React Native Header Motion

High-level APIs for orchestrating header motion driven by scroll — built on top of React Native Reanimated.

This library is 100% a wrapper around Reanimated. All the credit for the underlying animation engine, worklets, and primitives goes to Reanimated (and react-native-worklets). This package focuses on a specific use case: header motion + scroll orchestration (including multi-scroll/tab scenarios).

What this is (and isn’t)

✅ This is

- A small set of components + hooks that expose a single progress shared value and a few measurement helpers.
- A scroll orchestration layer that can keep multiple scrollables in sync (e.g. tabs + pager).

❌ This is NOT

- An out-of-the-box “collapsible header” component with a baked-in look.

You build any header motion you want by animating based on progress.

Requirements (peer dependencies)

You must have these installed in your app:

- react-native-reanimated >= 4.0.0
- react-native-worklets >= 0.4.0

This package declares them as peer dependencies, so your app owns those versions. Remember to install a version of Worklets compatible with your version of Reanimated.

Installation

``bash
npm i react-native-header-motion
`

or

`bash
yarn add react-native-header-motion
`

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Follow the official Reanimated installation instructions for your environment (Expo / bare RN).

Mental model

There are three key concepts:

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progress is a Reanimated SharedValue that represents the normalized progress of your header animation.

- 0 → animation start (initial state)
- 1 → animation end (final state)

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progressThreshold is the distance needed for progress to move from 0 → 1.

You can provide it as:

- a number, or
- a function (measuredDynamic) => threshold

If you provide a function, it uses the value measured by measureDynamic.

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The library gives you two measurement callbacks that you pass to your header layout:

- measureTotalHeight – attach to the _outer_ header container to measure the total header height. Scrollables use this to add paddingTop so content starts below the header.
- measureDynamic – attach to the part of the header that determines the threshold (often the animated/dynamic portion).

Why HeaderMotion.Header exists

When you pass a header component to React Navigation / Expo Router, that header is rendered by the navigator in a different part of the React tree.

Because of that, the navigation header cannot read the HeaderMotion context, so calling useMotionProgress() inside that header would throw.

HeaderMotion.Header solves this by acting as a bridge: it runs inside the provider, reads context, and passes the values to your navigation header via a render function.

Why HeaderBase / AnimatedHeaderBase uses absolute positioning

Navigation headers are special:

- Even with headerTransparent: true, the navigator can still reserve layout space for the header container.
- If you animate with translations without absolute positioning, you can end up with:
- content below becoming unclickable (an invisible parent header still sits on top), or
- content hidden under the header container.

HeaderBase and AnimatedHeaderBase are absolutely positioned to avoid those layout traps, which is especially important when you use transforms/translations.

When to use components vs hooks

You can use either style; pick based on your integration needs:

- Prefer components when you want a “batteries included” wiring:

- HeaderMotion.ScrollView / HeaderMotion.FlatList for common scrollables
- HeaderMotion.ScrollManager for custom scrollables via render-props

- Prefer hooks when you want to build your own wrappers:
- useScrollManager() (same engine as HeaderMotion.ScrollManager, but hook-based)
- useMotionProgress() when your header is inside the provider tree

Also:

- Use HeaderMotion.Header when your header is rendered by navigation.
- Use useMotionProgress when your header is rendered inside the same tree as HeaderMotion.

Examples

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Examples live in the example app: example/. They demonstrate a few cases, from simple animations, to scroll orchestration and persisted header animation state between different tabs (e.g. with react-native-pager-view).

Those examples use Expo Router as the navigation library, but it should be fairly simple to do the same with plain React Navigation.

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This is the core pattern used in the example app (example/src/app/simple.tsx).

`tsx
import HeaderMotion, {
AnimatedHeaderBase,
type WithCollapsibleHeaderProps,
} from 'react-native-header-motion';
import { Stack } from 'expo-router';
import Animated, {
Extrapolation,
interpolate,
useAnimatedStyle,
} from 'react-native-reanimated';
import { useSafeAreaInsets } from 'react-native-safe-area-context';
import { View } from 'react-native';

export default function Screen() {
return (


{(headerProps) => (
options={{
header: () => ,
}}
/>
)}



{/ your scrollable content /}


);
}

function MyHeader({
progress,
measureTotalHeight,
measureDynamic,
progressThreshold,
}: WithCollapsibleHeaderProps) {
const insets = useSafeAreaInsets();

const containerStyle = useAnimatedStyle(() => {
const translateY = interpolate(
progress.value,
[0, 1],
[0, -progressThreshold],
Extrapolation.CLAMP
);
return { transform: [{ translateY }] };
});

return (
onLayout={measureTotalHeight}
style={[{ paddingTop: insets.top }, containerStyle]}
>

{/ “dynamic” part of the header /}


{/ "regular" part of the header /}

);
}
`

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In React Navigation you typically configure headers via navigation.setOptions().

Important: the header itself can’t call useMotionProgress(), so we still use HeaderMotion.Header as a bridge.

