Get started with custom builds

Create a custom build config

To get started, create directories and a file named .eas/build/hello-world.yml at the same level as eas.json. The location and name of both directories are important for EAS Build to identify that a project contains a custom build config.

Inside the hello-world.yml, you'll write your custom build config. The filename is unimportant; you can name it whatever you want. The only requirement is that the file extension uses .yml.

Add the following custom build config steps in the file:

build:
  name: Hello World!
  steps:
    - run: echo "Hello, world!"

Add config property in eas.json

To use the custom build config, add the config property in eas.json under a build profile.

Let's create a new build profile called test under build to run the custom config from the test.yml file:

{
  "build": {
    %%placeholder-start%%... %%placeholder-end%%
    "test": {
      "config": "test.yml",
    },
}

If you wish to use separate configs for each platform, you can create separate YAML config files for Android and iOS. For example:

{
  "build": {
    %%placeholder-start%%... %%placeholder-end%%
    "test": {
      "ios": {
        "config": "hello-ios.yml",
      },
      "android": {
        "config": "hello-android.yml",
      }
    },
}

Run a build to test the custom build config

To test the custom build config, run the following command:

After the build is complete, you can verify that the echo "Hello World!" script was executed by checking the logs on the build's detail page.