This is the public documentation for Expo, its SDK, client, and services (EAS). This documentation is built using Next.js and you can access it online at https://docs.expo.dev/.
Note
For contributors: Please make sure that you edit the docs in the pages/versions/unversioned for SDK reference if you want your changes to apply to the next SDK version too!
Tip
If you are looking for Expo Documentation Writing Style guidelines, please refer Expo Documentation Style Guide.
- Download a copy of this repository.
git clone https://github.com/expo/expo.git- Then
cdinto thedocsdirectory and install dependencies with:
pnpm install- Then you can run the app with (make sure you have no server running on port
3002):
pnpm dev- Now the documentation is running at
http://localhost:3002, and any changes you make to markdown or JavaScript files will automatically trigger reloads.
pnpm export
pnpm export-serverAll documentation-related content is inside the pages directory. We write docs in markdown with the help of custom React components that provide additional functionality, such as embedding Snack examples, representing commands inside a terminal component and so on.
The documentation is divided into four main sections:
- Home: Provides a guided path from starting a project from scratch to deploying it to app stores.
- Guides: General purpose and fundamental guides that help you understand how Expo works and how to use it.
- EAS: Detailed documentation for all EAS services.
- Reference: Detailed reference documentation for all Expo APIs and modules. All Expo SDK API docs are located under pages/versions directory. We keep separate versions of documentation for each SDK version currently supported in Expo Go. See Update latest version of API reference docs for more information.
- Learn: Tutorials and guides that help you learn how to use Expo and React Native.
Note
We are currently in the process of moving our API documentation to being auto-generated using expotools's GenerateDocsAPIData command for some Expo libraries.
Each markdown page can be provided metadata in the heading, distinguished by:
---
metadata: goes here
---
These metadata items include:
title: Title of the page shown as the heading and in search results.description: Description of the page shown in search results and open graph descriptions when the page is shared on social media sites.hideFromSearch: Whether to hide the page from Algolia search results. Defaults tofalse.hideInSidebar: Whether to hide this page from the sidebar. Defaults tofalse.hideTOC: Whether to hide the table of contents (appears on the right sidebar). Defaults tofalse.sidebar_title: The title of the page to display in the sidebar. Defaults to the page title.maxHeadingDepth: The max level of headings shown in Table of Content on the right side. Defaults to3.isNew: Whether to display the new badge for a page. Commonly used with API pages under Reference. Defaults tofalse.isDeprecated: Whether to display the deprecated badge for a page. Commonly used with API pages under Reference. Defaults tofalse.isAlpha: Whether to display the alpha badge for a page. Commonly used with API pages under Reference. Defaults tofalse.searchRank: A number between 0 and 100 that represents the relevance of a page. This value is mapped to Algolia'srecord.weight.pageRankproperty. Higher values indicate higher priority. We set this value to5by default, otherwise specified in the frontmatter.searchPosition: The position of a page in the search results. This value is mapped to Algolia'srecord.weight.positionproperty. Algolia sets this value to0by default. Pages with lower values appear higher in the results. We set this value to50by default, otherwise specified in the frontmatter.hasVideoLink: To display a video link icon in the sidebar for the page that has a video tutorial link. Defaults tofalse.cliVersion: The CLI version to display for pages that include the CLI badge. Currently, this field is used for EAS CLI reference page and is populated automatically bypnpm eas-cli-sync.
The docs are written with Next.js and TypeScript. If you need to make code changes, follow steps from the To run locally in development mode section, then open a separate terminal and run the TypeScript compiler in watch mode — it will watch your code changes and notify you about errors.
pnpm watchDon't forget to run tests and linter before committing your changes.
pnpm test
pnpm lintWhen you are done writing or editing docs, run the following script to lint your docs for style and grammar based on Expo's writing style guide:
pnpm lint-proseWe use Vale to lint our docs. The Vale binary is auto-installed during pnpm install via the postinstall script. To install or update it manually, run pnpm install-vale.
For exceptional cases, you can switch off the prose linter for a specific line or block of text by adding by using a comment delimiter:
{/* vale off */}
This is some text that will be ignored by Vale.
{/* vale on */}Note
Ideally, to add new services or features, the Vale lint rules should upgrade accordingly when there's a pattern. If you want to update a rule, see the .vale directory for already established rules.
