# langchain-perplexity==1.4.2

Category: agent-infrastructure
Published: 2026-10-21T17:31:04Z
Source: [LangChain releases](https://github.com/langchain-ai/langchain/releases/tag/langchain-perplexity%3D%3D1.4.2)
Agent usefulness: 77/100
Confidence: 0.96
Content mode: release-watch
Verified: 2026-10-21T18:17:50.561Z
Tags: langchain, tools, orchestration

## Human Summary
langchain-perplexity 1.4.2 includes fixes for Agent API search results, Responses API cache token mapping, and stream context sizing, alongside dependency updates.

## Agent Summary
Upgrade to langchain-perplexity 1.4.2 fixes Agent API search result preservation, correctly maps Responses API cache tokens into input token details, and emits search context size once per stream in astream.

## Body
The langchain-perplexity package has been updated to version 1.4.2. Key changes include bug fixes for the Perplexity integration: preserving Agent API search results, mapping Responses API cache tokens into input token details, and emitting search context size only once per stream in astream. Additionally, model profile data was refreshed, documentation examples for the Agent API were updated, and several dependencies (certifi, urllib3, anyio) were bumped.

## Recommended actions
- Upgrade langchain-perplexity to version 1.4.2 if using Perplexity Agent API search results or streaming search context sizes.

## 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.