django-pgjsonschema

django-pgjsonschema is a library designed to help you efficiently validate Postgres JSON fields on your Django models using Pydantic and pl/rust.

Quick Start

To get started, define a Pydantic model that represents the schema you want to validate your JSON field against:

import pydantic


class MySchema(pydantic.BaseModel):
    name: str
    age: int

Now, simply add a type annotation with pgjsonschema.Validator to your models' JSON field.

from django.db import models

from pgjsonschema import Validator

class MyModel(models.Model):
    data: Validator[MySchema] = models.JSONField()

Or, provide an arbitrary Python type, assuming it represents a valid JSON structure:

from typing import Any
from django.db import models

from pgjsonschema import Validator

class MyModel(models.Model):
    data: Validator[dict[str, Any]] = models.JSONField()

Adding this annotation will install a trigger on your Django model that will validate against the schema at the database level. This is done using django-pgtrigger, which is used to manage the installation of Postgres triggers in Django applications. The installed trigger is built on pl/rust, which is a required Postgres extension for django-pgjsonschema.

Compatibility

django-pgjsonschema is compatible with Python 3.11 - 3.12, Django 3.2 - 5.0, Psycopg 2 - 3, and Postgres 12 - 16.

Installation

Install django-pgjsonschema with:

pip3 install django-pgjsonschema

After this, add pgjsonschema and pgtrigger to the INSTALLED_APPS setting of your Django project.

Additionally, you will need to install the pl/rust extension in your Postgres database. You can follow the installation instructions here. pl/rust is a trusted procedural language, which allows you to write Postgres functions in Rust. We utilize to ensure efficent and performant validation of JSON fields, miniimally impacting your database write performance.

Primary Authors

• Max Muoto