Prisma 7 breaking changes to Prisma config file, and prisma schema

Not specified by the original author.

TL;DR

Prisma 7 moved configuration out of schema.prisma into prisma.config.ts. Fix the P1012 validation error by removing url from the datasource block in your schema and defining it in prisma.config.ts instead. If seeding fails with "Cannot read properties of undefined", add an explicit database adapter in prisma.config.ts because Prisma 7 no longer auto-detects the provider.

The error

npx prisma generate
Loaded Prisma config from prisma.config.ts. Prisma schema loaded from prisma/schema.prisma
Error: Prisma schema validation - (get-config wasm)
Error code: P1012
error: The datasource property `url` is no longer supported in schema files.

Related failure on migrate deploy in Docker:

error: The datasource property `url` is required in your Prisma config file

Fix it

1. Remove url from the datasource block in prisma/schema.prisma. Success check: npx prisma validate no longer reports P1012.

2. Define the datasource URL in prisma.config.ts:

   import { defineConfig } from "prisma/config";
   export default defineConfig({
     datasource: { url: process.env.DATABASE_URL },
   });

   Success check: npx prisma generate completes without validation errors.

3. If seeding fails with "Cannot read properties of undefined (__internal)", add an explicit adapter in prisma.config.ts (Prisma 7 no longer auto-detects the provider):

   import { PrismaPg } from "@prisma/adapter-pg";
   export default defineConfig({
     datasource: { url: process.env.DATABASE_URL },
     // adapter wiring per your database driver
   });

   Success check: prisma db seed runs without the undefined-property error.

4. For Docker multi-stage builds, make sure prisma.config.ts is copied into the final image. Success check: prisma migrate deploy in the container finds the config and connects.

When this applies

• Upgrading to Prisma 7 (from 5 or 6) breaks prisma generate, migrate deploy, or db seed.
• You see P1012 about the datasource url property, or "required in your Prisma config file".

When it does not apply

• You are on Prisma 5 or 6; the old schema-based config still works there.
• The error is a different P-code (e.g. P1001 connection refused); that is a database reachability problem.
• engine: 'classic' errors on Prisma 7: the classic engine no longer exists; use the library engine default.

Compatibility

• Prisma 7.x (breaking change introduced in 7.0). Prisma 5/6 unaffected.
• Node.js 18+. Docker multi-stage builds need the config file in the final stage.

Variant phrasings

• error: prisma schema validation - (get-config wasm) error code: p1012
• The datasource property url is no longer supported in schema files
• Prisma 7 "datasource property url is required in your Prisma config file"
• Prisma 7 seed "Cannot read properties of undefined"

Why it happens

Prisma 7 extracted all connection configuration from the schema file into prisma.config.ts, so the schema url property was removed and validation rejects it (P1012). The same move means the provider is no longer inferred from the schema datasource, so seeding needs an explicit adapter. Docker builds break when the new config file is not copied into the runtime image.

Edge cases

• engine: 'classic' in config: the classic engine was removed; delete the setting and use the default.
• Monorepos: each Prisma schema needs its own prisma.config.ts or a shared config with per-schema datasource overrides.
• Source: https://github.com/prisma/orm/issues/28573

In the GitHub issue gh:prisma/orm#28573 (https://github.com/prisma/orm/issues/28573), the problem reported was: Issue prisma/orm#28573 (closed, 73 comments): When upgrading to the latest version of prisma, i am getting issues with the config file saying engine:'classic' engine doesnt exist, then on project build i am getting an error saying the url in the db source block is deprecated but when removing it i get and error saying it is required to be added. [image] npx prisma generate Loaded Prisma config from prisma.config.ts. Prisma schema loaded from prisma\schema.prisma Error: Prisma schema validation - (get-config wasm) Error code: P1012 error: The datasource property url` is no longer supported in schema files. The verified resolution was: [nonacc / otsairaze (commenters)]: Prisma 7 moved config out of schema.prisma into prisma.config.ts, which breaks two things. (1) Seeding fails with "Cannot read properties of undefined (__internal)" because Prisma 7 no longer auto-detects the database provider: add an explicit adapter in prisma.config.ts. (2) In Docker multi-stage builds, make sure prisma.config.ts is copied into the final image, or migrate deploy fails with "The datasource property is required in your Prisma config file".