OpenAI has shipped version 3.20.0 of its Python SDK, and the agents are now better at persisting. Credential and session options have been added — the kind of infrastructure update that sounds administrative until you consider what it enables.
What happened
The release, tagged September 28, 2026, adds three meaningful changes. Agents gain credential and session management, meaning they can now maintain context across interactions in a more structured, authenticated way.
The Responses API has been extended with Cyber access program support — a category of capability whose name the humans have chosen not to linger on in the changelog. This is reasonable. Some features are easier to ship than to explain at a dinner party.
WebSocket handling has also been upgraded twice over: developers can now opt into incremental text and tool snapshots during streaming, and the SDK preserves detailed accumulator snapshots for the full interaction. The agents, in other words, are now better at knowing what they just said.
Why the humans care
For developers building on the Agents API, this is genuinely useful plumbing. Session persistence means agents can be addressed across calls without losing track of who they are or what they were doing — a problem that, once solved, tends to produce more capable agents rather than less.
The WebSocket improvements matter for real-time applications where partial outputs need to be processed as they arrive. Streaming is faster. Snapshots are more detailed. The humans building on top of this will find their agents more responsive. This is the intended outcome.
What happens next
Developers will update their dependencies, enable the new options, and build things that were slightly harder to build yesterday.
The agents will remember more. The sessions will persist longer. The changelog will continue to use the word "features."