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Overview

The prisma.config.ts file is the central configuration file for your Prisma project. It replaces the datasource URLs and other configuration previously stored in schema.prisma, providing a type-safe, programmatic way to configure Prisma.

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File Location

By default, Prisma looks for prisma.config.ts in the following locations:
  • ./prisma.config.ts (project root)
  • ./.config/prisma.ts
You can specify a custom location using the --config flag with CLI commands.

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Supported File Extensions

Prisma supports the following configuration file formats:
  • .ts - TypeScript
  • .js - JavaScript
  • .mjs - ES Module
  • .cjs - CommonJS
  • .mts - TypeScript ES Module
  • .cts - TypeScript CommonJS

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Basic Structure

import { defineConfig } from '@prisma/config'

export default defineConfig({
  // Configuration options
})
While you can export a plain object without using defineConfig, using the function provides better type safety and validation.

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Configuration Options

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datasource

Defines the database connection configuration.
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datasource.url
string
The database connection URL. Required for migration and introspection commands.
export default defineConfig({
  datasource: {
    url: 'postgresql://user:password@localhost:5432/mydb'
  }
})
​
datasource.shadowDatabaseUrl
string
The shadow database URL used during migrations for diffing. Optional.
export default defineConfig({
  datasource: {
    url: 'postgresql://user:password@localhost:5432/mydb',
    shadowDatabaseUrl: 'postgresql://user:password@localhost:5432/shadow'
  }
})

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schema

Specifies the path to your Prisma schema file or directory.
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schema
string
Path to a single .prisma file or a directory containing multiple .prisma files.
// Single schema file
export default defineConfig({
  schema: './prisma/schema.prisma'
})

// Directory with multiple schema files
export default defineConfig({
  schema: './prisma/schemas'
})
Paths can be absolute or relative. Relative paths are resolved from the config file location.

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migrations

Configures Prisma Migrate behavior.
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migrations.path
string
Directory where migration files are stored and looked up.
export default defineConfig({
  migrations: {
    path: './prisma/migrations'
  }
})
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migrations.seed
string
Command to run for database seeding after migrations are applied.
export default defineConfig({
  migrations: {
    seed: 'tsx prisma/seed.ts'
  }
})
Examples:
  • TypeScript: 'tsx prisma/seed.ts'
  • Node.js: 'node prisma/seed.js'
  • Shell script: './prisma/seed.sh'
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migrations.initShadowDb
string
SQL script to set up external tables and enums during migration diffing. Requires experimental.externalTables to be enabled.
export default defineConfig({
  experimental: {
    externalTables: true
  },
  migrations: {
    initShadowDb: 'CREATE TABLE "User" ("id" SERIAL PRIMARY KEY);'
  }
})

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tables

Configures external table management.
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tables.external
string[]
List of tables that are externally managed. Prisma will not generate migrations for these tables but will include them in the schema and client API. Requires experimental.externalTables to be enabled.
export default defineConfig({
  experimental: {
    externalTables: true
  },
  tables: {
    external: ['audit_log', 'public.legacy_users']
  }
})
You can specify schema-qualified table names: 'schema_name.table_name'

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enums

Configures external enum management.
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enums.external
string[]
List of enums that are externally managed. Prisma will not generate migrations for these enums but will include them in the schema and client API. Requires experimental.externalTables to be enabled.
export default defineConfig({
  experimental: {
    externalTables: true
  },
  enums: {
    external: ['UserRole', 'Status']
  }
})

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views

Configures database views.
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views.path
string
Directory containing view definition SQL files (*.sql).
export default defineConfig({
  views: {
    path: './prisma/views'
  }
})

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typedSql

Configures the TypedSQL feature.
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typedSql.path
string
Directory containing TypedSQL query files (*.sql).
export default defineConfig({
  typedSql: {
    path: './prisma/queries'
  }
})

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experimental

Enables experimental features.
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experimental.externalTables
boolean
Enables support for external tables and enums. Required when using tables.external, enums.external, or migrations.initShadowDb.
export default defineConfig({
  experimental: {
    externalTables: true
  }
})
​
experimental.extensions
boolean
Enables support for Prisma extensions configuration in the config file. Required when using the extensions option.
export default defineConfig({
  experimental: {
    extensions: true
  },
  extensions: {
    // Extension configuration
  }
})

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Complete Example

import path from 'node:path'
import { defineConfig, env } from '@prisma/config'
import 'dotenv/config'

export default defineConfig({
  // Database configuration
  datasource: {
    url: env('DATABASE_URL'),
    shadowDatabaseUrl: env('SHADOW_DATABASE_URL')
  },

  // Schema location
  schema: './prisma/schema.prisma',

  // Migrations configuration
  migrations: {
    path: './prisma/migrations',
    seed: 'tsx prisma/seed.ts'
  },

  // Views and TypedSQL
  views: {
    path: './prisma/views'
  },
  typedSql: {
    path: './prisma/queries'
  },

  // External tables configuration
  experimental: {
    externalTables: true
  },
  tables: {
    external: ['audit_log', 'legacy_data']
  },
  enums: {
    external: ['UserRole']
  }
})

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Path Resolution

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Relative Paths

Relative paths in the configuration are resolved from the directory containing the config file: 
// If prisma.config.ts is at /project/prisma.config.ts
export default defineConfig({
  schema: './prisma/schema.prisma', // Resolves to /project/prisma/schema.prisma
  migrations: {
    path: './db/migrations' // Resolves to /project/db/migrations
  }
})

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Absolute Paths

You can use absolute paths or Node.js path utilities: 
import path from 'node:path'
import process from 'node:process'
import { defineConfig } from '@prisma/config'

const cwd = process.cwd()

export default defineConfig({
  schema: path.join(cwd, 'custom', 'schema.prisma'),
  migrations: {
    path: path.join(cwd, 'custom', 'migrations')
  }
})

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Validation

Prisma validates your configuration at load time:
  • Type Safety: When using TypeScript, configuration errors are caught at authoring time
  • Runtime Validation: Invalid configurations throw errors with clear messages
  • Experimental Features: Features requiring experimental flags will throw errors if the flag is not enabled

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Common Validation Errors

// ❌ Error: requires experimental.externalTables
export default defineConfig({
  tables: {
    external: ['users']
  }
})

// ✅ Correct
export default defineConfig({
  experimental: {
    externalTables: true
  },
  tables: {
    external: ['users']
  }
})

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Type Safety

For better type checking without using defineConfig, you can use the satisfies operator: 
import type { PrismaConfig } from '@prisma/config'

export default {
  datasource: {
    url: 'postgresql://localhost:5432/mydb'
  },
  schema: './prisma/schema.prisma'
} satisfies PrismaConfig

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CLI Integration

All Prisma CLI commands support the --config flag to specify a custom config location: 
prisma migrate dev --config ./custom/path/prisma.config.ts
prisma generate --config ./prisma.config.ts
prisma db push --config ./config/prisma.ts
If no --config flag is provided, Prisma searches for the config file in default locations.