Custom build configuration schema

A reference of configuration options for custom builds with EAS Build.

This functionality is in preview, under active development, and likely to change.

Creating custom workflows for EAS Build helps customize the build process for your project.

YAML syntax for workflows

Workflow files are stored inside the .eas/build directory path. They use YAML syntax and must have a .yml or .yaml file extension. If you are new to YAML or want to learn more about the syntax, see Learn YAML in Y minutes.

build

Defined to describe a custom workflow. All config options to create a workflow are specified under it.

name

The name of your workflow that is used to identify the workflow in the build logs. EAS Build uses this property to display the name of your workflow in the dashboard.

For example, the workflow's name is Run tests:

build:
  name: Run tests
  steps:
    - eas/checkout
    - run:
        name: Install dependencies
        command: npm install

steps

Steps are used to describe a list of actions either in the form of commands or function calls. These actions are executed when a workflow runs on EAS Build. You can define single or multiple steps in a workflow. However, it is required to define at least one step per workflow.

Each step is configured with the following properties:

steps[].run

The run key is used to trigger a set of instructions. For example, a run key is used to install dependencies using the npm install command:

build:
  name: Install npm dependencies
  steps:
    - eas/checkout
    - run:
        name: Install dependencies
        command: npm install

You can also use steps[].run to execute single or multiline shell commands:

build:
  name: Run inline shell commands
  steps:
    - run: echo "Hello world"
    - run: |
        echo "Multiline"
        echo "bash commands"

Use a single step

For example, a workflow with the following steps will print "Hello world":

build:
  name: Greeting
  steps:
    - run: echo "Hello world"

Note: - before run counts as indentation.

Use multiple steps

When multiple steps are defined, they are executed sequentially. For example, a workflow with the following steps will first check out the project, install npm dependencies, and then run a command to run tests:

build:
  name: Run tests
  steps:
    - eas/checkout
    - run:
        name: Install dependencies
        command: npm install
    - run:
        name: Run tests
        command: |
          echo "Running tests..."
          npm test

steps[].run.name

The name that is used in build logs to display the name of the step.

steps[].run.command

The command defines a custom shell command to run when a step is executed. It is required to define a command for each step. It can be a multiline shell command:

build:
  name: Run tests
  steps:
    - eas/checkout
    - run:
        name: Run tests
        command: |
          echo "Running tests..."
          npm test

steps[].run.working_directory

The working_directory is used to define an existing directory from the project's root directory. After an existing path is defined in a step, using it changes the current directory for that step. For example, a step is created to list all the assets inside the assets directory, which is a directory in your Expo project. The working_directory is set to assets:

build:
  name: Demo
  steps:
    - eas/checkout
    - run:
        name: List assets
        working_directory: assets
        command: ls -la

steps[].run.shell

Used to define the default executable shell for a step. For example, the step's shell is set to /bin/sh:

build:
  name: Demo
  steps:
    - run:
        shell: /bin/sh
        command: |
          echo "Steps can use another shell"
          ps -p $$

steps[].run.inputs

Input values are provided to a step. For example, you can use input to provide a value:

build:
  name: Demo
  steps:
    - run:
        name: Say Hi
        inputs:
          name: Expo
        command: echo "Hi, ${ inputs.name }!"

steps[].run.outputs

An output value is expected during a step. For example, a step has an output value of Hello world:

build:
  name: Demo
  steps:
    - run:
        name: Produce output
        outputs: [value]
        command: |
          echo "Producing output for another step"
          set-output value "Output from another step..."

steps[].run.outputs.required

An output value can use a boolean to indicate if the output value is required or not. For example, a function does not have a required output value:

build:
  name: Demo
  steps:
    - run:
        name: Produce another output
        id: id456
        outputs:
          - required_param
          - name: optional_param
            required: false
        command: |
          echo "Producing more output"
          set-output required_param "abc 123 456"

steps[].run.id

Defining an id for a step allows:

• Calling the same function that produces one or more outputs multiple times
• Using the output from one step to another

Call the same function one or more times

For example, the following function generates a random number:

functions:
  random:
    name: Generate random number
    outputs: [value]
    command: set-output value `random_number`

