candid-chrome-qa

Candid Chrome QA

Drive a real Chrome session against a running web app, find issues, and write structured findings to disk for downstream triage. Part of the Candid plugin's QA workflow — sits alongside /candid-review (code) and /candid-ship (release).

This is a technique skill. Follow the order. The schema is non-negotiable.

Inputs

When invoked, the user provides (or you confirm):

• goal — surface to test, e.g. "Agent Config / AI Setup, all 16 tabs". Skipped if --goal "<text>" is passed.
• prompt — free-form QA plan (what to exercise, edge cases, hot spots). Skipped if --prompt "<text>" is passed.
• app URL — usually http://localhost:<port>. Verify before you start. Skipped if the user passes --url or chromeQA.defaultUrl is set in .candid/config.json.

CLI flags (full set):

Flag	Purpose
--url <url>	Provide the app URL up front, skipping the prompt.
--goal "<text>"	Pre-fill the goal prompt. Skip the interactive ask.
--prompt "<text>"	Pre-fill the QA-plan prompt. Skip the interactive ask.
--routes "/p1,/p2"	Comma-separated list of routes to walk. Each becomes one target, bypassing goal-derived target inference.
--severity-floor P3	Persist only findings at or above this severity (P0 highest, P5 lowest). Default P5 (all). Findings below the floor are still walked and counted toward the summary block — they're just not appended to the file.
--viewports "1440x900,390x844"	Override chromeQA.desktopViewport / chromeQA.mobileViewport from config. First value = desktop, second = mobile.
--findings-dir <path>	Override findings output directory (default .context/findings). The directory is mkdir -p'd on each pass.
--mobile-only	Explicit opt-out from the desktop pass. Runs only the mobile pass. Documented exception to Hard Rule 6.
--desktop-only	Explicit opt-out from the mobile pass. Runs only the desktop pass. Second documented exception to Hard Rule 6.

--mobile-only and --desktop-only are mutually exclusive — if both are passed, error out and ask the user which one they meant.

If any required input is missing after flags + config, ask. Don't guess.

Pre-flight — MANDATORY before any QA work

Run in order. If any step fails, stop and surface to the user — do not invent workarounds.

0. Verify Claude in Chrome is available

Run ToolSearch with query: "mcp__claude-in-chrome". If it returns zero mcp__claude-in-chrome__* tools, stop:

Claude in Chrome MCP is not installed in this Claude Code environment.
Install it before running /candid-chrome-qa:
  https://github.com/anthropics/claude-in-chrome
Then restart Claude Code.

If it does return tools, batch-load every tool you'll need so subsequent calls don't pay per-tool ToolSearch overhead:

ToolSearch query: "select:mcp__claude-in-chrome__tabs_context_mcp,mcp__claude-in-chrome__tabs_create_mcp,mcp__claude-in-chrome__resize_window,mcp__claude-in-chrome__navigate,mcp__claude-in-chrome__read_page,mcp__claude-in-chrome__read_console_messages,mcp__claude-in-chrome__read_network_requests,mcp__claude-in-chrome__javascript_tool"

1. Load project context

• If Technical.md exists in the project root, read it and note any QA-relevant rules: browser support matrix, accessibility target (WCAG A/AA/AAA), API base path, design-system constraints, auth setup. Use these rules during the pass — every Technical.md violation you find should be a finding tagged with surface: "Technical.md" and category matching the rule's domain.

• If .candid/config.json exists, read the optional chromeQA block:

  {
    "chromeQA": {
      "defaultUrl": "http://localhost:3000",
      "apiPathPattern": "/api/",
      "desktopViewport": "1440x900",
      "mobileViewport": "390x844"
    }
  }
  

  All fields optional. Defaults: URL prompted, apiPathPattern: "/api/", viewports as shown.

  Precedence: --viewports CLI flag > chromeQA.desktopViewport/chromeQA.mobileViewport config > built-in defaults. --findings-dir CLI flag overrides the built-in .context/findings path. Record the resolved viewports and output directory in context.environment of the findings file so re-runs are reproducible.

2. Verify the dev server

curl -s -o /dev/null -w "%{http_code}" <url>. Anything other than 2xx/3xx → ask the user to start it. The HTTP code is the source of truth — don't run lsof or process probes.

3. Get tab context and reuse policy

mcp__claude-in-chrome__tabs_context_mcp. Re-use a tab only if the user explicitly says so; otherwise create a fresh tab with tabs_create_mcp.

4. Resize to desktop default

resize_window to the configured desktopViewport (default 1440x900).

