
Big things just dropped at OpenAI DevDay 2025. If you’re building with AI or considering it, this is the moment to pay attention.
DevDay 2025 is OpenAI’s main event for developers, showcasing the latest breakthroughs in conversational AI and creative tools. On October 6, 2025, Fort Mason was full of excitement as developers, founders, and tech leaders gathered to explore what’s next.
OpenAI DevDay 2025 kicked off with staggering growth metrics—4M developers, 800M weekly ChatGPT users, and 6B tokens per minute. Image credit: OpenAI DevDay
If you missed OpenAI’s DevDay 2025, the main takeaway is that turning an idea into a finished product is now faster and easier than ever.
Sam Altman started the keynote by sharing some impressive numbers. At the first DevDay two years ago, OpenAI had 2 million developers and 100 million people using ChatGPT each week. Currently, 4 million developers are building on the platform, and over 800 million people use ChatGPT each week. The API (Application Programming Interface), a way developers plug into OpenAI’s models, allows developers to connect to OpenAI’s models and now handles 6 billion tokens per minute, which is 20 times more than in 2023.
But DevDay was more than a celebration of growth. It focused on giving developers the tools and support they need to create the next big things.
Here’s everything that launched.
Image credit: OpenAI DevDay
At OpenAI DevDay 2025, one of the most exciting announcements was the launch of the Apps SDK. This toolkit lets developers create interactive apps right inside ChatGPT. Now in preview, it offers a fresh way to connect with users where they already spend their time.
The SDK uses the Model Context Protocol (MCP), giving developers control over both backend logic and frontend design. If you already use MCP, you can upgrade your setup by adding a resource that returns an HTML template. This makes your app work smoothly across ChatGPT’s web, mobile, and desktop platforms.
People can ask for apps by name, such as saying, “Notion, help me organize this brainstorm into a project plan.” ChatGPT can also suggest apps during a conversation. For example, if someone is planning a dinner menu, it might recommend using Instacart to find ingredients or create a grocery list.
The Apps SDK is currently in preview. Later this year, developers will be able to submit their apps for review and publication. OpenAI also plans to launch an app directory, where standout apps will be featured and suggested during conversations.
For monetization, users can log in to your product directly from ChatGPT. OpenAI will offer several payment options, including a new Agentic Commerce Protocol that allows instant checkout within the chat.
Image credit: OpenAI DevDay
Building AI agents used to take a lot of time and technical know-how. You had to set up workflows, connect tools, run evaluations, and design a user interface just to test your idea.
AgentKit changes that. It’s a complete toolkit for turning your ideas into working products quickly.
Christina from OpenAI built and launched a DevDay agent in just over seven minutes. The agent featured:
She previewed the workflow, published it, and added it to the DevDay site using ChatKit with custom branding. Attendees could immediately use the agent to find sessions and ask questions.
Albertsons built an agent for more than 2,000 stores. For example, when sales drop by 32% for ice cream, the agent looks at trends and recommends actions like changing displays or starting local promotions.
HubSpot improved its AI tool Breeze. For instance, when a customer asked why a plant was not thriving in Arizona, the agent gathered information from the knowledge base, looked at climate treatments, checked policy details, and suggested several solutions.
Image credit: OpenAI DevDay
Codex is now officially out of preview and available to all developers. It’s OpenAI’s coding agent, designed to help teams write, review, and ship software faster.
Codex now runs on GPT-5-Codex, a model fine-tuned for complex coding tasks. It excels at refactoring and reviewing code, and can adjust its reasoning time depending on the problem’s difficulty.
Romain from OpenAI showed what Codex can do in real time. He asked it to:
The audience cheered when the lights changed and Codex created credits with attendees’ names, all without anyone having to write code.
Cisco rolled out Codex across its engineering teams. They’ve cut code review time in half and shortened project timelines from weeks to days.
OpenAI DevDay 2025 focused on more than just new tools. The event highlighted upgrades to the technology powering them. These new models offer developers greater control, improved performance, and lower costs for voice, image, video, and reasoning tasks.
GPT-5 Pro is now available in the API and is OpenAI’s most advanced model so far. It is designed for high-stakes use cases such as legal, financial, and medical fields, or any area where precision and deep reasoning are important. Startups like Cursor, Windsurf, and Vercel are already using it to change how software is built, from agent workflows to complete coding solutions.
This compact voice model offers the same natural tone and responsiveness as its larger version, but at a much lower cost. It is 70% cheaper and built for real-time interaction, making voice-based AI more accessible for everyday use. Altman emphasized that voice will become a primary way to interact with AI, and this model moves us closer to that goal.
This lightweight image generation model costs 80% less than the full version. It is ideal for production use, where speed and cost are important, but quality still matters.
Developers now have access to the same video generation model that powers Sora 2. It’s a game-changer for creators, educators, designers, and filmmakers.
Sora 2 does more than generate visuals; it also pairs them with immersive audio. From ambient sounds to synchronized effects, the model creates a layered experience that feels realistic. In one demo, a kayaking scene included the splash of paddles and environmental sounds that matched the visuals perfectly.
Mattel is using Sora 2 to turn sketches into shareable product videos. Instead of static mockups, designers can show how toys move, how kids might interact with them, and share those ideas with stakeholders more quickly than with traditional prototyping.
Sam Altman closed the keynote with a powerful reminder:
“Software used to take months or years to build. You saw today. It takes minutes now. And to build with AI you don’t need a huge team. You don’t need a bunch of infrastructure. You just need a good idea.”
The demos proved it..
You can now build and share apps with 800 million weekly users without waiting for app store approval or spending heavily on marketing. You can launch advanced agents without a large engineering team, and you can prototype and improve your ideas much faster than was possible just two years ago.
The Cisco example shows that teams are finishing code reviews up to 50% faster and reducing project timelines from weeks to days. These are not just small improvements; they represent major changes in how software is developed.
The keynote highlighted global examples of what’s possible.
You don’t need a computer science degree or venture funding. What matters is finding a problem worth solving and having the curiosity to explore new solutions.
All the products announced at OpenAI DevDay 2025 are now available.
Later this year, developers can submit their apps for review and publication. OpenAI will also introduce an app directory that makes it easy to browse and discover apps through conversation.
OpenAI DevDay 2025 focused on more than just small updates. The event highlighted infrastructure as the groundwork for future innovations.
The gap between ideas and execution is shrinking. Developers on stage had processed from 10 billion up to over a trillion tokens with OpenAI’s platform. This isn’t just about usage; it shows that people are building real solutions for real users, and doing so at scale.
This shift is not only technical but also behavioral. Teams are working faster, creators are launching products without code, and solo founders are reaching global audiences. These tools are changing both how we build and who has the opportunity to build.
As OpenAI CTO Mira Murati put it:
We’re not just building tools. We’re building collaborators that understand your goals, adapt to your workflows, and help you move faster.
The future is not on hold; it is already taking shape. What will you build next?