ZCode: the official GLM-5.3 harness, defined as an ADE rather than an editor
ZCode is the official harness Z.ai built for GLM-5.3, and it defines itself as neither an AI editor nor a CLI but an ADE (Agentic Development Environment): it turns the 1M context window and long-horizon capability of GLM-5.3 into a stable desktop experience covering planning, coding, review and iteration, keeping goal, files, terminal output, browser context, execution mode and Git state inside one task so continuity survives from plan through implementation to verification, with model capability, tool calling and the execution chain tuned over multiple rounds against GLM-5.3. The most distinctive design is /goal mode: after a goal is set, every round ends with an automatic check of whether the goal is met, and the agent continues into the next round on its own until completion is confirmed (the documented example is a research task running twenty-plus rounds, with a right-hand panel showing what each round did). One session holds one goal at a time; /goal shows it, /goal sets it (replacing any existing goal), /goal replace swaps it explicitly, /goal pause suspends it, and the docs are honest about the fit - work that is easy to state in one sentence but takes many rounds to finish. The card metric keeps the verifiable price fact layer: GLM-5.3 API at $1.4 input / $4.4 output per million tokens. Boundaries: the client is not open source and the deep tuning only covers the GLM-5.3 family; a stable 1M context is a vendor claim and mid-context recall is an industry-wide weakness, so stuffing a whole repo is no substitute for retrieval; idle-time tasks are being rolled out to subscribers rather than always available; the free quota is a 5-day window, not a lasting benefit. Confidence C (vendor-claim).