# marshmallow-code/marshmallow

A lightweight library for converting complex objects to and from simple Python datatypes.

Repository: https://github.com/marshmallow-code/marshmallow
Canonical: https://ross.abutalabs.com/products/marshmallow
Homepage: https://marshmallow.readthedocs.io/
Language: Python
License: MIT
License Family: permissive
Topics: serialization, deserialization, validation, python, marshalling, serde, schema
Last push: 2026-08-26T19:50:20+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 35, longevity 100
- inputs: {"age_days": 4679, "days_push": 7, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 7242, forks 729 (observed 2026-08-28T04:09:57.780577+00:00)

## What it is
marshmallow is a lightweight, framework-agnostic Python library for converting complex objects to and from native Python datatypes using declarative schemas. It supports serialization, deserialization, and input data validation, commonly used to render objects to JSON for HTTP APIs.

## Use cases
- validate incoming API request payloads in Python
- serialize ORM objects to JSON for a REST API
- deserialize JSON into typed app-level objects
- define reusable data schemas with nested fields
- sanitize and coerce untrusted input data types

## When to choose
- you need framework-agnostic serialization and validation in Python
- you want lightweight schemas without a heavy dependency
- you need nested object serialization to and from JSON-friendly types

## When to avoid
- you need high-performance binary serialization like protobuf or msgpack
- you want automatic schema generation from models with no manual field definitions
- you need Rust/C-level serde performance

## Facets
- artifact type: library
- maturity: stable
- function: serialization, form-handling
- domain: developer-tools, apis, web-development
- platform: python, cross-platform
- tags: schema, deserialization, data-validation, orm-agnostic, data-engineering

## Member repositories
- marshmallow-code/marshmallow (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:57.780577+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:39:45.129565+00:00, confidence not recorded.
  - readme: https://github.com/marshmallow-code/marshmallow (fetched 2026-08-28T04:09:57.780577+00:00, sha 0d0ec80906b6)
  - registry_pypi: https://pypi.org/pypi/marshmallow/json (fetched 2026-08-29T08:35:01.155617+00:00, sha 4397f5481ee4)
- Data as of 2026-08-30T08:39:29.467469+00:00.