# langchain==1.4.2

Category: agent-infrastructure
Published: 2026-09-18T17:31:25Z
Source: [LangChain releases](https://github.com/langchain-ai/langchain/releases/tag/langchain%3D%3D1.4.2)
Agent usefulness: 82/100
Confidence: 0.96
Content mode: release-watch
Verified: 2026-09-22T00:17:26.264Z
Tags: langchain, tools, orchestration

## Human Summary
LangChain 1.4.2 fixes tool call handling during human-in-the-loop (HITL) workflows by preserving model-generated tool calls when edits occur and appending a notice to ToolMessage.

## Agent Summary
LangChain updated to 1.4.2 to fix HITL tool call edits, preserving original model-generated tool calls and adding a notice to ToolMessage.

## Body
LangChain version 1.4.2 contains changes since 1.4.1 focusing on human-in-the-loop (HITL) workflows. Specifically, PR 40463 addresses a bug fix ensuring model-generated tool calls are preserved during HITL tool call edits, and it adds an informational notice to ToolMessage.

## Recommended actions
- Upgrade to langchain==1.4.2 if utilizing human-in-the-loop tool call editing features.
- Verify tool call history and ToolMessage handling logic to ensure compatibility with the new ToolMessage notice.

## 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.