What changed
Pydantic AI 2.62 adds typed authentication, rejection and not-found errors; mid-conversation reasoning changes; append-only instruction and memory updates; realtime tool-failure delivery; prompt-cache preservation; and deterministic durable-workflow ordering.
Why it matters
Typed failures and append-only state make agent recovery easier to reason about, while the broadcast-order change can alter replay of workflows already paused during an upgrade.
What to do
Treat this as a catch-up: pin 2.62.0 in staging, replay a paused branch graph, rotate reasoning effort mid-session, fail one realtime tool and one model credential, then compare history and recovery before upgrading durable runs.
Caveat
This 26 October release surfaced during the 72-hour sweep and retains that date. Compatibility notes are maintainer claims; several behaviors depend on provider support, and paused durable workflows need explicit replay tests.