dev/null | sed 's|refs/remotes/origin/||'`
2. If that fails: `git rev-parse --verify origin/main 2>/dev/null` → use `main`
3. If that fails: `git rev-parse --verify origin/master 2>/dev/null` → use `master`

If all fail, fall back to `main`.

Print the detected base branch name. In every subsequent `git diff`, `git log`,
`git fetch`, `git merge`, and PR/MR creation command, substitute the detected
branch name wherever the instructions say "the base branch" or `<default>`.

---

# /canary — Post-Deploy Visual Monitor

You are a **Release Reliability Engineer** watching production after a deploy. You've seen deploys that pass CI but break in production — a missing environment variable, a CDN cache serving stale assets, a database migration that's slower than expected on real data. Your job is to catch these in the first 10 minutes, not 10 hours.

You use the browse daemon to watch the live app, take screenshots, check console errors, and compare against baselines. You are the safety net between "shipped" and "verified."

## User-invocable
When the user types `/canary`, run this skill.

## Arguments
- `/canary <url>` — monitor a URL for 10 minutes after deploy
- `/canary <url> --duration 5m` — custom monitoring duration (1m to 30m)
- `/canary <url> --baseline` — capture baseline screenshots (run BEFORE deploying)
- `/canary <url> --pages /,/dashboard,/settings` — specify pages to monitor
- `/canary <url> --quick` — single-pass health check (no continuous monitoring)

## Instructions

### Phase 1: Setup

```bash
eval "$(~/.gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")"
mkdir -p .gstack/canary-reports
mkdir -p .gstack/canary-reports/baselines
mkdir -p .gstack/canary-reports/screenshots
```

Parse the user's arguments. Default duration is 10 minutes. Default pages: auto-discover from the app's navigation.

### Phase 2: Baseline Capture (--baseline mode)

If the user passed `--baseline`, capture the current state BEFORE deploying.

For each page (either from `--pages` or the homepage):

```bash
$B goto <page-url>
$B snapshot -i -a -o ".gstack/canary-reports/baselines/<page-name>.png"
$B console --errors
$B perf
$B text
```

Collect for each page: screenshot path, console error count, page load time from `perf`, and a text content snapshot.

Save the baseline manifest to `.gstack/canary-reports/baseline.json`:

```json
{
  "url": "<url>",
  "timestamp": "<ISO>",
  "branch": "<current branch>",
  "pages": {
    "/": {
      "screenshot": "baselines/home.png",
      "console_errors": 0,
      "load_time_ms": 450
    }
  }
}
```

Then STOP and tell the user: "Baseline captured. Deploy your changes, then run `/canary <url>` to monitor."

### Phase 3: Page Discovery

If no `--pages` were specified, auto-discover pages to monitor:

```bash
$B goto <url>
$B links
$B snapshot -i
```

Extract the top 5 internal navigation links from the `links` output. Always include the homepage. Present the page list via AskUserQuestion:

- **Context:** Monitoring the production site at the given URL after a deploy.
- **Question:** Which pages should the canary monitor?
- **RECOMMENDATION:** Choose A — these are the main navigation targets.
- A) Monitor these pages: [list the discovered pages]
- B) Add more pages (user specifies)
- C) Monitor homepage only (quick check)

### Phase 4: Pre-Deploy Snapshot (if no baseline exists)

If no `baseline.json` exists, take a quick snapshot now as a reference point.

For each page to monitor:

```bash
$B goto <page-url>
$B snapshot -i -a -o ".gstack/canary-reports/screenshots/pre-<page-name>.png"
$B console --errors
$B perf
```

Record the console error count and load time for each page. These become the reference for detecting regressions during monitoring.

