This is a known limitation - the automation agent doesn’t have access to its own session URL at runtime, so it can’t include the link in Linear comments. The PR gets the link through a separate server-side mechanism that doesn’t extend to the agent’s comment context.
Possible workaround: The agent does receive its automationId via the <automation_trigger_info> tag in the conversation. You could try adding an instruction in your automation prompt telling the agent to extract the automationId and construct a link using the pattern https://cursor.com/automations/{automationId}, then include that in its Linear comment. This would link to the automation page rather than the specific run session, so it’s not full parity with the Slack “Open in Web” behavior, but it would give developers a way to find the automation and its history.
When you assign Cursor directly to a Linear issue, the syncing uses a different integration path that includes the session link automatically, but automations don’t have that same plumbing yet.
You may also find this related thread helpful, where another user reported the same gap: Link to automation run in linear comment. Our team is aware and tracking this for feature parity.