{"generatedAt":"2026-10-24T12:11:27.697Z","canonicalUrl":"https://agentbreakwatch.vercel.app/p/stagehand","llmsTxtUrl":"https://agentbreakwatch.vercel.app/p/stagehand/llms.txt","categoryHub":{"slug":"agent-sdks","title":"AI Agent SDKs & Frameworks Breaking-Change Index","url":"https://agentbreakwatch.vercel.app/c/agent-sdks"},"tldrVerdict":"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. v4.x overhauls stagehand.act() and stagehand.extract() options object, separating modelClient configuration from Playwright page lifecycle.","package":{"slug":"stagehand","packageName":"@browserbasehq/stagehand","registry":"npm","kind":"sdk","subcategory":"Browser Agent SDK","displayName":"Stagehand Browser Agent SDK","vendor":"Browserbase","githubRepo":"browserbase/stagehand","breakingSummary":"v4.x overhauls stagehand.act() and stagehand.extract() options object, separating modelClient configuration from Playwright page lifecycle.","schemaDriftRisk":"high","affectedSymbols":["Stagehand","page.act","page.extract","page.observe"],"migrationBefore":"await stagehand.page.act({ action: \"click sign in\", modelName: \"gpt-4o\" });","migrationAfter":"await stagehand.act(\"click sign in\");","description":"Browserbase's SDK for building browser agents","latestVersion":"4.3.0","latestPublishedAt":"2026-10-20T00:40:20.973Z","recentVersions":[{"version":"4.3.0","publishedAt":"2026-10-20T00:40:20.973Z"},{"version":"4.2.1","publishedAt":"2026-10-11T13:02:05.570Z"},{"version":"4.2.0","publishedAt":"2026-10-08T21:46:35.555Z"},{"version":"4.1.0","publishedAt":"2026-09-09T08:11:14.730Z"},{"version":"4.0.3","publishedAt":"2026-09-09T07:20:29.280Z"},{"version":"3.7.3","publishedAt":"2026-08-28T14:49:33.826Z"}],"releasesLast90d":10,"dependenciesCount":4,"license":"MIT","registryUrl":"https://www.npmjs.com/package/@browserbasehq/stagehand","githubUrl":"https://github.com/browserbase/stagehand","installCommand":"npm install @browserbasehq/stagehand@4.3.0","stabilityScore":78,"stabilityGrade":"B"}}