---
name: prisma-client-api-constructor
description: PrismaClient Constructor
license: MIT
metadata:
author: prisma
version: "7.0.0"
---
# PrismaClient Constructor
Configure Prisma Client when instantiating.
## Basic Instantiation (v7)
```typescript
import { PrismaClient } from '../generated/client'
import { PrismaPg } from '@prisma/adapter-pg'
const adapter = new PrismaPg({
connectionString: process.env.DATABASE_URL
})
const prisma = new PrismaClient({ adapter })
```
## Constructor Options
### adapter (Required in v7)
Driver adapter instance:
```typescript
import { PrismaPg } from '@prisma/adapter-pg'
const adapter = new PrismaPg({
connectionString: process.env.DATABASE_URL
})
const prisma = new PrismaClient({ adapter })
```
### accelerateUrl (For Accelerate users)
```typescript
import { withAccelerate } from '@prisma/extension-accelerate'
const prisma = new PrismaClient({
accelerateUrl: process.env.DATABASE_URL, // prisma:// URL
}).$extends(withAccelerate())
```
### log
Configure logging:
```typescript
const prisma = new PrismaClient({
adapter,
log: ['query', 'info', 'warn', 'error'],
})
```
#### Log levels
| Level | Description |
|-------|-------------|
| `query` | All SQL queries |
| `info` | Informational messages |
| `warn` | Warnings |
| `error` | Errors |
#### Log to events
```typescript
const prisma = new PrismaClient({
adapter,
log: [
{ level: 'query', emit: 'event' },
{ level: 'error', emit: 'stdout' },
],
})
prisma.$on('query', (e) => {
console.log('Query:', e.query)
console.log('Duration:', e.duration, 'ms')
})
```
### errorFormat
Control error formatting:
```typescript
const prisma = new PrismaClient({
adapter,
errorFormat: 'pretty', // 'pretty' | 'colorless' | 'minimal'
})
```
### transactionOptions
Default transaction settings:
```typescript
const prisma = new PrismaClient({
adapter,
transactionOptions: {
maxWait: 5000, // Max wait to acquire transaction (ms)
timeout: 10000, // Max transaction duration (ms)
isolationLevel: 'Serializable',
},
})
```
## Singleton Pattern
Prevent multiple client instances in development:
```typescript
// lib/prisma.ts
import { PrismaClient } from '../generated/client'
import { PrismaPg } from '@prisma/adapter-pg'
const globalForPrisma = globalThis as unknown as {
prisma: PrismaClient | undefined
}
function createPrismaClient() {
const adapter = new PrismaPg({
connectionString: process.env.DATABASE_URL!
})
return new PrismaClient({ adapter })
}
export const prisma = globalForPrisma.prisma ?? createPrismaClient()
if (process.env.NODE_ENV !== 'production') {
globalForPrisma.prisma = prisma
}
```
## Next.js Pattern
```typescript
// lib/prisma.ts
import { PrismaClient } from '@/generated/client'
import { PrismaPg } from '@prisma/adapter-pg'
const createAdapter = () => new PrismaPg({
connectionString: process.env.DATABASE_URL!
})
const prismaClientSingleton = () => {
return new PrismaClient({ adapter: createAdapter() })
}
declare const globalThis: {
prismaGlobal: ReturnType<typeof prismaClientSingleton>
} & typeof global
const prisma = globalThis.prismaGlobal ?? prismaClientSingleton()
export default prisma
if (process.env.NODE_ENV !== 'production') {
globalThis.prismaGlobal = prisma
}
```
## Query Events
Listen to query events:
```typescript
const prisma = new PrismaClient({
adapter,
log: [{ level: 'query', emit: 'event' }],
})
prisma.$on('query', (e) => {
console.log('Query:', e.query)
console.log('Params:', e.params)
console.log('Duration:', e.duration)
})
```
## Log Events
```typescript
prisma.$on('info', (e) => console.log(e.message))
prisma.$on('warn', (e) => console.warn(e.message))
prisma.$on('error', (e) => console.error(e.message))
```
