Cloudflare Workers

Yes, Prisma Postgres works on Cloudflare Workers.

Standard PostgreSQL clients (like pg or postgres.js) use TCP connections, and Cloudflare Workers doesn't support TCP by default. That's why most Postgres databases can't be accessed directly from Workers. There are two ways around it with Prisma Postgres:

1. Node.js compatibility mode: add the nodejs_compat flag to your wrangler.jsonc and Prisma ORM can use TCP via Cloudflare's Node.js TCP API. That's what this guide does.
2. Serverless HTTP driver: the @prisma/ppg driver connects over HTTP instead of TCP, so no compatibility flag is needed.

This guide uses the nodejs_compat approach. Prisma Postgres handles connection pooling, so you don't have to worry about Workers spinning up a new connection per request.

You can find a complete example on GitHub.

• Node.js 20+
• A Cloudflare account

Create a new Cloudflare Workers project:

bunx create-cloudflare prisma-cloudflare-worker --type hello-world --ts=true --git=true --deploy=false

pnpm create cloudflare prisma-cloudflare-worker --type=hello-world --ts=true --git=true --deploy=false

yarn create cloudflare prisma-cloudflare-worker --type=hello-world --ts=true --git=true --deploy=false

npm create cloudflare@latest prisma-cloudflare-worker -- --type=hello-world --ts=true --git=true --deploy=false

Navigate into the newly created project directory:

cd prisma-cloudflare-worker

To get started with Prisma, you'll need to install a few dependencies:

bun add prisma@prev dotenv-cli @types/pg --dev

pnpm add prisma@prev dotenv-cli @types/pg --save-dev

yarn add prisma@prev dotenv-cli @types/pg --dev

npm install prisma@prev dotenv-cli @types/pg --save-dev

bun add @prisma/client@7 @prisma/adapter-pg dotenv pg

pnpm add @prisma/client@7 @prisma/adapter-pg dotenv pg

yarn add @prisma/client@7 @prisma/adapter-pg dotenv pg

npm install @prisma/client@7 @prisma/adapter-pg dotenv pg

Once installed, initialize Prisma in your project:

bunx --bun prisma init

pnpm prisma init

yarn prisma init

npx prisma init

This will create:

• A prisma/ directory with a schema.prisma file
• A prisma.config.ts file with your Prisma configuration
• A .env file with a local DATABASE_URL already set

Create a Prisma Postgres database and replace the generated DATABASE_URL in your .env file with the postgres://... connection string from the CLI output:

bunx create-db

pnpm dlx create-db

yarn dlx create-db

npx create-db

Cloudflare Workers needs Node.js compatibility enabled to work with Prisma. Add the nodejs_compat compatibility flag to your wrangler.jsonc:

{

  "name": "prisma-cloudflare-worker",

  "main": "src/index.ts",

  "compatibility_flags": ["nodejs_compat"], 

  "compatibility_date": "2024-01-01"

}

In the prisma/schema.prisma file, add the following User model and set the runtime to cloudflare:

generator client {

  provider = "prisma-client"

  runtime  = "cloudflare"

  output   = "../src/generated/prisma"

}

datasource db {

  provider = "postgresql"

}

model User { 

  id    Int    @id @default(autoincrement()) 

  email String

  name  String

} 

This creates a User model with an auto-incrementing ID, email, and name.

Add the following scripts to your package.json to work with Prisma in the Cloudflare Workers environment:

{

  "scripts": {

    "migrate": "prisma migrate dev", 

    "generate": "prisma generate", 

    "studio": "prisma studio"

    // ... existing scripts

  }

}

Now, run the following command to create the database tables:

bun run migrate

pnpm run migrate

yarn migrate

npm run migrate

When prompted, name your migration (e.g., init).

Then generate the Prisma Client:

bun run generate

pnpm run generate

yarn generate

npm run generate

This generates the Prisma Client in the src/generated/prisma/client directory.

At the top of src/index.ts, import the generated Prisma Client and the PostgreSQL adapter, and define the Env interface for type-safe environment variables:

import { PrismaClient } from "./generated/prisma/client"; 

import { PrismaPg } from "@prisma/adapter-pg"; 

export interface Env {

  DATABASE_URL: string; 

} 

export default {

  async fetch(request, env, ctx): Promise<Response> {

    return new Response("Hello World!");

  },

} satisfies ExportedHandler<Env>;

Add a check to filter out favicon requests, which browsers automatically send and can clutter your logs:

import { PrismaClient } from "./generated/prisma/client";

import { PrismaPg } from "@prisma/adapter-pg";

export interface Env {

  DATABASE_URL: string;

}

export default {

  async fetch(request, env, ctx): Promise<Response> {

    const path = new URL(request.url).pathname; 

    if (path === "/favicon.ico")

      return new Response("Resource not found", {

        status: 404, 

        headers: {

          "Content-Type": "text/plain", 

        }, 

      }); 

    return new Response("Hello World!");

