Ability to generate json schema via custom generator

Problem

There are some servers like fastify that allow to define json schemas in order to provide better performance and input / output data validation. Right now I am using prisma with fastify and have to manually define such schemas. Most of these, however, would match types generated by prisma 1 to 1. I looked around and found few tools like json-schema-to-typescript and typebox that convert json schemas to types, but nothing that does the opposite.

Besides these servers there are some services like aws api gateway that also utalise such schemas. It would be awesome to have these generated by prisma alongside types (say under a flag in cli?), as I think prisma has all data to do this.

Suggested solution

Perhaps introduce a new cli flag like --json-schema to prisma generate command that would output these alongside types so they can be imported an used?

Alternatives

Right now these have to be written manually.

Additional context

Example below shows how a simple prisma model can be converted to json schema, there are more examples available at https://json-schema.org/understanding-json-schema that show various data type outputs for json schemas.

prisma schema

model User {
  id        Int      @id @default(autoincrement())
  createdAt DateTime @default(now())
  email     String   @unique
  name      String?
  role      Role     @default(USER)
  posts     Post[]
}

And I believe json schema for this would look as simple as

json schema output

const UserSchema = {
   id: 'number',
   createdAt: 'string',
   email: 'string',
   name: 'string',
   role: {
     type: 'string',
     enum: ['ADMIN', 'AUTHOR']
   },
   posts: {
      type: 'array',
      items: {
         type: 'object',
         properties: {
            id: 'number'
         }
      }
   }
}

[valentinpalkovic]

And here it is! https://www.npmjs.com/package/prisma-json-schema-generator

It is my first npm package though. Just give me a hint, if something is not working from the beginning on and create an issue if you miss a functionality or something is not working like expected!

[valentinpalkovic]

I would like to give it a try 😃 Progress can be trailed here: https://github.com/valentinpalkovic/prisma-json-schema-generator