Remix v2 Code Review

Arguments

• --parallel: Spawn specialized subagents per technology area
• Path: Target directory (default: current working directory)

Step 1: Identify Changed Files

git diff --name-only $(git merge-base HEAD main)..HEAD | grep -E '\.(tsx?|jsx?|mjs|cjs|css)$|^(remix|vite)\.config\.'

If nothing is returned, ask the user for an explicit path list before continuing.

Step 2: Detect Remix v2 + Techs

# Detect Remix v2 in package.json (any official adapter)
grep -E '"@remix-run/(react|node|cloudflare|deno|serve)"' package.json | head -3

# Confirm app router layout
ls app/routes/ 2>/dev/null | head -5

# meta exports (route metadata)
grep -rE 'export const meta|export function meta|export let meta' app/ --include="*.tsx" --include="*.ts" -l | head -3

# Sessions / cookies / auth
grep -rE 'createCookieSessionStorage|getSession\(|commitSession\(|destroySession\(' app/ --include="*.ts" --include="*.tsx" -l | head -3

# Form primitives (forms-review)
grep -rE 'useFetcher\(|<Form|useSubmit\(|useNavigation\(' app/ --include="*.tsx" -l | head -3

# Form anti-patterns: native form / manual fetch (forms-review trigger even without Remix imports)
grep -rE '(^|[^.])<form |fetch\(' app/ --include="*.tsx" -l | head -3

# Error boundaries
grep -rE 'export function ErrorBoundary|export const ErrorBoundary|useRouteError|isRouteErrorResponse' app/ --include="*.tsx" -l | head -3

# Headers / streaming / server-only modules
grep -rE 'export const headers|export function headers|defer\(' app/ --include="*.tsx" --include="*.ts" -l | head -3
find app -type f \( -name '*.server.ts' -o -name '*.server.tsx' -o -name '*.client.ts' -o -name '*.client.tsx' \) | head -5

# Prefetch hygiene (perf-ssr-review)
grep -rE 'prefetch=|<PrefetchPageLinks' app/ --include="*.tsx" -l | head -3

# Loaders / actions (data flow)
grep -rE 'export (async )?function (loader|action)|export const (loader|action)' app/ --include="*.tsx" --include="*.ts" -l | head -3

If the package.json check returns nothing, stop and tell the user: this skill expects a Remix v2 project.

Step 3: Load Verification Protocol

Load beagle-core:review-verification-protocol before any substantive judgment on code. This is the canonical cross-plugin protocol; do not substitute a framework-specific copy.

Pass before Step 5: The skill is loaded (or its checklist is open in context). Do not classify severity or write findings until this gate clears.

Step 4: Load Skills

Use the Skill tool to load each applicable skill (e.g., Skill(skill: "beagle-react:remix-v2-routing-review")).

Always load (a non-trivial Remix v2 app exercises all six areas):

• beagle-react:remix-v2-routing-review
• beagle-react:remix-v2-data-flow-review
• beagle-react:remix-v2-forms-review
• beagle-react:remix-v2-error-boundaries-review
• beagle-react:remix-v2-perf-ssr-review
• beagle-react:remix-v2-meta-sessions-review

Detection telemetry (records what each area review will actually find; does not gate loading — all six skills always load, but record matches/non-matches for the final report's coverage section):

Condition	Skill
app/routes/ present	remix-v2-routing-review
loader / action exports found	remix-v2-data-flow-review
<Form>, useFetcher, useSubmit, useNavigation, native <form, or manual fetch( found	remix-v2-forms-review
ErrorBoundary / useRouteError found	remix-v2-error-boundaries-review
headers export, defer(, or .server.ts / .client.ts files or prefetch=/<PrefetchPageLinks found	remix-v2-perf-ssr-review
meta export or session/cookie helpers found	remix-v2-meta-sessions-review

If a detection row returns no matches, record that explicitly in the report's coverage section — the skill still loads, but the reviewer should note the area had no surface to review.

Step 5: Review

Sequential (default):

1. Load applicable skills
2. Review routing + nested route structure first
3. Review loader/action data flow
4. Review forms and progressive enhancement
5. Review error boundaries
6. Review meta, sessions, and headers/SSR
7. Consolidate findings

Parallel (--parallel flag):

1. Detect all areas upfront
2. Spawn one subagent per area with the Task tool
3. Each agent loads its skill and reviews its domain only
4. Wait for all agents
5. Consolidate findings into a single output

Step 6: Verify Findings

Before reporting any issue:

1. Re-read the actual code (not just diff context)
2. For "unused" claims — did you search all references, including route-file conventions?
3. For "missing" claims — did you check parent routes, root.tsx, or framework defaults?
4. For syntax issues — did you verify against Remix v2 docs (not v1, not React Router v7)?
5. Remove findings that are style preferences, not actual issues

Pass before promoting to Critical/Major: For that item, (2)–(4) are satisfied with a concrete artifact — opened file at FILE:LINE, grep output for references, or cited parent/framework code — not only diff context.

Step 7: Review Convergence

• Single-pass: report ALL issues across routing, data flow, forms, errors, SSR/perf, meta/sessions, types, and security in one pass. Before submitting, ask whether your recommended fixes would themselves trigger new findings — if yes, include those now.
• Scope: review only code in the diff and directly related existing code. Missing test coverage is ONE Minor issue, no implementation prescriptions. No new dependencies.
• Fix complexity: real severity for fixes to existing code. Requests for net-new code (new modules, dependencies, test suites, extracted abstractions) are Informational, not blocking.
• Re-review: verify previous fixes only — no new discovery, no re-flagging unfixed Minor/Nice-to-Have items.

Output Format

## Review Summary
[1-2 sentence overview]

## Issues

### Critical (Blocking)
1. [FILE:LINE] ISSUE_TITLE
   - Issue / Why / Fix

### Major (Should Fix)
2. [FILE:LINE] ISSUE_TITLE
   - Issue / Why / Fix

### Minor (Nice to Have)
N. [FILE:LINE] ISSUE_TITLE
   - Issue / Why / Fix

### Informational (For Awareness)
N. [FILE:LINE] SUGGESTION_TITLE
   - Suggestion / Rationale

## Good Patterns
- [FILE:LINE] Pattern description (preserve this)

## Verdict
Ready: Yes | No | With fixes 1-N (Critical/Major only; Minor items are acceptable)
Rationale: [1-2 sentences]

Post-Fix Verification

After fixes are applied, run:

npm run lint
npm run typecheck
npm run test

All checks must pass before approval.

Gates

Advance in order; do not skip a pass condition by restating it informally.

1. Scope recorded — Pass when: You have the output of the Step 1 command (or an explicit substitute path list) naming what is in scope.
2. Protocol + always skills loaded — Pass when: beagle-core:review-verification-protocol and all six beagle-react:remix-v2-*-review skills are loaded before the first severity judgment.
3. Conditional skills audited — Pass when: For each Step 2 detection row you either confirmed a match or recorded that the command returned no results.
4. Critical/Major evidence — Pass when: Each such finding cites a FILE:LINE that exists in the tree and meets the Step 6 pass rule for that finding type.
5. Single output — Pass when: The Issues section uses one continuous numbering sequence and the deliverable satisfies Step 7 single-pass completeness.

Rules

• Load skills BEFORE reviewing — not after.
• Number every issue sequentially with FILE:LINE and clear Issue / Why / Fix.
• This is Remix v2 — do not apply React Router v7, Remix v1, or Next.js ("use client", server components) conventions.
• Run the Post-Fix Verification block after fixes; Verdict ignores Minor and Informational items.