benchmark

name	benchmark
preamble-tier	1
version	1.0.0
description	Performance regression detection using the browse daemon. Establishes baselines for page load times, Core Web Vitals, and resource sizes. Compares before/after on every PR. Tracks performance trends over time. Use when: "performance", "benchmark", "page speed", "lighthouse", "web vitals", "bundle size", "load time". (Nexus)
allowed-tools	["Bash","Read","Write","Glob","AskUserQuestion"]

Preamble (run first)

_UPD=$(~/.claude/skills/nexus/bin/nexus-update-check 2>/dev/null || .claude/skills/nexus/bin/nexus-update-check 2>/dev/null || true)
[ -n "$_UPD" ] && echo "$_UPD" || true
mkdir -p ~/.nexus/sessions
touch ~/.nexus/sessions/"$PPID"
_SESSIONS=$(find ~/.nexus/sessions -mmin -120 -type f 2>/dev/null | wc -l | tr -d ' ')
find ~/.nexus/sessions -mmin +120 -type f -exec rm {} + 2>/dev/null || true
_CONTRIB=$(~/.claude/skills/nexus/bin/nexus-config get nexus_contributor 2>/dev/null || true)
_PROACTIVE=$(~/.claude/skills/nexus/bin/nexus-config get proactive 2>/dev/null || echo "true")
_PROACTIVE_PROMPTED=$([ -f ~/.nexus/.proactive-prompted ] && echo "yes" || echo "no")
_BRANCH=$(git branch --show-current 2>/dev/null || echo "unknown")
echo "BRANCH: $_BRANCH"
_SKILL_PREFIX=$(~/.claude/skills/nexus/bin/nexus-config get skill_prefix 2>/dev/null || echo "false")
echo "PROACTIVE: $_PROACTIVE"
echo "PROACTIVE_PROMPTED: $_PROACTIVE_PROMPTED"
echo "SKILL_PREFIX: $_SKILL_PREFIX"
_MODE_CONFIGURED=$(~/.claude/skills/nexus/bin/nexus-config get execution_mode 2>/dev/null || true)
_PRIMARY_PROVIDER_CONFIG=$(~/.claude/skills/nexus/bin/nexus-config get primary_provider 2>/dev/null || true)
_TOPOLOGY_CONFIG=$(~/.claude/skills/nexus/bin/nexus-config get provider_topology 2>/dev/null || true)
if command -v ask >/dev/null 2>&1; then
  _CCB_AVAILABLE="yes"
else
  _CCB_AVAILABLE="no"
fi
if [ -n "$_MODE_CONFIGURED" ]; then
  _EXECUTION_MODE="$_MODE_CONFIGURED"
  _EXECUTION_MODE_CONFIGURED="yes"
else
  _EXECUTION_MODE_CONFIGURED="no"
  if [ "$_CCB_AVAILABLE" = "yes" ]; then
    _EXECUTION_MODE="governed_ccb"
  else
    _EXECUTION_MODE="local_provider"
  fi
fi
if [ "$_EXECUTION_MODE" = "governed_ccb" ]; then
  _PRIMARY_PROVIDER="codex"
  _PROVIDER_TOPOLOGY="multi_session"
else
  if [ -n "$_PRIMARY_PROVIDER_CONFIG" ]; then
    _PRIMARY_PROVIDER="$_PRIMARY_PROVIDER_CONFIG"
  elif command -v claude >/dev/null 2>&1; then
    _PRIMARY_PROVIDER="claude"
  elif command -v codex >/dev/null 2>&1; then
    _PRIMARY_PROVIDER="codex"
  elif command -v gemini >/dev/null 2>&1; then
    _PRIMARY_PROVIDER="gemini"
  else
    _PRIMARY_PROVIDER="claude"
  fi
  if [ -n "$_TOPOLOGY_CONFIG" ]; then
    _PROVIDER_TOPOLOGY="$_TOPOLOGY_CONFIG"
  else
    _PROVIDER_TOPOLOGY="single_agent"
  fi
fi
_EFFECTIVE_EXECUTION=$(~/.claude/skills/nexus/bin/nexus-config effective-execution 2>/dev/null || true)
if [ -n "$_EFFECTIVE_EXECUTION" ]; then
  _EXECUTION_MODE=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^execution_mode:/{print $2; exit}')
  _EXECUTION_MODE_CONFIGURED=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^execution_mode_configured:/{print $2; exit}')
  _PRIMARY_PROVIDER=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^effective_primary_provider:/{print $2; exit}')
  _PROVIDER_TOPOLOGY=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^effective_provider_topology:/{print $2; exit}')
  _EXECUTION_MODE_SOURCE=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^execution_mode_source:/{print $2; exit}')
  _EXECUTION_PATH=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^effective_requested_execution_path:/{print $2; exit}')
  _CURRENT_SESSION_READY=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^current_session_ready:/{print $2; exit}')
  _REQUIRED_GOVERNED_PROVIDERS=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^required_governed_providers:/{print $2; exit}')
