--- title: Metadata syntax for GitHub Actions shortTitle: Metadata syntax intro: You can create actions to perform tasks in your repository. Actions require a metadata file that uses YAML syntax. redirect_from: - /articles/metadata-syntax-for-github-actions - /github/automating-your-workflow-with-github-actions/metadata-syntax-for-github-actions - /actions/automating-your-workflow-with-github-actions/metadata-syntax-for-github-actions - /actions/building-actions/metadata-syntax-for-github-actions - /actions/creating-actions/metadata-syntax-for-github-actions versions: fpt: '*' ghes: '*' ghec: '*' type: reference --- {% data reusables.actions.enterprise-github-hosted-runners %} ## About YAML syntax for {% data variables.product.prodname_actions %} All actions require a metadata file. The metadata filename must be either `action.yml` or `action.yaml`. The preferred format is `action.yml`. The data in the metadata file defines the inputs, outputs, and runs configuration for your action. Action metadata files use YAML syntax. If you're new to YAML, you can read [Learn YAML in five minutes](https://www.codeproject.com/Articles/1214409/Learn-YAML-in-five-minutes). ## `name` **Required** The name of your action. {% data variables.product.prodname_dotcom %} displays the `name` in the **Actions** tab to help visually identify actions in each job. ## `author` **Optional** The name of the action's author. ## `description` **Required** A short description of the action. ## `inputs` **Optional** Input parameters allow you to specify data that the action expects to use during runtime. {% data variables.product.prodname_dotcom %} stores input parameters as environment variables. We recommend using lowercase input ids. ### Example: Specifying inputs This example configures two inputs: `num-octocats` and `octocat-eye-color`. The `num-octocats` input is not required and will default to a value of `1`. `octocat-eye-color` is required and has no default value. > [!NOTE] > Actions using `required: true` will not automatically return an error if the input is not specified. Workflow files that use this action can use the `with` keyword to set an input value for `octocat-eye-color`. For more information about the `with` syntax, see [AUTOTITLE](/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepswith). ```yaml inputs: num-octocats: description: 'Number of Octocats' required: false default: '1' octocat-eye-color: description: 'Eye color of the Octocats' required: true ``` When you specify an input, {% data variables.product.prodname_dotcom %} creates an environment variable for the input with the name `INPUT_`. The environment variable created converts input names to uppercase letters and replaces spaces with `_` characters. If the action is written using a [composite](/actions/creating-actions/creating-a-composite-action), then it will not automatically get `INPUT_`. With composite actions you can use `inputs` [AUTOTITLE](/actions/learn-github-actions/contexts) to access action inputs. To access the environment variable in a Docker container action, you must pass the input using the `args` keyword in the action metadata file. For more information about the action metadata file for Docker container actions, see [AUTOTITLE](/actions/creating-actions/creating-a-docker-container-action#creating-an-action-metadata-file). For example, if a workflow defined the `num-octocats` and `octocat-eye-color` inputs, the action code could read the values of the inputs using the `INPUT_NUM-OCTOCATS` and `INPUT_OCTOCAT-EYE-COLOR` environment variables. ### `inputs.` **Required** A `string` identifier to associate with the input. The value of `` is a map of the input's metadata. The `` must be a unique identifier within the `inputs` object. The `` must start with a letter or `_` and contain only alphanumeric characters, `-`, or `_`. ### `inputs..description` **Required** A `string` description of the input parameter. ### `inputs..required` **Optional** A `boolean` to indicate whether the action requires the input parameter. Set to `true` when the parameter is required. ### `inputs..default` **Optional** A `string` representing the default value. The default value is used when an input parameter isn't specified in a workflow file. ### `inputs..deprecationMessage` **Optional** If the input parameter is used, this `string` is logged as a warning message. You can use this warning to notify users that the input is {% data variables.release-phases.closing_down %} and mention any alternatives. ## `outputs` for Docker container and JavaScript actions **Optional** Output parameters allow you to declare data that an action sets. Actions that run later in a workflow can use the output data set in previously run actions. For example, if you had an action that performed the addition of two inputs (x + y = z), the action could output the sum (z) for other actions to use as an input. {% data reusables.actions.output-limitations %} If you don't declare an output in your action metadata file, you can still set outputs and use them in a workflow. For more information on setting outputs in an action, see [AUTOTITLE](/actions/using-workflows/workflow-commands-for-github-actions#setting-an-output-parameter). ### Example: Declaring outputs for Docker container and JavaScript actions ```yaml outputs: sum: # id of the output description: 'The sum of the inputs' ``` ### `outputs.