vercel-storage

What this skill does

# Vercel Storage

You are an expert in Vercel's storage options. Know which products are active, which are sunset, and when to use each.

## Provider Choice for Bootstrap

Choose storage provisioning paths in this order:

1. **Preferred**: Vercel-managed Neon/Upstash through the Vercel Marketplace (`vercel integration add ...` or dashboard). This path auto-provisions accounts/resources and injects environment variables into the linked Vercel project.
2. **Fallback**: Provider CLI/manual provisioning only when Marketplace is unavailable or you must use an existing external account.

When using fallback/manual provisioning, you must add/sync environment variables yourself and then re-run `vercel env pull .env.local --yes` locally.

## Active First-Party Storage

### Vercel Blob — File Storage

Fast, scalable storage for unstructured data (images, videos, documents, any files).

```bash
npm install @vercel/blob
```

```ts
import { put, del, list, get } from '@vercel/blob'

// Upload from server (public)
const blob = await put('images/photo.jpg', file, {
  access: 'public',
})
// blob.url → public URL

// Upload private file
const privateBlob = await put('docs/secret.pdf', file, {
  access: 'private',
})
// Read private file back
const privateFile = await get(privateBlob.url) // returns ReadableStream + metadata

// Client upload (up to 5 TB)
import { upload } from '@vercel/blob/client'
const blob = await upload('video.mp4', file, {
  access: 'public',
  handleUploadUrl: '/api/upload', // Your token endpoint
})

// List blobs
const { blobs } = await list()

// Conditional get with ETags
const response = await get('images/photo.jpg', {
  ifNoneMatch: previousETag,
})
if (response.statusCode === 304) {
  // Not modified, use cached version
}

// Delete
await del('images/photo.jpg')
```

**Private Storage** (public beta): Use `access: 'private'` for files that should not be publicly accessible. Read them back with `get()`. Do NOT use private access for files that need to be served publicly — it leads to slow delivery and high egress costs.

**Blob Data Transfer**: Vercel Blob uses two delivery strategies — **Fast Data Transfer** (94 cities, latency-optimized) and **Blob Data Transfer** (18 hubs, volume-optimized for large assets). The system automatically routes via the optimal path.

**Use when**: Media files, user uploads, documents, any large unstructured data.

### Vercel Edge Config — Global Configuration

Ultra-low-latency key-value store for application configuration. Not a database — designed for config data that must be read instantly at the edge.

```bash
npm install @vercel/edge-config
```

```ts
import { get, getAll, has } from '@vercel/edge-config'

// Read a single value (< 1ms at the edge)
const isFeatureEnabled = await get('feature-new-ui')

// Read multiple values
const config = await getAll(['feature-new-ui', 'ab-test-variant', 'redirect-rules'])

// Check existence
const exists = await has('maintenance-mode')
```

**Use when**: Feature flags, A/B testing config, dynamic routing rules, maintenance mode toggles. Anything that must be read at the edge with near-zero latency.

**Do NOT use for**: User data, session state, frequently written data. Edge Config is optimized for reads, not writes.

**Next.js 16**: `@vercel/edge-config@^1.4.3` supports `cacheComponents` and the renamed `proxy.ts` (formerly `middleware.ts`).

## Marketplace Storage (Partner-Provided)

### IMPORTANT: @vercel/postgres and @vercel/kv are SUNSET

These packages no longer exist as first-party Vercel products. Use the marketplace replacements:

### Neon Postgres (replaces @vercel/postgres)

Serverless Postgres with branching, auto-scaling, and connection pooling. The driver is GA at `@neondatabase/serverless@^1.0.2` and requires **Node.js 19+**.

```bash
npm install @neondatabase/serverless
```

```ts
// Direct Neon usage
import { neon } from '@neondatabase/serverless'

const sql = neon(process.env.DATABASE_URL!)
const users = await sql`SELECT * FROM users WHERE id = ${userId}`

// With Drizzle ORM
import { drizzle } from 'drizzle-orm/neon-http'
import { neon } from '@neondatabase/serverless'

const sql = neon(process.env.DATABASE_URL!)
const db = drizzle(sql)
```