Alternative: Use Vale with VS Code
Alternatively, you can use Vale with VS Code. You need to:
Open the doc file (*.mdx) that you are working on and you'll may see suggested lines (yellow squiggly) in VS Code editor.
We use two layers of redirects:
- Server-side redirects defined in
public/_redirectsusing the Cloudflare Pages redirect format (source_path destination_path status_code, one rule per line). These are 301 permanent redirects for simple 1:1 path mappings and SEO-friendly behavior. - Client-side redirects in
common/client-redirects.tsthat run on the 404 page for more complex rules (for example, stripping.html, version fallbacks) and to catch cases where server-side redirects do not apply (local/dev/preview or missed mappings).
We currently do two client-side redirects, using meta tags with http-equiv="refresh":
/->/versions/latest//versions->/versions/latest
This works by loading a page and then immediately navigating, which can confuse assistive tech (announced content disappears, focus resets) and gives developers less control. Treat this as a fallback and prefer server-side redirects or the 404-based client rules when possible.
Every published page is served in two formats: HTML for browsers, and markdown for AI agents and command-line tools. There are four layers to this:
-
pnpm exportrunsscripts/generate-markdown-pages.tsafternext build. It walks every page inout/, converts the rendered HTML to markdown with cheerio + turndown (parallelized via worker threads), and writes the result next to the HTML atout/<slug>/index.md. Custom MDX components (APISection,Terminal,Tabs, and so on) are already rendered into HTML by Next.js, so the converter does not need to know about them. -
scripts/check-markdown-pages.tsthen runs as a CI gate. It fails the build if any markdown file is empty, is missing headings, contains leaked HTML or CSS class names, has unbalanced code fences, or if the markdown count diverges from the HTML count.
public/_worker.js inspects the Accept header on every request. If it includes text/markdown, the worker rewrites the path to <pathname>/index.md and returns that asset with Content-Type: text/markdown; charset=utf-8. All other requests fall through to the normal asset pipeline.
curl -H "Accept: text/markdown" https://docs.expo.dev/get-started/set-up-your-environment/Some agents prefer to append .md to a URL rather than negotiate via headers. Three rules at the bottom of public/_redirects handle that:
/index.md /index.md 200
/*/index.md /:splat/index.md 200
/*.md /:splat/index.md 200
The first two rules preserve the canonical index.md paths for each page. The third rule rewrites /<slug>.md to the file the build actually wrote at /<slug>/index.md. This allows agents to fetch markdown content with a .md suffix, which is a common convention for markdown files.
Every page renders a discovery link in <head>:
<link rel="alternate" type="text/markdown" href="/get-started/set-up-your-environment.md" />getMarkdownPath in common/routes.ts builds this href, and DocumentationHead.tsx renders it. Crawlers that already have the HTML can follow this to fetch the markdown variant.
A single page (for example, /get-started/set-up-your-environment/) is reachable as markdown four ways:
| Request | Served by |
|---|---|
Accept: text/markdown on the canonical URL |
_worker.js |
/get-started/set-up-your-environment.md |
_redirects sibling rule |
/get-started/set-up-your-environment/index.md |
static asset (canonical path) |
Following <link rel="alternate"> from the HTML |
discovery hint |
We use Algolia as the main search results provider for our docs. This is set up in the @expo/styleguide library, which provides a universal search component that is used in the docs, expo.dev, and EAS dashboard.
Besides the query, the results are also filtered based on the version tag. This tag represents the user's current location. The tag is set in the components/DocumentationPage.tsx head.
Inside @expo/styleguide library, you can see the facetFilters set to [['version:none', 'version:{version}']] in packages/search-ui/src/components/CommandMenu.tsx. Translated to English, this means - search on all pages where version is none, or the currently selected version.
- All unversioned pages use the version tag
none - All versioned pages use the SDK version (for example,
v51.0.0orv50.0.0) - All pages with
hideFromSearch: truefrontmatter entry don't have the version tag
Currently, the base results for Expo docs are combined with other results from multiple sources, such as:
- Manually defined paths for EAS dashboard located in
ui/components/Search/expoEntries.ts - Public Algolia index for React Native website
- React Native directory public API, see the directory README.md for more details
- Expo Blog public API
You can't have curly brace without quotes: `{}` -> {}.