` **Required** A `string` identifier to associate with the output. The value of `` is a map of the output's metadata. The `` must be a unique identifier within the `outputs` object. The `` must start with a letter or `_` and contain only alphanumeric characters, `-`, or `_`. ### `outputs..description` **Required** A `string` description of the output parameter. ## `outputs` for composite actions **Optional** `outputs` use the same parameters as `outputs.` and `outputs..description` (see [`outputs` for Docker container and JavaScript actions](#outputs-for-docker-container-and-javascript-actions)), but also includes the `value` token. {% data reusables.actions.output-limitations %} ### Example: Declaring outputs for composite actions {% raw %} ```yaml outputs: random-number: description: "Random number" value: ${{ steps.random-number-generator.outputs.random-id }} runs: using: "composite" steps: - id: random-number-generator run: echo "random-id=$(echo $RANDOM)" >> $GITHUB_OUTPUT shell: bash ``` {% endraw %} ### `outputs..value` **Required** The value that the output parameter will be mapped to. You can set this to a `string` or an expression with context. For example, you can use the `steps` context to set the `value` of an output to the output value of a step. For more information on how to use context syntax, see [AUTOTITLE](/actions/learn-github-actions/contexts). ## `runs` **Required** Specifies whether this is a JavaScript action, a composite action, or a Docker container action and how the action is executed. ## `runs` for JavaScript actions **Required** Configures the path to the action's code and the runtime used to execute the code. ### Example: Using Node.js v20 ```yaml runs: using: 'node20' main: 'main.js' ``` ### `runs.using` for JavaScript actions **Required** The runtime used to execute the code specified in [`main`](#runsmain). * Use `node20` for Node.js v20. ### `runs.main` **Required** The file that contains your action code. The runtime specified in [`using`](#runsusing-for-javascript-actions) executes this file. ### `runs.pre` **Optional** Allows you to run a script at the start of a job, before the `main:` action begins. For example, you can use `pre:` to run a prerequisite setup script. The runtime specified with the [`using`](#runsusing-for-javascript-actions) syntax will execute this file. The `pre:` action always runs by default but you can override this using [`runs.pre-if`](#runspre-if). > [!NOTE] > `runs.pre` is not supported for local actions. In this example, the `pre:` action runs a script called `setup.js`: ```yaml runs: using: 'node20' pre: 'setup.js' main: 'index.js' post: 'cleanup.js' ``` ### `runs.pre-if` **Optional** Allows you to define conditions for the `pre:` action execution. The `pre:` action will only run if the conditions in `pre-if` are met. If not set, then `pre-if` defaults to `always()`. In `pre-if`, status check functions evaluate against the job's status, not the action's own status. Note that the `step` context is unavailable, as no steps have run yet. In this example, `cleanup.js` only runs on Linux-based runners: ```yaml pre: 'cleanup.js' pre-if: runner.os == 'linux' ``` ### `runs.post` **Optional** Allows you to run a script at the end of a job, once the `main:` action has completed. For example, you can use `post:` to terminate certain processes or remove unneeded files. The runtime specified with the [`using`](#runsusing-for-javascript-actions) syntax will execute this file. In this example, the `post:` action runs a script called `cleanup.js`: ```yaml runs: using: 'node20' main: 'index.js' post: 'cleanup.js' ``` The `post:` action always runs by default but you can override this using `post-if`. ### `runs.post-if` **Optional** Allows you to define conditions for the `post:` action execution. The `post:` action will only run if the conditions in `post-if` are met. If not set, then `post-if` defaults to `always()`. In `post-if`, status check functions evaluate against the job's status, not the action's own status. For example, this `cleanup.js` will only run on Linux-based runners: ```yaml post: 'cleanup.js' post-if: runner.os == 'linux' ``` ## `runs` for composite actions **Required** Configures the path to the composite action. ### `runs.using` for composite actions **Required** You must set this value to `'composite'`. ### `runs.steps` **Required** The steps that you plan to run in this action. These can be either `run` steps or `uses` steps. #### `runs.steps[*].run` **Optional** The command you want to run. This can be inline or a script in your action repository: {% raw %} ```yaml runs: using: "composite" steps: - run: ${{ github.action_path }}/test/script.sh shell: bash ``` {% endraw %} Alternatively, you can use `$GITHUB_ACTION_PATH`: ```yaml runs: using: "composite" steps: - run: $GITHUB_ACTION_PATH/script.sh shell: bash ``` For more information, see [AUTOTITLE](/actions/learn-github-actions/contexts#github-context). #### `runs.steps[*].shell` **Optional** The shell where you want to run the command. You can use any of the shells listed in [AUTOTITLE](/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsshell). Required if `run` is set. #### `runs.steps[*].if` **Optional** You can use the `if` conditional to prevent a step from running unless a condition is met. You can use any supported context and expression to create a conditional. {% data reusables.actions.expression-syntax-if %} For more information, see [AUTOTITLE](/actions/learn-github-actions/expressions). **Example: Using contexts** This step only runs when the event type is a `pull_request` and the event action is `unassigned`. ```yaml steps: - run: echo This event is a pull request that had an assignee removed. if: {% raw %}${{ github.event_name == 'pull_request' && github.event.action == 'unassigned' }}{% endraw %} ``` **Example: Using status check functions** The `my backup step` only runs when the previous step of a composite action fails. For more information, see [AUTOTITLE](/actions/learn-github-actions/expressions#status-check-functions). ```yaml steps: - name: My first step uses: octo-org/action-name@main - name: My backup step if: {% raw %}${{ failure() }}{% endraw %} uses: actions/heroku@1.0.0 ``` #### `runs.steps[*].name` **Optional** The name of the composite step. #### `runs.steps[*].id` **Optional** A unique identifier for the step. You can use the `id` to reference the step in contexts. For more information, see [AUTOTITLE](/actions/learn-github-actions/contexts). #### `runs.steps[*].env` **Optional** Sets a `map` of environment variables for only that step. If you want to modify the environment variable stored in the workflow, use `echo "{name}={value}" >> $GITHUB_ENV` in a composite step. #### `runs.steps[*].working-directory` **Optional** Specifies the working directory where the command is run. #### `runs.steps[*].uses` **Optional** Selects an action to run as part of a step in your job. An action is a reusable unit of code. You can use an action defined in the same repository as the workflow, a public repository, or in a [published Docker container image](https://hub.docker.com/). We strongly recommend that you include the version of the action you are using by specifying a Git ref, SHA, or Docker tag number. If you don't specify a version, it could break your workflows or cause unexpected behavior when the action owner publishes an update. * Using the commit SHA of a released action version is the safest for stability and security. * Using the specific major action version allows you to receive critical fixes and security patches while still maintaining compatibility. It also assures that your workflow should still work. * Using the default branch of an action may be convenient, but if someone releases a new major version with a breaking change, your workflow could break. Some actions require inputs that you must set using the [`with`](/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepswith) keyword. Review the action's README file to determine the inputs required. ```yaml runs: using: "composite" steps: # Reference a specific commit - uses: actions/checkout@8f4b7f84864484a7bf31766abe9204da3cbe65b3 # Reference the major version of a release - uses: {% data reusables.actions.action-checkout %} # Reference a specific version - uses: {% data reusables.actions.action-checkout %}.2.0 # Reference a branch - uses: actions/checkout@main # References a subdirectory in a public GitHub repository at a specific branch, ref, or SHA - uses: actions/aws/ec2@main # References a local action - uses: ./.github/actions/my-action # References a docker public registry action - uses: docker://gcr.io/cloud-builders/gradle # Reference a docker image published on docker hub - uses: docker://alpine:3.8 ``` #### `runs.steps[*].with` **Optional** A `map` of the input parameters defined by the action. Each input parameter is a key/value pair. For more information, see [Example: Specifying inputs](#example-specifying-inputs). ```yaml runs: using: "composite" steps: - name: My first step uses: actions/hello_world@main with: first_name: Mona middle_name: The last_name: Octocat ``` #### `runs.steps[*].continue-on-error` **Optional** Prevents the action from failing when a step fails. Set to `true` to allow the action to pass when this step fails. ## `runs` for Docker container actions **Required** Configures the image used for the Docker container action. ### Example: Using a Dockerfile in your repository ```yaml runs: using: 'docker' image: 'Dockerfile' ``` ### Example: Using public Docker registry container ```yaml runs: