Harness profile

Codex

Apache-2.0Rust + TypeScript107k GitHub stars (Aug 2026)

MakerOpenAI

LicenseApache-2.0

StackRust + TypeScript

ModelsOpenAI models only

Runs whereManaged product on a subscription

Behavior changed byMarkdown instruction files (AGENTS.md)

Durable memoryLimited

Drives other agentsNo

Best for

Teams standardized on OpenAI models; the counterpart to Claude Code for that stack.

Main weakness

One vendor's models.

Official docs / repo · Not sure? Run the chooser

Profile facts from the winder.ai comparison of nine agent harnesses (table checked Aug 19, 2026; DeepSeek Harness star count updated Sep 25, 2026 from the live GitHub repo) and vendor documentation. If something here is stale, the vendor page wins - tell us via the kit signup and we will fix it.