Appreciate the framing, Mark: but the cross-harness truth problem you describe is already solved in virtual-context. We ship a command called VCATTACH that lets any client (Claude Code, Cursor, an OpenAI-compatible editor, anything that routes through the proxy) attach to an existing conversation's context. Two harnesses, five harnesses, doesn't matter. After VCATTACH, they share segments, facts, and compaction state: ultimately they share the same 'memory'.

The virtual-context proxy layer is harness-agnostic by design. It speaks both Anthropic and OpenAI formats. So the answer to "who owns truth when you use five harnesses" is: the context layer beneath all of them, which is what VC is.

There are other unsolved problems with this approach, and plenty of work to do in virtual-context to make it even more robust, but the architecture is enabled.