---
title: Use GitHub Actions
description: Learn how to use GitHub Actions to automate publishing updates with EAS Update.
---

import { Step } from '~/ui/components/Step';

A GitHub Action is a cloud function that runs every time an event on GitHub occurs. We can use GitHub Actions to automate building and publishing updates when you or members of your team merge to a branch, like "production". This makes the process of deploying consistent and fast, leaving you more time to develop your app.

## Publish updates on push

We can configure GitHub Actions to run on any GitHub event. One of the most common use cases is to publish an update when code is pushed. Below are the steps to publish an update every time an update is pushed:

<Step label="1">

Create a file path named **.github/workflows/update.yml** at the root of your project.

</Step>

<Step label="2">

Inside **update.yml**, copy and paste the following snippet:

```yaml update.yml
name: update
on: push

jobs:
  update:
    name: EAS Update
    runs-on: ubuntu-latest
    steps:
      - name: Check for EXPO_TOKEN
        run: |
          if [ -z "${{ secrets.EXPO_TOKEN }}" ]; then
            echo "You must provide an EXPO_TOKEN secret linked to this project's Expo account in this repo's secrets. Learn more: https://docs.expo.dev/eas-update/github-actions"
            exit 1
          fi

      - name: Checkout repository
        uses: actions/checkout@v3

      - name: Setup Node
        uses: actions/setup-node@v3
        with:
          node-version: 18.x
          cache: yarn

      - name: Setup EAS
        uses: expo/expo-github-action@v8
        with:
          eas-version: latest
          token: ${{ secrets.EXPO_TOKEN }}

      - name: Install dependencies
        run: yarn install

      - name: Publish update
        run: eas update --auto
```

In the code above, we set the action to run every time code is pushed to any branch. In the `update` job, we set up Node, in addition to Expo's GitHub Action: `expo-github-action`. We then add a couple of steps to cache any dependencies installed from the last run to speed this script up on subsequent runs. In the end, we install dependencies (`yarn install`), then publish the update with `eas update --auto`. Since we're using the `--auto` flag, the EAS branch will be named after the GitHub branch, and the message for the update will match the commit's message.

</Step>

<Step label="3">

Finally, we need to give the script above permission to run by providing an `EXPO_TOKEN` environment variable.

1.  Navigate to [https://expo.dev/settings/access-tokens](https://expo.dev/settings/access-tokens).
2.  Click "Create" to create a new access token.
3.  Copy the token generated.
4.  Navigate to https://github.com/your-username/your-repo-name/settings/secrets/actions, replacing "your-username" and "your-repo-name" with your project's info.
5.  Click "New repository secret"
6.  Make the secret's name "EXPO_TOKEN", then paste the access token in as the value.

Your GitHub Action should be set up now. Whenever a developer merges code into the repo, this action will build an update and publish it, making it available to all of our devices with builds that have access to the EAS branch.

> Some repositories or organizations might need to explicitly enable GitHub Workflows and allow third-party Actions.

</Step>

## Publish previews on pull requests

Another common use case it to create a new update for every pull request. This allows you to test the changes in the pull request on a device before merging the code, and without having to start the project locally. Below are the steps to publish an update every time a pull request is opened:

<Step label="1">

Create a file path named **.github/workflows/preview.yml** at the root of your project.

</Step>

<Step label="2">

Inside **preview.yml**, copy and paste the following snippet:

```yaml preview.yml
name: preview
on: pull_request

jobs:
  update:
    name: EAS Update
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write
    steps:
      - name: Check for EXPO_TOKEN
        run: |
          if [ -z "${{ secrets.EXPO_TOKEN }}" ]; then
            echo "You must provide an EXPO_TOKEN secret linked to this project's Expo account in this repo's secrets. Learn more: https://docs.expo.dev/eas-update/github-actions"
            exit 1
          fi

      - name: Checkout repository
        uses: actions/checkout@v3

      - name: Setup Node
        uses: actions/setup-node@v3
        with:
          node-version: 18.x
          cache: yarn

      - name: Setup EAS
        uses: expo/expo-github-action@v8
        with:
          eas-version: latest
          token: ${{ secrets.EXPO_TOKEN }}

      - name: Install dependencies
        run: yarn install

      - name: Create preview
        uses: expo/expo-github-action/preview@v8
        with:
          command: eas update --auto
```

Although the code above is similar to the example in the previous section, there are a few differences. In this action, we changed the workflow event (`on`) to run every time a pull request is opened or updated. In the `update` job, we still set up Node, Expo's GitHub Action, and the dependencies using GitHub action's built-in cache. But, instead of running `eas update --auto` ourselves, we let the [preview subaction](https://github.com/expo/expo-github-action/tree/main/preview#readme) run it for us. This will add a comment to the pull request with basic information about the update and a QR code to scan the update.

> Don't forget to add the `permissions` section to the job. This enables the job to add comments to the pull request.

</Step>

<Step label="3">


You can skip this step if you have already set up `EXPO_TOKEN` in the previous section. Only one valid `EXPO_TOKEN` is required to authenticate GitHub Actions with your Expo account.

If you haven't, you must give the script above permission to run by providing an `EXPO_TOKEN` environment variable.

1.  Navigate to [https://expo.dev/settings/access-tokens](https://expo.dev/settings/access-tokens).
2.  Click "Create" to create a new access token.
3.  Copy the token generated.
4.  Navigate to https://github.com/your-username/your-repo-name/settings/secrets/actions, replacing "your-username" and "your-repo-name" with your project's info.
5.  Click "New repository secret"
6.  Make the secret's name "EXPO_TOKEN", then paste the access token in as the value.

Your GitHub Action should be set up now. Whenever a developer creates a pull request, this action will build an update and publish it, making it available to all reviewers with builds that have access to the EAS branch.

> Some repositories or organizations might need to explicitly enable GitHub Workflows and allow third-party Actions.

</Step>