Edge Runtime Driver Adapters

Use Prisma ORM in edge runtimes with serverless database drivers

Edge Runtime Driver Adapters

Prisma ORM provides driver adapters optimized for edge runtimes and serverless platforms. These adapters use HTTP-based connections and are compatible with environments like Cloudflare Workers, Vercel Edge Functions, and other edge platforms.

Cloudflare D1 Adapter

The @prisma/adapter-d1 package enables usage of Cloudflare D1, Cloudflare’s serverless SQLite database.

Installation

npm install @prisma/adapter-d1
npm install --save-dev @cloudflare/workers-types
npm install --save-dev wrangler

Usage in Cloudflare Workers

import { PrismaClient } from '@prisma/client'
import { PrismaD1 } from '@prisma/adapter-d1'

export interface Env {
  // This must match the binding name in wrangler.toml
  MY_DATABASE: D1Database
}

export default {
  async fetch(request: Request, env: Env, ctx: ExecutionContext): Promise<Response> {
    // Initialize Prisma Client with D1 adapter
    const adapter = new PrismaD1(env.MY_DATABASE)
    const prisma = new PrismaClient({ adapter })

    // Execute queries
    const usersCount = await prisma.user.count()

    return new Response(`Users: ${usersCount}`)
  },
}

Wrangler Configuration

Configure your D1 database binding in wrangler.toml:

[[d1_databases]]
binding = "MY_DATABASE"              # Available in Worker as env.MY_DATABASE
database_name = "my_database_name"
database_id = "<unique-ID-for-your-database>"

JavaScript Example

import { PrismaClient } from '@prisma/client'
import { PrismaD1 } from '@prisma/adapter-d1'

export default {
  async fetch(request, env, ctx) {
    const adapter = new PrismaD1(env.MY_DATABASE)
    const prisma = new PrismaClient({ adapter })

    const users = await prisma.user.findMany()

    return new Response(JSON.stringify(users))
  },
}

Features

• Cloudflare Workers runtime support
• SQLite compatibility
• HTTP-based queries (no TCP connections)
• Automatic connection management
• Full Prisma Client API support

Limitations

• Transactions are not supported (D1 limitation)
• Interactive transactions ($transaction) will throw an error
• No migration execution from Workers (use Wrangler CLI)

Migrations

Migrations must be applied using the Wrangler CLI, not from your Worker:

# Generate migration
npx prisma migrate dev --name init

# Apply migration to local D1
npx wrangler d1 execute MY_DATABASE --local --file=./prisma/migrations/*/migration.sql

# Apply migration to production D1
npx wrangler d1 execute MY_DATABASE --file=./prisma/migrations/*/migration.sql

See the Cloudflare D1 documentation for detailed migration workflows.

Local Development

Test your Worker locally with Wrangler:

npx wrangler dev

---

PlanetScale Adapter

The @prisma/adapter-planetscale package enables usage of PlanetScale’s serverless driver for MySQL databases over HTTP.

Installation

npm install @prisma/adapter-planetscale
npm install undici  # For Node.js < 18

Usage

import { PrismaPlanetScale } from '@prisma/adapter-planetscale'
import { PrismaClient } from '@prisma/client'
import { fetch as undiciFetch } from 'undici'  // Only for Node.js < 18

const connectionString = process.env.DATABASE_URL

const adapter = new PrismaPlanetScale({ 
  url: connectionString,
  fetch: undiciFetch  // Optional: only needed for Node.js < 18
})

const prisma = new PrismaClient({ adapter })

Node.js 18+

Node.js 18 and later include built-in fetch, so you don’t need undici:

import { PrismaPlanetScale } from '@prisma/adapter-planetscale'
import { PrismaClient } from '@prisma/client'

const adapter = new PrismaPlanetScale({ 
  url: process.env.DATABASE_URL 
})

const prisma = new PrismaClient({ adapter })

Configuration Options

The adapter accepts PlanetScale client configuration:

import { PrismaPlanetScale } from '@prisma/adapter-planetscale'

const adapter = new PrismaPlanetScale({
  url: process.env.DATABASE_URL,
  fetch: globalThis.fetch,           // Custom fetch implementation
  cast: (field, value) => value,     // Custom type casting
})

Connection String Format

Update your connection string to use PlanetScale’s HTTP endpoint:

DATABASE_URL="mysql://user:[e-mail]/database_name?sslaccept=strict"

Important: Use aws.connect.psdb.cloud as the host for HTTP connections.

Transaction Support

The adapter supports transactions:

const result = await prisma.$transaction(async (tx) => {
  const user = await tx.user.create({
    data: { email: '[e-mail]' }
  })
  
  const profile = await tx.profile.create({
    data: { userId: user.id, bio: 'Hello' }
  })
  
  return { user, profile }
})

Isolation Levels

Supported isolation levels:

• READ UNCOMMITTED
• READ COMMITTED
• REPEATABLE READ (default)
• SERIALIZABLE

const result = await prisma.$transaction(
  async (tx) => {
    // Your queries
  },
  {
    isolationLevel: 'SERIALIZABLE'
  }
)

Edge Runtime Support

The adapter works in edge runtimes:

Vercel Edge Functions

import { PrismaPlanetScale } from '@prisma/adapter-planetscale'
import { PrismaClient } from '@prisma/client'

export const config = {
  runtime: 'edge',
}

export default async function handler(request: Request) {
  const adapter = new PrismaPlanetScale({ 
    url: process.env.DATABASE_URL 
  })
  const prisma = new PrismaClient({ adapter })
  
  const users = await prisma.user.findMany()
  
  return new Response(JSON.stringify(users))
}

Cloudflare Workers

import { PrismaPlanetScale } from '@prisma/adapter-planetscale'
import { PrismaClient } from '@prisma/client'

export default {
  async fetch(request: Request, env: any) {
    const adapter = new PrismaPlanetScale({ 
      url: env.DATABASE_URL 
    })
    const prisma = new PrismaClient({ adapter })
    
    const users = await prisma.user.findMany()
    
    return new Response(JSON.stringify(users))
  },
}

Features

• HTTP-based connections (no TCP required)
• Edge runtime compatible
• Full transaction support
• Savepoints for nested transactions
• Improved connection reliability and performance with HTTP/3

Performance Benefits

• Faster MySQL with HTTP/3
• Reduced connection overhead in serverless environments
• No connection pooling required

Limitations

• Requires PlanetScale database
• Must use HTTP connection endpoint (aws.connect.psdb.cloud)

---

Edge Runtime Comparison

Feature	Cloudflare D1	PlanetScale
Database	SQLite	MySQL
Protocol	HTTP	HTTP
Transactions	No	Yes
Savepoints	No	Yes
Platform	Cloudflare Workers	Any edge runtime
Migration Execution	Wrangler CLI only	Standard Prisma Migrate
Best For	Cloudflare-native apps	Multi-platform edge apps

Other Edge-Compatible Adapters

These adapters also support edge runtimes:

• Neon HTTP mode: PostgreSQL over HTTP
• libSQL/Turso: SQLite over HTTP with edge support

Error Handling

Edge runtime adapters map database errors to Prisma error codes:

try {
  await prisma.user.create({
    data: { email: '[e-mail]' }
  })
} catch (error) {
  if (error.code === 'P2002') {
    console.log('Unique constraint violation')
  }
}

Next Steps

• PostgreSQL Adapters
• SQLite Adapters
• MySQL/MariaDB Adapters
• Driver Adapters Overview