What happened to the URL on file for Sierra?

URL unreachable The URL on file (https://deepresearcher.net) did not respond across three consecutive checks; the streak completed on 2026-09-19.

This reports what that URL did, not a claim that Sierra itself is gone: the address on file does not confidently match Sierra's own domain, so if it turns out to be a marketplace or listing page rather than Sierra's own site, this observation is still accurate about the URL, just not about the product. See the methodology for how the match is made.

The vendor's own description, unedited:
Sierra is a conversational AI platform for businesses that enables companies to elevate their customer experience with AI. It helps businesses build better, more human customer experiences by deploying AI agents that are always available, empathetic, and aligned to their brand tone and voice. Sierra supports customers in real-time, helping them with complex issues and adapting swiftly to changes in the business. The platform allows companies to build personalized AI agents grounded in their company’s identity, policies, processes, and knowledge.