1. Project Overview & Quickstart (pmndrs/zustand)
A small, fast and scalable bearbones state-management solution using simplified flux principles. Has a comfy API based on hooks, isn't boilerplatey or opinionated.
Don't disregard it because it's cute. It has quite the claws, lots of time was spent dealing with common pitfalls, like the dreaded zombie child problem, react concurrency, and context loss between mixed renderers. It may be the one state-manager in the React space that gets all of these right.
You can try a live demo and read the docs.
npm install zustand:warning: This readme is written for JavaScript users. If you are a TypeScript user, be sure to check out our TypeScript Usage section.
First create a store
Your store is a hook! You can put anything in it: primitives, objects, functions. State has to be updated immutably and the set function merges state to help it.
import { create } from 'zustand'
const useBearStore = create((set) => ({
bears: 0,
increasePopulation: () => set((state) => ({ bears: state.bears + 1 })),
removeAllBears: () => set({ bears: 0 }),
}))Then bind your components, and that's it!
Use the hook anywhere, no providers are needed. Select your state and the component will re-render on changes.
function BearCounter() {
const bears = useBearStore((state) => state.bears)
return <h1>{bears} around here ...</h1>
}
function Controls() {
const increasePopulation = useBearStore((state) => state.increasePopulation)
return one up
}Why zustand over redux?
- Simple and un-opinionated
- Makes hooks the primary means of consuming state
- Doesn't wrap your app in context providers
- Can inform components transiently (without causing render)
Why zustand over context?
- Less boilerplate
- Renders components only on changes
- Centralized, action-based state management
Recipes
Fetching everything
You can, but bear in mind that it will cause the component to update on every state change!
const state = useBearStore()Selecting multiple state slices
It detects changes with strict-equality (old === new) by default, this is efficient for atomic state picks.
const nuts = useBearStore((state) => state.nuts)
const honey = useBearStore((state) => state.honey)If you want to construct a single object with multiple state-picks inside, similar to redux's mapStateToProps, you can use useShallow to prevent unnecessary rerenders when the selector output does not change according to shallow equal.
import { create } from 'zustand'
import { useShallow } from 'zustand/react/shallow'
const useBearStore = create((set) => ({
nuts: 0,
honey: 0,
treats: {},
// ...
}))
// Object pick, re-renders the component when either state.nuts or state.honey change
const { nuts, honey } = useBearStore(
useShallow((state) => ({ nuts: state.nuts, honey: state.honey })),
)
// Array pick, re-renders the component when either state.nuts or state.honey change
const [nuts, honey] = useBearStore(
useShallow((state) => [state.nuts, state.honey]),
)
// Mapped picks, re-renders the component when state.treats changes in order, count or keys
const treats = useBearStore(useShallow((state) => Object.keys(state.treats)))For more control over re-rendering, you may provide any custom equality function (this example requires the use of createWithEqualityFn).
const treats = useBearStore(
(state) => state.treats,
(oldTreats, newTreats) => compare(oldTreats, newTreats),
)Overwriting state
The set function has a second argument, false by default. Instead of merging, it will replace the state model. Be careful not to wipe out parts you rely on, like actions.
const useFishStore = create((set) => ({
salmon: 1,
tuna: 2,
deleteEverything: () => set({}, true), // clears the entire store, actions included
deleteTuna: () => set(({ tuna, ...rest }) => rest, true),
}))Async actions
Just call set when you're ready, zustand doesn't care if your actions are async or not.
const useFishStore = create((set) => ({
fishies: {},
fetch: async (pond) => {
const response = await fetch(pond)
set({ fishies: await response.json() })
},
}))Read from state in actions
set allows fn-updates set(state => result), but you still have access to state outside of it through get.
const useSoundStore = create((set, get) => ({
sound: 'grunt',
action: () => {
const sound = get().sound
...Reading/writing state and reacting to changes outside of components
Sometimes you need to access state in a non-reactive way or act upon the store. For these cases, the resulting hook has utility functions attached to its prototype.
