satonotdead announced Horizon AI Gists, a new theme component designed to display discourse-ai topic summaries on Horizon’s topic cards. Since Horizon’s “high context cards” do not natively support the outlets required by discourse-ai, this component renders gists directly under the topic title.
Key Features
High Context Cards: The AI gist replaces the standard excerpt. If no gist exists, the original excerpt is retained.
Simple Cards: Maintains the discourse-ai gist layout in suggested and related lists.
User Control: When used with the Topic Excerpts & AI Gists Button, users can toggle between compact views, excerpts, and AI summaries.
Requirements
To function correctly, the site must have Horizon and discourse-ai installed, running Discourse 2026.5.0 or later. Administrators must enable ai_summarization_enabled, ai_summary_gists_enabled, and ensure ai_summary_gists_agent permissions include the relevant viewer groups. ai_summary_backfill_maximum_topics_per_hour must also be set above 0 to generate gists.
Limitations
The component relies on Horizon’s internal CSS classes, meaning updates to the main Horizon theme could break functionality. Additionally, hiding gists is cosmetic only (data is still sent in payloads), gists are client-side rendered (invisible to search engines), and screen readers default to excerpts to maintain title brevity.
Community Discussion
merefield criticized the need for bespoke components to integrate standard extensions, suggesting this indicates a design flaw in the Horizon theme itself. In response, satonotdead defended the open-source model, noting that community contributions allow users to fill gaps left by core developers’ focus on minimalism and core features. They emphasized that personalization is part of the Discourse experience and welcomed further community contributions to improve the Horizon ecosystem.
Horizon’s high context cards don’t include the outlets discourse-ai uses, so gists don’t show there. This component renders them under the topic title.
Screenshots
What it does
High context cards: the gist replaces the excerpt. Topics without a gist keep their excerpt.
Simple cards (suggested and related lists): keep discourse-ai’s gist in the card’s layout.
discourse-docs lists: one blurb per row.
Optional selector: with Topic Excerpts & AI Gists Button installed, members can switch between compact, excerpts and AI summaries.
It also works alongside Horizon Topic Thumbnails, for offer a curated and eye-catching experience.
Requirements
Horizon and discourse-ai
ai_summarization_enabled and ai_summary_gists_enabled on
ai_summary_gists_agent set to an agent whose allowed groups include your viewers; add everyone for signed-out visitors
ai_summary_backfill_maximum_topics_per_hour above 0, so gists get generated
Discourse 2026.5.0 or later
Settings
Setting
Default
gist_hidden_categories
empty
Categories that show neither gist nor excerpt, as a title-only index
Known limits
It depends on Horizon’s internal classes, so a Horizon update can break it.
Hiding is cosmetic: gists are still generated and sent in the topic list payload.
Gists render client-side, so search engines don’t see them.
Screen readers get the excerpt, not the gist, to keep Horizon’s title heading short.
It sets each browser’s discourse-ai layout preference to table-ai. Removing the component doesn’t reset it.
Can’t help thinking there’s a fundamental design and approach flaw in the Horizon theme that forces you to jump through hoops to incorporate standard extensions that have existed for … years.
Having to deploy two bespoke Theme Components (more coming?!) that target a single Theme??
That’s, imho, a symptom of failure earlier in the process.
Well, I do not see myself in a position to question the core design team’s decisions at all, but I can share my thoughts as a user and admin.
And being honest, I also have “Custom Horizon Mods” with more updates/changes I think that is the beauty of Discourse and I am here because of it. I like to personalize.
I saw the framing to offer a “simple modern theme” landed very well and also gained a lot of traction/influence to further core (including Foundation) development and features. I am with minimalism and I really like the simple digital interfaces → “less is better”.
In the meantime, I see that some of the most expected features of the theme for non-technical users who love Horizon were taken off, and I thought that perhaps they could be revisited. I also expect that because they were two real pain points while using the theme.
Meanwhile, the open-source philosophy of Discourse and this fantastic community here on Meta, plus a good harness, curiosity and ultra-focus, have given me the ability to improve the user experience on Horizon in a couple of months, and I think that is good.
There were a lot of recent changes in Discourse, and I understand there are probably too many open fronts. It is expected while we —folks who use forums like in the old days— adapt ourselves to new designs and common standards like scrolls, chats, video, drastic changes in UI/UX, and so on.
I hope my humble contributions can fill the gap and help others with the issues we faced. I am also open to contributions and/or integrations from everyone who wants to do so.
I think that is the beauty of Discourse and I am here because of it. I like to personalize.