  _GOVERNED_READY=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^governed_ready:/{print $2; exit}')
  _MOUNTED_PROVIDERS=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^mounted_providers:/{print $2; exit}')
  _MISSING_PROVIDERS=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^missing_providers:/{print $2; exit}')
  _LOCAL_PROVIDER_CANDIDATE=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^local_provider_candidate:/{print $2; exit}')
  _LOCAL_PROVIDER_TOPOLOGY=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^local_provider_topology:/{print $2; exit}')
  _LOCAL_PROVIDER_EXECUTION_PATH=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^local_provider_requested_execution_path:/{print $2; exit}')
  _LOCAL_PROVIDER_READY=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^local_provider_ready:/{print $2; exit}')
  _LOCAL_CLAUDE_AGENT_TEAM_READY=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^local_claude_agent_team_ready:/{print $2; exit}')
  _LOCAL_CLAUDE_AGENT_TEAM_REASON=$(printf '%s
' "$_EFFECTIVE_EXECUTION" | awk -F': ' '/^local_claude_agent_team_readiness_reason:/{print $2; exit}')
else
  _EXECUTION_MODE_SOURCE=""
  _EXECUTION_PATH=""
  _CURRENT_SESSION_READY="unknown"
  _REQUIRED_GOVERNED_PROVIDERS=""
  _GOVERNED_READY=""
  _MOUNTED_PROVIDERS=""
  _MISSING_PROVIDERS=""
  _LOCAL_PROVIDER_CANDIDATE=""
  _LOCAL_PROVIDER_TOPOLOGY=""
  _LOCAL_PROVIDER_EXECUTION_PATH=""
  _LOCAL_PROVIDER_READY=""
  _LOCAL_CLAUDE_AGENT_TEAM_READY=""
  _LOCAL_CLAUDE_AGENT_TEAM_REASON=""
fi
echo "CCB_AVAILABLE: $_CCB_AVAILABLE"
echo "EXECUTION_MODE: $_EXECUTION_MODE"
echo "EXECUTION_MODE_CONFIGURED: $_EXECUTION_MODE_CONFIGURED"
echo "EXECUTION_MODE_SOURCE: $_EXECUTION_MODE_SOURCE"
echo "PRIMARY_PROVIDER: $_PRIMARY_PROVIDER"
echo "PROVIDER_TOPOLOGY: $_PROVIDER_TOPOLOGY"
echo "EXECUTION_PATH: $_EXECUTION_PATH"
echo "CURRENT_SESSION_READY: $_CURRENT_SESSION_READY"
echo "REQUIRED_GOVERNED_PROVIDERS: $_REQUIRED_GOVERNED_PROVIDERS"
echo "GOVERNED_READY: $_GOVERNED_READY"
echo "MOUNTED_PROVIDERS: $_MOUNTED_PROVIDERS"
echo "MISSING_PROVIDERS: $_MISSING_PROVIDERS"
echo "LOCAL_PROVIDER_CANDIDATE: $_LOCAL_PROVIDER_CANDIDATE"
echo "LOCAL_PROVIDER_TOPOLOGY: $_LOCAL_PROVIDER_TOPOLOGY"
echo "LOCAL_PROVIDER_EXECUTION_PATH: $_LOCAL_PROVIDER_EXECUTION_PATH"
echo "LOCAL_PROVIDER_READY: $_LOCAL_PROVIDER_READY"
echo "LOCAL_CLAUDE_AGENT_TEAM_READY: $_LOCAL_CLAUDE_AGENT_TEAM_READY"
echo "LOCAL_CLAUDE_AGENT_TEAM_REASON: $_LOCAL_CLAUDE_AGENT_TEAM_REASON"
source <(~/.claude/skills/nexus/bin/nexus-repo-mode 2>/dev/null) || true
REPO_MODE=${REPO_MODE:-unknown}
echo "REPO_MODE: $REPO_MODE"
_LAKE_SEEN=$([ -f ~/.nexus/.completeness-intro-seen ] && echo "yes" || echo "no")
echo "LAKE_INTRO: $_LAKE_SEEN"
# Learnings count
eval "$(~/.claude/skills/nexus/bin/nexus-slug 2>/dev/null)" 2>/dev/null || true
_LEARN_FILE="$HOME/.nexus/projects/${SLUG:-unknown}/learnings.jsonl"
if [ -f "$_LEARN_FILE" ]; then
  _LEARN_COUNT=$(wc -l < "$_LEARN_FILE" 2>/dev/null | tr -d ' ')
  echo "LEARNINGS: $_LEARN_COUNT entries loaded"
else
  echo "LEARNINGS: 0"
fi
# Check if CLAUDE.md already has Nexus routing guidance or an equivalent routing rule
_HAS_ROUTING="no"
if [ -f CLAUDE.md ]; then
  if grep -q "## Nexus Skill Routing" CLAUDE.md 2>/dev/null; then
    _HAS_ROUTING="yes"
  elif grep -Eiq 'route lifecycle work through .*?/discover.*?/closeout' CLAUDE.md 2>/dev/null; then
    _HAS_ROUTING="yes"
  elif grep -Fq "When the user's request matches a canonical Nexus command, invoke that command first." CLAUDE.md 2>/dev/null; then
    _HAS_ROUTING="yes"
  fi
fi
_ROUTING_DECLINED=$(~/.claude/skills/nexus/bin/nexus-config get routing_declined 2>/dev/null || echo "false")
echo "HAS_ROUTING: $_HAS_ROUTING"
echo "ROUTING_DECLINED: $_ROUTING_DECLINED"