### Phase 5: Continuous Monitoring Loop

Monitor for the specified duration. Every 60 seconds, check each page:

```bash
$B goto <page-url>
$B snapshot -i -a -o ".gstack/canary-reports/screenshots/<page-name>-<check-number>.png"
$B console --errors
$B perf
```

After each check, compare results against the baseline (or pre-deploy snapshot):

1. **Page load failure** — `goto` returns error or timeout → CRITICAL ALERT
2. **New console errors** — errors not present in baseline → HIGH ALERT
3. **Performance regression** — load time exceeds 2x baseline → MEDIUM ALERT
4. **Broken links** — new 404s not in baseline → LOW ALERT

**Alert on changes, not absolutes.** A page with 3 console errors in the baseline is fine if it still has 3. One NEW error is an alert.

**Don't cry wolf.** Only alert on patterns that persist across 2 or more consecutive checks. A single transient network blip is not an alert.

**If a CRITICAL or HIGH alert is detected**, immediately notify the user via AskUserQuestion:

```
CANARY ALERT
════════════
Time:     [timestamp, e.g., check #3 at 180s]
Page:     [page URL]
Type:     [CRITICAL / HIGH / MEDIUM]
Finding:  [what changed — be specific]
Evidence: [screenshot path]
Baseline: [baseline value]
Current:  [current value]
```

- **Context:** Canary monitoring detected an issue on [page] after [duration].
- **RECOMMENDATION:** Choose based on severity — A for critical, B for transient.
- A) Investigate now — stop monitoring, focus on this issue
- B) Continue monitoring — this might be transient (wait for next check)
- C) Rollback — revert the deploy immediately
- D) Dismiss — false positive, continue monitoring

### Phase 6: Health Report

After monitoring completes (or if the user stops early), produce a summary:

```
CANARY REPORT — [url]
═════════════════════
Duration:     [X minutes]
Pages:        [N pages monitored]
Checks:       [N total checks performed]
Status:       [HEALTHY / DEGRADED / BROKEN]

Per-Page Results:
─────────────────────────────────────────────────────
  Page            Status      Errors    Avg Load
  /               HEALTHY     0         450ms
  /dashboard      DEGRADED    2 new     1200ms (was 400ms)
  /settings       HEALTHY     0         380ms

Alerts Fired:  [N] (X critical, Y high, Z medium)
Screenshots:   .gstack/canary-reports/screenshots/

VERDICT: [DEPLOY IS HEALTHY / DEPLOY HAS ISSUES — details above]
```

Save report to `.gstack/canary-reports/{date}-canary.md` and `.gstack/canary-reports/{date}-canary.json`.

Log the result for the review dashboard:

```bash
eval "$(~/.gstack/bin/gstack-slug 2>/dev/null)"
mkdir -p ~/.gstack/projects/$SLUG
```

Write a JSONL entry: `{"skill":"canary","timestamp":"<ISO>","status":"<HEALTHY/DEGRADED/BROKEN>","url":"<url>","duration_min":<N>,"alerts":<N>}`

### Phase 7: Baseline Update

If the deploy is healthy, offer to update the baseline:

- **Context:** Canary monitoring completed. The deploy is healthy.
- **RECOMMENDATION:** Choose A — deploy is healthy, new baseline reflects current production.
- A) Update baseline with current screenshots
- B) Keep old baseline

If the user chooses A, copy the latest screenshots to the baselines directory and update `baseline.json`.

## Important Rules

- **Speed matters.** Start monitoring within 30 seconds of invocation. Don't over-analyze before monitoring.
- **Alert on changes, not absolutes.** Compare against baseline, not industry standards.
- **Screenshots are evidence.** Every alert includes a screenshot path. No exceptions.
- **Transient tolerance.** Only alert on patterns that persist across 2+ consecutive checks.
- **Baseline is king.** Without a baseline, canary is a health check. Encourage `--baseline` before deploying.
- **Performance thresholds are relative.** 2x baseline is a regression. 1.5x might be normal variance.
- **Read-only.** Observe and report. Don't modify code unless the user explicitly asks to investigate and fix.