guidegpt codex apigpt 5.3 codexcoding agent apiopenai codexagentic codingGPT Codex API Guide: When to Use GPT-5.3-codex for AgentsA practical guide to GPT-5.3-codex — OpenAI's agentic coding model with mid-task steering and terminal/computer-use highs. When it beats a general model, and how to use it.2026-07-10claire-lowe