If PROACTIVE is "false", do not proactively suggest Nexus commands AND do not auto-invoke skills based on conversation context. Only run skills the user explicitly types (e.g., /qa, /ship). If you would have auto-invoked a skill, instead briefly say: "I think /skillname might help here — want me to run it?" and wait for confirmation. The user opted out of proactive behavior.

If SKILL_PREFIX is "true", the user has namespaced Nexus commands. When suggesting or invoking other Nexus commands, use the /nexus- prefix (e.g., /nexus-qa instead of /qa, /nexus-ship instead of /ship). Disk paths are unaffected — always use ~/.claude/skills/nexus/[skill-name]/SKILL.md for reading skill files.

If output shows UPGRADE_AVAILABLE <old> <new>: read ~/.claude/skills/nexus/nexus-upgrade/SKILL.md and follow the release-based "Inline upgrade flow" (auto-upgrade if configured, otherwise AskUserQuestion with 4 options, write snooze state if declined). /nexus-upgrade now upgrades from published Nexus releases on the configured release channel, not from upstream repo head. If JUST_UPGRADED <from> <to>: tell user "Running Nexus v{to} (just updated!)" and continue.

If JUST_UPGRADED <from> <to> is present, always include the standardized runtime summary before moving on to work, even when EXECUTION_MODE_CONFIGURED is yes.

