Cisco and OpenAI redefine enterprise engineering with Codex

For decades, Cisco has built and operated some of the world’s most complex, mission-critical software systems. As generative AI matured from experimentation to real operational capability, Cisco leaned into what it knows best: scaling advanced technology inside demanding, real-world environments .

That approach is already shaping how Cisco builds new products, including AI Defense , where Codex helped compress critical engineering work from several quarters to weeks.

Rather than treat Codex as a standalone developer tool, Cisco began integrating it directly into production engineering workflows, exposing it to massive multi-repository systems, C/C++-heavy codebases, and the security, compliance, and governance requirements of a global enterprise.

Codex was used by Cisco’s team to write the majority of AI Defense and nearly every new feature that Cisco is building.

This work also reflects Cisco’s broader role in advancing AI security. Cisco is among the leading security organizations working with OpenAI’s Daybreak initiative, which brings together OpenAI models, Codex, and security partners to accelerate cyber defense and continuously secure software. As part of this program, they have governed access to GPT‑5.5‑Cyber, a model for cyber defenders.

By working directly with OpenAI, Cisco engineers were able to give feedback on how these capabilities behaved in real environments, shaping areas like workflow orchestration, security controls, and support for long-running engineering tasks—all of which are critical for enterprise use.

In the process, Cisco helped shape Codex into something fundamentally different from a developer productivity tool: an AI engineering teammate capable of operating at enterprise scale .

Cisco’s work on AI Defense shows what that model can look like in practice. AI Defense is Cisco’s end-to-end AI security solution that protects against safety and security risks introduced by AI.

Cisco also used Codex to help build their Defense Squad, an open-source tool that moved from ideation to the developer community in under one week.