Astro

Introduction

Astro is a web framework for content-driven sites. In this guide, an Astro API route is where you call Prisma ORM to read from a Prisma Postgres database.

In this guide, you'll learn to integrate Prisma ORM with a Prisma Postgres database in an Astro project from scratch. You can find a complete example of this guide on GitHub.

Quick start

Run one command to scaffold an Astro project with Prisma ORM and Prisma Postgres ready to go:

title="bun"

bunx create-prisma@stable --template astro

pnpm

pnpm create prisma@stable --template astro

yarn

yarn create prisma@stable --template astro

npm

npm create prisma@stable -- --template astro

Or follow the steps below to set it up manually.

Prerequisites

1. Set up your project

Create a new Astro project:

bunx create-astro@latest

Bash

pnpm dlx create-astro@latest

Bash

yarn dlx create-astro@latest

Bash

npx create-astro@latest

[!NOTE]
Where should we create your new project? astro-prisma
How would you like to start your new project? Use minimal (empty) template
Install dependencies? (recommended) Yes
Initialize a new git repository? (optional) Yes

Navigate into the newly created project directory:

Bash

cd astro-prisma

Navigate into the newly created project directory:

cd astro-prisma

2. Install and Configure Prisma

2.1. Install dependencies

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

title="bun"

bun add prisma@prev tsx @types/pg --dev

pnpm

pnpm add prisma@prev tsx @types/pg --save-dev

yarn

yarn add prisma@prev tsx @types/pg --dev

npm

npm install prisma@prev tsx @types/pg --save-dev

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

Bash

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

Bash

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

Bash

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

[!NOTE] If you are using a different database provider (MySQL, SQL Server, SQLite), install the corresponding driver adapter package instead of @prisma/adapter-pg. For more information, see Database drivers.

Once installed, initialize Prisma in your project:

bunx --bun prisma init --output ../prisma/generated

Bash

pnpm prisma init --output ../prisma/generated

Bash

yarn prisma init --output ../prisma/generated

Bash

npx prisma init --output ../prisma/generated

[!NOTE] prisma init creates the Prisma scaffolding and a local DATABASE_URL. In the next step, you will create a Prisma Postgres database and replace that value with a direct postgres://... connection string.

This will create:

A prisma/ directory with a schema.prisma file
A prisma.config.ts file for configuring Prisma
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:

This will create:

A prisma/ directory with a schema.prisma file
A prisma.config.ts file for configuring Prisma
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:

title="bun"

bunx create-db

pnpm

pnpm dlx create-db

yarn

yarn dlx create-db

npm

npx create-db

2.2. Define your Prisma Schema

In the prisma/schema.prisma file, add the following models and change the generator to use the prisma-client provider:

title="prisma/schema.prisma"

generator client {

  provider   = "prisma-client"

  output     = "../prisma/generated"

}

datasource db {

  provider = "postgresql"

}

model User { 

  id    Int     @id @default(autoincrement()) 

  email String  @unique

  name  String?

  posts Post[]

} 

model Post { 

  id        Int     @id @default(autoincrement()) 

  title     String

  content   String?

  published Boolean @default(false) 

  authorId  Int

  author    User    @relation(fields: [authorId], references: [id]) 

}

This creates two models: User and Post, with a one-to-many relationship between them.

2.3 Add `dotenv` to `prisma.config.ts`

To get access to the variables in the .env file, they can either be loaded by your runtime, or by using dotenv. Include an import for dotenv at the top of the prisma.config.ts

import "dotenv/config"; 

import { defineConfig, env } from "prisma/config";

export default defineConfig({

  schema: "prisma/schema.prisma",

  migrations: {

    path: "prisma/migrations",

  },

  datasource: {

    url: env("DATABASE_URL"),

  },

});

2.4. Run migrations and generate Prisma Client

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

title="bun"

bunx prisma migrate dev --name init

pnpm

pnpm prisma migrate dev --name init

yarn

yarn prisma migrate dev --name init

npm

npx prisma migrate dev --name init

Then generate Prisma Client:

title="bun"

bunx prisma generate

pnpm

pnpm prisma generate

yarn

yarn prisma generate

npm

npx prisma generate

2.5. Seed the database

Add some seed data to populate the database with sample users and posts.