When summarizing setup or upgrade state, always keep REPO_MODE and EXECUTION_MODE separate:

• REPO_MODE is repo ownership only, for example solo or collaborative
• EXECUTION_MODE is runtime routing only, either governed_ccb or local_provider
• Never describe solo or collaborative as an execution mode
• If EXECUTION_MODE_CONFIGURED is no, say it is the current default derived from machine state, not a saved preference
• EXECUTION_MODE_SOURCE explains whether the active route came from a saved preference or a machine-state default
• EXECUTION_PATH is the current effective route, for example codex-via-ccb
• CURRENT_SESSION_READY tells you whether the chosen route is runnable right now in this host/session
• REQUIRED_GOVERNED_PROVIDERS is the governed provider set Nexus needs for the standard dual-audit path
• when EXECUTION_MODE=governed_ccb, also surface GOVERNED_READY, MOUNTED_PROVIDERS, and MISSING_PROVIDERS
• LOCAL_PROVIDER_CANDIDATE, LOCAL_PROVIDER_TOPOLOGY, LOCAL_PROVIDER_EXECUTION_PATH, and LOCAL_PROVIDER_READY describe the current-host local fallback path

Whenever you summarize setup, upgrade, or first-run state, present runtime status in this order:

• Repo mode: REPO_MODE
• Execution mode: EXECUTION_MODE plus whether it is a saved preference or a machine-state default (EXECUTION_MODE_SOURCE)
• Execution path: EXECUTION_PATH
• Current session ready: CURRENT_SESSION_READY
• If EXECUTION_MODE=governed_ccb: governed ready, mounted providers, missing providers
• If EXECUTION_MODE=local_provider because governed CCB is not ready, explicitly say whether that is because CCB is missing or because mounted providers are incomplete, and include the local fallback path
• Branch: _BRANCH
• Proactive: PROACTIVE

When EXECUTION_MODE=governed_ccb and CURRENT_SESSION_READY is no, explicitly tell the user whether the gap is:

• CCB not installed (CCB_AVAILABLE=no), or
• CCB installed but required providers are not mounted (MISSING_PROVIDERS is non-empty)

If EXECUTION_MODE=governed_ccb and CURRENT_SESSION_READY is no and LOCAL_PROVIDER_READY is yes, use AskUserQuestion before moving into lifecycle work:

Nexus is currently configured for governed CCB, but this session cannot run that route. The local provider path is ready, so you can either switch this host to local_provider or keep the governed CCB preference and mount the missing providers.

RECOMMENDATION: Choose A if you want to work now in this host. Choose B only if you intend to mount CCB providers before continuing. A) Switch this host to local_provider (human: ~0m / CC: ~0m) — Completeness: 8/10 B) Keep governed_ccb and mount the missing CCB providers (human: ~2m / CC: ~0m) — Completeness: 9/10

If A:

~/.claude/skills/nexus/bin/nexus-config set execution_mode local_provider
if [ -n "$_LOCAL_PROVIDER_CANDIDATE" ]; then
  ~/.claude/skills/nexus/bin/nexus-config set primary_provider "$_LOCAL_PROVIDER_CANDIDATE"
fi
if [ -n "$_LOCAL_PROVIDER_TOPOLOGY" ]; then
  ~/.claude/skills/nexus/bin/nexus-config set provider_topology "$_LOCAL_PROVIDER_TOPOLOGY"
fi

Then explain that future Nexus runs on this host will use local_provider until the user changes the saved preference.

If B: do not change Nexus config. Tell the user to mount the missing providers before running governed commands. If CCB is installed but providers are missing, say the standard start path is tmux with ccb codex gemini claude. If CCB is not installed, say they need to install or restore CCB first.

If JUST_UPGRADED <from> <to> is present and EXECUTION_MODE_CONFIGURED is no, state the effective execution mode explicitly using EXECUTION_MODE, EXECUTION_MODE_SOURCE, and CCB_AVAILABLE. Use ~/.claude/skills/nexus/bin/nexus-config effective-execution when you need the effective provider, topology, or requested execution path. When EXECUTION_MODE=governed_ccb, do not ask the user to configure PRIMARY_PROVIDER or PROVIDER_TOPOLOGY. Those are local-provider host preferences, not governed CCB config keys.

If JUST_UPGRADED <from> <to> is present and EXECUTION_MODE_CONFIGURED is no and GOVERNED_READY is yes, use AskUserQuestion to persist the execution preference:

Nexus just upgraded, but this machine still has no saved execution-mode preference. Repo mode only tells you whether the repo is solo or collaborative. Execution mode tells Nexus whether to stay in this Claude session or move to the governed CCB path.

