# rbgirshick/yacs

YACS -- Yet Another Configuration System

Repository: https://github.com/rbgirshick/yacs
Canonical: https://ross.abutalabs.com/products/yacs
Language: Python
License: Apache-2.0
License Family: permissive
Topics: research, configuration-management, experimental-design, python
Last push: 2022-04-13T12:22:36+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 2934, "days_push": 1603, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1338, forks 90 (observed 2026-08-28T04:04:25.761093+00:00)

## What it is
YACS (Yet Another Configuration System) is a lightweight Python library for defining and managing system configurations, originally built for scientific and ML experiment settings. It provides a CfgNode object with sensible defaults, YAML-based serialization, merging of experiment-specific overrides, and a freeze mechanism for reproducibility.

## Use cases
- manage hyperparameters for machine learning experiments
- serialize experiment configs to yaml for reproducibility
- override default config values per experiment
- define a single defaults file for all project options
- freeze configuration after setup to prevent accidental changes
- manage configs for computer vision model training like detectron

## When to choose
- you run scientific or ML experiments and need reproducible, serializable configs
- you want a small, focused config library with defaults plus per-experiment yaml overrides
- your project follows the detectron/py-faster-rcnn style config paradigm

## When to avoid
- you need dynamic or schema-validated configs with complex types
- you want runtime-reloadable or environment-variable-driven configuration for services
- you need a general-purpose settings library for web apps (e.g. pydantic-settings, dynaconf)

## Facets
- artifact type: library
- maturity: maintenance
- function: configuration-management, serialization
- domain: developer-tools, machine-learning
- platform: python, cross-platform
- tags: yaml-config, experiment-config, reproducibility, hyperparameters, cfg-node, research, automation

## Member repositories
- rbgirshick/yacs (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:25.761093+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 2026-08-30T04:44:01.265974+00:00, confidence not recorded.
  - readme: https://github.com/rbgirshick/yacs (fetched 2026-08-28T04:04:25.761093+00:00, sha 85506666b186)
  - registry_pypi: https://pypi.org/pypi/yacs/json (fetched 2026-08-29T12:03:09.205186+00:00, sha 20107d8c32c0)
- Data as of 2026-08-30T08:39:29.467469+00:00.