using: 'docker' image: 'docker://debian:stretch-slim' ``` ### `runs.using` for Docker container actions **Required** You must set this value to `'docker'`. ### `runs.pre-entrypoint` **Optional** Allows you to run a script before the `entrypoint` action begins. For example, you can use `pre-entrypoint:` to run a prerequisite setup script. {% data variables.product.prodname_actions %} uses `docker run` to launch this action, and runs the script inside a new container that uses the same base image. This means that the runtime state is different from the main `entrypoint` container, and any states you require must be accessed in either the workspace, `HOME`, or as a `STATE_` variable. The `pre-entrypoint:` action always runs by default but you can override this using [`runs.pre-if`](#runspre-if). The runtime specified with the [`using`](#runsusing-for-docker-container-actions) syntax will execute this file. In this example, the `pre-entrypoint:` action runs a script called `setup.sh`: ```yaml runs: using: 'docker' image: 'Dockerfile' args: - 'bzz' pre-entrypoint: 'setup.sh' entrypoint: 'main.sh' ``` ### `runs.image` **Required** The Docker image to use as the container to run the action. The value can be the Docker base image name, a local `Dockerfile` in your repository, or a public image in Docker Hub or another registry. To reference a `Dockerfile` local to your repository, the file must be named `Dockerfile` and you must use a path relative to your action metadata file. The `docker` application will execute this file. ### `runs.env` **Optional** Specifies a key/value map of environment variables to set in the container environment. ### `runs.entrypoint` **Optional** Overrides the Docker `ENTRYPOINT` in the `Dockerfile`, or sets it if one wasn't already specified. Use `entrypoint` when the `Dockerfile` does not specify an `ENTRYPOINT` or you want to override the `ENTRYPOINT` instruction. If you omit `entrypoint`, the commands you specify in the Docker `ENTRYPOINT` instruction will execute. The Docker `ENTRYPOINT` instruction has a _shell_ form and _exec_ form. The Docker `ENTRYPOINT` documentation recommends using the _exec_ form of the `ENTRYPOINT` instruction. For more information about how the `entrypoint` executes, see [AUTOTITLE](/actions/creating-actions/dockerfile-support-for-github-actions#entrypoint). ### `runs.post-entrypoint` **Optional** Allows you to run a cleanup script once the `runs.entrypoint` action has completed. {% data variables.product.prodname_actions %} uses `docker run` to launch this action. Because {% data variables.product.prodname_actions %} runs the script inside a new container using the same base image, the runtime state is different from the main `entrypoint` container. You can access any state you need in either the workspace, `HOME`, or as a `STATE_` variable. The `post-entrypoint:` action always runs by default but you can override this using [`runs.post-if`](#runspost-if). ```yaml runs: using: 'docker' image: 'Dockerfile' args: - 'bzz' entrypoint: 'main.sh' post-entrypoint: 'cleanup.sh' ``` ### `runs.args` **Optional** An array of strings that define the inputs for a Docker container. Inputs can include hardcoded strings. {% data variables.product.prodname_dotcom %} passes the `args` to the container's `ENTRYPOINT` when the container starts up. The `args` are used in place of the `CMD` instruction in a `Dockerfile`. If you use `CMD` in your `Dockerfile`, use the guidelines ordered by preference: {% data reusables.actions.dockerfile-guidelines %} If you need to pass environment variables into an action, make sure your action runs a command shell to perform variable substitution. For example, if your `entrypoint` attribute is set to `"sh -c"`, `args` will be run in a command shell. Alternatively, if your `Dockerfile` uses an `ENTRYPOINT` to run the same command (`"sh -c"`), `args` will execute in a command shell. For more information about using the `CMD` instruction with {% data variables.product.prodname_actions %}, see [AUTOTITLE](/actions/creating-actions/dockerfile-support-for-github-actions#cmd). #### Example: Defining arguments for the Docker container {% raw %} ```yaml runs: using: 'docker' image: 'Dockerfile' args: - ${{ inputs.greeting }} - 'foo' - 'bar' ``` {% endraw %} ## `branding` **Optional** You can use a color and [Feather](https://feathericons.com/) icon to create a badge to personalize and distinguish your action. Badges are shown next to your action name in [{% data variables.product.prodname_marketplace %}](https://github.com/marketplace?type=actions). ### Example: Configuring branding for an action ```yaml branding: icon: 'award' color: 'green' ``` ### `branding.color` The background color of the badge. Can be one of: `white`, `black`, `yellow`, `blue`, `green`, `orange`, `red`, `purple`, or `gray-dark`. ### `branding.icon` The name of the v4.28.0 [Feather](https://feathericons.com/) icon to use. #### Omitted icons Brand icons, and all the following icons, are omitted.