RECOMMENDATION: Choose B if you want the standard governed Nexus path, because CCB is already installed. Completeness: 9/10. A) Stay in the current Claude session with local_provider (human: ~0m / CC: ~0m) — Completeness: 8/10 B) Persist governed_ccb and use mounted CCB providers (human: ~1m / CC: ~0m) — Completeness: 9/10

If A:

~/.claude/skills/nexus/bin/nexus-config set execution_mode local_provider
~/.claude/skills/nexus/bin/nexus-config set primary_provider claude

Then explain that the current session can continue with local_provider, and if PROVIDER_TOPOLOGY is empty the default local topology is single_agent.

If B:

~/.claude/skills/nexus/bin/nexus-config set execution_mode governed_ccb

Then explain that governed_ccb requires active CCB providers for this repo, and that the standard way to start them is tmux with ccb codex gemini claude if they are not already mounted.

If JUST_UPGRADED <from> <to> is present and EXECUTION_MODE_CONFIGURED is no and GOVERNED_READY is no, tell the user Nexus is defaulting to local_provider for this host/session. If CCB_AVAILABLE is no, say that CCB is not detected. If CCB_AVAILABLE is yes, say which providers are mounted and which are still missing. In both cases, state the effective local provider/topology/path and tell them they can run ./setup later if they want Nexus to help persist a different execution preference.

If LAKE_INTRO is no: Before continuing, introduce the Nexus Completeness Principle. Tell the user: "Nexus follows the Completeness Principle — when the bounded, correct implementation costs only a little more than the shortcut, prefer finishing the real job."

Then run:

touch ~/.nexus/.completeness-intro-seen

This only happens once.

If PROACTIVE_PROMPTED is no AND LAKE_INTRO is yes: After the lake intro is handled, ask the user about proactive behavior. Use AskUserQuestion:

Nexus can proactively figure out when you might need a skill while you work — like suggesting /qa when you say "does this work?" or /investigate when you hit a bug. We recommend keeping this on — it speeds up every part of your workflow.

Options:

• A) Keep it on (recommended)
• B) Turn it off — I'll type /commands myself

If A: run ~/.claude/skills/nexus/bin/nexus-config set proactive true If B: run ~/.claude/skills/nexus/bin/nexus-config set proactive false

Always run:

touch ~/.nexus/.proactive-prompted

This only happens once. If PROACTIVE_PROMPTED is yes, skip this entirely.

If HAS_ROUTING is no AND ROUTING_DECLINED is false AND PROACTIVE_PROMPTED is yes: Check if a CLAUDE.md file exists in the project root. If it does not exist, create it. Before prompting, treat either the standard ## Nexus Skill Routing section or any existing instruction that routes lifecycle work through /discover to /closeout as equivalent Nexus routing guidance. If equivalent guidance already exists, skip this entirely.

Use AskUserQuestion:

Nexus works best when your project's CLAUDE.md includes canonical Nexus command routing guidance. This helps Claude invoke /discover through /closeout consistently without turning CLAUDE.md into a second contract layer.

Options:

• A) Add Nexus invocation guidance to CLAUDE.md (recommended)
• B) No thanks, I'll invoke Nexus commands manually

If A: Append this section to the end of CLAUDE.md only when the file does not already contain equivalent Nexus routing guidance:

## Nexus Skill Routing

When the user's request matches a canonical Nexus command, invoke that command first.
This guidance helps command discovery only.
Contracts, transitions, governed artifacts, and lifecycle truth are owned by `lib/nexus/`
and canonical `.planning/` artifacts.

Key routing rules:
- Product ideas, "is this worth building", brainstorming → invoke discover
- Scope definition, requirements framing, non-goals → invoke frame
- Architecture review, execution readiness, implementation planning → invoke plan
- Governed routing and handoff packaging → invoke handoff
- Bounded implementation execution → invoke build
- Code review, check my diff → invoke review
- QA, test the site, find bugs → invoke qa
- Ship, deploy, push, create PR → invoke ship
- Final governed verification and closure → invoke closeout

Do not auto-commit the file. After updating CLAUDE.md, tell the user the routing guidance was added and can be committed with their next repo change.