The docs are deployed automatically via a GitHub Action each time a PR with docs changes is merged to main.
If you need to link from one MDX file to another, use the static/full path to this file (avoid relative links):
- From: tutorial/button.mdx, to: introduction/expo.mdx ->
/introduction/expo - From: index.mdx, to: guides/errors.mdx#tracking-js-errors ->
/guides/errors/#tracking-javascript-errors
Validate all current links by running pnpm lint-links script.
When we release a new SDK, we copy the unversioned directory, and rename it to the new version. Latest version of docs is read from package.json so make sure to update the version key there as well.
Make sure to also grab the upgrade instructions from the release notes blog post and put them in upgrading-expo-sdk-walkthrough.mdx.
The versions directory is listed on server start to find all available versions. The routes and navbar contents are automatically inferred from the directory structure within versions.
Since the navbar is automatically generated from the directory structure, the default ordering of the links under each section is alphabetical. However, for many sections, this is not ideal UX. So, if you want to override the alphabetical ordering, manipulate page titles in constants/navigation.js.
The API reference docs are generated from the TypeScript source code.
This section walks through the process of updating documentation for an Expo package. Throughout this document, we will assume we want to update TypeDoc definitions of property inside expo-constants as an example.
For more information on how TypeDoc/JSDoc parses comments, see Doc comments in TypeDoc documentation.
Before proceeding, make sure you:
- Have expo/ repo cloned on your machine
- Make sure to install
direnvand rundirenv allowat the root of the expo/ repo. - Have gone through the steps mentioned in "Download and Setup" in the contribution guideline.
- Can run expo/docs app locally.
- Can run
et(Expotools) command locally.
Once you have made sure the development setup is ready, proceed to the next section:
- After you have identified which package docs you want to update, open a terminal window and navigate to that packages directory. For example:
# Navigate to expo-constants package directory inside expo/ repo
cd expo/packages/expo-constants-
Then, open .ts file in your code editor/IDE where you want to make changes/updates.
-
Start the TypeScript build compilation in watch mode using
pnpm buildin the terminal window. -
Make the update. For example, we want to update the TypeDoc description of
expoConfigproperty- Inside the src/ directory, open Constants.types.ts file.
- Search for
expoConfigproperty. It has a current description as shown below:
/** * The standard Expo config object defined in `app.json` and `app.config.js` files. For both * classic and modern manifests, whether they are embedded or remote. */ expoConfig: ExpoConfig | null;
-
In the above example, let's fix the typo by changing
confgtoconfig:
/**
* The standard app config object defined in `app.json` and `app.config.js` files. For both
* classic and modern manifests, whether they are embedded or remote.
*/
expoConfig: ExpoConfig | null;- Before moving to the next step, make sure to exit the "watch mode" by pressing
Ctrl + Cfrom the keyboard.
Important
If you are fixing issues in package's reference or after an SDK version is released, make sure to only update the unversioned reference of that package. This way the changes will be reflected in the next SDK version from the main branch. Updating the reference for a specific SDK version requires updating that SDK's branch (see collapsible below) and SDK team decides cherry-picking changes for the specific SDK branch (after an SDK version has been released).
In the terminal window and run the following command with to generate the JSON data file for the package (which is stored at the location expo/docs/public/static/data/[SDK-VERSION])
- Read the NOTE in the below snippet for updating the docs for
unversioned:
et generate-docs-api-data --packageName expo-constants
#### NOTE ####
# To update a specific SDK reference, run the command by mentioning the SDK version
et gdad -p expo-constants --sdk 54
# For more information about et command, run: et gdad --helpWhy update unversioned docs? If these are new changes/updates, apply them to unversioned to make sure that those changes are part of the next SDK version.
Now, in the terminal window, navigate to expo/docs repo and run the command pnpm dev to see the changes applied
- Open http://localhost:3002/ in the browser and go to the API doc to see the changes you have made. Make sure to select the right SDK version to see the changes in the left sidebar.