  },

} satisfies ExportedHandler<Env>;

Create a database adapter and initialize Prisma Client with it. This must be done for each request in edge environments:

import { PrismaClient } from "./generated/prisma/client";

import { PrismaPg } from "@prisma/adapter-pg";

export interface Env {

  DATABASE_URL: string;

}

export default {

  async fetch(request, env, ctx): Promise<Response> {

    const path = new URL(request.url).pathname;

    if (path === "/favicon.ico")

      return new Response("Resource not found", {

        status: 404,

        headers: {

          "Content-Type": "text/plain",

        },

      });

    const adapter = new PrismaPg({

      connectionString: env.DATABASE_URL, 

    }); 

    const prisma = new PrismaClient({

      adapter, 

    }); 

    return new Response("Hello World!");

  },

} satisfies ExportedHandler<Env>;

Now use Prisma Client to create a new user and count the total number of users:

import { PrismaClient } from "./generated/prisma/client";

import { PrismaPg } from "@prisma/adapter-pg";

export interface Env {

  DATABASE_URL: string;

}

export default {

  async fetch(request, env, ctx): Promise<Response> {

    const path = new URL(request.url).pathname;

    if (path === "/favicon.ico")

      return new Response("Resource not found", {

        status: 404,

        headers: {

          "Content-Type": "text/plain",

        },

      });

    const adapter = new PrismaPg({

      connectionString: env.DATABASE_URL,

    });

    const prisma = new PrismaClient({

      adapter,

    });

    const user = await prisma.user.create({

      data: {

        email: `Prisma-Postgres-User-${Math.ceil(Math.random() * 1000)}@gmail.com`, 

        name: "Jon Doe", 

      }, 

    }); 

    const userCount = await prisma.user.count(); 

    return new Response("Hello World!");

  },

} satisfies ExportedHandler<Env>;

Finally, update the response to display the newly created user and the total user count:

import { PrismaClient } from "./generated/prisma/client";import { PrismaPg } from "@prisma/adapter-pg";export interface Env {  DATABASE_URL: string;}export default {  async fetch(request, env, ctx): Promise<Response> {    const path = new URL(request.url).pathname;    if (path === "/favicon.ico")      return new Response("Resource not found", {        status: 404,        headers: {          "Content-Type": "text/plain",        },      });    const adapter = new PrismaPg({      connectionString: env.DATABASE_URL,    });    const prisma = new PrismaClient({      adapter,    });    const user = await prisma.user.create({      data: {        email: `Prisma-Postgres-User-${Math.ceil(Math.random() * 1000)}@gmail.com`,        name: "Jon Doe",      },    });    const userCount = await prisma.user.count();    return new Response(`\       Created new user: ${user.name} (${user.email}).      Number of users in the database: ${userCount}.    `);   },} satisfies ExportedHandler<Env>;

First, generate the TypeScript types for your Worker environment:

bunx wrangler types --no-strict-vars

pnpm dlx wrangler types --no-strict-vars

yarn dlx wrangler types --no-strict-vars

npx wrangler types --no-strict-vars

Then start the development server:

bun run dev

pnpm run dev

yarn dev

npm run dev

Created new user: Jon Doe (Prisma-Postgres-User-742@gmail.com).
Number of users in the database: 5.

Open http://localhost:8787 in your browser. Each time you refresh the page, a new user will be created. You should see output similar to:

Created new user: Jon Doe (Prisma-Postgres-User-742@gmail.com).

Number of users in the database: 5.

To view your database contents, open Prisma Studio:

bun run studio

pnpm run studio

yarn studio

npm run studio

This will open a browser window where you can view and edit your User table data.

Before deploying, you need to set your DATABASE_URL as a secret in Cloudflare Workers. This keeps your database connection string secure in production.

bunx wrangler secret put DATABASE_URL

pnpm dlx wrangler secret put DATABASE_URL

yarn dlx wrangler secret put DATABASE_URL

npx wrangler secret put DATABASE_URL

When prompted, paste your database connection string from the .env file.

Deploy your Worker to Cloudflare:

bun run deploy

pnpm run deploy

yarn deploy

npm run deploy

Once deployed, Cloudflare will provide you with a URL where your Worker is live (e.g., https://prisma-postgres-worker.your-subdomain.workers.dev).

Visit the URL in your browser, and you'll see your Worker creating users in production!

Now that you have a working Cloudflare Workers app connected to a Prisma Postgres database, you can:

• Add routes to handle different HTTP methods (GET, POST, PUT, DELETE)
• Extend your Prisma schema with more models and relationships
• Implement authentication and authorization
• Use Hono for routing and middleware on Cloudflare Workers (see our Hono guide)
• Use the @prisma/ppg serverless driver to connect over HTTP instead of TCP, which removes the need for the nodejs_compat flag
• Read Deploy to Cloudflare for a deeper reference on edge deployment options
• Cloudflare Workers documentation
• Prisma ORM documentation