brownie

name	brownie
description	Provides guidance for shared state in React Native brownfield apps with @callstack/brownie. Define stores in TypeScript, run brownfield codegen, use the generated APIs in React Native and native hosts, and package native artifacts for integration.
license	MIT
metadata	{"author":"Callstack","tags":"react-native, expo, brownfield, state-management, brownie"}

Overview

Brownie provides cross-platform shared state for React Native brownfield apps. The workflow starts from *.brownie.ts store definitions, runs brownfield codegen (or packaging commands that include codegen), then uses typed APIs on TypeScript, Android, and iOS sides.

When to Apply

Reference this skill when:

• Setting up @callstack/brownie in an existing brownfield app
• Defining or changing store schemas in *.brownie.ts
• Using useStore, subscribe, getSnapshot, or setState on the JS side
• Registering and consuming stores in Android or iOS hosts
• Packaging and embedding iOS frameworks that include Brownie

Quick Reference

• Install Brownie:

npm install @callstack/brownie

• Generate native types:

npx brownfield codegen

• Packaging commands also include Brownie codegen:

# iOS
npx brownfield package:ios --scheme YourScheme --configuration Release

# Android
npx brownfield package:android --module-name :YourModuleName --variant release
npx brownfield publish:android --module-name :YourModuleName

Routing (concern -> file)

Concern	Read
Initial install, prerequisites, setup sequence, first integration pass	getting-started.md
*.brownie.ts schema rules, BrownieStores augmentation, type mapping, when to rerun codegen	store-definition-and-codegen.md
useStore selectors, update patterns, low-level APIs (subscribe, getSnapshot, setState)	typescript-usage.md
Android registration lifecycle, serializer options, package settings, build and publish flow	android-usage.md
Swift store registration and UI usage, plus XCFramework packaging and embedding	swift-and-xcframework.md

Retrieval and Response Rules

• Single-reference-first: choose exactly one primary reference from the table above that best matches the request before opening any other file.
• Stop-after-sufficiency: once the required command/API is found for the request, stop reading additional references.
• Cross-reference only when blocked: open a second reference only if the first one does not contain the needed command/API.
• Testing-context response budget:
  • Return compact actionable steps only.
  • Use at most one code snippet.
  • Do not restate overview/scope/background sections.