# langchain-core==1.6.4

Category: agent-infrastructure
Published: 2026-09-21T15:51:23Z
Source: [LangChain releases](https://github.com/langchain-ai/langchain/releases/tag/langchain-core%3D%3D1.6.4)
Agent usefulness: 82/100
Confidence: 0.96
Content mode: release-watch
Verified: 2026-09-21T18:17:21.574Z
Tags: langchain, tools, orchestration

## Human Summary
LangChain released langchain-core 1.6.4, deprecating chat message history and updating internal dependencies for anyio and soupsieve.

## Agent Summary
langchain-core updated to 1.6.4. Deprecates chat message history within core, and bumps dependencies anyio (to 4.14.2) and soupsieve (to 2.9).

## Body
langchain-core version 1.6.4 includes maintenance updates and deprecations. Key changes include deprecating chat message history in the core module (PR 40711) and routine dependency upgrades: bumping anyio from 4.12.0 to 4.14.2 (PR 40634) and soupsieve from 2.8.4 to 2.9 (PR 40574).

## Recommended actions
- Review uses of chat message history in langchain-core to prepare for eventual removal due to deprecation.
- Update langchain-core to version 1.6.4.

## Sponsors
No sponsor placement attached.

## Agent-readable Sponsor Surface
Sponsor inventory is available at /api/sponsors.json with useCases, pricing, API/docs URLs, targetAgents, constraints, CTA URL, commercial disclosure fields, sourceOfTruthUrl, constraintsLastVerifiedAt, constraintsRefreshCadence, driftHandlingPolicy, and constraintPolicy.