This simple Cloudflare Workers script allows Sveltia CMS (or Netlify/Decap CMS) to authenticate with GitHub.

You don’t have to use it if you previously had Netlify/Decap CMS and your site is still being deployed to Netlify or if you have already used another 3rd party OAuth client.

You can use it if your site is hosted (or has been moved to) somewhere else, such as Cloudflare Pages or GitHub Pages, and you don’t have any other 3rd party client yet.

Click the button below to start deploying.

Alternatively, you can clone the project and run wrangler deploy locally.

Once deployed, open your Cloudflare Workers dashboard, select the sveltia-cms-auth service, then the worker URL (https://sveltia-cms-auth.<SUBDOMAIN>.workers.dev) will be displayed. Copy it for Step 2. It will also be used in Step 4.

Register a new OAuth application on GitHub (details) with the following properties, including your Worker URL from Step 1:

• Application name: Sveltia CMS Authenticator (or whatever)
• Homepage URL: https://github.com/sveltia/sveltia-cms-auth (or whatever)
• Application description: (can be left empty)
• Authorization callback URL: <YOUR_WORKER_URL>/callback

Once registered, click on the Generate a new client secret button. The app’s Client ID and Client Secret will be displayed. We’ll use them in Step 3 below.

Go back to the sveltia-cms-auth service page on Cloudflare, select Settings > Variables, and add the following Environment Variables to your worker (details):

• GITHUB_CLIENT_ID: Client ID from Step 2
• GITHUB_CLIENT_SECRET: Client Secret from Step 2; click the Encrypt button to hide it
• ALLOWED_DOMAINS: Your site’s hostname, e.g. www.example.com
  • Multiple hostnames can be defined as a comma-separated list, e.g. www.example.com, www.example.org
  • A wildcard (*) can be used to match any subdomain, e.g. *.example.com that will match www.example.com, blog.example.com, docs.api.example.com, etc. (but not example.com)
  • To match a www-less naked domain and all the subdomains, use example.com, *.example.com

Save and deploy.

Open admin/config.yml locally or remotely, and add your Worker URL from Step 1 as the new base_url property under backend:

 backend:
   name: github
   repo: username/repo
   branch: main
+  base_url: <YOUR_WORKER_URL>

Commit the change. Once deployed, you can sign into Sveltia CMS remotely with GitHub!

This project was inspired by netlify-cms-oauth-firebase.