Claude Mods: Flipping the Harness Inside Out

For the last few weeks I’ve used Claude Mods to mold Claude Code to my AI engineering workflow. Claude Code is great out of the box, but every engineering workflow is different. Claude Mods let you make Claude Code yours, in the way you want to pay attention. The “paying attention” part is now the most important thing. In a recent Latent Space post, The Evolution of the Agent Harness, I argued that as models absorb more of the harness into their weights, the part that’s left faces the human. It becomes the Attention Interface: the layer that decides when the agent interrupts you, what it shows you, and which decisions it needs you to make. Claude Mods are an early version of the Attention Interface, and one you can shape yourself. Here’s my bet: ultimately, the harness becomes a platform that other companies build on, with models as the engine. Just as the browser became a platform for web apps, the harness could become a platform for the interfaces between people and agents. A mod is a Claude Code plugin that consists of TypeScript or JavaScript functions that run inside Claude Code. These functions customize the behavior and appearance…