5.0.9

* chore(deps): update dev dependencies

* fix devtools test

* update old ts test

* update older ts test

* possible fix

* testing old ts

* move it to older ts

.github/workflows/compressed-size.yml

@@ -6,7 +6,7 @@ jobs:
   compressed_size:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:

.github/workflows/preview-release.yml

@@ -6,7 +6,7 @@ jobs:
   preview_release:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:

.github/workflows/publish.yml

@@ -4,11 +4,15 @@ on:
   release:
     types: [published]
 
+permissions:
+  id-token: write
+  contents: read
+
 jobs:
   publish:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:
@@ -18,6 +22,4 @@ jobs:
       - run: pnpm install
       - run: pnpm run build
       - run: npm publish
-        env:
-          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
         working-directory: dist

.github/workflows/test-multiple-builds.yml

@@ -15,7 +15,7 @@ jobs:
         build: [cjs, esm]
         env: [development] # [development, production]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:
@@ -41,7 +41,7 @@ jobs:
         if: ${{ matrix.build == 'esm' }}
         run: |
           sed -i~ "s/resolve('\.\/src\(.*\)\.ts')/resolve('\.\/dist\/esm\1.mjs')/" vitest.config.mts
-          sed -i~ "1s/^/import.meta.env=import.meta.env||{};import.meta.env.MODE='${NODE_ENV}';/" tests/*.tsx
+          sed -i~ "1s/^/import.meta.env.MODE='${NODE_ENV}';/" tests/*.tsx
         env:
           NODE_ENV: ${{ matrix.env }}
       - name: Test ${{ matrix.build }} ${{ matrix.env }}

.github/workflows/test-multiple-versions.yml

@@ -22,7 +22,7 @@ jobs:
           - 19.2.0-canary-0bdb9206-20250818
           - 0.0.0-experimental-0bdb9206-20250818
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:

.github/workflows/test-old-typescript.yml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         typescript:
-          - 5.9.2
+          - 5.9.3
           - 5.8.3
           - 5.7.3
           - 5.6.3
@@ -29,7 +29,7 @@ jobs:
           - 4.6.4
           - 4.5.5
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:
@@ -45,14 +45,19 @@ jobs:
         run: |
           sed -i~ 's/"verbatimModuleSyntax": true,//' tsconfig.json
       - name: Patch for Old TS
+        if: ${{ matrix.typescript == '5.3.3' || matrix.typescript == '5.2.2' || matrix.typescript == '5.1.6' || matrix.typescript == '5.0.4' || matrix.typescript == '4.9.5' || matrix.typescript == '4.8.4' || matrix.typescript == '4.7.4' || matrix.typescript == '4.6.4' || matrix.typescript == '4.5.5' }}
         run: |
           sed -i~ 's/"moduleResolution": "bundler",/"moduleResolution": "node",/' tsconfig.json
           sed -i~ 's/"allowImportingTsExtensions": true,//' tsconfig.json
           sed -i~ 's/"zustand": \["\.\/src\/index\.ts"\],/"zustand": [".\/dist\/index.d.ts"],/' tsconfig.json
           sed -i~ 's/"zustand\/\*": \["\.\/src\/\*\.ts"\]/"zustand\/*": [".\/dist\/*.d.ts"]/' tsconfig.json
           sed -i~ 's/"include": .*/"include": ["src\/types.d.ts", "dist\/**\/*", "tests\/**\/*"],/' tsconfig.json
+      - name: Patch for Older TS
+        if: ${{ matrix.typescript == '4.7.4' || matrix.typescript == '4.6.4' || matrix.typescript == '4.5.5' }}
+        run: |
           pnpm json -I -f package.json -e "this.resolutions={}; this.resolutions['@types/node']='18.13.0';"
           pnpm add -D @types/node@18.13.0
+          pnpm add -D vitest@3.2.4 @vitest/coverage-v8@3.2.4 @vitest/ui@3.2.4
       - name: Install old TypeScript
         run: pnpm add -D typescript@${{ matrix.typescript }}
       - name: Test ${{ matrix.typescript }}

.github/workflows/test.yml

@@ -10,7 +10,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: pnpm/action-setup@v4
       - uses: actions/setup-node@v6
         with:

README.md

@@ -8,6 +8,12 @@
 [![Downloads](https://img.shields.io/npm/dt/zustand.svg?style=flat&colorA=000000&colorB=000000)](https://www.npmjs.com/package/zustand)
 [![Discord Shield](https://img.shields.io/discord/740090768164651008?style=flat&colorA=000000&colorB=000000&label=discord&logo=discord&logoColor=ffffff)](https://discord.gg/poimandres)
 