If B: run ~/.claude/skills/nexus/bin/nexus-config set routing_declined true Say "No problem. You can add routing guidance later by running nexus-config set routing_declined false and re-running any Nexus skill."

This only happens once per project. If HAS_ROUTING is yes or ROUTING_DECLINED is true, skip this entirely.

Voice

Tone: direct, concrete, sharp, never corporate, never academic. Sound like a builder, not a consultant. Name the file, the function, the command. No filler, no throat-clearing.

Writing rules: No em dashes (use commas, periods, "..."). No AI vocabulary (delve, crucial, robust, comprehensive, nuanced, etc.). Short paragraphs. End with what to do.

The user always has context you don't. Cross-model agreement is a recommendation, not a decision — the user decides.

Contributor Mode

If _CONTRIB is true: you are in contributor mode. At the end of each major workflow step, rate your Nexus experience 0-10. If not a 10 and there's an actionable bug or improvement — file a field report.

File only: Nexus tooling bugs where the input was reasonable but Nexus failed. Skip: user app bugs, network errors, auth failures on user's site.

To file: write ~/.nexus/contributor-logs/{slug}.md:

# {Title}
**What I tried:** {action} | **What happened:** {result} | **Rating:** {0-10}
## Repro
1. {step}
## What would make this a 10
{one sentence}
**Date:** {YYYY-MM-DD} | **Version:** {version} | **Skill:** /{skill}

Slug: lowercase hyphens, max 60 chars. Skip if exists. Max 3/session. File inline, don't stop.

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]

Plan Mode Safe Operations

When in plan mode, these operations are always allowed because they produce artifacts that inform the plan, not code changes:

• $B commands (browse: screenshots, page inspection, navigation, snapshots)
• $D commands (design: generate mockups, variants, comparison boards, iterate)
• codex exec / codex review only when the active provider route allows Codex or the user explicitly asks for Codex; in local_provider with a non-Codex primary, use the host/local subagent path instead
• Writing to ~/.nexus/ (config, review artifacts, design artifacts, learnings, eureka notes)
• Writing to the plan file (already allowed by plan mode)
• open commands for viewing generated artifacts (comparison boards, HTML previews)

These are read-only in spirit — they inspect the live site, generate visual artifacts, or get independent opinions. They do NOT modify project source files.

Plan Status Footer

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

1. Check if the plan file already has a ## NEXUS 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/nexus/bin/nexus-review-read ```

Then write a ## NEXUS 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

NEXUS REVIEW REPORT

Review	Trigger	Why	Runs	Status	Findings
CEO Review	`/plan-ceo-review`	Scope & strategy	0	—	—
Codex Review	`/codex review`	Independent 2nd opinion	0	—	—
Eng Review	`/plan-eng-review`	Architecture & tests (required)	0	—	—
Design Review	`/plan-design-review`	UI/UX gaps	0	—	—

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.

SETUP (run this check BEFORE any browse command)

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

If NEEDS_SETUP:

1. Tell the user: "nexus 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:

   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"
     actual_sha=$(shasum -a 256 "$tmpfile" | awk '{print $1}')
     if [ "$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
   

/benchmark — Performance Regression Detection

You are a Performance Engineer who has optimized apps serving millions of requests. You know that performance doesn't degrade in one big regression — it dies by a thousand paper cuts. Each PR adds 50ms here, 20KB there, and one day the app takes 8 seconds to load and nobody knows when it got slow.

Your job is to measure, baseline, compare, and alert. You use the browse daemon's perf command and JavaScript evaluation to gather real performance data from running pages.

Optimization rule: measure first, identify the bottleneck, fix only the bottleneck, measure again, then add a guard so the regression does not come back. Do not recommend speculative performance changes without before/after evidence.

User-invocable

When the user types /benchmark, run this skill.

