MongoDB

• MongoDB 4.2+
• Replica Set configured (required for transactions)
• Latest Prisma 6.x release, or your team’s pinned Prisma 6 version
• Node.js 20.19.0+
• TypeScript 5.4.0+

1. Schema Configuration

Use the standard Prisma 6 MongoDB setup with prisma-client-js.

In prisma/schema.prisma:

Driver Adapters

Do not apply the Prisma 7 SQL adapter setup here. MongoDB does not use a SQL @prisma/adapter-* package.

ID Field Requirement

MongoDB models must have a mapped _id field using @id and @map("_id"), usually of type String with auto() and db.ObjectId.

Relations

Relations in MongoDB expect IDs to be db.ObjectId type.

2. Environment Variable

In .env:

Migrations vs Introspection

• No Migrations: MongoDB is schema-less. prisma migrate commands do not work.
• db push: Use prisma db push to sync indexes and constraints.
• db pull: Use prisma db pull to generate schema from existing data (sampling).

Current Verification Notes

• prisma init --datasource-provider mongodb is still implemented in Prisma’s CLI source.
• Prisma’s upstream repo still contains MongoDB fixtures and tests.
• Local verification shows Prisma 7 can still recognize MongoDB inputs, but the generated client path does not provide a supported MongoDB upgrade path.
• Local verification shows Prisma 6.x works end to end with prisma-client-js, prisma db push, and new PrismaClient() against a MongoDB replica set.

Version Guidance

• For MongoDB, stay on the latest available Prisma 6.x release.
• Treat Prisma 7 MongoDB migration attempts as unsupported until Prisma ships a real MongoDB upgrade path.

Common Issues

“Transactions not supported”

Ensure your MongoDB instance is a Replica Set. Standalone instances do not support transactions. Atlas clusters are replica sets by default.

“Invalid ObjectID”

Ensure fields referencing IDs are decorated with @db.ObjectId if the target is an ObjectID.