# rails/spring

Rails application preloader

Repository: https://github.com/rails/spring
Canonical: https://ross.abutalabs.com/products/rails-spring
Language: Ruby
License: MIT
License Family: permissive
Last push: 2026-06-30T16:30:38+00:00

## Health v2 (maintenance only)
Score: 92/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 90, release rhythm 90, longevity 100
- inputs: {"age_days": 4995, "days_push": 64, "days_rel": 64, "gap_med": 0, "n_releases_24m": 50}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2814, forks 342 (observed 2026-08-28T04:07:23.805918+00:00)

## What it is
Spring is a Ruby gem that preloads Rails applications into a background process to speed up development commands. It automatically reloads application code and restarts when configuration or dependencies change.

## Use cases
- speed up running rails tests without booting the app each time
- avoid slow boot times for rake tasks and migrations
- keep a rails app warm in the background during development
- reduce iteration time when running rails commands repeatedly
- automatically reload changed application code between runs

## When to choose
- you develop a Rails 7.1+ app on macOS or Linux and run tests, rake tasks, or migrations frequently
- you want a zero-configuration preloader that manages itself automatically
- your environment supports forking (MRI Ruby, not Windows or JRuby)

## When to avoid
- you are on Windows or JRuby, which lack the fork support Spring relies on
- your Rails version is older than 7.1 or Ruby is older than 3.1
- you need predictable memory usage, since the background server keeps the app resident
- you run reloading-disabled or exotic configurations that conflict with Spring's assumptions

## Facets
- artifact type: library
- maturity: active
- function: developer-tools, build-tool, cli
- domain: web-development, developer-tools, backend
- platform: ruby, cli
- tags: rails, preloader, forking, test-speed, development-workflow, linux, macos

## Member repositories
- rails/spring (main) score 92

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:23.805918+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 2026-08-30T08:13:29.140114+00:00, confidence not recorded.
  - readme: https://github.com/rails/spring (fetched 2026-08-28T04:07:23.805918+00:00, sha 298d0e535f08)
- Data as of 2026-08-30T08:39:29.467469+00:00.