In a workflow, let's use the random function to generate two random numbers and print them:

build:
  name: Functions Demo
  steps:
    - random:
        id: random_1
    - random:
        id: random_2
    - run:
        name: Print random numbers
        inputs:
          random_1: ${ steps.random_1.value }
          random_2: ${ steps.random_2.value }
        command: |
          echo "${ inputs.random_1 }"
          echo "${ inputs.random_2 }"

Use output from one step to another

For example, the following workflow demonstrates how to use output from one step to another:

build:
  name: Outputs demo
  steps:
    - run:
        name: Produce output
        id: id123 # <---- !!!
        outputs: [foo]
        command: |
          echo "Producing output for another step"
          set-output foo bar
    - run:
        name: Use output from another step
        inputs:
          foo: ${ steps.id123.foo }
        command: |
          echo "foo = \"${ inputs.foo }\""

functions

Defined to describe a reusable function that can be used in a workflow. All config options to create a function are specified with the following properties:

functions.[function_name]

The [function_name] is the name of a function that you define to identify it in the build.steps. For example, you can define a function with the name greetings:

functions:
  greetings:
    name: Say Hi!

functions.[function_name].name

The name that is used in build logs to display the name of the function. For example, a function with the display name Say Hi!:

functions:
  greetings:
    name: Say Hi!

functions.[function_name].inputs

Input values are provided to a function.

inputs[].name

The name of the input value. It is used as an identifier to access the input value such as in bash command interpolation.

functions:
  greetings:
    name: Say Hi!
    inputs:
      - name: name
        default_value: Hello world
    command: echo "${ inputs.name }!"

inputs[].required

Boolean to indicate if the input value is required or not. For example, a function does not have a required value:

functions:
  greetings:
    name: Say Hi!
    inputs:
      - name: name
        required: false

inputs[].type

The type of the input value. It can be either string, num or json.

Input values set in the function call as well as default_value and allowed_values for the function are validated against the type.

The default input type is string.

For example, a function has an input value of type string:

functions:
  greetings:
    name: Say Hi!
    inputs:
      - name: name
        type: string
      - name: age
        type: num
      - name: other_data
        type: json

inputs[].default_value

You can use default_value to provide one default input. For example, a function has a default value of Hello world:

functions:
  greetings:
    name: Say Hi!
    inputs:
      - name: name
        default_value: Hello world

inputs[].allowed_values

You can use allowed_values to provide multiple values in an array. For example, a function has multiple allowed values:

functions:
  greetings:
    name: Say Hi!
    inputs:
      - name: name
        default_value: Hello world
        allowed_values: [Hi, Hello, Hey]
        type: string

Multiple input values

Multiple input values can be provided to a function.

functions:
  greetings:
    name: Say Hi!
    inputs:
      - name: name
        default_value: Expo
      - name: greeting
        default_value: Hi
        allowed_values: [Hi, Hello]
    command: echo "${ inputs.greeting }, ${ inputs.name }!"

functions.[function_name].outputs

An output value is expected from a function. For example, a function has an output value of Hello world:

functions:
  greetings:
    name: Say Hi!
    outputs: [value]
    command: set-output value "Hello world"

outputs[].name

The name of the output value. It is used as an identifier to access the output value in another step:

functions:
  greetings:
    name: Say Hi!
    outputs:
      - name: name

outputs[].required

Boolean to indicate if the output value is required or not. For example, a function does not have a required output value:

functions:
  greetings:
    name: Say Hi!
    outputs:
      - name: value
        required: false

functions.[function_name].command

Used to define the command to run when a function is executed, if you wish the function to be a simple shell script. Each function is required to define either a command or a path to JS/TS module implementing the function. For example, the command echo "Hello world" is used to print a message:

functions:
  greetings:
    name: Say Hi!
    command: echo "Hi!"

functions.[function_name].path

Used to define the path to a JavaScript/TypeScript module implementing the function. Each function is required to define either a command or a path property. For example, the path ./greetings is used to execute a greetings function declared in the greetings module:

functions:
  greetings:
    name: Say Hi!
    path: ./greetings

Learn more about building and using custom TypeScript/JavaScript functions here.

functions.[function_name].shell

Used to define the default executable shell for a step where a function is executed. For example, the step's shell is set to /bin/sh:

functions:
  greetings:
    name: Say Hi!
    shell: /bin/sh
    command: echo "Hi!"

functions.[function_name].supported_platforms

Used to define the supported platforms for a function. Defaults to all platforms. Allowed platforms: darwin, linux.

