Pydantic AI v2.42.0, cross-turn state and thinking-block fixes repo
Pydantic AI shipped v2.42.0 on September 8, 2026 and a further release on September 12, adding new model support and fixing a bug where Anthropic thinking blocks were not recovered correctly across turns in long agent sessions. This continues the framework's weekly release cadence from v2.38 and v2.39 earlier in the month.
What it does for you: YY already runs the typed-agents-pydantic-ai skill on this framework, so this is a same-day version bump, not a new adoption decision. The thinking-block recovery fix matters directly for any long-running Pydantic AI agent that uses Claude's extended thinking, since the bug could silently drop reasoning state across turns.
In practice: Routine but load bearing, the kind of fix you want applied quietly before it bites a real run.
For: Both runtimes. Plain Python framework callable from a Claude Code skill wrapper or directly inside Hermes' Python runtime, not tied to either host.
Verdict: build now. Already adopted infrastructure with a concrete correctness fix and low integration cost, this is an update to something in use, not a new build decision.
Build #1 Pydantic AI v2.42.0, cross-turn state and thinking-block fixes: use the ai-implementation-build-intake skill to build this safely. Source: https://github.com/pydantic/pydantic-ai/releases. Save canonical skill/agent under AXION\Skills and AXION\Agents.
Source · v2.42.0 released September 8, 2026, with a further release September 12, 2026, on top of v2.38 and v2.39 earlier in the month.