@browserbasehq/stagehand

Stagehand Browser Agent SDK by Browserbase

Browserbase's SDK for building browser agents

Live Registry Versionv4.3.0Previous: v4.2.1Published 2026-10-20

Stability Grade

B (78/100)

90-Day Velocity

10 releases

Moderate cadence

Dependencies

4 direct

NPM manifest

License

MIT

Verified on NPM

Recommended Exact Pin: npm install @browserbasehq/stagehand@4.3.0

NPM Registry ->GitHub Repo ->

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

Stagehand Browser Agent SDK (@browserbasehq/stagehand) is currently at v4.3.0 on NPM (published 2026-10-20), with a 90-day stability score of 78/100 (B) and HIGH schema drift risk across 10 releases in the past 90 days. v4.x overhauls stagehand.act() and stagehand.extract() options object, separating modelClient configuration from Playwright page lifecycle. Production teams should pin npm install @browserbasehq/stagehand@4.3.0 rather than using unpinned @latest tags.

Breaking Changes & Tool Schema Drift Analysis

v4.x overhauls stagehand.act() and stagehand.extract() options object, separating modelClient configuration from Playwright page lifecycle.

Watched Exports / MCP Tool Signatures:

Stagehandpage.actpage.extractpage.observe

Before (Deprecated / Unpinned Pattern)

await stagehand.page.act({ action: "click sign in", modelName: "gpt-4o" });

After (Verified v4.3.0 Pattern)

await stagehand.act("click sign in");

Frequently Asked Questions: @browserbasehq/stagehand

What is the latest version of @browserbasehq/stagehand on NPM?

As of 2026-10-24, the latest stable version of @browserbasehq/stagehand (Stagehand Browser Agent SDK by Browserbase) on NPM is v4.3.0, published on 2026-10-20. It has shipped 10 releases in the last 90 days.

Does @browserbasehq/stagehand v4.3.0 have breaking changes or MCP schema drift risk?

@browserbasehq/stagehand currently carries a HIGH schema drift risk rating with a Stability Score of 78/100 (Grade B). v4.x overhauls stagehand.act() and stagehand.extract() options object, separating modelClient configuration from Playwright page lifecycle.

How do I safely pin @browserbasehq/stagehand in production?

Avoid unpinned @latest tags in production agent configs. Pin the exact verified version using `npm install @browserbasehq/stagehand@4.3.0` and monitor Stagehand, page.act, page.extract, page.observe for parameter or schema changes.

30-Min Registry & Schema Poller

Get Instant Breaking-Change Alerts for @browserbasehq/stagehand

We poll NPM and browserbase/stagehand every 30 minutes. Get an email with the exact diff when @browserbasehq/stagehand ships a breaking release beyond v4.3.0.