OpenAI Python SDK 3.20.0: Agents credential/session options, Cyber access programs on Responses, opt-in WebSocket text/tool snapshots

Core Background & Industry Pain Points

Python clients for Agents and Responses/Realtime are the default orchestration surface. Pain points: credential rotation forcing full auth replace; missing typed Cyber access-program fields; WebSocket streams that omit HTTP/SSE scaffolding leave callers without cumulative text/tool mid-states.

Architecture Highlights & Internals

v3.20.0 adds Agents credential metadata and update-without-replace auth, session ultrafast tier, and misalignment_policy_violation (#3967). Responses accept access_programs.cyber (standard/daybreak_blue/daybreak_red) (#3956). Opt-in ResponsesWebSocketAccumulator yields immutable incremental text/tool snapshots without owning the socket (#3973). Live/Realtime WebSocket query/queue/TLS retries are hardened.

Authoritative Benchmarks & Measured Scores

No public SWE-bench/latency table. PR #3973 reports 190 WebSocket/accumulator + 23 Responses tests on Pydantic v1/v2—validate Cyber fields, snapshot/terminal consistency, and Live hang fixes on your stack.

Developer Hands-on Guide

pip install -U "openai>=3.20.0". Supply metadata when constructing Agents Credentials; set Cyber programs where required; enable Accumulator for streaming observability. See api.md and the release notes.