For example, the function's supported platform is darwin (macOS):

functions:
  greetings:
    name: Say Hi!
    supported_platforms: [darwin]
    command: echo "Hi!"

import

A config file path list used to import functions from other config files. Imported files cannot have the build section.

For example, the following workflow imports two files and calls two imported functions - say_hi and say_bye.

import:
  - common-functions.yml
  - another-file.yml

build:
  steps:
    - say_hi
    - say_bye

functions:
  say_hi:
    name: Say Hi!
    command: echo "Hi!"

functions:
  say_bye:
    name: Say bye :(
    command: echo "Bye!"

Functions

Built-in EAS functions

EAS provides a set of built-in reusable functions that you can use in a workflow without defining the function definition.

Tip: Any function that is built-in and provided by EAS must start with the eas/ prefix.

eas/checkout

Checks out you project source files.

For example, a workflow with the following steps will check out the project and list the files in the assets directory:

build:
  name: List files
  steps:
    - eas/checkout
    - run:
        name: List assets
        run: ls assets

eas/use_npm_token

Configures node package managers (npm, pnpm, or Yarn) for use with private packages, published either to npm or private registry. Set NPM_TOKEN in your project's secrets, and this function will configure the build environment by creating .npmrc with the token.

build:
  name: Install private npm modules
  steps:
    - eas/checkout
    - eas/use_npm_token
    - run:
        name: Install dependencies
        run: npm install # <---- Can now install private packages

eas/install_node_modules

Installs node modules using the package manager (npm, pnpm, or Yarn) detected based on your project. Works with monorepos.

build:
  name: Install node modules
  steps:
    - eas/checkout
    - eas/install_node_modules

eas/resolve_apple_team_id_from_credentials

This function is only available for iOS builds

Resolves the Apple team ID value based on build credentials provided in the inputs.credentials. The resolved Apple team ID is stored in the outputs.apple_team_id output value.

build:
  name: Run prebuild script
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/resolve_apple_team_id_from_credentials:
        id: resolve_apple_team_id_from_credentials
    - eas/prebuild:
        inputs:
          apple_team_id: ${ steps.resolve_apple_team_id_from_credentials.apple_team_id }

eas/prebuild

Runs the expo prebuild command using the package manager (npm, pnpm, or Yarn) detected based on your project with the command best suited for your build type and build environment.

build:
  name: Run prebuild script
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/resolve_apple_team_id_from_credentials:
        id: resolve_apple_team_id_from_credentials
    - eas/prebuild:
        inputs:
          clean: false
          apple_team_id: ${ steps.resolve_apple_team_id_from_credentials.apple_team_id }

build:
  name: Run prebuild script
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/prebuild

eas/configure_eas_update

To use this function you need to have EAS Update configured for your project

Configures runtime version and release channel for your build.

build:
  name: Configure EAS Update
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/prebuild
    - eas/configure_eas_update

build:
  name: Configure EAS Update
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/prebuild
    - eas/configure_eas_update:
        inputs:
          runtime_version: 1.0.0
          channel: mychannel

eas/inject_android_credentials

This function is only available for Android builds

Configures Android keystore with credentials on the builder and injects app signing config using these credentials into gradle config.

build:
  name: Android credentials
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/prebuild
    - eas/inject_android_credentials

eas/configure_ios_credentials

This function is only available for iOS builds

Configures iOS credentials on the builder. Modifies the configuration of the Xcode project by assigning provisioning profiles to the targets.

build:
  name: iOS credentials
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/resolve_apple_team_id_from_credentials:
        id: resolve_apple_team_id_from_credentials
    - eas/prebuild:
        inputs:
          clean: false
          apple_team_id: ${ steps.resolve_apple_team_id_from_credentials.apple_team_id }
    - eas/configure_ios_credentials

eas/configure_android_version

This function is only available for Android builds

Configures the version of your Android app. It's used to set a version when using remote app version management.

