GPT-5.4 Complete Guide: What's New, API Access, and How to Use It

OpenAI just released GPT-5.4, and it's a significant leap forward. The new model delivers 83% win rates against industry professionals on knowledge work, uses 47% fewer tokens in tool-heavy workflows, and introduces native computer use capabilities that surpass human performance on certain benchmarks. This guide combines everything you need to know: what GPT-5.4 is, how to access the API, and how to use it in your applications with working code examples. What Is GPT-5.4? GPT-5.4 is OpenAI's most advanced frontier model for professional work. It combines the coding excellence of GPT-5.3-Codex with enhanced reasoning, computer use, and tool integration into a single model. Key Improvements Over GPT-5.2 1. Factual Accuracy: False claims dropped 33% at the individual claim level. Full responses contain 18% fewer errors overall. 2. Token Efficiency: GPT-5.4 uses significantly fewer tokens to solve problems. In tool-heavy workflows with MCP Atlas benchmarks, token usage dropped 47% while mai