5. Navigate

navigate to the app URL. Wait 2s for the initial render to settle.

6. Confirm logged-in state

read_page interactive or javascript_tool for ({url: location.href, title: document.title}). If on a login or onboarding route, ask the user explicitly:

You're on <url>. Should I:
  (a) Wait while you log in (then continue),
  (b) Switch to a different account / URL, or
  (c) Stop?

Do not attempt to log in for them.

7. Clear console baseline

read_console_messages with pattern: ".", clear: true — sets the high-water mark so per-target probes only show fresh entries.

8. Verify required data

If the goal touches lists/details that need seeded data and the account is empty, ask the user: create test data, seed via fixture, switch accounts, or downgrade to source-review. Do not silently switch to source review.

9. Open the findings file

1. Resolve the output directory: --findings-dir <path> if passed, else .context/findings. Make the directory: mkdir -p <dir>.
2. Generate the slug from goal: lowercase the first 4 words, replace non-alphanumerics with -, collapse repeated -, trim trailing -, truncate to 40 chars. Example: goal "Agent Config / AI Setup, all 16 tabs" → agent-config-ai-setup.
3. Choose the filename: <dir>/<YYYY-MM-DD>-<slug>.json. If that file already exists, switch to <YYYY-MM-DD>-<HHmm>-<slug>.json (current local time, 24h). Never overwrite a prior pass.
4. Write the initial schema with findings: [], the context block populated, and summary omitted (it's added at end-of-pass). Append findings to disk after each one — never batch-write at the end.

Per-target loop (one route or one tab at a time)

Target selection:

• If --routes "/p1,/p2,/p3" was passed, the target list is exactly those routes (each one a target). Bypasses goal-derived routing.
• Otherwise, derive targets from goal + prompt as today (sidebar nav inferred from read_page interactive plus user-named surfaces).

For each target, use the flush-capture cycle so each step's telemetry is clean:

1. Navigate / click into target. Use sidebar buttons rather than direct URL when the app has client-side routing.
2. Flush telemetry. read_network_requests({clear: true}) and read_console_messages({pattern: ".", clear: true}) — discard prior chatter.
3. read_page interactive to enumerate elements.
4. Action. Exercise 2–3 main interactions (toggle, type, save, cancel) and 1 edge case (empty input, invalid format, rapid double-click, navigation while dirty).
5. Wait 1–2s for in-flight requests to complete.
6. Capture telemetry.
   • read_console_messages({pattern: "error|warn|fail|hydration|nested|aria|deprecat|key"}) — apply console triage table below.
   • read_network_requests({urlPattern: "<chromeQA.apiPathPattern>"}) (default /api/; or supabase, or whatever Technical.md / config indicates) — apply network health thresholds below.
   • Fallback if entries are redacted ([BLOCKED: Cookie/query string data]): run javascript_tool with performance.getEntriesByType('resource').filter(r => r.responseStatus >= 400 || r.responseStatus === 0).map(r => ({url: r.name, status: r.responseStatus, type: r.initiatorType})) to recover full URLs from inside the page.
7. Append findings. Each finding written to disk immediately, not buffered. Severity floor: if --severity-floor <P> was passed (default P5 = all), drop findings whose severity is below the floor at this step. Severity order, highest first: P0 > P1 > P2 > P3 > P4 > P5. Findings dropped at this step are still counted in the end-of-pass summary block — they just don't land in the findings array. This keeps the summary honest about what was walked.
8. Reset state if you mutated something that affects subsequent targets (escape dirty-form modals via Discard, etc.).

If a target produces no findings, append a single confidence: "definite", severity: "P5", title: "✓ no issues — probes ran clean" finding so coverage is provable.

Console triage table

Console output	Severity
Uncaught TypeError / ReferenceError	P0
Unhandled Promise rejection	P0
React: "Cannot update a component while rendering a different component"	P1
React: "Each child in a list should have a unique 'key' prop" (if data-dependent)	P1
Hydration mismatch (<button> inside <button>, etc.)	P2
CORS policy errors	P1
Any Error: in red not in the ignorable list	P1
componentWillMount/findDOMNode deprecation	P2
"Can't perform a React state update on an unmounted component"	P2
Large-payload performance warnings	P3
Ignorable: "Download the React DevTools", /favicon.ico 404, source map warnings, Clerk dev-mode warning, third-party analytics errors	skip

Network health thresholds

Metric	Good	Concerning	Bad
Error rate (4xx/5xx)	< 1%	1–5%	> 5%
Avg response time	< 200 ms	200 ms – 1 s	> 1 s
Payload per request	< 100 KB	100 KB – 1 MB	> 1 MB
Duplicate requests within 200 ms	0	1–2	3+ identical

Anything in Bad → P0/P1. Concerning → P2/P3.