:warning: This technique is not recommended for adding state in React Server Components (typically in Next.js 13 and above). It can lead to unexpected bugs and privacy issues for your users. For more details, see #2200.
const useDogStore = create(() => ({ paw: true, snout: true, fur: true }))
// Getting non-reactive fresh state
const paw = useDogStore.getState().paw
// Listening to all changes, fires synchronously on every change
const unsub1 = useDogStore.subscribe(console.log)
// Updating state, will trigger listeners
useDogStore.setState({ paw: false })
// Unsubscribe listeners
unsub1()
// You can of course use the hook as you always would
function Component() {
const paw = useDogStore((state) => state.paw)
...Using subscribe with selector
If you need to subscribe with a selector,subscribeWithSelector middleware will help.
With this middleware subscribe accepts an additional signature:
subscribe(selector, callback, options?: { equalityFn, fireImmediately }): Unsubscribeimport { subscribeWithSelector } from 'zustand/middleware'
const useDogStore = create(
subscribeWithSelector(() => ({ paw: true, snout: true, fur: true })),
)
// Listening to selected changes, in this case when "paw" changes
const unsub2 = useDogStore.subscribe((state) => state.paw, console.log)
// Subscribe also exposes the previous value
const unsub3 = useDogStore.subscribe(
(state) => state.paw,
(paw, previousPaw) => console.log(paw, previousPaw),
)
// Subscribe also supports an optional equality function
const unsub4 = useDogStore.subscribe(
(state) => [state.paw, state.fur],
console.log,
{ equalityFn: shallow },
)
// Subscribe and fire immediately
const unsub5 = useDogStore.subscribe((state) => state.paw, console.log, {
fireImmediately: true,
})Using zustand without React
Zustand core can be imported and used without the React dependency. The only difference is that the create function does not return a hook, but the API utilities.
import { createStore } from 'zustand/vanilla'
const store = createStore((set) => ...)
const { getState, setState, subscribe, getInitialState } = store
export default storeYou can use a vanilla store with useStore hook available since v4.
import { useStore } from 'zustand'
import { vanillaStore } from './vanillaStore'
const useBoundStore = (selector) => useStore(vanillaStore, selector):warning: Note that middlewares that modify set or get are not applied to getState and setState.
Transient updates (for often occurring state-changes)
The subscribe function allows components to bind to a state-portion without forcing re-render on changes. Best combine it with useEffect for automatic unsubscribe on unmount. This can make a drastic performance impact when you are allowed to mutate the view directly.
const useScratchStore = create((set) => ({ scratches: 0, ... }))
const Component = () => {
// Fetch initial state
const scratchRef = useRef(useScratchStore.getState().scratches)
// Connect to the store on mount, disconnect on unmount, catch state-changes in a reference
useEffect(() => useScratchStore.subscribe(
state => (scratchRef.current = state.scratches)
), [])
...Sick of reducers and changing nested states? Use Immer!
Reducing nested structures is tiresome. Have you tried immer?
import { produce } from 'immer'
const useLushStore = create((set) => ({
lush: { forest: { contains: { a: 'bear' } } },
clearForest: () =>
set(
produce((state) => {
state.lush.forest.contains = null
}),
),
}))
const clearForest = useLushStore((state) => state.clearForest)
clearForest()Alternatively, there are some other solutions.
Persist middleware
You can persist your store's data using any kind of storage.
import { create } from 'zustand'
import { persist, createJSONStorage } from 'zustand/middleware'
const useFishStore = create(
persist(
(set, get) => ({
fishes: 0,
addAFish: () => set({ fishes: get().fishes + 1 }),
}),
{
name: 'food-storage', // name of the item in the storage (must be unique)
storage: createJSONStorage(() => sessionStorage), // (optional) by default, 'localStorage' is used
},
),
)See the full documentation for this middleware.
