@langchain/core

LangChain Core JS by LangChain

Core LangChain.js abstractions and schemas

Live Registry Versionv1.3.0Previous: v1.2.20Published 2026-10-22

Stability Grade

B+ (82/100)

90-Day Velocity

17 releases

High release cadence

Dependencies

7 direct

NPM manifest

License

MIT

Verified on NPM

Recommended Exact Pin: npm install @langchain/core@1.3.0

NPM Registry ->GitHub Repo ->

TL;DR Verdict & Quick Citation Summary (2026-10-24)Source: AgentBreakWatch Live NPM Index

LangChain Core JS (@langchain/core) is currently at v1.3.0 on NPM (published 2026-10-22), with a 90-day stability score of 82/100 (B+) and MEDIUM schema drift risk across 17 releases in the past 90 days. v1.x removes deprecated RunnableBinding legacy call signatures and standardizes ToolMessage artifact and content_blocks metadata. Production teams should pin npm install @langchain/core@1.3.0 rather than using unpinned @latest tags.

Breaking Changes & Tool Schema Drift Analysis

v1.x removes deprecated RunnableBinding legacy call signatures and standardizes ToolMessage artifact and content_blocks metadata.

Watched Exports / MCP Tool Signatures:

StructuredToolRunnableSequenceAIMessagebindTools

Before (Deprecated / Unpinned Pattern)

const res = await model.call(messages, { functions: toolDefs });

After (Verified v1.3.0 Pattern)

const modelWithTools = model.bindTools(toolDefs);
const res = await modelWithTools.invoke(messages);

Frequently Asked Questions: @langchain/core

What is the latest version of @langchain/core on NPM?

As of 2026-10-24, the latest stable version of @langchain/core (LangChain Core JS by LangChain) on NPM is v1.3.0, published on 2026-10-22. It has shipped 17 releases in the last 90 days.

Does @langchain/core v1.3.0 have breaking changes or MCP schema drift risk?

@langchain/core currently carries a MEDIUM schema drift risk rating with a Stability Score of 82/100 (Grade B+). v1.x removes deprecated RunnableBinding legacy call signatures and standardizes ToolMessage artifact and content_blocks metadata.

How do I safely pin @langchain/core in production?

Avoid unpinned @latest tags in production agent configs. Pin the exact verified version using `npm install @langchain/core@1.3.0` and monitor StructuredTool, RunnableSequence, AIMessage, bindTools for parameter or schema changes.

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