OpenAI opens Agents API: companies can run long-lived cloud agents without their own infrastructure
Prepared by Sintelligent with the help of SI. Publication time restored from the build log. . Updated: .
Building your own SI agent that works on a task for hours has become almost as simple as calling a chatbot — agents are moving out of the labs into ordinary products.
In an open beta, developers get a managed Codex "harness": OpenAI itself handles session orchestration, context compaction and recovery, long-running sessions, work with tools and MCP servers, and coordination of helper subagents. There is no separate platform fee — only the tokens of the chosen model and standard rates for tools and sandboxes. The company shut down the previous Assistants API on August 26.
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