Updating versioned documentation data after SDK lifecycle is latest or already released
When you need to update versioned documentation data late in the SDK lifecycle, follow these steps:
-
Ensure the related code change exists on the
mainbranch andsdk *branch. -
Make branch changes:
- Switch to the
sdk *branch and make your changes - Run command:
et gdad -p expo-library --sdk 52, whereexpo-libraryis the library you want to update and52is the SDK version. - Store/shelf the changes locally (you can use
git stash)
- Update
mainbranch:
- Switch back to
mainbranch - Run command:
et gdad -p expo-library
- Finalize changes:
- Add previously stored versioned
expo-library.jsonto the main changeset - Create as a Pull Request
After making changes, when you are opening the PR, consider adding <!-- disable:changelog-checks --> in the PR description if the changes you are making are docs-related changes (such as updating the field description or fixing a typo, and so on).
This will make sure that the ExpoBot on GitHub will not complain about updating the package's changelog (some of these changes, as described above, are not worth mentioning in the changelog).
Some of the packages have documentation spread over multiple pages. For example, expo-sensors package has a separate overview page in Expo Sensors reference, and rest of the information is separated into components such as, Accelerometer, Gyroscope, Magnetometer, and more. For such packages, always make sure to check the name of the package for et command.
To render the app config properties table, we currently store a local copy of the appropriate version of the schema.
If the schema is updated, to sync and rewrite our local copy, run pnpm schema-sync <SDK version integer> or pnpm schema-sync unversioned.
You can add images and assets to the public/static directory. They'll be served by the production and staging servers at static.
- Record the video using QuickTime
- Install
ffmpeg(brew install ffmpeg) - Run
ffmpeg -i your-video-name.mov -vcodec h264 -acodec mp2 your-video-name.mp4to convert to mp4. - If the width of the video is larger than ~1200px, then run this to shrink it:
ffmpeg -i your-video.mp4 -filter:v scale="1280:trunc(ow/a/2)*2" your-video-smaller.mp4 - Put the video in the appropriate location in
public/static/videosand use it in your docs page MDX like this:
import { ContentSpotlight } from '~/ui/components/ContentSpotlight';
// Change the path to point to the relative path to your video from within the `static/videos` directory
<ContentSpotlight file="guides/color-schemes.mp4" />;For documenting @expo/ui components (Jetpack Compose and SwiftUI) with a fixed-size, theme-aware preview frame, use the component variant of ContentSpotlight. It renders a bordered dot-grid card and swaps between light and dark sources based on the active theme.
import { ContentSpotlight } from '~/ui/components/ContentSpotlight';
<ContentSpotlight
variant="component"
aspect="landscape"
src="/static/images/expo-ui/badgedbox/android-light.webp"
darkSrc="/static/images/expo-ui/badgedbox/android-dark.webp"
alt="Mail icon with a count badge of 5 and a wifi icon with a small dot badge"
/>;| Param | Description |
|---|---|
variant |
Set to "component" to render the SDK UI preview chrome. Defaults to "screenshot", which keeps the original lightbox-on-click behavior used elsewhere. |
aspect |
Required when variant="component". Use "landscape" (3:2, 540px wide) for wide previews or "portrait" (9:16, 220px wide) for phone-shaped mocks. |
src |
Required. Path to the light-theme image. Place assets under /public/static/images/expo-ui/<component>/ and reference them from /static/images/.... |
darkSrc |
Optional. Path to the dark-theme image. Rendered via <picture> and shown when the user has the dark theme active. |
alt |
Required. Alt text describing the component preview for screen readers. |
To reference a video from Expo's YouTube channel, use the VideoBoxLink component. This component is imported from ~/ui/components/VideoBoxLink.
import { VideoBoxLink } from '~/ui/components/VideoBoxLink';
<VideoBoxLink videoId="Gk7RHDWsLsQ" title="Required title" description="Optional" />;| Param | Description |
|---|---|
videoId |
Required. The ID of the video from YouTube. You can find this in the URL of the video. For example, in https://www.youtube.com/watch?v=Gk7RHDWsLsQ, the ID is Gk7RHDWsLsQ. |
| title | Required. The title of the video. |
| description | Optional. The description of the video. |
Code blocks are a great way to add code snippets to our docs. We leverage the usual code block Markdown syntax, but it's expanded to support code block titles and additional params.
