Codex, Behind the Harness
Dominik Kundel
- When
- Thursday, July 21:30 PM – 1:50 PM · 20 min
- Where
- Track 8San Francisco, CA · imported from ai.engineer's public schedule feed
About this session
Agents have evolved a lot in the last year both in capabilities and in the overall structure. Increasingly sandbox-powered coding agents are breaking out to do general purpose work.
In this talk we’ll be taking apart the open-source Codex agent harness. Understand how it works, what makes it so suitable to do work beyond coding tasks, how it handles key aspects like context management, tools and file system access. We’ll also tie these back to concrete actions you can take to bring these patterns into your own agents, whether you are building on top of the Codex agent or building your own.
Speaker
Developer Experience Lead, OpenAI
Dominik Kundel works on Developer Experience at OpenAI, where he helps builders get the most out of Codex and the OpenAI APIs. His work has spanned the Agents SDK, GPT-OSS, and most recently Codex. Before OpenAI, he led Product & Design for Twilio’s Emerging Tech & Innovation team, working on developer tools and customer-aware AI agents. Dominik has spent more than a decade in developer tools, usually across APIs, CLIs, JavaScript, and strange demos. Outside work, he’s probably tinkering with cocktails, food, photography, or something that should not need JavaScript but somehow does.
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For developers: this programme is open data — JSON, iCal, schedule XML and an MCP endpoint.Show endpointsHide
- JSONEvery published session and speaker, in one request./aie-worldsfair-2026-import/feed.json
- iCalSubscribe in Google, Apple or Outlook Calendar./aie-worldsfair-2026-import/feed.ics
- Schedule XMLfrab / pentabarf — the format conference apps import./aie-worldsfair-2026-import/feed.xml
- MCP + RESTPoint Claude at the programme. OpenAPI 3.1 included./agents
No key, no signup, CORS open. Everything here is generated from the same data the organisers edit.