# alecthomas/voluptuous

CONTRIBUTIONS ONLY: Voluptuous, despite the name, is a Python data validation library.

Repository: https://github.com/alecthomas/voluptuous
Canonical: https://ross.abutalabs.com/products/voluptuous
Homepage: https://pypi.org/project/voluptuous
Language: Python
License: BSD-3-Clause
License Family: permissive
Last push: 2026-07-25T15:03:12+00:00

## Health v2 (maintenance only)
Score: 73/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 94, release rhythm 30, longevity 100
- inputs: {"age_days": 5893, "days_push": 39, "days_rel": 258, "gap_med": null, "n_releases_24m": 1}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1850, forks 236 (observed 2026-08-28T04:05:44.215148+00:00)

## What it is
Voluptuous is a Python data validation library intended for validating data coming into Python as JSON, YAML, and similar formats. It emphasizes simplicity, support for complex data structures, and useful error messages, with schemas defined as plain Python data structures.

## Use cases
- validate incoming JSON payloads in a Python API
- validate YAML configuration files
- coerce and check nested dict and list structures
- validate API request bodies against a schema
- produce helpful error messages for invalid user input
- validate data parsed from external sources before processing

## When to choose
- you want schema definitions as plain Python data structures
- you need validation of complex nested JSON/YAML data
- you want simple callable validators without subclassing
- you value clear, useful validation error messages

## When to avoid
- you need a maintainer to fix bugs for you (project is contributions-only)
- you want a library under active feature development
- you need Pydantic-style typed model parsing with IDE support
- you need high-performance validation of very large datasets

## Facets
- artifact type: library
- maturity: maintenance
- function: serialization, developer-tools
- domain: developer-tools, apis
- platform: python
- tags: data-validation, schema-validation, -validation, yaml, contributions-only, data-engineering

## Member repositories
- alecthomas/voluptuous (main) score 73

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:44.215148+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 2026-08-30T03:16:56.876700+00:00, confidence not recorded.
  - readme: https://github.com/alecthomas/voluptuous (fetched 2026-08-28T04:05:44.215148+00:00, sha c0f19f6a6349)
  - homepage: https://pypi.org/project/voluptuous (fetched 2026-08-29T10:56:41.296961+00:00, sha 4b4e8fead74a)
  - registry_pypi: https://pypi.org/pypi/voluptuous/json (fetched 2026-08-29T10:56:41.307553+00:00, sha ad2e1cb52765)
- Data as of 2026-08-30T08:39:29.467469+00:00.