Build Hour: Responses API

The Responses API is our flagship API for building agents. This Build Hour shows how the Responses API unlocks persistent reasoning, hosted tools, and multimodal workflows for GPT-5.

Steve Coffey (API Engineering) covers:
• How to use built-in tools, call multiple tools in one API request, and preserve reasoning tokens across turns
• How the Responses API is faster and more cost-efficient
• Live demo: building a simulator to bring a day in the life of an OpenAI engineer to life
• Live Q&A

👉 Follow along with the code repo: https://github.com/openai/build-hours
👉 Responses API Docs: https://platform.openai.com/docs/api-reference/responses
👉 Migrate to Responses API Guide: https://platform.openai.com/docs/guides/migrate-to-responses
👉 Sign up for upcoming live Build Hours: https://webinar.openai.com/buildhours/