`tsx
import React from 'react';
import HeaderMotion, {
AnimatedHeaderBase,
type WithCollapsibleHeaderProps,
} from 'react-native-header-motion';
import { useNavigation } from '@react-navigation/native';
import Animated, {
Extrapolation,
interpolate,
useAnimatedStyle,
} from 'react-native-reanimated';
import { View } from 'react-native';

export function MyScreen() {
return (


{(headerProps) => (

)}

{/ content /}

);
}

function NavigationHeaderInstaller({
headerProps,
}: {
headerProps: WithCollapsibleHeaderProps;
}) {
const navigation = useNavigation();

React.useLayoutEffect(() => {
navigation.setOptions({
header: () => ,
});
}, [navigation, headerProps]);

return null;
}

function MyHeader({
progress,
measureTotalHeight,
measureDynamic,
progressThreshold,
}: WithCollapsibleHeaderProps) {
const insets = useSafeAreaInsets();

const containerStyle = useAnimatedStyle(() => {
const translateY = interpolate(
progress.value,
[0, 1],
[0, -progressThreshold],
Extrapolation.CLAMP
);
return { transform: [{ translateY }] };
});

return (
onLayout={measureTotalHeight}
style={[{ paddingTop: insets.top }, containerStyle]}
>

{/ “dynamic” part of the header /}


{/ "regular" part of the header /}

);
}
`

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If you have multiple scrollables (e.g. pages in react-native-pager-view), you can keep a single header progress by:

1. Creating a shared “active scroll id” using useActiveScrollId()
2. Passing activeScrollId.sv to
3. Rendering each page scrollable with a unique scrollId

The example app shows this pattern in example/src/app/collapsible-pager.tsx using HeaderMotion.ScrollManager.

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Sometimes you want to keep the native navigation header for back buttons + title, but still animate a custom header section below it.

In that case:

- set headerTransparent: true
- do not provide a custom header component
- render your animated header content _inside the screen_ under the native header

Sketch:

`tsx
import HeaderMotion, {
AnimatedHeaderBase,
useMotionProgress,
} from 'react-native-header-motion';
import { Stack } from 'expo-router';
import Animated, {
Extrapolation,
interpolate,
useAnimatedStyle,
} from 'react-native-reanimated';
import { View } from 'react-native';

export default function Screen() {
return (
<>




{/ rest of content /}



);
}

function InlineAnimatedHeader() {
const { progress, measureTotalHeight, measureDynamic, progressThreshold } =
useMotionProgress();

const containerStyle = useAnimatedStyle(() => {
const translateY = interpolate(
progress.value,
[0, 1],
[0, -progressThreshold],
Extrapolation.CLAMP
);
return { transform: [{ translateY }] };
});

return (


{/ custom animated header content below the native header /}

{/ sticky part /}

);
}
`

API

The package exports a default compound component plus hooks, types, and a couple base components.

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HeaderMotion is a compound component:

- HeaderMotion (provider)
- HeaderMotion.Header (bridge for navigation headers)
- HeaderMotion.ScrollView (pre-wired Animated.ScrollView)
- HeaderMotion.FlatList (pre-wired Animated.FlatList)
- HeaderMotion.ScrollManager (render-prop API for custom scrollables)

#### Props

- progressThreshold?: number | (measuredDynamic: number) => number
- Defines how many pixels correspond to progress going from 0 to 1.
- If you pass a function, it uses the value measured from measureDynamic.
- measureDynamic?: (e) => number
- What value to read from the onLayout event (defaults to height).
- measureDynamicMode?: 'mount' | 'update'
- Whether measureDynamic updates only once or on every layout recalculation.
- activeScrollId?: SharedValue
- Enables multi-scroll orchestration (tabs/pager).
- progressExtrapolation?: ExtrapolationType
- Controls how progress behaves outside the threshold range (useful for overscroll).

#### HeaderMotion.Header

Render-prop component that passes motion progress props to a header you render via navigation.

`tsx

{(headerProps) => / pass headerProps into navigation header /}

`

Use this instead of useMotionProgress() when your header is rendered by React Navigation / Expo Router.

#### HeaderMotion.ScrollView

Animated ScrollView wired with:

- onScroll handler
- ref
- automatic paddingTop based on measured header height

Supports scrollId?: string for multi-scroll scenarios.

#### HeaderMotion.FlatList

Animated FlatList wired similarly to the ScrollView.

Supports scrollId?: string for multi-scroll scenarios.

#### HeaderMotion.ScrollManager

Render-prop API for custom scrollables (pager pages, 3rd party lists, etc.).

`tsx

{(
scrollableProps,
{ originalHeaderHeight, minHeightContentContainerStyle }
) => (
{...scrollableProps}
contentContainerStyle={[
minHeightContentContainerStyle,
{ paddingTop: originalHeaderHeight },
]}
/>
)}

`

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#### useMotionProgress()

Returns:

- progress (SharedValue)
- progressThreshold (number)
- measureTotalHeight (onLayout callback)
- measureDynamic (onLayout callback)

Only use inside the HeaderMotion provider tree.

#### useScrollManager(scrollId?)

Lower-level orchestration hook that powers the component APIs. Returns:

- scrollableProps: { onScroll, scrollEventThrottle, ref }
- headerMotionContext:
- originalHeaderHeight
- minHeightContentContainerStyle (helps when content is shorter than the threshold)

#### useActiveScrollId(initialId)

Helper for multi-scroll scenarios (tabs/pager). Returns:

- [active, setActive]
- active.state (React state)
- active.sv (SharedValue)

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#### HeaderBase

Non-animated absolutely positioned header base.

#### AnimatedHeaderBase

Reanimated-powered, absolutely positioned header base.

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- WithCollapsibleHeaderProps – convenience type for headers using motion progress props.
- WithCollapsiblePagedHeaderProps – like above, plus activeTab and onTabChange`.

Contributing

- Development workflow: see CONTRIBUTING.md
- Code of conduct: see CODE_OF_CONDUCT.md

License

MIT

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