The unsung hero behind OpenAI’s 2026 transformation is a technology that rarely gets mentioned, and that most of its 1 billion monthly users have never even heard of. Since The Deep View audience is AI-savvy, you probably think I’m talking about Codex, the company’s coding agent that competes with Claude Code and has recently grown to 10 million monthly users, generating plenty of buzz among AI builders. But I’m actually talking about the technology underneath Codex: OpenAI’s agent harness that now powers both Codex and ChatGPT Work. In an exclusive interview with The Deep View, OpenAI engineers and product leads shared how the harness has become OpenAI’s secret sauce. Surprisingly, the Codex agent harness is also open-source, unlike Anthropic’s Claude Code harness.

Full feature : A look at OpenAI’s open-source agent harness that now powers Codex and ChatGPT Work, as the company works to optimize the harness to cut runaway token usage.