This is not a product. 9times/10 I rely on Agentic Discovery. And I don't see that changing. 9times/10 that agent is Claude Code. If you're looking for a product that does your own context building or provides a different context building experience I recommend RepoPrompt. The founder's quite bearish on Agent Discovery & agentic context building.
The prompt tower experience is completely offline other than a proxy, so I can download zips from GitHub. I didn't feel like rolling out any formally authenticated experience. If you upload your own folder, all code stays in the browser.