Immer middleware
Immer is available as middleware too.
import { create } from 'zustand'
import { immer } from 'zustand/middleware/immer'
const useBeeStore = create(
immer((set) => ({
bees: 0,
addBees: (by) =>
set((state) => {
state.bees += by
}),
})),
)Can't live without redux-like reducers and action types?
const types = { increase: 'INCREASE', decrease: 'DECREASE' }
const reducer = (state, { type, by = 1 }) => {
switch (type) {
case types.increase:
return { grumpiness: state.grumpiness + by }
case types.decrease:
return { grumpiness: state.grumpiness - by }
}
}
const useGrumpyStore = create((set) => ({
grumpiness: 0,
dispatch: (args) => set((state) => reducer(state, args)),
}))
const dispatch = useGrumpyStore((state) => state.dispatch)
dispatch({ type: types.increase, by: 2 })Or, just use our redux-middleware. It wires up your main-reducer, sets the initial state, and adds a dispatch function to the state itself and the vanilla API.
import { redux } from 'zustand/middleware'
const useGrumpyStore = create(redux(reducer, initialState))Redux devtools
Install the Redux DevTools Chrome extension to use the devtools middleware.
import { devtools } from 'zustand/middleware'
// Usage with a plain action store, it will log actions as "setState"
const usePlainStore = create(devtools((set) => ...))
// Usage with a redux store, it will log full action types
const useReduxStore = create(devtools(redux(reducer, initialState)))One redux devtools connection for multiple stores
import { devtools } from 'zustand/middleware'
// Usage with a plain action store, it will log actions as "setState"
const usePlainStore1 = create(devtools((set) => ..., { name, store: storeName1 }))
const usePlainStore2 = create(devtools((set) => ..., { name, store: storeName2 }))
// Usage with a redux store, it will log full action types
const useReduxStore1 = create(devtools(redux(reducer, initialState)), { name, store: storeName3 })
const useReduxStore2 = create(devtools(redux(reducer, initialState)), { name, store: storeName4 })Assigning different connection names will separate stores in redux devtools. This also helps group different stores into separate redux devtools connections.
devtools takes the store function as its first argument, optionally you can name the store or configure serialize options with a second argument.
Name store: devtools(..., {name: "MyStore"}), which will create a separate instance named "MyStore" in the devtools.
Serialize options: devtools(..., { serialize: { options: true } }).
Logging Actions
devtools will only log actions from each separated store unlike in a typical combined reducers redux store. See an approach to combining stores https://github.com/pmndrs/zustand/issues/163
You can log a specific action type for each set function by passing a third parameter:
const useBearStore = create(devtools((set) => ({
...
eatFish: () => set(
(prev) => ({ fishes: prev.fishes > 1 ? prev.fishes - 1 : 0 }),
undefined,
'bear/eatFish'
),
...You can also log the action's type along with its payload:
...
addFishes: (count) => set(
(prev) => ({ fishes: prev.fishes + count }),
undefined,
{ type: 'bear/addFishes', count, }
),
...If an action type is not provided, it is defaulted to "anonymous". You can customize this default value by providing an anonymousActionType parameter:
devtools(..., { anonymousActionType: 'unknown', ... })If you wish to disable devtools (on production for instance). You can customize this setting by providing the enabled parameter:
devtools(..., { enabled: false, ... })React context
The store created with create doesn't require context providers. In some cases, you may want to use contexts for dependency injection or if you want to initialize your store with props from a component. Because the normal store is a hook, passing it as a normal context value may violate the rules of hooks.
The recommended method available since v4 is to use the vanilla store.
import { createContext, useContext } from 'react'
import { createStore, useStore } from 'zustand'
const store = createStore(...) // vanilla store without hooks
const StoreContext = createContext()
const App = () => (
<StoreContext.Provider value={store}>
...
</StoreContext.Provider>
)
const Component = () => {
const store = useContext(StoreContext)
const slice = useStore(store, selector)
...TypeScript Usage
Basic typescript usage doesn't require anything special except for writing create<State>()(...) instead of create(...)...
import { create } from 'zustand'
import { devtools, persist } from 'zustand/middleware'
import type {} from '@redux-devtools/extension' // required for devtools typing
interface BearState {
bears: number
increase: (by: number) => void
}
const useBearStore = create()(
devtools(
persist(
(set) => ({
bears: 0,
increase: (by) => set((state) => ({ bears: state.bears + by })),
}),
{
name: 'bear-storage',
},
),
),
)A more detailed TypeScript guide is here and there.
