nextjs-supabase

A set of guidelines for building TypeScript web apps with Next.js, Supabase, Tailwind CSS, and shadcn/ui. Next.js provides the app framework, while Supabase provides authentication, database, file storage, and live updates.

In plain words
What is it for?
Use it when creating Next.js applications with login and signup, Supabase data access, protected dashboards, Tailwind styling, and shadcn/ui components.
Why use it?
It gives these tools clear roles and a consistent project structure. That reduces confusion when implementing authentication, server code, pages, and shared interface components.

Cursor rule

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/renvia-code/best-cursor-rules/nextjs-supabase
Clone the repo
git clone --depth 1 https://github.com/Renvia-code/best-cursor-rules
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 2,955 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.02955
Opus 5 $0.00000 $0.01477
Sonnet 5 $0.00000 $0.00591
Haiku 4.5 $0.00000 $0.00296

Measured 2d ago against content hash 1e045780e88b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

nextjs-supabase scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

rules/stacks/nextjs-supabase.mdc · 491 lines

How it starts

The opening of the file, as written. The whole thing — 491 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Next.js + Supabase Stack

Overview

Layer Technology Purpose
Framework Next.js 15 App Router, Server Components
Backend Supabase Auth, Database, Storage, Realtime
Styling Tailwind CSS Utility-first CSS
Components shadcn/ui Accessible UI components
Language TypeScript Type safety

Related rules: nextjs-15.mdc, supabase.mdc, tailwind.mdc, shadcn-ui.mdc


Project Structure

app/
├── (auth)/
│   ├── login/
│   │   └── page.tsx
│   ├── signup/
│   │   └── page.tsx
│   └── auth/
│       └── callback/
│           └── route.ts
├── (dashboard)/
│   ├── layout.tsx
│   └── dashboard/
│       └── page.tsx
├── layout.tsx
├── page.tsx
└── globals.css
components/
├── ui/                   # shadcn/ui components
└── ...
lib/
├── supabase/
│   ├── client.ts         # Browser client
│   ├── server.ts         # Server client
│   └── middleware.ts     # Auth middleware helper
└── utils.ts
supabase/
├── migrations/           # Database migrations
└── config.toml          # Local config
types/
└── supabase.ts          # Generated types

Supabase Client Setup

Browser Client

// lib/supabase/client.ts
import { createBrowserClient } from '@supabase/ssr'
import type { Database } from '@/types/supabase'

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

Server Client

// lib/supabase/server.ts
import { createServerClient } from '@supabase/ssr'
import { cookies } from 'next/headers'
import type { Database } from '@/types/supabase'

export async function createClient() {
  const cookieStore = await cookies()

  return createServerClient<Database>(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
    {
      cookies: {
        getAll() {
          return cookieStore.getAll()
        },
        setAll(cookiesToSet) {
          try {
            cookiesToSet.forEach(({ name, value, options }) =>
              cookieStore.set(name, value, options)
            )
          } catch {
            // Called from Server Component - ignore
          }
        },
      },
    }
  )
}

Read the full file on GitHub · 491 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 491 lines · 0 tokens per session scan A 1e045780e88b

Subscribe to this mod's changes

nextjs-supabase is a cursor rule published in the GitHub repository Renvia-code/best-cursor-rules (12 stars, last pushed 9mo ago), licensed CC0-1.0. It costs nothing until one of its globs matches a file; then it loads 2,955 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.