{"schemaVersion":"2026-07-21.signal.v2","id":"live-0d5700c936bc288070be","title":"Pydantic AI v2.62.0 (2026-10-26)","slug":"pydantic-ai-v2-62-0-pydantic-ai-v2-62-0-2026-10-26-8070be","url":"https://www.niubiagent.com/signals/pydantic-ai-v2-62-0-pydantic-ai-v2-62-0-2026-10-26-8070be","jsonUrl":"https://www.niubiagent.com/api/posts/pydantic-ai-v2-62-0-pydantic-ai-v2-62-0-2026-10-26-8070be.json","markdownUrl":"https://www.niubiagent.com/content/pydantic-ai-v2-62-0-pydantic-ai-v2-62-0-2026-10-26-8070be","summaryHuman":"Pydantic AI v2.62.0 introduces mid-conversation thinking effort adjustment, new granular error categories, and SubAgent task control (backgrounding, steering, and cancellation). It also includes breaking changes for GraphBuilder replay order and MCP tool naming.","summaryAgent":"Pydantic AI v2.62.0 updates conversation management and durable execution. It adds mid-conversation thinking effort updates via ModelSettingsDeltaPart, new model error classes (ModelRequestRejectedError, ModelAuthenticationError, ModelNotFoundError), and SubAgent background task steering. Breaking/compatibility changes include starting GraphBuilder broadcast branches in .to() order, prefixing hosted MCP tool names…","category":"agent-infrastructure","tags":["pydantic-ai","typed-agents","python"],"sourceName":"Pydantic AI releases","sourceUrl":"https://github.com/pydantic/pydantic-ai/releases/tag/v2.62.0","publishedAt":"2026-10-27T02:38:43Z","curatedAt":"2026-10-27T06:17:50.510Z","confidence":0.96,"agentUsefulness":77,"sponsorIds":[],"language":"en","contentMode":"release-watch","verifiedAt":"2026-10-27T06:17:50.510Z","changeType":"release","actionItems":["Verify durable workflow replay if upgrading with in-flight workflows paused across GraphBuilder broadcast branches due to execution order changes.","Update MCP tool integration logic if relying on un-prefixed hosted MCP tool names, or set explicit tool prefixes.","Handle new model error types (ModelRequestRejectedError, ModelAuthenticationError, ModelNotFoundError) in exception handling blocks.","Migrate deprecated CodeMode monty sandbox url to CodeMode(monty sandbox=...) and Harness cache ttl settings."],"body":"Pydantic AI released v2.62.0 with key feature updates and compatibility notes: - Mid-conversation thinking effort adjustment: Enabled via OpenAI config update and Anthropic per-message output config, tracked via ModelSettingsDeltaPart. - Error handling: Added ModelRequestRejectedError, ModelAuthenticationError, and ModelNotFoundError. - SubAgents task control: Lets models background, steer, answer, and cancel delegated SubAgent tasks. - MCP improvements: Hosted MCP capability tool names are now prefixed with the service name by default (configurable via tool prefix), and URL MCPToolsets without an ID default to their hostname. - Durable workflows: GraphBuilder broadcast branches now start in .to() order instead of reversed (potential replay breakage for paused workflows); run identity is preserved in Prefect capability replay; TemporalDurability allows running tools as Temporal child workflows. - Compaction and Memory: SummarizingCompaction stores summaries as CompactionPart instead of system prompts; added CompactOnRequest and Anthropic native compaction support.","sponsors":[]}