For a static blog like this one, supporting comments from readers is not easy. The site is entirely generated ahead-of-time and published to an Amazon S3 bucket, made accessible over Amazon CloudFront. Without a compute instance, there is no way to store and retrieve dynamic content like comments. For the most part, I have considered the absence of comments to be a “feature”. Recently, however, I decided that reader engagement wouldn’t be so bad after all.

And so, as of yesterday, it is now possible to comment on posts on this blog. I eschewed solutions like Disqus because they pull in cruft I don’t care for, and I avoided systems like Staticman as they’ve become fairly heavyweight over time.

Instead, I built a custom solution using a free version of Cloudflare worker. The server-side code is less than 200 lines long (all under the worker sub-folder in my public repository). The server-side code uses a bot account with GitHub to post incoming comments as pull requests to the repository. Once I review and approve a request, it gets merged into the repository and triggers a fresh build and deployment of the site. To limit spam, the server-side code has some tricks up its sleeve, including a spam check with Akismet and an in-built honeypot to catch drive-by spammers.

On the client-side application, I render the comments for each post along with a form to post new comments. All existing comments are organized as a single new section, but the frontmatter of each comment indicates which post it belongs to. The rendering logic filters by this information to only render relevant comments in linear chronological order. New comment submission is, of course, handled using JavaScript, and includes some in-built speedbumps to reduce spam.

While the current approach works reasonably well in my opinion, a key point of friction is that comments don’t show up for some undefined period of time until they are approved (or never, if the comment is rejected). Readers submitting comments see a message indicating that the comment has been submitted and is pending approval, but don’t see their own comment rendered on the page until much later.