Create a new file called seed.ts in the prisma/ directory:

title="prisma/seed.ts"

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

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

const adapter = new PrismaPg({

  connectionString: process.env.DATABASE_URL!,

});

const prisma = new PrismaClient({

  adapter,

});

const userData: Prisma.UserCreateInput[] = [

  {

    name: "Alice",

    email: "alice@prisma.io",

    posts: {

      create: [

        {

          title: "Join the Prisma Discord",

          content: "https://pris.ly/discord",

          published: true,

        },

        {

          title: "Prisma on YouTube",

          content: "https://pris.ly/youtube",

        },

      ],

    },

  },

  {

    name: "Bob",

    email: "bob@prisma.io",

    posts: {

      create: [

        {

          title: "Follow Prisma on Twitter",

          content: "https://www.twitter.com/prisma",

          published: true,

        },

      ],

    },

  },

];

export async function main() {

  console.log("Starting to seed...");

  for (const u of userData) {

    await prisma.user.upsert({

      where: { email: u.email },

      update: {},

      create: u,

    });

  }

  console.log("Seeding finished.");

}

main()

  .catch((e) => {

    console.error(e);

    process.exit(1);

  })

  .finally(async () => {

    await prisma.$disconnect();

  });

Now, tell Prisma how to run this script by updating your prisma.config.ts:

title="prisma.config.ts"

import "dotenv/config";

import { defineConfig, env } from "prisma/config";

export default defineConfig({

  schema: "prisma/schema.prisma",

  migrations: {

    path: "prisma/migrations",

    seed: `tsx prisma/seed.ts`,

  },

  datasource: {

    url: env("DATABASE_URL"),

  },

});

Run the seed script:

title="bun"

bunx prisma db seed

pnpm

pnpm prisma db seed

yarn

yarn prisma db seed

npm

npx prisma db seed

And open Prisma Studio to inspect your data:

title="bun"

bunx prisma studio

pnpm

pnpm prisma studio

yarn

yarn prisma studio

npm

npx prisma studio

3. Integrate Prisma into Astro

3.1. Create TypeScript environment definitions

First, create an env.d.ts file in your src directory to provide TypeScript definitions for environment variables:

title="src/env.d.ts"

interface ImportMetaEnv {

  readonly DATABASE_URL: string;

}

interface ImportMeta {

  readonly env: ImportMetaEnv;

}

3.2. Create a Prisma Client

Inside of /src, create a lib directory and a prisma.ts file inside it. This file will be used to create and export your Prisma Client instance.

mkdir src/lib

touch src/lib/prisma.ts

Set up the Prisma client like this:

title="src/lib/prisma.ts"

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

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

const adapter = new PrismaPg({

  connectionString: import.meta.env.DATABASE_URL,

});

const prisma = new PrismaClient({

  adapter,

});

export default prisma;

3.3. Create an API route

An API route lets you query the database on the server and reuse the result from your pages.

Create a new file called api/users.ts in the src/pages directory:

mkdir src/pages/api

touch src/pages/api/users.ts

Now, create a GET route that fetches the Users data from your database, making sure to include each user's Posts by adding them to the include field:

title="src/pages/api/users.ts"

import type { APIRoute } from "astro";

import prisma from "../../lib/prisma";

export const GET: APIRoute = async () => {

  const users = await prisma.user.findMany({

    include: { posts: true },

  });

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

    headers: { "Content-Type": "application/json" },

  });

};

3.4. Fetch the data from the API route (Recommended Method)

Instead of using fetch() with HTTP requests, Astro recommends importing endpoint functions directly. This approach is more efficient and avoids URL parsing issues.

Start by creating a new type that combines the User and Post models called UserWithPosts:

title="src/pages/index.astro"

--import type { User, Post } from "../../prisma/generated/client"; import { GET } from "./api/users.ts"; type UserWithPosts = User & { posts: Post[] }; const response = await GET(Astro); const users: UserWithPosts[] = await response.json(); --<html lang="en">  <head>    <meta charset="utf-8" />    <link rel="icon" type="image/svg+xml" href="/favicon.svg" />    <meta name="viewport" content="width=device-width" />    <meta name="generator" content={Astro.generator} />    <title>Astro + Prisma</title>  </head>  <body>    <h1>Astro + Prisma</h1>    <ul>      {users.map((user: UserWithPosts) => (         <li>          <h2>{user.name}</h2>          <ul>            {user.posts.map((post: Post) => (               <li>{post.title}</li>             ))}          </ul>        </li>       ))}    </ul>  </body></html>

3.5. Run your app

Now start your development server to see your Astro app in action:

bun run dev

Bash

pnpm run dev

Bash

yarn dev

Bash

npm run dev

Open your browser at http://localhost:4321 to see the users and their posts displayed on the page.

Summary

Your Astro app now reads users and their posts from a Prisma Postgres database through the API route.

Next Steps

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

Extend your Prisma schema with more models and relationships
Add create/update/delete routes and forms
Explore authentication and validation