Edge-case bug patterns to probe

When picking your "1 edge case" per target, reach for one of these — they catch the majority of production-only failures:

• Race condition — fire 3+ identical requests within 500 ms (rapid double-click save). Look for mixed 200/500 on the same endpoint.
• Stale state — mutate → navigate away → come back. Does it show the new data? Missing re-fetch after mutation = stale state.
• Silent failure — perform action that returns 200, then refresh and verify the change actually persisted. Optimistic UI lies.
• Memory drift — repeat an action 20× and snapshot document.querySelectorAll('*').length early vs late. Significant growth = leak.
• Idle WebSocket — for real-time features, idle 60s and check console for close events without reconnect. Skip on multi-target passes (>5 targets) unless the user explicitly asks — a 60s idle per target adds up fast.

Cross-cutting probes — run once per pass

Use javascript_tool to probe the DOM systematically. These catch things click-by-click won't.

// A11y probe — count and enumerate
({
  iconButtonsNoLabel: Array.from(document.querySelectorAll('button')).filter(b =>
    !b.innerText.trim() && !b.getAttribute('aria-label') && !b.getAttribute('aria-labelledby')).length,
  imagesNoAlt: Array.from(document.querySelectorAll('img')).filter(i => !i.alt && i.getAttribute('aria-hidden') !== 'true').length,
  inputsNoLabel: Array.from(document.querySelectorAll('input, textarea, select')).filter(i => {
    if (i.type === 'hidden') return false;
    if (i.getAttribute('aria-label') || i.getAttribute('aria-labelledby')) return false;
    if (i.id && document.querySelector('label[for="'+i.id+'"]')) return false;
    return !i.closest('label');
  }).length
})

// Touch-target probe (mobile only)
Array.from(document.querySelectorAll('button, a, [role="button"]'))
  .map(el => ({label: (el.innerText||el.getAttribute('aria-label')||'').slice(0,40), w: el.offsetWidth, h: el.offsetHeight}))
  .filter(x => x.w > 0 && (x.w < 44 || x.h < 44))
  .slice(0,15)

Mobile pass — required by default

After desktop pass:

1. resize_window to the configured mobileViewport (default 390x844).
2. Re-walk the 5 most-used targets (or user-specified subset).
3. Run the touch-target probe above.
4. Note layout overflow, hidden CTAs, modal dismissal, keyboard behaviour for inputs, fixed-position elements that overlap content.

Resize ceiling fallback: Chrome may enforce a minimum content width of ~1075 px on the active tab depending on UI chrome. If resize_window to 390 wide doesn't take effect, try the smallest you can reach (often ~500 px) — the mobile breakpoint still triggers, the desktop sidebar still hides, and the hamburger drawer still appears. Note the actual width reached in the finding's evidence.

--mobile-only flag inverts the default: skip the desktop pass entirely and run only the mobile sequence above. This is an explicit opt-out of Hard Rule 6 (which forbids running mobile without desktop). Use sparingly — most QA passes need both.

--desktop-only flag skips the mobile pass entirely. Use when the surface is admin-only, internal tooling, or otherwise has no mobile contract to honor. Like --mobile-only, it's an explicit opt-out — without the flag, mobile is required.

--mobile-only + --desktop-only are mutually exclusive. If both are passed, error and ask the user which one they meant. Don't silently pick one.

Hot-spot stress — when the user provides recent commits or known weak points

For each: drive the recently-changed surface harder. Resize to 700px tall to stress sidebar/scroll fixes; switch orgs mid-edit to stress org-scope; trigger validation; double-click save.

Output schema (v2.0) — exact, do not modify

Every finding file looks like this. Producers write the schemaVersion, context, findings, and (at end of pass) summary blocks. Consumers should target schemaVersion: "2.0".

