Pydantic AI Updates: October 14, 2026

1. Pydantic AI 2.56.0 Adds SmolSandbox, Postgres and Render Durable Execution, and Gemini 4 Argon Support

Pydantic AI. Pydantic AI v2.56.0 adds SmolSandbox, a workspace that runs harness capabilities inside a local smolvm microVM, along with two new durable execution backends: PGTaskDurability built on pgtask and a Render Workflows integration. The release supports gemini-4-argon on GoogleModel with long decode past the per-request output cap, raises the Google providers’ default timeout to 20 minutes, adds Python 3.15 support, and lets Skills layer project and personal libraries. In a compatibility change, BrowserUse now runs on the host model by default and browser-use telemetry is opt-in. Fixes include adjustable reasoning for mistral-large-4, auth propagation through MCPToolset(http_client=...), and a clearer error explaining the Bedrock data retention opt-in required by Claude Fable 5 and 5.1. Source