Best practices
- You may wonder how to organize your code for better maintenance: Splitting the store into separate slices.
- Recommended usage for this unopinionated library: Flux inspired practice.
- Calling actions outside a React event handler in pre-React 18.
- Testing
- For more, have a look in the docs folder
Third-Party Libraries
Some users may want to extend Zustand's feature set which can be done using third-party libraries made by the community. For information regarding third-party libraries with Zustand, visit the doc.
Comparison with other libraries
2. Official Technical Reference & Guides (pmndrs/docs)
File: README.md
docs/getting-started/introduction.mdx
Usage
Read
$ npx @pmndrs/docs # the reader: every library, every page
$ npx @pmndrs/docs drei # straight into one
$ npx @pmndrs/docs drei/performances/instances # straight to a page
$ npx @pmndrs/docs search instanced mesh # one result per line, on stdoutโโ drives whichever pane has the focus โ the list of pages, or the page itself. โ or โฅ
hands the focus over, esc or โฅ hands it back, and the lit border says where it is โ the
wheel moves whichever pane it points at, focus or no focus. โโ changes library, b folds the sidebar away, / searches every library at once, o opens the
page in a browser, q quits. Links inside a page are clickable wherever the terminal honours
OSC 8 hyperlinks โ iTerm2, Ghostty, WezTerm, Kitty, Windows Terminal.
search is the half a pipe or an agent can use: results read {lib} {path} - {title}, the
shape the MCP server publishes its index in, and nothing found exits 1.--in drei narrows to one library, --in drei/performances/instances to the matching lines of
one page.
Both read the published llms-full.txt of each library, cached for an hour under~/.cache/pmndrs-docs โ --refresh fetches again. Outside a terminal, a page target is
written to stdout, so npx @pmndrs/docs drei/performances/instances | glow works.
Build
$ cat foo.mdx | npx @pmndrs/docs@latest build # one HTML fragment, on stdout
$ npx @pmndrs/docs@latest build docs out # one .html per .mdx, assets alongside
$ npx @pmndrs/docs@latest build docs out --format website # the whole website, statically exported--format fragment (the default) needs nothing but node โ no next build, no bundler. A
fragment is the compiled MDX and nothing else: no layout, no stylesheet, no script. Mermaid
diagrams stay fenced blocks, and Sandpack shows its code without the editor.
build --help lists every website option โ --libname, --base-path, --icon, --theme-*โฆ Each
one falls back to the environment variable it maps to, the same ones
configuration documents.
Preview a folder of MDX, served
$ curl -sL https://raw.githubusercontent.com/pmndrs/docs/refs/heads/main/preview.sh | \
MDX="docs" \
ICON="๐ฅ" \
shBuilds the website, then serves it โ alongside the MDX folder itself, so relative assets
resolve while you edit. Any option from
configuration goes in the same way, andVERSION picks a published version of the CLI.
Releasing
Every push to main redeploys docs.pmnd.rs via ci.yml โ no changeset needed for that.
Add one (pnpm changeset) only when downstream consumers pinning pmndrs/docs/.github/workflows/build.yml@v4 or @pmndrs/docs@4 should pull the change. It bumps package.json, publishes to npm, and tags vX.Y.Z + vX โ so @v4 resolves to the latest.
TL;DR โ site-only tweak: skip. Anything consumers see (workflow, build behavior, templates): add one.
Test
Visual tests are performed in the cloud, through chromatic.yml.
You can also replay locally:
$ npx playwright test --update-snapshots
$ npx chromatic --playwright --project-token $CHROMATIC_PROJECT_TOKENFile: Readme.md
Poimandres
git clone https://github.com/pmndrs/website.git
cd website
yarn
yarn devFile: readme.md
Poimandres
git clone https://github.com/pmndrs/website.git
cd website
yarn
yarn devFile: docs/getting-started/introduction.mdx
title: pmndrs/docs nav: 0
A static MDX documentation generator, with a GitHub reusable workflow. It is primarily used for some pmndrs/* projects, but will work for anyone.