+<a href="https://dai-shi.github.io/zustand-banner-sponsorship/sponsors/" target="_blank" rel="noopener">
+  <p align="center">
+    <img src="https://dai-shi.github.io/zustand-banner-sponsorship/api/banner.png" />
+  </p>
+</a>
+
 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](https://react-redux.js.org/api/hooks#stale-props-and-zombie-children), [react concurrency](https://github.com/bvaughn/rfcs/blob/useMutableSource/text/0000-use-mutable-source.md), and [context loss](https://github.com/facebook/react/issues/13332) between mixed renderers. It may be the one state-manager in the React space that gets all of these right.

examples/demo/src/components/Details.jsx

@@ -6,18 +6,17 @@ export default function Details() {
         <a href="https://github.com/pmndrs/zustand">Github</a>
       </nav>
       <div className="bottom">
-        <a
-          href="https://github.com/pmndrs/zustand/tree/main/examples/demo"
-          className="bottom-right"
-        >
-          {'<Source />'}
-        </a>
-        <a
-          href="https://www.instagram.com/tina.henschel/"
-          className="bottom-left"
-        >
+        <a href="https://www.instagram.com/tina.henschel/">
           Illustrations @ Tina Henschel
         </a>
+        <div className="bottom-links">
+          <a href="https://github.com/pmndrs/zustand/tree/main/examples/demo">
+            {'<Source />'}
+          </a>
+          <a href="https://stackblitz.com/github/pmndrs/zustand/tree/main/examples/starter?file=src%2Findex.tsx">
+            {'<Playground />'}
+          </a>
+        </div>
       </div>
       <span className="header-left">Zustand</span>
     </>

examples/demo/src/styles.css

@@ -158,14 +158,26 @@ a {
   flex: 0 0 auto;
 }
 
-a.bottom-left {
+.bottom {
+  position: fixed;
   bottom: 40px;
   left: 40px;
+  right: 40px;
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  justify-content: space-between;
+  gap: 12px;
 }
 
-a.bottom-right {
-  bottom: 40px;
-  right: 40px;
+.bottom a {
+  position: static;
+}
+
+.bottom-links {
+  display: flex;
+  gap: 16px;
+  align-items: center;
 }
 
 .snippet-container {

package.json

@@ -3,7 +3,7 @@
   "description": "🐻 Bear necessities for state management in React",
   "private": true,
   "type": "commonjs",
-  "version": "5.0.8",
+  "version": "5.0.9",
   "main": "./index.js",
   "types": "./index.d.ts",
   "typesVersions": {
@@ -116,7 +116,7 @@
   "homepage": "https://github.com/pmndrs/zustand",
   "packageManager": "pnpm@10.18.3",
   "devDependencies": {
-    "@eslint/js": "^9.38.0",
+    "@eslint/js": "^9.39.1",
     "@redux-devtools/extension": "^3.3.0",
     "@rollup/plugin-alias": "^6.0.0",
     "@rollup/plugin-node-resolve": "^16.0.3",
@@ -124,37 +124,37 @@
     "@rollup/plugin-typescript": "12.3.0",
     "@testing-library/jest-dom": "^6.9.1",
     "@testing-library/react": "^16.3.0",
-    "@types/node": "^24.9.2",
-    "@types/react": "^19.2.2",
-    "@types/react-dom": "^19.2.2",
+    "@types/node": "^24.10.1",
+    "@types/react": "^19.2.7",
+    "@types/react-dom": "^19.2.3",
     "@types/use-sync-external-store": "^1.5.0",
-    "@vitest/coverage-v8": "^3.2.4",
-    "@vitest/eslint-plugin": "^1.3.26",
-    "@vitest/ui": "^3.2.4",
-    "esbuild": "^0.25.11",
-    "eslint": "9.38.0",
+    "@vitest/coverage-v8": "^4.0.14",
+    "@vitest/eslint-plugin": "^1.5.0",
+    "@vitest/ui": "^4.0.14",
+    "esbuild": "^0.27.0",
+    "eslint": "9.39.1",
     "eslint-import-resolver-typescript": "^4.4.4",
     "eslint-plugin-import": "^2.32.0",
     "eslint-plugin-jest-dom": "^5.5.0",
     "eslint-plugin-react": "^7.37.5",
     "eslint-plugin-react-hooks": "^7.0.1",
-    "eslint-plugin-testing-library": "^7.13.3",
-    "immer": "^10.2.0",
-    "jsdom": "^27.0.1",
+    "eslint-plugin-testing-library": "^7.13.5",
+    "immer": "^11.0.1",
+    "jsdom": "^27.2.0",
     "json": "^11.0.0",
-    "prettier": "^3.6.2",
+    "prettier": "^3.7.2",
     "react": "19.2.0",
     "react-dom": "19.2.0",
     "redux": "^5.0.1",
-    "rollup": "^4.52.5",
+    "rollup": "^4.53.3",
     "rollup-plugin-esbuild": "^6.2.1",
     "shelljs": "^0.10.0",
     "shx": "^0.4.0",
     "tslib": "^2.8.1",
     "typescript": "^5.9.3",
-    "typescript-eslint": "^8.46.2",
+    "typescript-eslint": "^8.48.0",
     "use-sync-external-store": "^1.6.0",
-    "vitest": "^3.2.4"
+    "vitest": "^4.0.14"
   },
   "peerDependencies": {
     "@types/react": ">=18.0.0",

