Zed 为什么不用自己造 Agent？OpenAI 架构师给出答案：Codex 重划 IDE × Coding Agent 的分工边界

Core Insights - Coding Agents have become one of the most active areas in applied AI, with a focus on maintaining rapid iteration and resilience amidst changing ecosystems [2] - OpenAI's Codex proposes a solution through the co-development of models and Harness, emphasizing the importance of understanding model behavior [4][6] Composition of Coding Agents - A Coding Agent consists of three main components: User Interface, Models, and Harness. The User Interface can be a command-line tool, integrated development environment (IDE), or cloud-based agent. Models include the latest GPT-5.1 series and others. Harness is a more complex part that interacts directly with the model, serving as the core agent loop [3][5] Importance of Harness - The Harness acts as the interface layer between the model and users, facilitating interaction and code generation. Building an efficient Harness is challenging due to issues like AV tool compatibility, latency management, and API changes [6][9] Challenges in Building Harness - Adapting models to the Harness requires extensive prompt design, as the model's training can lead to specific habits that must be understood for effective interaction. The relationship between steerability, intelligence, and habit is crucial for prompt engineering [7][8] Codex Capabilities - Codex is designed to function across various programming environments, allowing users to convert ideas into executable code, navigate code repositories, and execute commands. Its Harness must handle complex tasks, including parallel tool calls and security management [9][10] Future of Codex - Codex is rapidly evolving, currently serving hundreds of billions of tokens weekly, and is expected to handle more complex tasks with increased trust. The future will focus on large codebases and non-standard libraries, with continuous improvements in SDK capabilities [16][17] Building Custom Agents with Codex - Companies looking to integrate Codex into their agents can benefit from a model where the Harness serves as a new abstraction layer, allowing for easier updates and differentiation in product features [12][14] Successful Collaborations - Top partners like GitHub have successfully integrated Codex, allowing for direct interaction and optimization of their systems. The SDK facilitates various integrations, enhancing the capabilities of custom agents [15][16]