Previews

To enable any of GitHub’s API Previews, pass the previews option to the GitHub constructor

const octokit = new Octokit({
  previews: ["mercy-preview"],
});

Previews can also be enabled for a single request by passing the mediaType.preview option

const {
  data: { topics },
} = await octokit.repos.get({
  owner: "octokit",
  repo: "rest.js",
  mediaType: {
    previews: ["symmetra"],
  },
});

Octokit Rest API