# LangChain Core JS (@langchain/core) - AgentBreakWatch Reference

> TL;DR Verdict: 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 last 90 days. v1.x removes deprecated RunnableBinding legacy call signatures and standardizes ToolMessage artifact and content_blocks metadata.

## Live Telemetry Metadata
- Canonical Page: https://agentbreakwatch.vercel.app/p/langchain-core-js
- Category Hub: https://agentbreakwatch.vercel.app/c/agent-sdks (AI Agent SDKs & Frameworks Breaking-Change Index)
- Package Name: `@langchain/core`
- Registry: NPM (https://www.npmjs.com/package/@langchain/core)
- GitHub Repository: https://github.com/langchain-ai/langchainjs
- Vendor: LangChain
- Latest Live Version: v1.3.0
- Published Date: 2026-10-22T18:04:49.648Z
- 90-Day Release Count: 17
- Direct Dependencies: 7
- License: MIT
- Stability Score: 82/100 (Grade B+)
- Schema Drift Risk: MEDIUM
- Recommended Exact Pin Command: `npm install @langchain/core@1.3.0`
- Watched Symbols / MCP Tools: StructuredTool, RunnableSequence, AIMessage, bindTools
- Snapshot Timestamp: 2026-10-24T12:11:27.697Z

## Breaking Change & Schema Drift Summary
v1.x removes deprecated RunnableBinding legacy call signatures and standardizes ToolMessage artifact and content_blocks metadata.

## Migration Diff: Before (Deprecated / Unpinned Pattern)
```
const res = await model.call(messages, { functions: toolDefs });
```

## Migration Diff: After (Verified v1.3.0 Pattern)
```
const modelWithTools = model.bindTools(toolDefs);
const res = await modelWithTools.invoke(messages);
```

## Recent Verified Releases
- v1.3.0 (published 2026-10-22) [LATEST]
- v1.2.20 (published 2026-10-20)
- v1.2.19 (published 2026-10-20)
- v1.2.18 (published 2026-10-15)
- v1.2.17 (published 2026-10-06)
- v1.2.16 (published 2026-10-06)