Next.js + Supabase Auth

Overview

This public intake copy packages

plugins/antigravity-awesome-skills-claude/skills/nextjs-supabase-auth

https://github.com/sickn33/antigravity-awesome-skills

Use it when the operator needs the upstream workflow, support files, and repository context to stay intact while the public validator and private enhancer continue their normal downstream flow.

This intake keeps the copied upstream files intact and uses

metadata.json

ORIGIN.md

Next.js + Supabase Auth Expert integration of Supabase Auth with Next.js App Router

Imported source sections that did not map cleanly to the public headings are still preserved below or in the support files. Notable imported sections: Capabilities, Prerequisites, Patterns, Validation Checks, Collaboration, Limitations.

When to Use This Skill

Use this section as the trigger filter. It should make the activation boundary explicit before the operator loads files, runs commands, or opens a pull request.

• User mentions or implies: supabase auth next
• User mentions or implies: authentication next.js
• User mentions or implies: login supabase
• User mentions or implies: auth middleware
• User mentions or implies: protected route
• User mentions or implies: auth callback

Operating Table

metadata.json

ORIGIN.md

SKILL.md

SKILL.md

## Related Skills

Workflow

This workflow is intentionally editorial and operational at the same time. It keeps the imported source useful to the operator while still satisfying the public intake standards that feed the downstream enhancer flow.

1. Confirm the user goal, the scope of the imported workflow, and whether this skill is still the right router for the task.
2. Read the overview and provenance files before loading any copied upstream support files.
3. Load only the references, examples, prompts, or scripts that materially change the outcome for the current request.
4. Execute the upstream workflow while keeping provenance and source boundaries explicit in the working notes.
5. Validate the result against the upstream expectations and the evidence you can point to in the copied files.
6. Escalate or hand off to a related skill when the work moves out of this imported workflow's center of gravity.
7. Before merge or closure, record what was used, what changed, and what the reviewer still needs to verify.

Imported Workflow Notes

Imported: Capabilities

• nextjs-auth
• supabase-auth-nextjs
• auth-middleware
• auth-callback

Examples

Example 1: Ask for the upstream workflow directly

Use @nextjs-supabase-auth to handle <task>. Start from the copied upstream workflow, load only the files that change the outcome, and keep provenance visible in the answer.

Explanation: This is the safest starting point when the operator needs the imported workflow, but not the entire repository.

Example 2: Ask for a provenance-grounded review

Review @nextjs-supabase-auth against metadata.json and ORIGIN.md, then explain which copied upstream files you would load first and why.

Explanation: Use this before review or troubleshooting when you need a precise, auditable explanation of origin and file selection.

Example 3: Narrow the copied support files before execution

Use @nextjs-supabase-auth for <task>. Load only the copied references, examples, or scripts that change the outcome, and name the files explicitly before proceeding.

Explanation: This keeps the skill aligned with progressive disclosure instead of loading the whole copied package by default.

Example 4: Build a reviewer packet

Review @nextjs-supabase-auth using the copied upstream files plus provenance, then summarize any gaps before merge.

Explanation: This is useful when the PR is waiting for human review and you want a repeatable audit packet.

Best Practices

Treat the generated public skill as a reviewable packaging layer around the upstream repository. The goal is to keep provenance explicit and load only the copied source material that materially improves execution.

• Keep the imported skill grounded in the upstream repository; do not invent steps that the source material cannot support.
• Prefer the smallest useful set of support files so the workflow stays auditable and fast to review.
• Keep provenance, source commit, and imported file paths visible in notes and PR descriptions.
• Point directly at the copied upstream files that justify the workflow instead of relying on generic review boilerplate.
• Treat generated examples as scaffolding; adapt them to the concrete task before execution.
• Route to a stronger native skill when architecture, debugging, design, or security concerns become dominant.

Troubleshooting

Problem: The operator skipped the imported context and answered too generically

Symptoms: The result ignores the upstream workflow in

plugins/antigravity-awesome-skills-claude/skills/nextjs-supabase-auth

metadata.json

ORIGIN.md

Problem: The imported workflow feels incomplete during review

Symptoms: Reviewers can see the generated

SKILL.md

Problem: The task drifted into a different specialization

Symptoms: The imported skill starts in the right place, but the work turns into debugging, architecture, design, security, or release orchestration that a native skill handles better. Solution: Use the related skills section to hand off deliberately. Keep the imported provenance visible so the next skill inherits the right context instead of starting blind.

Related Skills

• @monte-carlo-monitor-creation

  - Use when the work is better handled by that native specialization after this imported skill establishes context.

• @monte-carlo-prevent

  - Use when the work is better handled by that native specialization after this imported skill establishes context.

• @monte-carlo-push-ingestion

  - Use when the work is better handled by that native specialization after this imported skill establishes context.

• @monte-carlo-validation-notebook

  - Use when the work is better handled by that native specialization after this imported skill establishes context.

