@lexmata/prisma-python-generator

A Prisma generator plugin that produces Python Pydantic v2 model classes from your Prisma schema.

Installation

npm install -D @lexmata/prisma-python-generator
# or
pnpm add -D @lexmata/prisma-python-generator

Setup

Add the generator to your schema.prisma:

generator python {
  provider = "prisma-python-generator"
  output   = "./generated/prisma_models"
}

Run the generator with the GENERATE_PYTHON environment variable enabled:

GENERATE_PYTHON=true npx prisma generate

The generator is disabled by default. If GENERATE_PYTHON is not set or is not "true", the generator will skip and print a message.

Output

Given a Prisma schema like this:

enum Role {
  USER
  ADMIN
}

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

The generator produces a Python package at the configured output path:

generated/prisma_models/
├── __init__.py
├── enums.py
├── user.py
├── post.py
└── py.typed

Enums

Prisma enums become Python str enums:

from enum import Enum

class Role(str, Enum):
    USER = "USER"
    ADMIN = "ADMIN"

Models

Prisma models become Pydantic BaseModel classes:

from __future__ import annotations

from datetime import datetime
from pydantic import BaseModel, ConfigDict, Field
from .enums import Role

class User(BaseModel):
    """A user in the system"""

    id: int
    email: str
    name: str | None = Field(default=None)
    role: Role = Field(default="USER")
    posts: list["Post"] = Field(default_factory=list)
    created_at: datetime = Field(alias="createdAt")

    model_config = ConfigDict(
        from_attributes=True,
        populate_by_name=True,
    )

Imports

All models and enums are re-exported from __init__.py:

from generated.prisma_models import User, Post, Role

Features

| Feature | Detail | |---|---| | Type mapping | String→str, Int→int, Float→float, Boolean→bool, DateTime→datetime, Decimal→Decimal, Json→Any, Bytes→bytes, BigInt→int | | Enums | Generated as class Name(str, Enum) with string values | | Relations | Forward-referenced as "ModelName" strings | | List fields | list[T] with default_factory=list | | Optional fields | T \| None with default=None | | Snake case | camelCase fields get alias="originalName" with populate_by_name=True | | Defaults | Static defaults (strings, numbers, booleans) carried over; auto-generated defaults (autoincrement, now, uuid) omitted | | Docstrings | Prisma /// comments become Python docstrings | | PEP 561 | py.typed marker included for type-checker support |

Environment Variable

| Variable | Values | Default | |---|---|---| | GENERATE_PYTHON | "true" to enable | Disabled (skips generation) |

This makes it safe to include the generator in a shared schema.prisma without it running on every prisma generate invocation. Only environments that explicitly opt in will produce output.

Development

# Install dependencies
pnpm install

# Build
pnpm build

# Run tests
pnpm test

# Generate from the example schema
GENERATE_PYTHON=true pnpm generate

License

MIT © Lexmata LLC