OpenAI Marketing Agents Hackathon is a hands-on hackathon focused on building marketing automation and agent-based workflows using OpenAI tools. Participants form teams to prototype marketing agents, growth automation flows, and LLM-powered campaigns, followed by demo judging and prizes. The event aims to surface product ideas, open-source demos, and practical templates for AI-driven marketing, and is intended for startup founders, growth engineers, and technical marketers seeking to prototype and validate agent-driven marketing use cases.