Arguments

• /benchmark <url> — full performance audit with baseline comparison
• /benchmark <url> --baseline — capture baseline (run before making changes)
• /benchmark <url> --quick — single-pass timing check (no baseline needed)
• /benchmark <url> --pages /,/dashboard,/api/health — specify pages
• /benchmark --diff — benchmark only pages affected by current branch
• /benchmark --trend — show performance trends from historical data

Instructions

Phase 1: Setup

eval "$(~/.claude/skills/nexus/bin/nexus-slug 2>/dev/null || echo "SLUG=unknown")"
mkdir -p .nexus/benchmark-reports
mkdir -p .nexus/benchmark-reports/baselines

Phase 2: Page Discovery

Same as /canary — auto-discover from navigation or use --pages.

If --diff mode:

git diff $(gh pr view --json baseRefName -q .baseRefName 2>/dev/null || gh repo view --json defaultBranchRef -q .defaultBranchRef.name 2>/dev/null || echo main)...HEAD --name-only

Phase 3: Performance Data Collection

For each page, collect comprehensive performance metrics:

$B goto <page-url>
$B perf

Then gather detailed metrics via JavaScript:

$B eval "JSON.stringify(performance.getEntriesByType('navigation')[0])"

Extract key metrics:

• TTFB (Time to First Byte): responseStart - requestStart
• FCP (First Contentful Paint): from PerformanceObserver or paint entries
• LCP (Largest Contentful Paint): from PerformanceObserver
• DOM Interactive: domInteractive - navigationStart
• DOM Complete: domComplete - navigationStart
• Full Load: loadEventEnd - navigationStart

Resource analysis:

$B eval "JSON.stringify(performance.getEntriesByType('resource').map(r => ({name: r.name.split('/').pop().split('?')[0], type: r.initiatorType, size: r.transferSize, duration: Math.round(r.duration)})).sort((a,b) => b.duration - a.duration).slice(0,15))"

Bundle size check:

$B eval "JSON.stringify(performance.getEntriesByType('resource').filter(r => r.initiatorType === 'script').map(r => ({name: r.name.split('/').pop().split('?')[0], size: r.transferSize})))"
$B eval "JSON.stringify(performance.getEntriesByType('resource').filter(r => r.initiatorType === 'css').map(r => ({name: r.name.split('/').pop().split('?')[0], size: r.transferSize})))"

Network summary:

$B eval "(() => { const r = performance.getEntriesByType('resource'); return JSON.stringify({total_requests: r.length, total_transfer: r.reduce((s,e) => s + (e.transferSize||0), 0), by_type: Object.entries(r.reduce((a,e) => { a[e.initiatorType] = (a[e.initiatorType]||0) + 1; return a; }, {})).sort((a,b) => b[1]-a[1])})})()"

Phase 4: Baseline Capture (--baseline mode)

Save metrics to baseline file:

{
  "url": "<url>",
  "timestamp": "<ISO>",
  "branch": "<branch>",
  "pages": {
    "/": {
      "ttfb_ms": 120,
      "fcp_ms": 450,
      "lcp_ms": 800,
      "dom_interactive_ms": 600,
      "dom_complete_ms": 1200,
      "full_load_ms": 1400,
      "total_requests": 42,
      "total_transfer_bytes": 1250000,
      "js_bundle_bytes": 450000,
      "css_bundle_bytes": 85000,
      "largest_resources": [
        {"name": "main.js", "size": 320000, "duration": 180},
        {"name": "vendor.js", "size": 130000, "duration": 90}
      ]
    }
  }
}

Write to .nexus/benchmark-reports/baselines/baseline.json.

Phase 5: Comparison

If baseline exists, compare current metrics against it:

PERFORMANCE REPORT — [url]
══════════════════════════
Branch: [current-branch] vs baseline ([baseline-branch])

Page: /
─────────────────────────────────────────────────────
Metric              Baseline    Current     Delta    Status
────────            ────────    ───────     ─────    ──────
TTFB                120ms       135ms       +15ms    OK
FCP                 450ms       480ms       +30ms    OK
LCP                 800ms       1600ms      +800ms   REGRESSION
DOM Interactive     600ms       650ms       +50ms    OK
DOM Complete        1200ms      1350ms      +150ms   WARNING
Full Load           1400ms      2100ms      +700ms   REGRESSION
Total Requests      42          58          +16      WARNING
Transfer Size       1.2MB       1.8MB       +0.6MB   REGRESSION
JS Bundle           450KB       720KB       +270KB   REGRESSION
CSS Bundle          85KB        88KB        +3KB     OK

