Kyle Gill: 0:00 To develop a Gatsby plugin, you need a site to run it in. You can quickly generate a new site running gatsby new using the default name my-gatsby-project and choosing a starter. I chose the hello-world starter. You should see a new directory created, called my-gatsby-project, that contains the example site.
0:14 Gatsby maintains a starter that can be used as an initial boilerplate for creating a new plugin. Copy the link to clone it from GitHub and run gatsby new again, this time passing in my-plugin as the first argument and the Git URL as the second argument. Another directory will be generated containing the plugin starter code.
0:34 You need to include your plugin in the example site's config so it knows to run the plugin. Navigate to the gatsby-config file. If you don't have one already, add a plugins array and include an entry for your plugin with require.resolve and the path to your plugin. In my case, in the my-plugin folder.
0:48 You could also link your plugin using npm link or yarn workspace, if you're familiar with them. Your plugin's code that implement Gatsby APIs, like in the gatsby-node file, will now be run when you start the site. This code in the onPreInit hook will log "Loaded gatsby-starter-plugin" to the console. Run the example site with gatsby develop. You should see the message in the log output.
1:20 Now you're set up to add other Gatsby APIs.