{
  "schemaVersion": "2.0",
  "context": {
    "createdAt": "2026-04-25T18:30:00Z",
    "scope": "Agent Config / AI Setup, all 16 tabs",
    "originatingPrompt": "Walk every tab; exercise save/cancel; hammer phone provisioning",
    "environment": {
      "url": "http://localhost:3000",
      "branch": "feature/agent-config-v2",
      "commit": "8001a89",
      "viewport": "1440x900",
      "agentModel": "claude-opus-4-7"
    }
  },
  "findings": [
    {
      "id": "F-a3f29b71",
      "severity": "P0",
      "category": "bug",
      "surface": "dashboard/agents/[id]/voice",
      "viewport": "both",
      "url": "http://localhost:3000/dashboard/agents/agent_123/voice",
      "title": "Save button does nothing on Voice tab when phone is unprovisioned",
      "repro": "1. Open agent\n2. Voice tab\n3. Click Save",
      "expected": "Either save or show validation error",
      "actual": "Click registers, no network call, no error, no state change",
      "evidence": {
        "consoleErrors": [
          {"level": "warn", "message": "[react-hook-form] missing required: phoneNumber"}
        ],
        "networkRequests": [
          {"method": "POST", "url": "/api/agents/agent_123", "status": 0, "durationMs": 0}
        ],
        "filesLikelyTouched": ["app/src/components/agent/VoiceTab.tsx:142"]
      },
      "suggestedFix": "Surface the form validation error in the UI; current handler swallows it",
      "groupHint": "form-state",
      "confidence": "definite",
      "capturedAt": "2026-04-25T18:34:12Z"
    }
  ],
  "summary": {
    "total": 19,
    "bySeverity": {"p0": 2, "p1": 5, "p2": 8, "p3": 2, "p4": 1, "p5": 1},
    "byCategory": {"bug": 8, "a11y": 4, "perf": 2, "ux": 3, "copy": 1, "security": 0, "compat": 1}
  }
}

Required per-finding fields

id, severity, category, surface, viewport, url, title, repro, expected, actual, suggestedFix, groupHint, confidence, capturedAt. evidence is optional but include any non-obvious signal you captured.

Enum values (use exactly these strings)

• severity: "P0", "P1", "P2", "P3", "P4", "P5"
• category: "bug", "a11y", "perf", "ux", "copy", "security", "compat"
• viewport: "desktop", "mobile", "both"
• confidence: "definite", "likely", "suspected" (default "definite" if uncertain)
• evidence.consoleErrors[].level: "error", "warn", "info"

ID generation (deterministic — enables dedup across passes)

id is F- + the first 8 hex chars of the SHA-1 of <url>|<title>. Example: F-a3f29b71. Use javascript_tool to compute it inside the page if needed:

crypto.subtle.digest('SHA-1', new TextEncoder().encode(`${url}|${title}`))
  .then(buf => 'F-' + Array.from(new Uint8Array(buf)).slice(0,4).map(b => b.toString(16).padStart(2,'0')).join(''))

Same finding (same URL + same title) in a re-run gets the same ID — downstream tools can dedup.

Severity scale

Maps to Linear priority:

Severity	Meaning	Linear
P0	feature broken, blocks user	Urgent
P1	clear bug or a11y violation	High
P2	UX polish	Medium
P3	perf concern	Medium
P4	copy / wording	Low
P5	enhancement idea	No priority

groupHint is a short slug shared across related findings — used by downstream tools to bundle into one workspace. Examples: form-state, phone-provisioning, analytics-defaults, mobile-layout. If a finding is unique, use a unique slug.

Schema migration note: This is v2.0. Downstream consumers must target schemaVersion: "2.0". v1 fields (body, status, tag, stringified consoleErrors/networkRequests) are dropped — consumers expecting them will break. The body field (rendered markdown view) is gone — render from the structured fields at read time. The status field is gone — finding lifecycle is the consumer's concern.

Final summary — required at end of pass

After the last finding is appended, before reporting back to the user, do all of the following atomically (do not declare done until every step lands):

1. Compute counts from the file's findings array.
2. Write the summary block to the JSON file. Preserve top-level key order: schemaVersion, context, findings, summary.
3. Mentally JSON.parse the file: scan for trailing commas, unquoted keys, unbalanced braces, missing required per-finding fields.
4. Print to stdout in this exact format. Always print all 6 severity rows and all 7 category rows (0 is meaningful — it documents what was looked for).

Chrome QA pass: <scope>
Total findings: <N>

Severity:
  P0 (urgent):   <n>
  P1 (high):     <n>
  P2 (medium):   <n>
  P3 (perf):     <n>
  P4 (copy):     <n>
  P5 (idea):     <n>

Category:
  bug:      <n>
  a11y:     <n>
  perf:     <n>
  ux:       <n>
  copy:     <n>
  security: <n>
  compat:   <n>

Top issues (P0 + P1):
  • [P0] <title> — <url>
  • [P1] <title> — <url>
  ...

Findings file: .context/findings/<filename>.json

If there are zero P0 and zero P1 findings, replace the "Top issues" block with Top issues: none — no P0/P1. If the entire pass has zero findings (every target appended a ✓ no issues entry), still print the format above with all rows showing 0, then add a final line: Result: clean pass.

