# redbadger/crux

Cross-platform app development in Rust

Repository: https://github.com/redbadger/crux
Canonical: https://ross.abutalabs.com/products/crux
Homepage: https://redbadger.github.io/crux/
Language: Rust
License: Apache-2.0
License Family: permissive
Topics: mobile-development, rust
Last push: 2026-08-26T10:54:34+00:00

## Health v2 (maintenance only)
Score: 98/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 96, longevity 100
- inputs: {"age_days": 1425, "days_push": 7, "days_rel": 26, "gap_med": 21.5, "n_releases_24m": 23}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2705, forks 113 (observed 2026-08-28T04:07:11.578725+00:00)

## What it is
Crux is a Rust framework for cross-platform app development that shares business logic in a single Rust core across iOS, Android, and web. Native shells (SwiftUI, Jetpack Compose, React, etc.) provide the UI, with generated type-safe interfaces and managed, testable effects between core and shell.

## Use cases
- build a mobile app with shared Rust business logic
- share app behavior across iOS, Android, and web
- write fast user journey tests without a device or emulator
- keep UI thin in SwiftUI or Jetpack Compose while logic lives in Rust
- generate type-safe Swift, Kotlin, and TypeScript bindings from Rust types
- make side effects explicit and testable in app architecture

## When to choose
- you want one Rust core powering apps on multiple platforms
- your team values testability and strict separation of logic, UI, and effects
- you prefer native UI toolkits over a fully Rust-rendered UI
- you need cross-language type safety at the core/shell boundary

## When to avoid
- you need a stable 1.0 API — Crux is pre-1.0 with occasional breaking changes
- you want a fully Rust UI across platforms rather than thin native shells
- your team has no Rust expertise
- you're building a simple single-platform app where a shared core adds overhead

## Facets
- artifact type: framework
- maturity: active
- function: mobile-framework, web-framework, serialization, testing, sdk
- domain: mobile-development, web-development, cross-platform, developer-tools
- platform: rust, cross-platform, jvm
- tags: shared-core, ffi, swiftui, jetpack-compose, react, type-generation, elm-architecture, side-effect-management, ios, android, web-server, swift, typescript

## Member repositories
- redbadger/crux (main) score 98

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:11.578725+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 2026-08-30T02:15:51.086964+00:00, confidence not recorded.
  - readme: https://github.com/redbadger/crux (fetched 2026-08-28T04:07:11.578725+00:00, sha ae6c269ba5d9)
  - homepage: https://redbadger.github.io/crux/ (fetched 2026-08-29T09:58:51.205092+00:00, sha 76c42b774479)
- Data as of 2026-08-30T08:39:29.467469+00:00.