It's not mandatory to use this function, if it's not used the version from native code generated during the prebuild phase will be used.

build:
  name: Configure Android version
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/prebuild
    - eas/configure_eas_update
    - eas/inject_android_credentials
    - eas/configure_android_version

build:
  name: Configure Android version
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/prebuild
    - eas/configure_eas_update
    - eas/inject_android_credentials
    - eas/configure_android_version:
        inputs:
          version_code: '123'
          version_name: '1.0.0'

eas/configure_ios_version

This function is only available for iOS builds

Configures the version of your iOS app. It's used to set a version when using remote app version management.

It's not mandatory to use this function, if it's not used the version from native code generated during the prebuild phase will be used.

build:
  name: Configure iOS version
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/resolve_apple_team_id_from_credentials:
        id: resolve_apple_team_id_from_credentials
    - eas/prebuild:
        inputs:
          clean: false
          apple_team_id: ${ steps.resolve_apple_team_id_from_credentials.apple_team_id }
    - eas/configure_eas_update
    - eas/configure_ios_credentials
    - eas/configure_ios_version

build:
  name: Configure iOS version
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/resolve_apple_team_id_from_credentials:
        id: resolve_apple_team_id_from_credentials
    - eas/prebuild:
        inputs:
          clean: false
          apple_team_id: ${ steps.resolve_apple_team_id_from_credentials.apple_team_id }
    - eas/configure_eas_update
    - eas/configure_ios_credentials
    - eas/configure_ios_version:
        inputs:
          build_number: '123'
          app_version: '1.0.0'

eas/run_gradle

This function is only available for Android builds

Runs a Gradle command to build an Android app.

build:
  name: Build Android app
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/prebuild
    - eas/configure_eas_update
    - eas/inject_android_credentials
    - eas/run_gradle

build:
  name: Build Android app
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/prebuild
    - eas/configure_eas_update
    - eas/inject_android_credentials
    - eas/run_gradle:
        inputs:
          command: :app:bundleRelease

eas/generate_gymfile_from_template

This function is only available for iOS builds

Generates a Gymfile used to build the iOS app using Fastlane from a template.

Default template used when credentials are passed:

suppress_xcode_output(true)
clean(<%- CLEAN %>)

scheme("<%- SCHEME %>")
<% if (BUILD_CONFIGURATION) { %>
configuration("<%- BUILD_CONFIGURATION %>")
<% } %>

export_options({
method: "<%- EXPORT_METHOD %>",
provisioningProfiles: {<% _.forEach(PROFILES, function(profile) { %>
    "<%- profile.BUNDLE_ID %>" => "<%- profile.UUID %>",<% }); %>
}<% if (ICLOUD_CONTAINER_ENVIRONMENT) { %>,
iCloudContainerEnvironment: "<%- ICLOUD_CONTAINER_ENVIRONMENT %>"
<% } %>
})

export_xcargs "OTHER_CODE_SIGN_FLAGS=\\"--keychain <%- KEYCHAIN_PATH %>\\""

disable_xcpretty(true)
buildlog_path("<%- LOGS_DIRECTORY %>")

output_directory("<%- OUTPUT_DIRECTORY %>")

Default template used when credentials are not passed (simulator build):

suppress_xcode_output(true)
clean(<%- CLEAN %>)

scheme("<%- SCHEME %>")
<% if (BUILD_CONFIGURATION) { %>
configuration("<%- BUILD_CONFIGURATION %>")
<% } %>

derived_data_path("<%- DERIVED_DATA_PATH %>")
skip_package_ipa(true)
skip_archive(true)
destination("<%- SCHEME_SIMULATOR_DESTINATION %>")

disable_xcpretty(true)
buildlog_path("<%- LOGS_DIRECTORY %>")

CLEAN, SCHEME, BUILD_CONFIGURATION, EXPORT_METHOD, PROFILES, ICLOUD_CONTAINER_ENVIRONMENT, KEYCHAIN_PATH, LOGS_DIRECTORY, OUTPUT_DIRECTORY, DERIVED_DATA_PATHand SCHEME_SIMULATOR_DESTINATION values are provided to the template based on the inputs and default internal configuration of EAS Build.

