A Look at the Open AI Dev Day which took place yesterday.
The main points :
The Apps SDK ebables Developers to make custom applications within the ChatGPT Environment.
Agent Kit simplifies AI Agent Development.
Codex has been updated with new integrations such as Slack and Admin Tools improving Efficiency.
API Updates including Sora 2 API and GPT Realtime Mini focus on affordability and Functionality.
A commitment to expanding the Ai ecosytem. can see more detail here https://www.geeky-gadgets.com/openai-chatgpt-devday-2025-overview/
A longer video here https://www.youtube.com/watch?v=-Q89wGnpyn4
can find the full keynote if that way inclined 
A bit more about Sora 2 here which is a video generative model https://openai.com/index/sora-2/
can see more of the Dev Day on official site if interested https://openai.com/devday/
