v3.20.0

3.20.0 (2026-09-28)

Features

• api: add Agents credential and session options (#3967) (bb68198)
• api: add Cyber access programs to Responses (#3956) (09c5b6f)
• responses: opt in to incremental WebSocket text and tool snapshots (#3973) (d0207b4)
• responses: preserve detailed WebSocket accumulator snapshots (#3981) (a380cf2)

Bug Fixes

• client: retry unmapped TLS transport errors (#3982) (0d35a26)
• live: avoid hangs at fractional transcript grouping deadlines (#3970) (4ef4129)
• live: keep query parameters out of WebSocket endpoint paths (#3972) (f9c458b)
• live: preserve caller queues and prevent uncertain WebSocket replay (#3980) (80e9686)
• realtime: preserve base URL queries in WebSocket upgrades (#3971) (f7bd4a7)
• realtime: retain configured queues without replaying attempted sends (#3978) (a52805c)

Chores

• api: clarify documented API error responses (#3965) (384fee3)
• api: document batch error responses (#3961) (6e4a79c)
• api: document files and uploads error responses (#3960) (a9d727f)
• api: document fine-tuning and model errors (#3964) (5d4003c)
• api: document Responses not-found errors (#3959) (63099e7)
• api: document stored chat completion errors (#3963) (a73fe0c)