Ix is more polished and purpose-built for agent integration, with a Claude Code plugin that hooks into every file read and grep automatically. But it's a paid product in early access, less proven, and the Claude Code plugin is Claude-specific — the AGENTS.md integration works with OpenCode but is less deep than the hook-based integration.
For my use case I think I would be perfectly fine on the free tier so the comment about it being paid might not be valid. It also seems false that Ix is early access / less proven compared to Graphify. I do think it's interesting that Sonnet made these apparently incorrect conclusions based on your website and whatever else it found online.In my case I went with graphify because I am using OpenCode, and it seemed plausible that Sonnet would at least have gotten that part right about Graphify having better support for OpenCode. Now that I take a second look though, I realize there is a plugin for adding Ix into OpenCode (https://github.com/ix-infrastructure/ix-opencode-plugin) so now I'm contemplating migrating to Ix - the hooks available in that plugin appear to be better than what I have now with Graphify. I really dislike that graphify hooks rebuild the graph post-commit, since I want to include the graph files in my git repo.