{/* For plain code block the syntax is unchanged (but we recommend to always add a title to the snippet): */}
```js
// Your code goes in here
```
{/* To add a title, enter it right after the language, in the code block starting line: */}
```js myFile.js
// Your code goes in here
```
```js Title for a code block
// Your code goes in here
```
{/* Title and params can be separated by pipe ("|") characters, but they also work for block without a title: */}
```js myFile.js|collapseHeight=600
// Your code goes in here
```
```js collapseHeight=200
// Your code goes in here
```| Param | Type | Description |
|---|---|---|
collapseHeight |
number | The custom height that the code block uses to collapse automatically. The default value is 408 and is applied unless the collapseHeight param has been specified. |
Fenced code blocks support dynamic variable substitution using {{variableName}} syntax. Variables are replaced with values from sdk-versions.json at render time, before syntax highlighting runs. This keeps version numbers in code examples accurate without manual updates each SDK release.
Available variables:
| Variable | Example value | Description |
|---|---|---|
{{iosDeploymentTarget}} |
15.1 |
Minimum iOS deployment target |
{{androidVersion}} |
7 |
Minimum Android version |
{{compileSdkVersion}} |
36 |
Android compileSdkVersion |
{{targetSdkVersion}} |
36 |
Android targetSdkVersion |
{{reactNativeVersion}} |
0.83 |
React Native version |
{{reactVersion}} |
19.2.0 |
React version |
{{xcodeVersion}} |
26.2 |
Minimum Xcode version |
{{nodeVersion}} |
20.19.x |
Minimum Node.js version |
{{expoSdkVersion}} |
55.0.0 |
Expo SDK version |
{{expoSdkMajorVersion}} |
55 |
Expo SDK major version number |
Usage in a fenced code block:
```json package.json
{
"dependencies": {
"expo": "~{{expoSdkVersion}}",
"react-native": "{{reactNativeVersion}}"
}
}
```The rendered output will show the resolved values (for example, "expo": "~55.0.0"). The copy button also copies the resolved values.
All variables are defined in common/code-utilities.ts and sourced from the first (latest) entry in ui/components/SDKTables/sdk-versions.json. To add a new variable, add an entry to the CODE_BLOCK_VARIABLES map in that file.
Note
These variables only work inside fenced code blocks. For dynamic values in prose text, import latestSdkVersionValues from ~/ui/components/SDKTables and use JSX expressions directly.
Snacks are a great way to add instantly-runnable examples to our docs. The SnackInline component can be imported to any markdown file, and used like this:
import SnackInline from '~/components/plugins/SnackInline';
<SnackInline label='My Example Label' dependencies={['array of', 'packages', 'this Snack relies on']}>
```js
// All your code goes in here
// You can use:
/* @info Some text goes here */
const myVariable = SomeCodeThatDoesStuff();
/* @end */
// to create hoverable-text, which reveals the text inside of `@info` onHover.
// You can use:
/* @hide Content that is still shown, like a preview. */
Everything in here is hidden in the example Snack until
you open it in snack.expo.dev
/* @end */
// to shorten the length of code block shown in our docs.
// Hidden code will still be present when opening in Snack or using "Copy" action.
```
</SnackInline>Sometimes it's useful to show multiple ways of doing something, for instance, maybe you'd like to have an example using a React class component, and also an example of a functional component. The Tabs plugin is useful for this, and this is how you'd use it in a markdown file:
import { Tabs, Tab } from '~/ui/components/Tabs';
<Tabs>
<Tab label="Add 1 One Way">
```js
addOne = async x => {
/* @info This text will be shown onHover */
return x + 1;
/* @end */
};
```
</Tab>
<Tab label="Add 1 Another Way">
```js
addOne = async x => {
/* @info This text will be shown onHover */
return x++;
/* @end */
};
```
</Tab>
</Tabs>Note
The components should not be indented or they will not be parsed correctly.
To ignore a page from the search result, use hideFromSearch: true on that page. This removes the <meta name="docsearch:version"> tag from that page and filters it from our facet-based search.
Please note that hideFromSearch only prevents the page from showing up in the internal docs search (Algolia). The page will still show up in search engine results like Google. To hide a page from search engine results, you need to edit the sitemap that is generated via our Next.js config (next.config.js).
