Write JavaScript Actions

Write your own GitHub JavaScript Action and automate customized tasks unique to your workflow.

Step 3: Create the metadata file

Nice work configuring your action 😄

Action metadata

Every GitHub Action that we write needs to be accompanied by a metadata file. This file has a few rules to it, as are indicated below:

• Filename must be action.yml.
• Required for both Docker container and JavaScript actions.
• Written in YAML syntax.

This file defines the following information about your action:

Parameter	Description	Required
Name	The name of your action. Helps visually identify the actions in a job.	✅
Description	A summary of what your action does.	✅
Inputs	Input parameters allow you to specify data that the action expects to use during runtime. These parameters become environment variables in the runner.	❌
Outputs	Specifies the data that subsequent actions can use later in the workflow after the action that defines these outputs has run.	❌
Runs	The command to run when the action executes.	✅
Branding	You can use a color and Feather icon to create a badge to personalize and distinguish your action in GitHub Marketplace.	❌

---

Read more about Action metadata

⌨️ Activity 1: Create the metadata file

All of the following steps take place inside of the .github/actions/joke-action directory.

Our action does not require much metadata for it to run correctly. We will not be accepting any inputs, we will however be setting a single output this time.

1. Update the action metadata file .github/actions/joke-action/action.yml with the following content:

   name: "my joke action"
   
   description: "use an external API to retrieve and display a joke"
   
   outputs:
     joke-output:
       description: The resulting joke from the icanhazdadjokes API
   
   runs:
     using: "node16"
     main: "main.js"

2. Save the action.yml file

3. Commit the changes and push them to GitHub:

   git add action.yml
   git commit -m 'add metadata for the joke action'
   git pull
   git push

4. Wait about 20 seconds then refresh this page (the one you're following instructions from). GitHub Actions will automatically update to the next step.

---

Get help: Post in our discussion board • Review the GitHub status page

© 2023 GitHub • Code of Conduct • MIT License