build:
  name: Generate Gymfile template
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/resolve_apple_team_id_from_credentials:
        id: resolve_apple_team_id_from_credentials
    - eas/prebuild:
        inputs:
          clean: false
          apple_team_id: ${ steps.resolve_apple_team_id_from_credentials.apple_team_id }
    - eas/configure_eas_update
    - eas/configure_ios_credentials
    - eas/generate_gymfile_template:
        inputs:
          credentials: ${ eas.job.secrets.buildCredentials }

build:
  name: Generate Gymfile template
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/prebuild
    - eas/generate_gymfile_template

However, you can also use other custom properties in the template, by specifying your custom template in inputs.template and providing the values for the custom properties in the inputs.extra object.

build:
  name: Generate Gymfile template
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/resolve_apple_team_id_from_credentials:
        id: resolve_apple_team_id_from_credentials
    - eas/prebuild:
        inputs:
          clean: false
          apple_team_id: ${ steps.resolve_apple_team_id_from_credentials.apple_team_id }
    - eas/configure_eas_update
    - eas/configure_ios_credentials
    - eas/generate_gymfile_template:
        inputs:
          credentials: ${ eas.job.secrets.buildCredentials }
          extra:
            MY_VALUE: my value
          template: |
            suppress_xcode_output(true)
            clean(<%- CLEAN %>)

            scheme("<%- SCHEME %>")
            <% if (BUILD_CONFIGURATION) { %>
            configuration("<%- BUILD_CONFIGURATION %>")
            <% } %>

            export_options({
            method: "<%- EXPORT_METHOD %>",
            provisioningProfiles: {<% _.forEach(PROFILES, function(profile) { %>
                "<%- profile.BUNDLE_ID %>" => "<%- profile.UUID %>",<% }); %>
            }<% if (ICLOUD_CONTAINER_ENVIRONMENT) { %>,
            iCloudContainerEnvironment: "<%- ICLOUD_CONTAINER_ENVIRONMENT %>"
            <% } %>
            })

            export_xcargs "OTHER_CODE_SIGN_FLAGS=\"--keychain <%- KEYCHAIN_PATH %>\""

            disable_xcpretty(true)
            buildlog_path("<%- LOGS_DIRECTORY %>")

            output_directory("<%- OUTPUT_DIRECTORY %>")

            sth_else("<%- MY_VALUE %>")

eas/run_fastlane

This function is only available for iOS builds

Runs fastlane gym command against the Gymfile located in the ios project directory to build the iOS app.

build:
  name: Build iOS app
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/resolve_apple_team_id_from_credentials:
        id: resolve_apple_team_id_from_credentials
    - eas/prebuild:
        inputs:
          clean: false
          apple_team_id: ${ steps.resolve_apple_team_id_from_credentials.apple_team_id }
    - eas/configure_eas_update
    - eas/configure_ios_credentials
    - eas/generate_gymfile_template:
        inputs:
          credentials: ${ eas.job.secrets.buildCredentials }
    - eas/run_fastlane

build:
  name: Build iOS app
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/prebuild
    - eas/configure_eas_update
    - eas/generate_gymfile_template
    - eas/run_fastlane

eas/find_and_upload_build_artifacts

You can currently upload each artifact type only once per workflow.

Automatically finds and uploads application archive, other build artifacts, and Xcode logs looking at default locations and respecting ${ eas.job.buildArtifactPaths } setting. Uploads found artifacts to the EAS servers.

build:
  name: Build iOS app
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/resolve_apple_team_id_from_credentials:
        id: resolve_apple_team_id_from_credentials
    - eas/prebuild:
        inputs:
          clean: false
          apple_team_id: ${ steps.resolve_apple_team_id_from_credentials.apple_team_id }
    - eas/configure_eas_update
    - eas/configure_ios_credentials
    - eas/generate_gymfile_template:
        inputs:
          credentials: ${ eas.job.secrets.buildCredentials }
    - eas/run_fastlane
    - eas/find_and_upload_build_artifacts

build:
  name: Build iOS app
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/prebuild
    - eas/configure_eas_update
    - eas/generate_gymfile_template
    - eas/run_fastlane
    - eas/find_and_upload_build_artifacts

build:
  name: Build Android app
  steps:
    - eas/checkout
    - eas/install_node_modules
    - eas/prebuild
    - eas/configure_eas_update
    - eas/inject_android_credentials
    - eas/run_gradle
    - eas/find_and_upload_build_artifacts

eas/upload_artifact

Uploads a build artifact.