src/middleware.ts

@@ -14,3 +14,4 @@ export {
   type PersistStorage,
   type PersistOptions,
 } from './middleware/persist.ts'
+export { ssrSafe as unstable_ssrSafe } from './middleware/ssrSafe.ts'

src/middleware/ssrSafe.ts

@@ -0,0 +1,25 @@
+import type { StateCreator, StoreMutatorIdentifier } from '../vanilla.ts'
+
+// This is experimental middleware. It will be changed before finalizing it.
+// https://github.com/pmndrs/zustand/discussions/2740
+// TODO Not very happy with the middleware name. Will revisit it later.
+export function ssrSafe<
+  T extends object,
+  U extends object,
+  Mps extends [StoreMutatorIdentifier, unknown][] = [],
+  Mcs extends [StoreMutatorIdentifier, unknown][] = [],
+>(
+  config: StateCreator<T, Mps, Mcs, U>,
+  isSSR: boolean = typeof window === 'undefined',
+): StateCreator<T, Mps, Mcs, U> {
+  return (set, get, api) => {
+    if (!isSSR) {
+      return config(set, get, api)
+    }
+    const ssrSet = () => {
+      throw new Error('Cannot set state of Zustand store in SSR')
+    }
+    api.setState = ssrSet
+    return config(ssrSet as never, get, api)
+  }
+}

tests/devtools.test.tsx

@@ -18,7 +18,7 @@ type TupleOfEqualLength<Arr extends unknown[], T> = number extends Arr['length']
 type Connection = {
   subscribers: ((message: unknown) => void)[]
   api: {
-    subscribe: Mock<any>
+    subscribe: Mock<(f: (message: unknown) => void) => () => void>
     unsubscribe: Mock<any>
     send: Mock<any>
     init: Mock<any>
@@ -93,7 +93,7 @@ const extensionConnector = {
       ? unnamedConnections
       : namedConnections
     const subscribers: Connection['subscribers'] = []
-    const api = {
+    const api: Connection['api'] = {
       subscribe: vi.fn((f: (m: unknown) => void) => {
         subscribers.push(f)
         return () => {}

tests/types.test.tsx

@@ -185,14 +185,16 @@ it('state is covariant', () => {
     foo: '',
   }))
 
-  const _testIsCovariant: StoreApi<{ count: number }> = store
+  const testIsCovariant: StoreApi<{ count: number }> = store
+  expect(testIsCovariant).toBeDefined()
 
   // @ts-expect-error should not compile
-  const _testIsNotContravariant: StoreApi<{
+  const testIsNotContravariant: StoreApi<{
     count: number
     foo: string
     baz: string
   }> = store
+  expect(testIsNotContravariant).toBeDefined()
 })
 
 it('StateCreator<T, [StoreMutatorIdentfier, unknown][]> is StateCreator<T, []>', () => {
@@ -229,8 +231,9 @@ it('StateCreator subtyping', () => {
 
   create<State>()(persist(foo(), { name: 'prefix' }))
 
-  const _testSubtyping: StateCreator<State, [['zustand/persist', unknown]]> =
+  const testSubtyping: StateCreator<State, [['zustand/persist', unknown]]> =
     {} as StateCreator<State, []>
+  expect(testSubtyping).toBeDefined()
 })
 
 it('set state exists on store with readonly store', () => {