OpenAI's Build Week is a global hackathon centered entirely on Codex, OpenAI's coding agent — and it's live right now with a $100,000 prize pool on the table. Unlike invite-only competitions, it's open to developers, students, and complete beginners worldwide. Here's exactly how to register, what to build, and how to actually get your project across the finish line.
What Is OpenAI Build Week?
Build Week is a week-long global hackathon run by OpenAI in partnership with Devpost, its official hackathon administrator. The challenge is straightforward: build something real using Codex and GPT-5.6, then submit it for judging. It's already drawn more than 8,600 developers, part of the same growth push behind OpenAI crossing 8 million active Codex and ChatGPT Work users.
Builders of all experience levels are welcome — this isn't restricted to professional engineers. You can enter solo or as a team, and there's no cost to participate.
Key Dates
- Registration period: July 9 – July 21, 2026 (5:00 PM PT)
- Submission period: July 13 – July 21, 2026 (5:00 PM PT)
- Judging period: July 22 – August 5, 2026
- Winners announced: On or around August 12, 2026
How to Register, Step by Step
- Go to the official Devpost hackathon page for OpenAI Build Week
- Click "Join Hackathon" and create a free Devpost account (or log in if you already have one)
- If entering as a team, appoint one member as the official Representative who submits on the group's behalf — every team member should still register individually
- Get access to Codex through your OpenAI/ChatGPT account to start building
Eligibility
- You must be at least the age of majority where you live
- You must reside in a country or territory where OpenAI's API is currently supported
- Residents of certain restricted regions (including Russia, Iran, North Korea, Cuba, Syria, and a few others under U.S. sanctions) are not eligible
Getting Codex Access — Including Free Credits
Every entrant needs working Codex access to build their project. If your existing usage runs out mid-hackathon, Build Week's official rules note that entrants can request $100 in free credits to keep building, while supplies last.
Separately, verified university students in the US and Canada can also claim a standing $100 Codex credit grant (2,500 credits) through OpenAI's Codex for Students program — worth checking if you're a student and haven't already claimed it, since it's not tied to the hackathon and doesn't expire when Build Week ends. Either way, budget your credits: a small bug fix runs around 10 credits, while a heavier multi-file refactor can cost 60 credits or more, so scope your project before you start building rather than exploring aimlessly.
What Judges Are Actually Looking For
Submissions are evaluated on four criteria:
- Technical implementation — does it actually work as a demo, not just a pitch?
- Design and user experience — is it usable and coherent?
- Potential impact — does it solve something real for real users?
- Quality of the idea — and specifically, how thoughtfully it uses Codex or GPT-5.6
OpenAI's own guidance to builders is blunt: start with the problem, not the model. The strongest entries use GPT-5.6 because the problem called for it, not because it needed to be shoehorned in.
What to Submit
Every submission needs:
- A written project description
- A demo video
- A public code repository
- Any additional materials the judging criteria call for
Tips for a Strong Entry
- Form your team early. OpenAI's own advice is to browse the Devpost Participants tab and the Build Week Discord's #build-week-chat channel in week one — the best teams form early, not the night before the deadline.
- Use office hours. Daily community office hours and OpenAI Academy sessions run throughout the week on Discord, alongside livestreams from the OpenAI product team.
- Check for local events. OpenAI is running 60+ in-person meetups worldwide through its Codex Ambassadors program — a good option if you want hands-on help and to meet teammates in person.
- Aim for a working demo over a polished pitch. Judging explicitly rewards technical implementation — a rough but functional prototype beats a slick idea with nothing built.