You can currently upload each artifact type only once per workflow.

For example, a workflow with the following steps will upload an artifact to the EAS servers:

build:
  name: Upload artifacts
  steps:
    - eas/checkout
    # - ...
    - eas/upload_artifact:
        name: Upload application archive
        inputs:
          path: fixtures/app-debug.apk
    - eas/upload_artifact:
        name: Upload build artifact
        inputs:
          type: build-artifact
          path: assets/icon.png

Using built-in EAS functions to build an app

Using the built-in EAS functions you can recreate the default EAS Build workflow for different build types.

For example, to trigger a build that creates internal distribution build for Android and a simulator build for iOS you can use the following configuration:

{
  ...,
  "build": {
    ...,
    "developmentBuild": {
      "distribution": "internal",
      "android": {
        "config": "development-build-android.yml"
      },
      "ios": {
        "simulator": true,
        "config": "development-build-ios.yml"
      }
    },
    ...
  },
  ...
}

build:
  name: Simple internal distribution Android build
  steps:
    - eas/checkout

    - eas/install_node_modules

    - eas/prebuild

    - eas/inject_android_credentials

    - eas/run_gradle

    - eas/find_and_upload_build_artifacts

build:
  name: Simple simulator iOS build
  steps:
    - eas/checkout

    - eas/install_node_modules

    - eas/prebuild

    - run:
        name: Install pods
        working_directory: ./ios
        command: pod install

    - eas/generate_gymfile_from_template

    - eas/run_fastlane

    - eas/find_and_upload_build_artifacts

To create Play Store build for Android and App Store build for iOS you can use the following configuration:

{
  ...,
  "build": {
    ...,
    "productionBuild": {
      "android": {
        "config": "production-build-android.yml"
      },
      "ios": {
        "config": "production-build-ios.yml"
      }
    },
    ...
  },
  ...
}

build:
  name: Customized Android Play Store build example
  steps:
    - eas/checkout

    - eas/install_node_modules

    - eas/prebuild

    - eas/inject_android_credentials

    - eas/run_gradle

    - eas/find_and_upload_build_artifacts

build:
  name: Customized iOS App Store build example
  steps:
    - eas/checkout

    - eas/install_node_modules

    - eas/resolve_apple_team_id_from_credentials:
        id: resolve_apple_team_id_from_credentials

    - eas/prebuild:
        inputs:
          apple_team_id: ${ steps.resolve_apple_team_id_from_credentials.apple_team_id }

    - run:
        name: Install pods
        working_directory: ./ios
        command: pod install

    - eas/configure_ios_credentials

    - eas/generate_gymfile_from_template:
        inputs:
          credentials: ${ eas.job.secrets.buildCredentials }

    - eas/run_fastlane

    - eas/find_and_upload_build_artifacts

Check out the example repository for more detailed examples:

Use a reusable function in a build

For example, a workflow with the following reusable function contains a single command to print a message that is echoed.

functions:
  greetings:
    - name: name
      default_value: Hello world
    inputs: [value]
    command: echo "${ inputs.name }, { inputs.value }"

The above function can be used in a build as follows:

build:
  name: Functions Demo
  steps:
    - greetings:
        inputs:
          value: Expo

Tip: build.steps can execute multiple reusable functions sequentially.

Override values in a build

You can override values for following properties:

• working_directory
• name
• shell

For example, a reusable function called list_files:

functions:
  list_files:
    name: List files
    command: ls -la

When list_files is called in a workflow, it lists all files in the root directory of a project:

build:
  name: List files
  steps:
    - eas/checkout
    - list_files

You can use the working_directory property to override the behavior in the function call to list the files in a different directory by specifying the path to that directory:

build:
  name: List files
    steps:
      - eas/checkout
      - list_files:
          working_directory: /a/b/c