# fxn/zeitwerk

Efficient and thread-safe code loader for Ruby

Repository: https://github.com/fxn/zeitwerk
Canonical: https://ross.abutalabs.com/products/zeitwerk
Language: Ruby
License: MIT
License Family: permissive
Last push: 2026-08-06T06:44:48+00:00

## Health v2 (maintenance only)
Score: 75/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 96, release rhythm 35, longevity 100
- inputs: {"age_days": 2791, "days_push": 27, "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 2138, forks 127 (observed 2026-08-28T04:06:18.141866+00:00)

## What it is
Zeitwerk is an efficient, thread-safe code loader for Ruby that maps file paths to constant paths. It supports autoloading, eager loading, reloading, and is the loader used by Ruby on Rails.

## Use cases
- autoload Ruby classes and modules from file paths
- eager load an entire Ruby application or gem
- reload code in development without restarting
- load code in a thread-safe web server environment
- enforce file-constant naming conventions in a project
- set up autoloading for a Ruby gem

## When to choose
- you are building a Ruby gem or application and want convention-based autoloading
- you need thread-safe lazy loading or eager loading
- you want Rails-style autoloading outside Rails

## When to avoid
- your project does not follow file-path-to-constant-path conventions and cannot be restructured
- you need dynamic loading of files with arbitrary names

## Facets
- artifact type: library
- maturity: stable
- function: developer-tools
- domain: developer-tools, web-development, programming-languages
- platform: ruby
- tags: autoloading, code-loading, thread-safe, eager-loading, ruby-gem, conventions

## Member repositories
- fxn/zeitwerk (main) score 75

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:18.141866+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 2026-08-30T02:51:36.505281+00:00, confidence not recorded.
  - readme: https://github.com/fxn/zeitwerk (fetched 2026-08-28T04:06:18.141866+00:00, sha cbd09ae55690)
- Data as of 2026-08-30T08:39:29.467469+00:00.