For the complete documentation index, see llms.txt. Markdown variants are available by appending .md to any URL or sending an Accept: text/markdown header. An agent skill is available at /.well-known/agent-skills/site-skill.md.
Paste a URL and see the link preview Nextdoor will build from it.
Nextdoor turns a shared link into a post card: a large og:image on top, a bold og:title below it, one to two lines of muted og:description, and the bare domain underneath. The card is text-led and neighborhood-scannable, so a plain-spoken title and a first line that says what the link is do the most work.
The card is driven by the standard tags — og:title, og:description, og:image, and og:url — read from the initial HTML response.
When a post shows a bare URL instead of a card, the fetch failed rather than a tag being absent. Nextdoor publishes no dedicated preview crawler, so the scan fetches the page with a standard browser user agent — a login wall, an internal host, or an og:image it cannot reach leaves only the link text either way.
The scan above requests the page the same way, so a check that passes here is a fetch that works in a Nextdoor post.
Set og:title, og:description, and og:image in the page head, server-rendered. Use an HTTPS image at 1200×630 when possible, keep it under 5 MB, and serve it without an avoidable redirect. Keep the title short and the description to two lines — that is all the card shows.
The scanner fetches both the page and its image the same way a Nextdoor unfurl would, so it can show whether the tags are reachable before you share the link.