Proxa works like a harness. It is what turns a capable language model into a working system. Instead of one-off chats with Claude, the agent works inside a persistent workspace for the entire team, where it can build, update, and maintain the Model over time. The harness provides the context, tools, permissions, state, and history needed to understand the domain and work with its data, logic, methods, and outputs — all guided, reviewed, and validated by the team.