OpenAI DevDay 2025: AI Tools Redefine Building

It’s the most exciting time ever to be a builder. This year, we’re unveiling a new generation of tools and models that empower developers to code faster, build more reliable agents, and scale applications directly within ChatGPT. With 4 million developers already using OpenAI for development, 800 million weekly active users on ChatGPT, and the API platform processing billions of tokens per minute, the momentum is clear. Product Announcements ChatGPT Apps: Launch applications directly within ChatGPT and interact with them through conversation. Developers can now build using the new ChatGPT App SDK, available in preview. Read the blog. AgentKit: Use our toolkit to build production-grade agents. Read the blog. Sora 2 in the API: Integrate video generation into your applications using the latest Sora model. View documentation (opens in new window). Codex: Explore new features including Slack integration, the Codex SDK, and enterprise controls—now fully available. Read the blog. View documentation (opens in new window). GPT-5 Pro in the API: The most intelligent model in our API suite, designed for high-precision tasks. View documentation (opens in new window). gpt-realtime-mini: A lightweight voice model that’s 70% cheaper than larger models. View documentation (opens in new window). gpt-image-1-mini: A compact image generation model that’s 80% more cost-effective than its larger counterparts. View documentation (opens in new window). OpenAI DevDay Agenda Opening Keynote The 2025 Developer Conference kicks off with bold ideas that challenge how we think about building. Join us for groundbreaking announcements, live demos, and a vision of how developers are reshaping the future with AI. Watch now (opens in new window). Cursor: Background Information Engineering Cursor has evolved from simple next-step prediction to fully autonomous coding agents. Learn how they build agent frameworks and tooling, perform background information engineering, and enable parallel execution across multiple agents. Watch now (opens in new window). Coordinating Large-Scale Agent Programs Click, connect, create. Discover how the new agent platform toolkit enables rapid design and deployment of enterprise-grade agents. Watch now (opens in new window). Building on OpenAI’s Technology How does OpenAI use its own AI? Explore how we’ve built reliable agents for sales, support, finance, and data teams—and learn how to identify and scale high-impact use cases. Watch now (opens in new window). Building Frameworks: AI Solutions for Urban Prosperity No city embraces the future like San Francisco. Draw inspiration from local developers using AI to solve real-world challenges—improving public services, optimizing housing access, and strengthening community ties. Watch now (opens in new window). Evaluation Practices: From Frontier Research to Real-World Impact How do you measure progress when pushing the boundaries of AI? Dive into the evolving world of AI evaluation, where new standards are redefining benchmarks for reasoning, reliability, and real-world performance. Watch now (opens in new window). Efficient Collaboration with Codex Hear from OpenAI engineers on how Codex is reimagining code writing, refactoring, and merging workflows. From local pair programming to cloud-based task assignment, see how Codex is accelerating the future of software development. Watch now (opens in new window). Model Behavior: The Science of AI Style Why does ChatGPT sound the way it does? Uncover the mechanisms behind model style, the trade-offs researchers make, and the future of tone and voice in human-AI interaction. Watch now (opens in new window). Live AMA: Scaling AI in Enterprises Join founders of Decagon and Clay, along with partners from Andreessen Horowitz, for a live Q&A on enterprise AI adoption. Explore why so many AI pilots fail, common founder mistakes, and how to scale into a unicorn. Watch now (opens in new window). Live Demos: Tools That Multiply Developer Impact Top engineering teams focus on amplifying impact, not just growing headcount. Watch founders from Charlie Labs, Warp, CodeRabbit, and Jam demonstrate tools that accelerate delivery, streamline code reviews, and keep codebases clean—turning small teams into high-performance units. Watch now (opens in new window). Building with Open Models With the new gpt-oss series, break free from the limitations of off-the-shelf models. Explore how to adapt, extend, and fine-tune models with gpt-oss, seamlessly integrating with GPT-5 to create flexible, high-impact solutions. Watch now (opens in new window). Sora, ImageGen, and Codex: The Next Wave of Creative Tools AI is accelerating the journey from idea to creation. Learn how we’re building custom tools for film, media, and brand marketing workflows. Discover best practices for rapid prototyping and how developers are redefining the future of creative production. Watch now (opens in new window). Measuring Agent Intelligence with Interactive Evaluation Agents can explore, plan, and execute complex, long-running tasks—challenges that static benchmarks can’t capture. Hear from Greg Kamradt, chair of the ARC Prize Foundation, on why interactive evaluation is essential for assessing true agent capability. Watch now (opens in new window). Developer Conference AI is transforming the developer experience. This conference dives deep into how Codex, gpt-oss, and our API are opening new paths for building, experimenting, and scaling. We’ll share the latest updates, demo new features, and show what’s possible for developers in the years ahead. Watch now (opens in new window). A Conversation with Sam and Jony Join Sam Altman and Jony Ive in a candid discussion on product creation in the AI era. They’ll explore the power of close collaboration, the essence of design, and how to build tools with care, responsibility, and beauty. Watch now (opens in new window).