The Rise of the Open Harness
I have been making one claim for months now, and I want to state it plainly before defending it:
The next Anthropic will be an open harness.
Follow me on The AI Supercycle as well!
Not a company. A position. The role Anthropic occupies today — the owner of the scaffolding around AI models where all the real value is compounding — is about to be re-occupied at the enterprise level by something open. Open weights. Open framework. Open runtime. Owned by the enterprise, not rented from a lab.
This piece is the argument for why that has to happen.
To follow it, you need three ideas up front. I will explain each one properly in the sections that follow — this is just so nothing catches you off guard.
Idea one — the harness. Every useful AI system today is a model plus a lot of scaffolding around it. The model is the brain. The scaffolding is everything else: the loop that decides what to do next, the memory system that keeps track of context, the tools the model can call, the guardrails that keep it safe, the runtime it executes in. That entire wrapper around the model is called a harness. When people talk about Claude Code or Codex, they are talking about harnesses, not models.
Idea two — where the value is. The models themselves are becoming commodities. Open-weight models are now nearly as good as the closed frontier at a fraction of the cost. What still creates lasting value — the moat, the lock-in, the compounding improvement — is the harness around the model, not the model itself. This is settled ground at this point. Every serious operator agrees.
Idea three — the split I am making. So far, the best harnesses have been closed. Anthropic built Claude Code around Claude. OpenAI built Codex around GPT. The lab owns both the model and the harness, and the tight integration between them is the edge. My claim is that this edge is about to move. The winning harness for the enterprise will not be closed. It will be open — because of what an enterprise structurally is, and what it structurally cannot outsource.
That is the whole piece in advance. Now let me build the case.
