OpenAI Codex harness is now open source
BorisMPower · x · 2026-09-30
Developer Boris MPower announced that OpenAI's Codex harness is now open source, making the underlying scheduling and execution framework of the Codex coding agent publicly viewable.
For coding-agent developers, this offers a direct look at how OpenAI structures the agent's tool calls and execution loop, beyond the product surface.
Related event: OpenAI Open-Sources Codex Harness Coding Agent Framework(2 posts)→
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