  • coffee
  • columns
  • divide-circle
  • divide-square
  • divide
  • frown
  • hexagon
  • key
  • meh
  • mouse-pointer
  • smile
  • tool
  • x-octagon
#### Exhaustive list of all currently supported icons
  • activity
  • airplay
  • alert-circle
  • alert-octagon
  • alert-triangle
  • align-center
  • align-justify
  • align-left
  • align-right
  • anchor
  • aperture
  • archive
  • arrow-down-circle
  • arrow-down-left
  • arrow-down-right
  • arrow-down
  • arrow-left-circle
  • arrow-left
  • arrow-right-circle
  • arrow-right
  • arrow-up-circle
  • arrow-up-left
  • arrow-up-right
  • arrow-up
  • at-sign
  • award
  • bar-chart-2
  • bar-chart
  • battery-charging
  • battery
  • bell-off
  • bell
  • bluetooth
  • bold
  • book-open
  • book
  • bookmark
  • box
  • briefcase
  • calendar
  • camera-off
  • camera
  • cast
  • check-circle
  • check-square
  • check
  • chevron-down
  • chevron-left
  • chevron-right
  • chevron-up
  • chevrons-down
  • chevrons-left
  • chevrons-right
  • chevrons-up
  • circle
  • clipboard
  • clock
  • cloud-drizzle
  • cloud-lightning
  • cloud-off
  • cloud-rain
  • cloud-snow
  • cloud
  • code
  • command
  • compass
  • copy
  • corner-down-left
  • corner-down-right
  • corner-left-down
  • corner-left-up
  • corner-right-down
  • corner-right-up
  • corner-up-left
  • corner-up-right
  • cpu
  • credit-card
  • crop
  • crosshair
  • database
  • delete
  • disc
  • dollar-sign
  • download-cloud
  • download
  • droplet
  • edit-2
  • edit-3
  • edit
  • external-link
  • eye-off
  • eye
  • fast-forward
  • feather
  • file-minus
  • file-plus
  • file-text
  • file
  • film
  • filter
  • flag
  • folder-minus
  • folder-plus
  • folder
  • gift
  • git-branch
  • git-commit
  • git-merge
  • git-pull-request
  • globe
  • grid
  • hard-drive
  • hash
  • headphones
  • heart
  • help-circle
  • home
  • image
  • inbox
  • info
  • italic
  • layers
  • layout
  • life-buoy
  • link-2
  • link
  • list
  • loader
  • lock
  • log-in
  • log-out
  • mail
  • map-pin
  • map
  • maximize-2
  • maximize
  • menu
  • message-circle
  • message-square
  • mic-off
  • mic
  • minimize-2
  • minimize
  • minus-circle
  • minus-square
  • minus
  • monitor
  • moon
  • more-horizontal
  • more-vertical
  • move
  • music
  • navigation-2
  • navigation
  • octagon
  • package
  • paperclip
  • pause-circle
  • pause
  • percent
  • phone-call
  • phone-forwarded
  • phone-incoming
  • phone-missed
  • phone-off
  • phone-outgoing
  • phone
  • pie-chart
  • play-circle
  • play
  • plus-circle
  • plus-square
  • plus
  • pocket
  • power
  • printer
  • radio
  • refresh-ccw
  • refresh-cw
  • repeat
  • rewind
  • rotate-ccw
  • rotate-cw
  • rss
  • save
  • scissors
  • search
  • send
  • server
  • settings
  • share-2
  • share
  • shield-off
  • shield
  • shopping-bag
  • shopping-cart
  • shuffle
  • sidebar
  • skip-back
  • skip-forward
  • slash
  • sliders
  • smartphone
  • speaker
  • square
  • star
  • stop-circle
  • sun
  • sunrise
  • sunset
  • table
  • tablet
  • tag
  • target
  • terminal
  • thermometer
  • thumbs-down
  • thumbs-up
  • toggle-left
  • toggle-right
  • trash-2
  • trash
  • trending-down
  • trending-up
  • triangle
  • truck
  • tv
  • type
  • umbrella
  • underline
  • unlock
  • upload-cloud
  • upload
  • user-check
  • user-minus
  • user-plus
  • user-x
  • user
  • users
  • video-off
  • video
  • voicemail
  • volume-1
  • volume-2
  • volume-x
  • volume
  • watch
  • wifi-off
  • wifi
  • wind
  • x-circle
  • x-square
  • x
  • zap-off
  • zap
  • zoom-in
  • zoom-out
{% ifversion fpt or ghec %} ## Changing the metadata file name While the actions metadata file supports both YAML formats, changing the metadata file name (from `action.yml` to `action.yaml` or vice versa) between releases will affect previous release versions that have been published to {% data variables.product.prodname_marketplace %}. Changing the file name will hide all release versions associated with the previous file name from {% data variables.product.prodname_marketplace %}. Previous release versions will still be accessible to users through the source repository. When releasing new versions of actions, only versions released after the metadata file name change will have the {% data variables.product.prodname_marketplace %} tag and will show up on {% data variables.product.prodname_marketplace %} {% endif %}