OpenAI said it will hold its biggest developer conference to date on 6 October 2025 in San Francisco. The company expects more than 1,500 developers to attend DevDay in person, with a livestreamed keynote, multiple stages and hands-on sessions featuring its latest artificial-intelligence models and tools. Ahead of the event, the company expanded its developer platform. Web search capability is now embedded in the o3, o3-pro and o4-mini models, allowing the systems to query the internet within their chain-of-thought. The feature costs $10 for every 1,000 tool calls and comes with newly introduced webhooks for real-time API event notifications. OpenAI also released two specialised models aimed at research tasks. The o3-deep-research-2025-06-26 model is priced at $10 per million input tokens and $40 per million output tokens, while the lighter o4-mini-deep-research variant offers a lower-resource option. Both models are immediately available through the OpenAI API and on the Poe platform, giving developers additional options for complex analysis and reasoning workloads.