The Responses API is a new way to interact with OpenAI models, designed to be simpler and more flexible than previous APIs. It makes it easy to build advanced AI applications that use multiple tools, handle multi-turn conversations, and work with different types of data (not just text).
Unlike older APIs—such as Chat Completions, which were built mainly for text, or the Assistants API, which can require a lot of setup—the Responses API is built from the ground up for:
- Seamless multi-turn interactions (carry on a conversation across several steps in a single API call)
- Easy access to powerful hosted tools (like file search, web search, and code interpreter)
- Fine-grained control over the context you send to the model
As AI models become more capable of complex, long-running reasoning, developers need an API that is both asynchronous and stateful. The Responses API is designed to meet these needs.
In this guide, you'll see some of the new features the Responses API offers, along with practical examples to help you get started.