OpenAI
ChatGPT-User
Fetches pages for user actions in ChatGPT and custom GPTs.
User-requested fetchLink previews
Slackbot-LinkExpanding
Retrieves shared links to build previews in Slack.
Operated by Slack
See your agent traffic PurposeLink previews
HTTP identifierSlackbot-LinkExpanding
IdentityVerify beyond the name
THE SIGNAL
What this visit tells you
A preview can indicate that someone shared a URL, but caching means requests are not a count of people, messages or clicks.
Preview fetch success
Metadata availability
Image fetch success
Your next move
Check public preview metadata and its image. If access requires login, decide what safe public summary you want a shared link to display.
The technical details
MarkdownHow to identify it
Look for the Slackbot-LinkExpanding identifier in a request’s User-Agent. This is a name match, not identity verification. Version strings may change.
How to check identity
Identity remains unverified from a User-Agent alone. Consult the operator before granting privileged access.
Access and robots.txt
Slack documents that this user-requested preview bot does not honor robots.txt.
Seeing 403 or 404 responses?
403 means access was denied; 404 means the resource was not found. Compare the public path, request time, edge security event and origin response to find the cause.
Separate intended restrictions and secret-file probes from pages that should work. A User-Agent name alone does not justify allowing a request.
SourcesReviewed 2026-09-14
Identity and purpose are based on these sources. Analytics interpretation and suggested checks are Apostl guidance.
APOSTL PulseSee Slackbot-LinkExpanding in context
See their requests. Find the pages that matter.
See your agent trafficKEEP EXPLORING
Different bots, different intent
UptimeRobot
UptimeRobot
Checks endpoints configured for availability monitoring.
Monitoring