Codex models, specifically gpt-5.2-codex, offer significant improvements in coding performance, emphasizing efficiency and intelligence. The article outlines how to optimize the use of this model through a detailed guide, which is especially useful for those utilizing the API for custom coding tasks. Key advancements include faster processing, reduced token usage, and enhanced autonomy, allowing the model to handle complex tasks over extended periods. The guide also highlights the model's improved performance in PowerShell and Windows environments. To get started with Codex, users with existing implementations can transition with minimal changes, while newcomers may need to adapt their prompts and tools more extensively. The recommended approach involves using a standard Codex-Max prompt as a base and refining it with specific elements that enhance autonomy and task persistence. Users should avoid prompting for unnecessary status updates, as these can disrupt the model's flow. The guide emphasizes the importance of efficient tool use and parallelization to maximize productivity. The article includes practical advice for coding practices, urging users to prioritize correctness and clarity over speed. It stresses following codebase conventions and ensuring that changes maintain intended behavior. Tight error handling is essential, and users are encouraged to avoid risky shortcuts or broad error catches that mask issues. The guide also advises on editing constraints, such as defaulting to ASCII and providing concise comments only when necessary. Overall, the article serves as a comprehensive resource for effectively leveraging the Codex model in coding tasks.