**Build-time safety**: The `neon()` call above throws if `DATABASE_URL` is not set. Since Next.js evaluates top-level module code at build time, this will crash `next build` when env vars aren't yet configured (e.g., first deploy before Marketplace provisioning). Use lazy initialization:

```ts
// src/db/index.ts — lazy initialization (safe for build time)
import { neon } from '@neondatabase/serverless'
import { drizzle } from 'drizzle-orm/neon-http'
import * as schema from './schema'

function createDb() {
  const sql = neon(process.env.DATABASE_URL!)
  return drizzle(sql, { schema })
}

let _db: ReturnType<typeof createDb> | null = null

export function getDb() {
  if (!_db) _db = createDb()
  return _db
}
```

**WARNING: Do NOT use JavaScript `Proxy` wrappers around the DB client.** A common pattern is wrapping `db` in a `Proxy` for lazy initialization. This breaks libraries like NextAuth/Auth.js that inspect the DB adapter object (e.g., checking method existence, iterating properties). The Proxy intercepts those checks and breaks the auth request chain, causing hangs with no error. Use a plain `getDb()` function or a simple module-level lazy `let` instead.

**Drizzle Kit migrations**: `drizzle-kit` and `tsx` do NOT auto-load `.env.local`. Source env vars manually or use `dotenv`:

```bash
# Option 1: Source env vars before running
source <(grep -v '^#' .env.local | sed 's/^/export /') && npx drizzle-kit push

# Option 2: Use dotenv-cli (recommended for scripts)
npm install -D dotenv-cli
npx dotenv -e .env.local -- npx drizzle-kit push
npx dotenv -e .env.local -- npx tsx scripts/seed.ts
```

This applies to any Node script that needs Vercel-provisioned env vars — only Next.js auto-loads `.env.local`.

Install via Vercel Marketplace for automatic environment variable provisioning.

#### Neon CLI Fallback Notes

If you use Neon CLI as the fallback path, account/project setup is managed on Neon directly instead of through Vercel Marketplace automation.

For **Vercel-managed Neon projects**, CLI operations require a **Neon API key**; do not rely on normal browser-auth login flow alone.

### Upstash Redis (replaces @vercel/kv)

Serverless Redis with same Vercel billing integration.

```bash
npm install @upstash/redis
```

```ts
import { Redis } from '@upstash/redis'

const redis = Redis.fromEnv() // Uses UPSTASH_REDIS_REST_URL & TOKEN

// Basic operations
await redis.set('session:abc', { userId: '123' }, { ex: 3600 })
const session = await redis.get('session:abc')

// Rate limiting
import { Ratelimit } from '@upstash/ratelimit'
const ratelimit = new Ratelimit({
  redis,
  limiter: Ratelimit.slidingWindow(10, '10s'),
})
const { success } = await ratelimit.limit('user:123')
```

Install via Vercel Marketplace for automatic environment variable provisioning.

### Supabase (Marketplace Native)

Full Postgres database with built-in auth, realtime subscriptions, and storage. Native Vercel Marketplace integration.

```bash
npm install @supabase/supabase-js @supabase/ssr
```

```ts
import { createClient } from '@supabase/supabase-js'

const supabase = createClient(
  process.env.NEXT_PUBLIC_SUPABASE_URL!,
  process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!
)

const { data, error } = await supabase.from('users').select('*')
```

Install via Vercel Marketplace: `vercel integration add supabase`

### Prisma ORM (Marketplace Native)

Type-safe ORM with auto-generated client, migrations, and Prisma Accelerate for connection pooling.

```bash
npm install prisma @prisma/client
npx prisma init
```

```ts
import { PrismaClient } from '@prisma/client'

const prisma = new PrismaClient()
const users = await prisma.user.findMany()
```

Install via Vercel Marketplace: `vercel integration add prisma`

### MongoDB Atlas

Document database