Those projects are known to be using this generator.
INSTALL
Pre-requisites:
- Install nvm, then:nb: if you want this node version to be your default nvm's one:sh
$ nvm install $ nvm use $ node -v # make sure your version satisfies package.json#engines.nodenvm alias default node
$ git clone https://github.com/pmndrs/docs.git
$ cd docs
$ pnpm installConfiguration
[!IMPORTANT]
Default value is always:
""(think empty).
| var | description | example |
|---|---|---|
MDX* |
Path to *.mdx folderNB: can be relative or absolute |
docs or ~/code/myproject/documentation |
NEXT_PUBLIC_LIBNAME* |
Library name | React Three Fiber |
NEXT_PUBLIC_LIBNAME_SHORT |
Library short name | r3f |
NEXT_PUBLIC_LIBNAME_DOTSUFFIX_LABEL |
Text for the ".docs" suffix link inside the header | docs |
NEXT_PUBLIC_LIBNAME_DOTSUFFIX_HREF |
Href for the ".docs" suffix link inside the header | https://docs.pmnd.rs |
BASE_PATH |
Base path for the final URL | /react-three-fiber |
DIST_DIR |
Path to the output folder (within project) | out or docs/out/react-three-fiber |
OUTPUT |
Set to export for static output |
export |
HOME_REDIRECT |
Where the home should redirect | /getting-started/introduction |
MDX_BASEURL |
Base URL for inlining relative images | http://localhost:60141or https://github.com/pmndrs/react-three-fiber/raw/master/docs |
SOURCECODE_BASEURL |
Base URL for sourcecode: code path |
https://github.com/pmndrs/react-three-fiber/tree/main |
EDIT_BASEURL |
Base URL for displaying "Edit this page" URLs | https://github.com/pmndrs/react-three-fiber/edit/master/docs |
NEXT_PUBLIC_URL |
Final URL of the published website | https://pmndrs.github.io/react-three-fiber |
ICON |
Emoji or image to use as (fav)icon (path local to MDX) |
๐จ๐ญ or /icon.png or /favicon.ico |
LOGO |
Logo src/path (either FQURL or local to MDX path) |
/logo.png or https://worldvectorlogo.com/r3f.png |
GITHUB |
Github URL | https://github.com/pmndrs/react-three-fiber |
DISCORD |
Discord URL | https://discord.com/channels/740090768164651008/740093168770613279 |
THEME_PRIMARY |
Primary accent color | #323e48 |
THEME_SCHEME |
Theme scheme | content or expressive or fidelity or monochrome or neutral or tonalSpot or vibrant |
THEME_CONTRAST |
Theme contrast -- value between -1 and 1 | 0 or -1 or 1 or -.6 |
THEME_NOTE |
"note" color | #1f6feb |
THEME_TIP |
"tip" color | #238636 |
THEME_IMPORTANT |
"important" color | #8957e5 |
THEME_WARNING |
"warning" color | #d29922 |
THEME_CAUTION |
"caution" color | #da3633 |
CONTRIBUTORS_PAT |
GitHub token for contributors API (see: https://docs.github.com/en/rest/collaborators/collaborators?apiVersion=2022-11-28#list-repository-collaborators) | ghp_1234567890 |
* Required
MDX_BASEURL
Given a advanced/introduction.mdx file in the MDX folder:
becomes (for a MDX_BASEURL=http://localhost:60141 value):
http://localhost:60141 being the MDX folder served.
[!TIP]
When deployed on GitHub Pages,MDX_BASEURLwill typically value something likehttps://github.com/pmndrs/uikit/raw/main/docs, thanks tobuild.ymlrule.
THEME_*
We implement m3 design system, using material-theme-builder.
[!NOTE]
- Material Color for more information
- We currently don't have secondary/tertiary colors (maybe some day).
