| name | remix-v2-meta-sessions-review |
| description | Reviews Remix v2 code for v1-shape meta exports (BREAKING in v2), cookie security gaps (httpOnly, secure, secrets rotation), auth gates in wrong layer, and missing CSRF. Use when reviewing meta/SEO, session, auth, or form-mutation code in a Remix v2 codebase. |
| user-invocable | false |
Remix v2 Meta, Sessions, Auth, and CSRF Code Review
Reviews Remix v2 meta/SEO, session, auth-gate, and CSRF code paths. Loaded
by the umbrella review-remix-v2 reviewer when a diff touches any of:
meta/links exports, root.tsx, *.server.ts session/cookie modules,
loaders/actions reading or writing session, or <Form>/useFetcher
mutations.
See remix-v2-meta-sessions for canonical patterns.
Quick Reference
| Issue Type | Reference |
|---|
meta returning v1 object shape (BREAKING), OG shorthand, document.title in effect, missing <Meta />/<Links />, parent merge | references/meta-v2-shape.md |
Missing httpOnly/secure, hardcoded secrets, single-string secrets, replace-not-prepend rotation | references/cookie-security.md |
Auth check in component, logout in loader, missing commitSession, flash without commit | references/auth-gates.md |
Manual fetch POST bypassing CSRF, token in session cookie, no CSRF protection, shared secrets | references/csrf.md |
Highest-stakes detection — call out first: v1 meta object shape (return { title, description }) in a v2 codebase. It typechecks, but the runtime ignores it and the page renders with no title and no meta tags. Grep every export const meta and confirm the return value starts with [, not {.
Review Checklist
Valid Patterns (Do NOT Flag)
These are correct usage — do not report as issues:
sameSite: "lax" — acceptable default. Not every app needs "strict"; flag only when threat model warrants stricter (e.g. CSRF protection is otherwise absent).meta returning [] — legitimate when the route intentionally emits no meta (inherits root tags or relies on a sibling).links returning [] — legitimate when the route has no route-specific stylesheets or preloads.session.flash(...) followed on the next line by commitSession(session) — the standard 2-line flash pattern. The separation is correct; do not flag it as "missing commit".- Auth check in
action (not loader) — correct for POST-only routes (e.g. logout, delete). Loaders gate GETs; actions gate mutations.
charset and viewport as plain JSX <meta> in root.tsx's <head> — preferred over the meta export to avoid duplicate-tag warnings under v2's no-merge behavior.secrets: [process.env.X!, process.env.X_OLD!] — ! non-null assertion is acceptable when a fail-fast guard above (if (!process.env.X) throw) is present.throw redirect(...) inside a loader/action — canonical Remix pattern; the thrown response is intentional.commitSession called in a loader (not just an action) — required when a loader reads a flash message and must clear it.
Context-Sensitive Rules
Only flag these issues when the specific context applies:
| Issue | Flag ONLY IF |
|---|
| Missing CSRF validation in action | App declares remix-utils/csrf as its protection mechanism, OR the action is public-facing (not internal/VPN-gated) AND no Origin check is present |
sameSite: "lax" | App has no library-based CSRF protection AND no Origin check — "lax" then becomes the only defense and is insufficient |
Missing secure flag | Cookie config is the production session/CSRF cookie (not a test fixture or commented example) |
meta returning [] | The route is documented as needing route-specific tags (e.g. a public landing page) — empty is usually intentional inheritance, do not flag by default |
Auth check in action not loader | Route is GET-renderable (has a loader) — for POST-only routes, action is the correct gate |
Logout in action AND <Form method="post"> | Never flag — that is the canonical pattern |
Manual fetch POST | The target is an internal Remix action AND no CSRF token is attached via headers |
secrets: [singleValue] | App is in production OR has been deployed for long enough to need rotation — flag as recommendation, not CRITICAL |
Hard gates (before writing findings)
Run these in order. Do not draft user-facing findings until every gate passes for the batch you are about to report.
-
Location evidence — Pass: Each issue lists a repo path and either a line range or a short verbatim quote from the file you read. Diff-only or memory-based claims do not pass. For meta/links/session issues, the cited file is a .ts/.tsx route module, root.tsx, or *.server.ts — not a generic config file.
-
Exemption check — Pass: For each issue, you can state in one line why it is not covered by Valid Patterns (Do NOT Flag). In particular: sameSite: "lax", empty meta/links arrays, and the standard flash + commitSession two-line pattern must be explicitly cleared.
-
Meta-shape check — Pass: Before flagging anything about meta, you read the actual function body and confirmed what it returns. TypeScript may have masked the shape (a v1 object can satisfy a poorly-typed MetaFunction alias). The check is: the return expression starts with [ and every element is a descriptor object. If it starts with {, that is the v1 shape — flag as CRITICAL. If it is [], that is valid (do not flag).
-
Protocol — Pass: You completed the Pre-Report Verification Checklist in review-verification-protocol for this review.
When to Load References
- Reviewing any
export const meta or export const links, or root.tsx → meta-v2-shape.md
- Reviewing
createCookieSessionStorage, createCookie, or any *.server.ts that configures cookies → cookie-security.md
- Reviewing loaders/actions that read or write
session, or any auth helper → auth-gates.md
- Reviewing forms, fetchers, or any mutating route → csrf.md
Review Questions
- Does every
meta export return an array, and is every OG/Twitter tag { property, content }?
- Does
root.tsx include <Meta /> and <Links /> inside <head>?
- Are cookies
httpOnly + secure: NODE_ENV === 'production' with secrets from env in an array (rotation-ready)?
- Is every session mutation followed by a
Set-Cookie: await commitSession(session) header?
- Is auth gated in the loader/action via a throwing helper, never in a component?
- Is logout an
action (POST), and do mutating actions validate CSRF (or document the threat model)?
Additional Documentation
- references/meta-v2-shape.md — v1 object shape in v2 codebases (BREAKING), OG shorthand,
document.title antipatterns, root scaffolding, parent merging
- references/cookie-security.md —
httpOnly/secure/sameSite, hardcoded secrets, rotation hygiene
- references/auth-gates.md — loader-level gates, logout-must-be-action, commit pairing, flash patterns
- references/csrf.md —
remix-utils/csrf wiring, manual-fetch bypass, dedicated cookie, shared-secret hygiene
Before Submitting Findings
Complete Hard gates (especially gate 3 — meta-shape check), then report only issues that still pass the review-verification-protocol pre-report checks.
