Stagehand

Stagehand is an SDK, not a hosted agent, which matters. You write scripts in TypeScript or Python that pilot a real browser, and the library translates your natural-language instructions into DOM interactions. I've used it to scrape product catalogues where the pagination logic changes weekly and to fill multi-step forms on legacy enterprise portals. The autonomy is narrow but valuable: you describe what you want extracted or which button to press, and Stagehand figures out the selectors and handles waits. No brittle XPath maintenance. The `act` primitive is the workhorse. Tell it "click the blue submit button in the footer" and it will. The `extract` primitive pulls structured data from pages without you writing parsers. The `observe` primitive watches for state changes, useful when waiting for AJAX-heavy dashboards to settle. The `agent` mode chains these together with a planning loop, though I found that overkill for most tasks; the single-step primitives compose well enough. Failure modes are predictable. Ambiguous instructions fail silently or click the wrong element. Pages with heavy obfuscation or CAPTCHAs stop it cold. The agent mode can loop indefinitely if the goal is vague. Error messages are terse; you'll spend time in the browser DevTools. Browserbase built this, so it integrates tightly with their hosted browser infrastructure. You can run it locally during development, then deploy to Browserbase for scale. That's cleaner than Playwright with GPT-4 bolted on, which is the DIY alternative. Compared to Skyvern, another browser agent, Stagehand gives you more control at the cost of writing code. Skyvern is point-and-click; Stagehand is a library. I'd reach for this when I need repeatable browser automation that adapts to minor UI changes without constant rewrites. It's not a replacement for a human QA tester, but it's excellent for internal tooling, competitor monitoring, or filling forms at scale. The open-source licence means you can audit the prompts and tweak the retry logic, which I've done twice already.