MongoDB

Create a Prisma ORM app with MongoDB, apply the first migration, and run your first query against seeded data.

Quick start

bun create prisma@latest --provider mongodb

Run this from a Node.js 22.18 or newer (on the 24 line, 24.11 or newer) environment; Node.js 24 is recommended. The command preselects MongoDB and prompts you for the contract authoring style (PSL or TypeScript) and your package manager.

Setup gives you the app template, a starter contract, prisma-8.md, project-level Prisma ORM skills for your coding agent, and package scripts for the database steps below. Answer no at the skills prompt, or pass --skills none, to skip the agent skill files; to remove them later, see skills sync and the skills config section. Sample users are seeded automatically the first time the app queries the database, so there is no separate seed step.

A standalone mongod is enough to work through this quickstart. A replica set is only needed for transactions and change streams, and MongoDB Atlas already gives you one. The connection string the scaffold writes assumes a single-node replica set named rs0 on port 27017, so either run one locally or edit the string to point at your standalone server. If you use a standalone mongod, remove replicaSet=rs0 from the connection strings below (keep directConnection=true); a URL that names a replica set only connects to a server that belongs to one.

1. Set the database connection

The scaffold writes a .env with a local replica-set connection string:

DATABASE_URL="mongodb://localhost:27017/mydb?replicaSet=rs0&directConnection=true"

The generated scripts read environment variables directly rather than .env, and the CLI and the app use different variable names: the CLI commands read MONGODB_URL, and the app reads DATABASE_URL. Export both in the shell you work in:

export MONGODB_URL="mongodb://localhost:27017/mydb?replicaSet=rs0&directConnection=true"
export DATABASE_URL="$MONGODB_URL"

If you use MongoDB Atlas, use the connection string from your Atlas cluster instead.

2. Create the migration plan

Create the first migration plan from the starter contract.

bun run migration:plan --name init

The output reports the planned operations: creating the users and posts collections and a unique index on users.email.

3. Apply the migration

Apply the planned migration to MongoDB.

bun run migrate

The output ends with a summary like Applied 3 operation(s) across 1 contract space. If it fails with a connection error, confirm MONGODB_URL is exported in this shell and points at a running MongoDB deployment; if the string still names replicaSet=rs0, that replica set has to exist.

4. Run the app

Start the app and confirm the sample query runs successfully.

bun run dev

Use the URL or terminal output shown by your template. You should see the seeded users returned from MongoDB.

Next steps

• Open src/prisma/contract.prisma or src/prisma/contract.ts and change the starter model.
• Use the MongoDB existing-project guide if you already have an app and database.
• Read the Prisma ORM overview when you want the concepts behind contracts, query APIs, and migrations.