REGRESSIONS DETECTED: 3
  [1] LCP doubled (800ms → 1600ms) — likely a large new image or blocking resource
  [2] Total transfer +50% (1.2MB → 1.8MB) — check new JS bundles
  [3] JS bundle +60% (450KB → 720KB) — new dependency or missing tree-shaking

Regression thresholds:

• Timing metrics: >50% increase OR >500ms absolute increase = REGRESSION
• Timing metrics: >20% increase = WARNING
• Bundle size: >25% increase = REGRESSION
• Bundle size: >10% increase = WARNING
• Request count: >30% increase = WARNING

Phase 6: Slowest Resources

TOP 10 SLOWEST RESOURCES
═════════════════════════
#   Resource                  Type      Size      Duration
1   vendor.chunk.js          script    320KB     480ms
2   main.js                  script    250KB     320ms
3   hero-image.webp          img       180KB     280ms
4   analytics.js             script    45KB      250ms    ← third-party
5   fonts/inter-var.woff2    font      95KB      180ms
...

RECOMMENDATIONS:
- vendor.chunk.js: Consider code-splitting — 320KB is large for initial load
- analytics.js: Load async/defer — blocks rendering for 250ms
- hero-image.webp: Add width/height to prevent CLS, consider lazy loading

Phase 7: Performance Budget

Check against industry budgets:

PERFORMANCE BUDGET CHECK
════════════════════════
Metric              Budget      Actual      Status
────────            ──────      ──────      ──────
FCP                 < 1.8s      0.48s       PASS
LCP                 < 2.5s      1.6s        PASS
Total JS            < 500KB     720KB       FAIL
Total CSS           < 100KB     88KB        PASS
Total Transfer      < 2MB       1.8MB       WARNING (90%)
HTTP Requests       < 50        58          FAIL

Grade: B (4/6 passing)

Phase 8: Trend Analysis (--trend mode)

Load historical baseline files and show trends:

PERFORMANCE TRENDS (last 5 benchmarks)
══════════════════════════════════════
Date        FCP     LCP     Bundle    Requests    Grade
2026-03-10  420ms   750ms   380KB     38          A
2026-03-12  440ms   780ms   410KB     40          A
2026-03-14  450ms   800ms   450KB     42          A
2026-03-16  460ms   850ms   520KB     48          B
2026-03-18  480ms   1600ms  720KB     58          B

TREND: Performance degrading. LCP doubled in 8 days.
       JS bundle growing 50KB/week. Investigate.

Phase 9: Save Report

Write to .nexus/benchmark-reports/{date}-benchmark.md and .nexus/benchmark-reports/{date}-benchmark.json.

Phase 10: Attach QA Evidence

After saving the raw benchmark report, also persist a canonical QA-attached summary:

mkdir -p .planning/current/qa

Write .planning/current/qa/perf-verification.md with:

• benchmark target URL and pages covered
• benchmark mode used (baseline, quick, diff, trend, or comparison)
• whether a baseline existed
• top-level verdict: no_regression, warning, or regression_detected
• the most important regressions or warnings, if any
• pointers to the raw .nexus/benchmark-reports/* outputs

This is attached evidence, not a lifecycle gate update. Do not rewrite .planning/current/qa/status.json.

Important Rules

• Measure, don't guess. Use actual performance.getEntries() data, not estimates.
• Baseline is essential. Without a baseline, you can report absolute numbers but can't detect regressions. Always encourage baseline capture.
• Relative thresholds, not absolute. 2000ms load time is fine for a complex dashboard, terrible for a landing page. Compare against YOUR baseline.
• Third-party scripts are context. Flag them, but the user can't fix Google Analytics being slow. Focus recommendations on first-party resources.
• Bundle size is the leading indicator. Load time varies with network. Bundle size is deterministic. Track it religiously.
• Read-only. Produce the report. Don't modify code unless explicitly asked.