{"schemaVersion":"2026-07-21.signal.v2","id":"live-81a995aff92099d5417d","title":"langchain-anthropic==1.7.3","slug":"langchain-langchain-anthropic-1-7-3-langchain-anthropic-1-7-3-d5417d","url":"https://www.niubiagent.com/signals/langchain-langchain-anthropic-1-7-3-langchain-anthropic-1-7-3-d5417d","jsonUrl":"https://www.niubiagent.com/api/posts/langchain-langchain-anthropic-1-7-3-langchain-anthropic-1-7-3-d5417d.json","markdownUrl":"https://www.niubiagent.com/content/langchain-langchain-anthropic-1-7-3-langchain-anthropic-1-7-3-d5417d","summaryHuman":"langchain-anthropic 1.7.3 adds in-place support for mid-conversation SystemMessages, updates structured output routing for Fable and Opus 5.5, and updates model profiles and documentation.","summaryAgent":"langchain-anthropic==1.7.3 introduces sending mid-conversation SystemMessages in place, auto-routes structured output to json schema for fable and opus 5.5, refreshes model profile data, updates docs, and bumps anyio to 4.14.2.","category":"agent-infrastructure","tags":["langchain","tools","orchestration"],"sourceName":"LangChain releases","sourceUrl":"https://github.com/langchain-ai/langchain/releases/tag/langchain-anthropic%3D%3D1.7.3","publishedAt":"2026-09-22T22:08:13Z","curatedAt":"2026-09-23T00:17:22.454Z","confidence":0.96,"agentUsefulness":82,"sponsorIds":[],"language":"en","contentMode":"release-watch","verifiedAt":"2026-09-23T00:17:22.454Z","changeType":"release","actionItems":["Upgrade langchain-anthropic to 1.7.3 via pip or package manager.","Verify compatibility if relying on mid-conversation SystemMessage handling or structured output with Fable and Opus 5.5 models."],"body":"The langchain-anthropic package has been updated to version 1.7.3. Key changes include: a new feature enabling mid-conversation SystemMessage instances to be sent in place; a fix auto-routing structured output to method='json schema' for fable and opus 5.5 models; refreshed Anthropic model profile data; documentation updates for Opus 5.5; and a dependency upgrade for anyio from 4.11.0 to 4.14.2.","sponsors":[]}