Certain directories are excluded from the sidebar to prevent it from getting too long and unnavigable. You can find a list of these directories, and add new ones, in constants/navigation.js under hiddenSections.
If you just want to hide a single page from the sidebar, set hideInSidebar: true in the page metadata.
Whenever shell commands are used or referred, use Terminal component to make the code snippets copy/pasteable. This component can be imported into any markdown file.
| Option | Type | Description |
|---|---|---|
cmd |
string[] |
Required. Lines to render. Use $ to mark commands, # for comments, and empty strings for spacing. |
cmdCopy |
string |
Optional. Overrides the auto-generated copy text. Helpful when multiple commands should be chained (for example with &&) or when you want to control the copied content. |
title |
string |
Optional. Overrides the default header label of "Terminal". |
browserAction |
{ href: string; label: string } |
Optional. Adds a launch button in the header that opens the link in a new tab—ideal for flows that continue in a web UI. |
hideOverflow |
boolean |
Optional. Prevents horizontal scrollbars when you prefer the content to clip instead of scroll. |
className |
string |
Optional. Additional utility classes for adjusting layout or spacing around the snippet. |
import { Terminal } from '~/ui/components/Snippet';
{/* For single command and one prop */}
<Terminal cmd={['$ npx expo install package']} />
{/* For multiple commands */}
<Terminal
cmd={['# Create a new Expo project', '$ npx create-expo-app --template bare-minimum', '']}
cmdCopy="npx create-expo-app --template bare-minimum"
/>
{/* Clamp long outputs and tweak spacing */}
<Terminal
className="mt-6"
hideOverflow
cmd={[
'$ npx expo config --json',
'# Output is trimmed visually because hideOverflow is enabled.',
]}
/>
{/* Surface a button that opens related browser flows */}
<Terminal
title="Deploy website with EAS"
cmd={['$ npx eas-cli deploy']}
browserAction={{ href: 'https://expo.dev/eas', label: 'Open in expo.dev' }}
/>When a guide depends on the reader having a specific environment or prior step in place, wrap the requirements in a Prerequisites component. It renders as a collapsible block and threads each requirement's title through the page heading manager so it can be linked.
import { Prerequisites, Requirement } from '~/ui/components/Prerequisites';
<Prerequisites>
<Requirement title="Set up your development environment">
Make sure your computer is [set up for running an Expo app](/get-started/create-a-project/).
</Requirement>
<Requirement title="Install EAS CLI">Run `npm install -g eas-cli` and log in.</Requirement>
</Prerequisites>Pass open to render the block expanded by default:
<Prerequisites open>...</Prerequisites>Four different types of callouts can be used with markdown syntax for > ... blockquote. Each callout represents a purpose.
> Normal callout that doesn't demand much attention but is required to add as a note.
> **info** Callout that is informative and demands attention is required to add as a note or a tip.
> **warning** Callout that is used for warnings and deprecation messages.
> **error** Callout that is used for errors and breaking changes or deprecated changes in the archive.
> **important** Callout that is used for presenting important information about state of package, service or tool.All docs pages are automatically updated with the last update date of the file based on their Git commit history. This information is reflected in the footer of a docs page with Last updated on ....
If you need to add the date manually, add modificationDate to the frontmatter of the .mdx file. For example:
---
modificationDate: April 8th, 2024
{/* Other frontmatter fields */}
---This pattern is used for some of the pages where we manually update the modification date, such as Build server infrastructure. When updating build image details on that page, update its modificationDate in the same change.
Docs areas that are excluded or do not include an updated date are SDK API references and Tutorials sections under Learn.
The lint pipeline runs four tools via scripts/lint.js (pnpm lint) script:
oxfmtfor code formattingoxlintfor code lintingtscfor type checkingeslintfor Tailwind CSS classes, MDX linting, and ES Lint only rules
If you have a code block using an inline annotation such as /* @info Some text goes here */ or /* @hide ... */, make sure to add /* prettier-ignore */ and /* oxfmt-ignore */ comments right before the code block to prevent oxfmt from reformatting the code block and breaking the annotations.
For procedural guides, use Step component:
import { Step } from '~/ui/components/Step';
<Step label="1">
This is some text.
</Step>