Prisma JSON Schema Generator

A generator, which takes a Prisma 2 schema.prisma and generates a JSON Schema in version 7 of the specification (https://json-schema.org/).

Getting Started

1. Install

npm:

npm install prisma-json-schema-generator --save-dev

yarn:

yarn add -D prisma-json-schema-generator

2. Add the generator to the schema

generator jsonSchema {
  provider = "prisma-json-schema-generator"
}

With a custom output path (default=./json-schema)

generator jsonSchema {
  provider = "prisma-json-schema-generator"
  output = "custom-output-path"
}

Additional options

generator jsonSchema {
  provider = "prisma-json-schema-generator"
  keepRelationScalarFields = "true"
  schemaId = "some-schema-id"
}

The generator currently supports a single option

Key	Default Value	Description
keepRelationScalarFields	"false"	By default, the JSON Schema that's generated will output only objects for related model records. If set to "true", this will cause the generator to also output foreign key fields for related records
schemaId	undefined	Add an id to the generated schema. All references will include the schema id

3. Run generation

prisma:

prisma generate

nexus with prisma plugin:

nexus build

Supported Node Versions

Node Version	Support
(Maintenance LTS) 12	✔️
(Maintenance LTS) 14	✔️
(Active) 16	✔️
(Current) 17	✔️

Examples

This generator converts a prisma schema like this:

datasource db {
	provider = "postgresql"
	url      = env("DATABASE_URL")
}

model User {
    id                  Int      @id @default(autoincrement())
    createdAt           DateTime @default(now())
    email               String   @unique
    weight              Float?
    is18                Boolean?
    name                String?
    number              BigInt   @default(34534535435353)
    favouriteDecimal    Decimal
    bytes               Bytes
    successorId         Int?
    successor           User?    @relation("BlogOwnerHistory", fields: [successorId], references: [id])
    predecessor         User?    @relation("BlogOwnerHistory")
    role                Role     @default(USER)
    posts               Post[]
    keywords            String[]
    biography           Json
}

model Post {
    id     Int   @id @default(autoincrement())
    user   User? @relation(fields: [userId], references: [id])
    userId Int?
}

enum Role {
    USER
    ADMIN
}

into:

{
    $schema: 'http://json-schema.org/draft-07/schema#',
    definitions: {
        Post: {
            properties: {
                id: { type: 'integer' },
                user: {
                    anyOf: [
                        { $ref: '#/definitions/User' },
                        { type: 'null' },
                    ],
                },
            },
            type: 'object',
        },
        User: {
            properties: {
                biography: { type: 'object' },
                createdAt: { format: 'date-time', type: 'string' },
                email: { type: 'string' },
                id: { type: 'integer' },
                is18: { type: ['boolean', 'null'] },
                keywords: { items: { type: 'string' }, type: 'array' },
                name: { type: ['string', 'null'] },
                number: { type: 'integer', default: '34534535435353' },
                bytes: { type: 'string' },
                favouriteDecimal: { type: 'number' },
                posts: {
                    items: { $ref: '#/definitions/Post' },
                    type: 'array',
                },
                predecessor: {
                    anyOf: [
                        { $ref: '#/definitions/User' },
                        { type: 'null' },
                    ],
                },
                role: { enum: ['USER', 'ADMIN'], type: 'string', default: 'USER' },
                successor: {
                    anyOf: [
                        { $ref: '#/definitions/User' },
                        { type: 'null' },
                    ],
                },
                weight: { type: ['integer', 'null'] },
            },
            type: 'object',
        },
    },
    properties: {
        post: { $ref: '#/definitions/Post' },
        user: { $ref: '#/definitions/User' },
    },
    type: 'object',
}

So the following input will correctly be validated:

{
    post: {
        id: 0,
        user: {
            id: 100,
        },
    },
    user: {
        id: 10,
        createdAt: '1997-07-16T19:20:30.45+01:00',
        email: '[email protected]',
        biography: {
            bornIn: 'Scharnow',
        },
        is18: true,
        keywords: ['prisma2', 'json-schema', 'generator'],
        name: null,
        posts: [
            {
                id: 4,
            },
            {
                id: 20,
            },
        ],
        predecessor: {
            id: 10,
            email: '[email protected]',
        },
        successor: null,
        role: 'USER',
        weight: 10.14,
    },
}

License: MIT

Copyright (c) 2020 Valentin Palkovič

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.