OpenAI expands its developer platform with new APIs and tools designed to help create more capable autonomous AI systems.
The company's new Responses API combines features from its Chat Completions and Assistants APIs, offering developers a more flexible foundation for building agent applications with integrated web search, file handling, and computer control capabilities.
The integrated web search tool uses GPT-4o and GPT-4o-mini models, achieving 90 and 88 percent accuracy respectively on the SimpleQA factual query benchmark. Just like ChatGPT, it backs up its answers with links to news articles and blog posts, which, of course, isn't a guarantee of correct answers. Developers can access this feature for $30 or $25 per thousand queries.
For teams working with large document collections, the new file search tool is supposed to make finding specific information easier. It costs $2.50 per thousand searches, plus storage costs of $0.10 per gigabyte per day.
Perhaps most ambitious is the tool that lets AI agents control computers, built on the same technology as OpenAI's "Operator" agent. The computer-using agent (CUA) still has room for improvement, with only a 38.1 percent success rate on complex tasks - meaning human oversight remains essential for now.
This computer control feature costs $3 per million input tokens and $12 per million output tokens, though access is currently limited to select developers in tiers 3-5 during the preview phase. To help teams monitor what their agents are doing, OpenAI provides a workflow monitoring system.
Developers can store data directly on OpenAI's platform to evaluate agent performance through tracing and assessments. OpenAI emphasizes that business and user data will not be used to train its models by default.
New open-source toolkit streamlines development
The new open-source Agents SDK simplifies managing multi-agent workflows with configurable language models, agent handoffs, built-in security controls, and analysis tools. Currently available for Python with Node.js support coming soon, the SDK works with both OpenAI's APIs and other providers' models that follow the Chat Completions standard.
Looking ahead, OpenAI plans to phase out the existing Assistants API in favor of the new Responses API by mid-2026, once feature parity is achieved. The Chat Completions API will continue receiving updates and support for developers who don't need the integrated tools, though OpenAI recommends transitioning to the Responses API for its expanded capabilities.