Usage
dev
$ (
trap 'kill -9 0' SIGINT
export _PORT=60141
export MDX=docs
export NEXT_PUBLIC_LIBNAME="Poimandres"
export NEXT_PUBLIC_LIBNAME_SHORT="pmndrs"
export NEXT_PUBLIC_LIBNAME_DOTSUFFIX_LABEL="docs"
export NEXT_PUBLIC_LIBNAME_DOTSUFFIX_HREF="https://docs.pmnd.rs"
export BASE_PATH=
export DIST_DIR=
export OUTPUT=
export HOME_REDIRECT=
export MDX_BASEURL=http://localhost:$_PORT
export SOURCECODE_BASEURL="vscode://file$(pwd)"
export EDIT_BASEURL="vscode://file$(pwd)/docs"
export NEXT_PUBLIC_URL=
export ICON=
export LOGO=gutenberg.jpg
export GITHUB=https://github.com/pmndrs/docs
export DISCORD=https://discord.com/channels/740090768164651008/1264328004172255393
export THEME_PRIMARY="#323e48"
export THEME_SCHEME="tonalSpot"
export THEME_CONTRAST="0"
export THEME_NOTE="#1f6feb"
export THEME_TIP="#238636"
export THEME_IMPORTANT="#8957e5"
export THEME_WARNING="#d29922"
export THEME_CAUTION="#da3633"
export CONTRIBUTORS_PAT=
kill $(lsof -ti:"$_PORT")
npx serve $MDX -p $_PORT --no-port-switching --no-clipboard &
pnpm run dev &
wait
)Then go to: http://localhost:3000
[!TIP]
IfHOME_REDIRECT=empty,/will not redirect, and instead displays an index of libraries.
build
$ (
trap 'kill -9 0' SIGINT
rm -rf out
export _PORT=60141
export MDX=docs
export NEXT_PUBLIC_LIBNAME="Poimandres"
export NEXT_PUBLIC_LIBNAME_SHORT="pmndrs"
export NEXT_PUBLIC_LIBNAME_DOTSUFFIX_LABEL="docs"
export NEXT_PUBLIC_LIBNAME_DOTSUFFIX_HREF="https://docs.pmnd.rs"
export BASE_PATH=
export DIST_DIR=
export OUTPUT=export
export HOME_REDIRECT=/getting-started/introduction
export MDX_BASEURL=http://localhost:$_PORT
export SOURCECODE_BASEURL=
export EDIT_BASEURL=
export NEXT_PUBLIC_URL=
export ICON=
export LOGO=gutenberg.jpg
export GITHUB=https://github.com/pmndrs/docs
export DISCORD=https://discord.com/channels/740090768164651008/1264328004172255393
export THEME_PRIMARY="#323e48"
export THEME_SCHEME="tonalSpot"
export THEME_CONTRAST="0"
export THEME_NOTE="#1f6feb"
export THEME_TIP="#238636"
export THEME_IMPORTANT="#8957e5"
export THEME_WARNING="#d29922"
export THEME_CAUTION="#da3633"
export CONTRIBUTORS_PAT=
pnpm run build
kill $(lsof -ti:"$_PORT")
npx serve $MDX -p $_PORT --no-port-switching --no-clipboard &
npx serve out &
wait
)CLI
No clone, no install โ the published CLI does the same build:
$ cd ~/code/pmndrs/react-three-fiber
$ (
trap 'kill -9 0' SIGINT
export _PORT=60141
export NEXT_PUBLIC_LIBNAME="React Three Fiber"
export NEXT_PUBLIC_LIBNAME_SHORT="r3f"
export BASE_PATH=/toto
export HOME_REDIRECT=/getting-started/introduction
export MDX_BASEURL=http://localhost:$_PORT
export ICON=๐จ๐ญ
export GITHUB=https://github.com/pmndrs/react-three-fiber
npx -y @pmndrs/docs@latest build docs docs/out --format website
kill $(lsof -ti:"$_PORT")
npx serve docs -p $_PORT --no-port-switching --no-clipboard &
npx -y serve docs/out &
wait
)Then go to: http://localhost:3000
Every option above has a flag too โ npx @pmndrs/docs@latest build --help lists them.
Agents
llms.txt dumps and the pmndrs MCP server moved to their own page: Agents.