dataclasses-json

Easily serialize dataclasses to and from JSON.

dataclasses-json Permissive license MIT Active ★ 1,486 v0.6.7 released 2024-06-09

Install

dataclasses-json on PyPI

pip

pip install dataclasses-json

uv

uv add dataclasses-json

poetry

poetry add dataclasses-json

Package facts

License	MIT (permissive)
Python support	supports the current Python release (<4.0,>=3.7)
Install friction	low — pure-Python wheel
Runtime dependencies	2 — marshmallow, typing-inspect
Maintenance	actively maintained — 795 days since the last release
Last repo commit	2026-05-05
First released	2018-04-21
Popularity	one of the top 1,000 most-downloaded packages on PyPI (30-day window, as of 2026-08-13)
Known vulnerabilities	none known (OSV.dev, checked 2026-08-13)

Evidence: dataclasses_json-0.6.7-py3-none-any.whl

License :: OSI Approved :: MIT LicenseProgramming Language :: Python :: 3Programming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.7Programming Language :: Python :: 3.8Programming Language :: Python :: 3.9

About dataclasses-json

from the package's own PyPI description — quoted content, verbatim

Dataclasses JSON

https://github.com/lidatong/dataclasses-json/workflows/dataclasses-json/badge.svg (image)

This library provides a simple API for encoding and decoding dataclasses to and from JSON.

It's very easy to get started.

README / Documentation website. Features a navigation bar and search functionality, and should mirror this README exactly -- take a look!

Quickstart

pip install dataclasses-json

```python from dataclasses import dataclass from dataclasses_json import dataclass_json

@dataclass_json @dataclass class Person: name: str

person = Person(name='lidatong') person.to_json() # '{"name": "lidatong"}' <- this is a string person.to_dict() # {'name': 'lidatong'} <- this is a dict Person.from_json('{"name": "lidatong"}') # Person(1) Person.from_dict({'name': 'lidatong'}) # Person(1)

You can also apply schema validation using an alternative API

This can be useful for "typed" Python code

Person.from_json('{"name": 42}') # This is ok. 42 is not a str, but # dataclass creation does not validate...

Read as markdown · JSON record · Source repository · Homepage · Docs

AI interpretation — verify before relying

AI-generated interpretation of the package facts above; every digit, version, license, or vulnerability id it cites is grounded in the facts already shown on this page

Serializes Python dataclasses to and from JSON with minimal boilerplate, supporting nested structures, custom field naming conventions, and schema validation via marshmallow.

Low friction: pure Python wheel with only two runtime dependencies (marshmallow and typing-inspect). Repository is actively maintained with recent commits and 1486 stars, indicating stable community support.

MIT license permits unrestricted use, modification, and distribution in both open and closed-source projects, with only attribution required.

Usage

pip install dataclasses-json

from dataclasses import dataclass
from dataclasses_json import dataclass_json

@dataclass_json
@dataclass
class Person:
    name: str

person = Person(name='example')
json_str = person.to_json()  # '{"name": "example"}'
person_restored = Person.from_json(json_str)

Requires Python 3.7 or later; dataclasses are built-in from 3.7 onward.

Verdict: Mature, actively maintained library with no known vulnerabilities and permissive licensing. Low install friction and broad Python version support (3.7–3.12) make it a reliable choice for dataclass-to-JSON serialization in production environments.

Needs verification

Performance characteristics when serializing deeply nested or large dataclass hierarchies
Behavior when encoding/decoding datetime objects with non-UTC timezones across system boundaries
Whether typing-inspect and marshmallow versions have known incompatibilities with specific Python 3.12 releases

dataclass json serializationserialize dataclasses to jsonjson encoder decoder dataclassdataclass json schema validationconvert dataclass jsondataclass marshmallow integrationpython dataclass json library