Working with Data Attributes

February 25, 2026

When embedding Pure Comments, you can keep setup minimal and let embed.js infer values automatically, or you can override behaviour with data attributes.

Quick Start (No Overrides)

If you do this:

<div id="comments"></div>
<script src="https://comments.example.com/public/embed.js" defer></script>

Then embed.js will:

infer the post slug from the current page URL
infer the API base URL from the script src

For many sites, that default behaviour is all you need.

data-post-slug (Optional)

You can use data-post-slug on the #comments container when you want to explicitly control the post/thread identifier.

<div id="comments" data-post-slug="my-first-post"></div>
<script src="https://comments.example.com/public/embed.js" defer></script>

When to use it

Your article URL might change over time (slug updates, permalink changes, route migrations).
You want multiple URLs to point to the same comment thread.
You use query-string or hash-based routing and want stable thread IDs.

Why it matters

Different slugs create different threads. If your blog's URL structure changes later, explicit slugs help prevent comment history from splitting across multiple threads.

data-base-url (Optional)

You can also use data-base-url on the script tag when API calls should go to a different origin than the script file.

<script src="https://comments.cdn.example.com/public/embed.js" data-base-url="https://comments.example.com" defer></script>

When to use it

You host embed.js on a CDN, but your API lives on your comments domain.
Static assets and API are intentionally split across domains.
You want to force a specific API origin for testing or staged environments.

Using Both Together

You can combine both overrides:

<div id="comments" data-post-slug="my-first-post"></div>
<script src="https://comments.cdn.example.com/public/embed.js" data-base-url="https://comments.example.com" defer></script>

This gives you:

stable thread mapping (data-post-slug)
explicit API target (data-base-url)

Practical Recommendation

Start with defaults first then add these attributes only when you need predictability across URL changes, multi-domain deployments, or custom routing.