# mobxjs/mobx

Simple, scalable state management.

Repository: https://github.com/mobxjs/mobx
Canonical: https://ross.abutalabs.com/products/mobx
Homepage: http://mobx.js.org
Language: TypeScript
License: MIT
License Family: permissive
Topics: mobx, reactive-programming, react, typescript, javascript
Last push: 2026-08-24T02:12:16+00:00

## Health v2 (maintenance only)
Score: 99/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 98, longevity 100
- inputs: {"age_days": 4190, "days_push": 10, "days_rel": 14, "gap_med": 0.5, "n_releases_24m": 29}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 28207, forks 1801 (observed 2026-08-28T04:11:48.200049+00:00)

## What it is
MobX is a battle-tested state management library for JavaScript and TypeScript applications built on transparent reactive programming with observables. It automatically tracks state dependencies and efficiently updates derived values and UI components when state changes.

## Use cases
- manage application state in a react app
- reactive state management with observables
- automatically update ui when data changes
- scalable state management for large frontend apps
- typescript state management library
- derive computed values from application state

## When to choose
- you want minimal-boilerplate, transparent reactivity instead of explicit reducers
- your app has complex derived/computed state that must stay in sync
- you use React (or plain JS/TS) and want fine-grained, efficient updates
- you prefer mutable-style state updates over immutable patterns

## When to avoid
- your team prefers unidirectional data flow with strict immutability (e.g., Redux conventions)
- you need a tiny single-file state solution for a very small app
- you want a framework-agnostic signal library with a smaller API surface
- implicit magic-style dependency tracking is undesirable in your codebase

## Facets
- artifact type: library
- maturity: stable
- function: state-management, frontend-framework
- domain: frontend, web-development
- platform: browser, cross-platform
- tags: reactive-programming, observable-state, react, typescript, javascript, nodejs

## Member repositories
- mobxjs/mobx (main) score 99

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:48.200049+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 2026-08-29T16:54:25.712238+00:00, confidence not recorded.
  - readme: https://github.com/mobxjs/mobx (fetched 2026-08-28T04:11:48.200049+00:00, sha b79e1f0d7d22)
  - homepage: http://mobx.js.org (fetched 2026-08-29T07:51:17.931661+00:00, sha a4094ba145fb)
- Data as of 2026-08-30T08:39:29.467469+00:00.