Updated 14 July 2019: Added the requirement of adding a custom domain according to this comment.

Updated 19 April 2019: Updated admin/index.html to the latest official version and fixed some minor (natural) language problems.

This post walks through the really fast process of adding Netlify CMS to an existing GitHub Pages site. At the end of this post you should have:

  • A functioning CMS for your static GitHub Pages site
  • Your GitHub Pages site still hosted by GitHub Pages, not Netlify
  • Logging into the CMS through GitHub OAuth, with Netlify auth servers (not git-gateway)

Let’s get started.

Creating an GitHub OAuth App

First, go to GitHub Dev Settings and click New OAuth App. Or just click here: https://github.com/settings/developers

Enter whatever you like for Application name and Homepage URL.

In Authorization callback URL, enter: https://api.netlify.com/auth/done.

Once finished, leave the page in the background. You will need the Client ID and Client Secret on this page later.

Creating a Netlify Site

… Relax! We’re just creating one, without actually using it. In fact, if you want to deploy Jekyll site on Netlify, you will need to include Jekyll (generator) in your git repo.

Go to Netlify and create a new site from… any repo. We are not really using Netlify to host that, anyway.

After that, go to Settings, and copy your Site name. It should be something like octopus-cat-123456.

From the sidebar go to Domain Management and add your GitHub Pages domain (you.github.io) as a custom domain. Choose Yes when asked if you are github.io’s owner.

From the sidebar go to Access control, scroll down to OAuth and click Install provider.

Choose GitHub as provider, and enter the Client ID and Client Secret from GitHub OAuth app page mentioned above.

Then you can close the Netlify and GitHub webpages.

“Installing” the CMS

Finally! We are now going to add the CMS files into our static Jekyll site.

Under the root directory of your site, create a folder named admin, and cd into it. All our work will be done here.

Create a file named index.html.

Copy and paste these into it:

<!doctype html>
  <meta charset="utf-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Content Manager</title>
  <!-- Include the script that builds the page and powers Netlify CMS -->
  <script src="https://unpkg.com/netlify-cms@^2.0.0/dist/netlify-cms.js"></script>

Then create another file named config.yml.

Copy and paste these into it:

  name: github
  repo: you/you.github.io
  branch: master
  site_domain: octopus-cat-123456.netlify.com

media_folder: "images/uploads"

  - name: "blog" # Used in routes, e.g., /admin/collections/blog
    label: "Blog" # Used in the UI
    folder: "_posts/" # The path to the folder where the documents are stored
    create: true # Allow users to create new documents in this collection
    slug: "{{year}}-{{month}}-{{day}}-{{slug}}" # Filename template, e.g., YYYY-MM-DD-title.md
    fields: # The fields for each document, usually in front matter
      - {label: "Title", name: "title", widget: "string"}
      - {label: "Publish Date", name: "date", widget: "datetime"}
      - {label: "Tags", name: "tags", widget: "list"}
      - {label: "Body", name: "body", widget: "markdown"}

Be sure to replace you/you.github.io with your repo, and octopus-cat-123456.netlify.com with your-site-name.netlify.com.

For more information about the fields field, please go to https://www.netlifycms.org/docs/add-to-your-site/#collections.

Save the files, commit, and push to GitHub. Done. Visit https://you.github.io/admin to see your CMS. :D