Additional Resources

Use this support matrix and the linked files below as the operator packet for this imported skill. They should reflect real copied source material, not generic scaffolding.

references

references/n/a

examples

examples/n/a

scripts

scripts/n/a

agents

agents/n/a

assets

assets/n/a

Imported Reference Notes

Imported: Prerequisites

• Required skills: nextjs-app-router, supabase-backend

Imported: Patterns

Supabase Client Setup

Create properly configured Supabase clients for different contexts

When to use: Setting up auth in a Next.js project

// lib/supabase/client.ts (Browser client) 'use client' import { createBrowserClient } from '@supabase/ssr'

export function createClient() { return createBrowserClient( process.env.NEXT_PUBLIC_SUPABASE_URL!, process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY! ) }

// lib/supabase/server.ts (Server client) import { createServerClient } from '@supabase/ssr' import { cookies } from 'next/headers'

export async function createClient() { const cookieStore = await cookies() return createServerClient( process.env.NEXT_PUBLIC_SUPABASE_URL!, process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!, { cookies: { getAll() { return cookieStore.getAll() }, setAll(cookiesToSet) { cookiesToSet.forEach(({ name, value, options }) => { cookieStore.set(name, value, options) }) }, }, } ) }

Auth Middleware

Protect routes and refresh sessions in middleware

When to use: You need route protection or session refresh

// middleware.ts import { createServerClient } from '@supabase/ssr' import { NextResponse, type NextRequest } from 'next/server'

export async function middleware(request: NextRequest) { let response = NextResponse.next({ request })

const supabase = createServerClient( process.env.NEXT_PUBLIC_SUPABASE_URL!, process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!, { cookies: { getAll() { return request.cookies.getAll() }, setAll(cookiesToSet) { cookiesToSet.forEach(({ name, value, options }) => { response.cookies.set(name, value, options) }) }, }, } )

// Refresh session if expired const { data: { user } } = await supabase.auth.getUser()

// Protect dashboard routes if (request.nextUrl.pathname.startsWith('/dashboard') && !user) { return NextResponse.redirect(new URL('/login', request.url)) }

return response }

export const config = { matcher: ['/((?!_next/static|_next/image|favicon.ico).*)'], }

Auth Callback Route

Handle OAuth callback and exchange code for session

When to use: Using OAuth providers (Google, GitHub, etc.)

// app/auth/callback/route.ts import { createClient } from '@/lib/supabase/server' import { NextResponse } from 'next/server'

export async function GET(request: Request) { const { searchParams, origin } = new URL(request.url) const code = searchParams.get('code') const next = searchParams.get('next') ?? '/'

if (code) { const supabase = await createClient() const { error } = await supabase.auth.exchangeCodeForSession(code) if (!error) { return NextResponse.redirect(

${origin}${next}

return NextResponse.redirect(

${origin}/auth/error

Server Action Auth

Handle auth operations in Server Actions

When to use: Login, logout, or signup from Server Components

// app/actions/auth.ts 'use server' import { createClient } from '@/lib/supabase/server' import { redirect } from 'next/navigation' import { revalidatePath } from 'next/cache'

export async function signIn(formData: FormData) { const supabase = await createClient() const { error } = await supabase.auth.signInWithPassword({ email: formData.get('email') as string, password: formData.get('password') as string, })

if (error) { return { error: error.message } }

revalidatePath('/', 'layout') redirect('/dashboard') }

export async function signOut() { const supabase = await createClient() await supabase.auth.signOut() revalidatePath('/', 'layout') redirect('/') }

Get User in Server Component

Access the authenticated user in Server Components

When to use: Rendering user-specific content server-side

// app/dashboard/page.tsx import { createClient } from '@/lib/supabase/server' import { redirect } from 'next/navigation'

export default async function DashboardPage() { const supabase = await createClient() const { data: { user } } = await supabase.auth.getUser()

if (!user) { redirect('/login') }

return ( <div> <h1>Welcome, {user.email}</h1> </div> ) }

Imported: Validation Checks

Using getSession() for Auth Checks

Severity: ERROR

Message: getSession() doesn't verify the JWT. Use getUser() for secure auth checks.

Fix action: Replace getSession() with getUser() for security-critical checks

OAuth Without Callback Route

Severity: ERROR

Message: Using OAuth but missing callback route at app/auth/callback/route.ts

Fix action: Create app/auth/callback/route.ts to handle OAuth redirects

Browser Client in Server Context

Severity: ERROR

Message: Browser client used in server context. Use createServerClient instead.

Fix action: Import and use createServerClient from @supabase/ssr

Protected Routes Without Middleware

Severity: WARNING

Message: No middleware.ts found. Consider adding middleware for route protection.

Fix action: Create middleware.ts to protect routes and refresh sessions

Hardcoded Auth Redirect URL

Severity: WARNING

Message: Hardcoded localhost redirect. Use origin for environment flexibility.

Fix action: Use window.location.origin or process.env.NEXT_PUBLIC_SITE_URL

Auth Call Without Error Handling

Severity: WARNING

Message: Auth operation without error handling. Always check for errors.

Fix action: Destructure { data, error } and handle error case

Auth Action Without Revalidation

Severity: WARNING

Message: Auth action without revalidatePath. Cache may show stale auth state.

Fix action: Add revalidatePath('/', 'layout') after auth operations

Client-Only Route Protection

Severity: WARNING

Message: Client-side route protection shows flash of content. Use middleware.

Fix action: Move protection to middleware.ts for better UX

Imported: Collaboration

Delegation Triggers

• database|rls|queries|tables -> supabase-backend (Auth needs database layer)
• route|page|component|layout -> nextjs-app-router (Auth needs Next.js patterns)
• deploy|production|vercel -> vercel-deployment (Auth needs deployment config)
• ui|form|button|design -> frontend (Auth needs UI components)

Full Auth Stack

Skills: nextjs-supabase-auth, supabase-backend, nextjs-app-router, vercel-deployment

Workflow:

1. Database setup (supabase-backend)
2. Auth implementation (nextjs-supabase-auth)
3. Route protection (nextjs-app-router)
4. Deployment config (vercel-deployment)

Protected SaaS

Skills: nextjs-supabase-auth, stripe-integration, supabase-backend

Workflow:

1. User authentication (nextjs-supabase-auth)
2. Customer sync (stripe-integration)
3. Subscription gating (supabase-backend)

Imported: Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.