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ksmithandClaude Sonnet 5
760d2cf5dd
Slack/Discord-style link unfurling: the first http(s) URL in a message's content gets a small preview card (title/description/image/site name) fetched from the page's Open Graph tags. Backend: - Message.preview_url (extracted at create/edit time, cheap regex, no I/O) points at a link_previews cache row keyed by URL -- the same URL posted in different messages/rooms fetches once, and a failed fetch is cached too so a dead URL isn't retried on every reference. - The actual fetch runs in a background asyncio.create_task from broadcast_new_message/broadcast_message_update, on its own DB session, so a slow third-party site never delays message delivery. A separate "link_preview" WS envelope carries the result once it resolves. - SSRF protection reuses app/services/ssrf.py's validate_target_url (renamed from UnsafeWebhookUrlError to UnsafeUrlError now that it's shared with webhooks), but re-validates before every hop of a redirect chain rather than once up front -- redirects are followed manually so each intermediate URL is checked before it's ever connected to. - Parsed with stdlib html.parser -- no new dependency. Frontend: a LinkPreviewCard rendered under message content when present, patched into state live via the new WS envelope and included in message history for reloads. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>