The JSON file is always the source of truth — stdout is a courtesy for users who don't run a triage tool.

Hard rules — do not violate

1. Never click destructive actions without explicit user approval each time: delete agent/account, disconnect Twilio/integrations, drop data, irreversible API operations, "force send", "publish", "purchase".
2. Never silently downgrade from live QA to source-only review. If data is missing, ask.
3. Never invent the schema. Use the v2.0 schema above byte-for-byte. Downstream consumers depend on it.
4. Never batch-write findings at the end. Append per-finding. Context can exhaust mid-pass.
5. Never claim "no issues" without running the cross-cutting probes. A ✓ no issues — probes ran clean finding is fine; skipping the probes is not.
6. Never resize to mobile without first finishing desktop. Mobile is additive, not a substitute. Exceptions: --mobile-only skips the desktop pass entirely; --desktop-only skips the mobile pass entirely. Both are explicit opt-outs — without one, run both. Passing both flags is an error — ask the user which they meant.
7. Never use a stale tab. Always tabs_context_mcp first. If reusing a tab, confirm with the user.
8. Never proceed without verifying Claude in Chrome is loaded (Pre-flight step 0). Without it, every subsequent tool call fails opaquely.

Stop conditions

Finished when all of:

• Every target in goal has at least one finding entry (real finding OR ✓ no issues — probes ran clean).
• Hot-spot tests requested by the user each have explicit ✓ or finding.
• Mobile pass covers the agreed subset (or --mobile-only was passed and you ran only mobile).
• Cross-cutting probes ran on at least one representative page.
• File on disk validates: mentally simulate JSON.parse. Reject if you spot trailing commas, unquoted keys, unbalanced braces, or any per-finding missing a required field.
• summary block populated at end of pass.
• Stdout summary printed.

If you hit a hard blocker (server down mid-pass, dirty-state trap, unrecoverable error), stop and surface — do not work around it silently.

Common rationalizations — STOP if you catch yourself

Excuse	Reality
"I'll write the schema my way, it's clearer"	Downstream consumers target schemaVersion: "2.0" — your custom fields get dropped, and missing v2-required fields break triage.
"Source review is fine since data is missing"	Silent downgrade. Ask first.
"I'll batch findings at the end for cleanliness"	Context exhausts. Findings lost. Append per-finding.
"Mobile is similar to desktop, skip it"	Found mobile-only bugs ~30% of pass. Don't skip unless --mobile-only was passed.
"Console looks clean, skip the probe"	Probes catch DOM-level a11y issues clicks miss. Run them.
"Click-tested ~all interactions, no need for edge cases"	Edge cases (empty/invalid/rapid-double-click) are where the bugs live. Run at least one per target.
"User said skip the pre-flight"	They didn't. Ask before skipping.
"I'll add body back, it's cleaner for humans"	v2 dropped body deliberately — pure derivation. Render at consumption time.
"I'll skip the stdout summary, the JSON has the data"	The summary is the pass's headline. Users without a triage tool need it.
"I'll use 'P0|P1|P2' as the severity since the schema example showed it"	The schema example shows real values like "P0". Pipe-delimited strings are TypeScript-style enum docs, not JSON values. Use one exact string.
"I don't need mkdir -p — the directory probably exists"	It probably doesn't. Make it explicitly.
"User passed --severity-floor P0 so I'll skip walking the lower-severity stuff"	Wrong layer. Walk everything; drop only at the persist step (#7). The summary block must reflect the full walk, otherwise Top issues: none becomes a lie when there were P3s you skipped.
"I'll silently override --viewports if the second value won't fit"	Use the resize-ceiling fallback (mobile-pass section) and record the actual width reached in the finding's evidence. Never silently change user-provided viewports.
"User passed --routes so I'll skip the cross-cutting probes"	Cross-cutting probes still run once per pass. --routes narrows the per-target loop, not the probes.

Red flags — STOP and re-read this skill

• About to write findings without repro/expected/actual structure
• About to skip the desktop pass without --mobile-only having been passed
• About to invent a new top-level field in the JSON
• About to click "Delete" / "Disconnect" / "Force" without asking
• About to silently use a stale tab from a prior session
• About to skip the final summary (JSON summary block + stdout block)
• About to call mcp__claude-in-chrome__* without having run Pre-flight step 0
• About to write "P0|P1|P2|P3|P4|P5" as the value of a severity field

All of these mean: stop, re-read the relevant section, follow the protocol.