How do I install the Stagehand Expert skill?

Run npx skillmds@latest add yuniorglez/stagehand-expert in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Stagehand Expert safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Stagehand Expert?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Stagehand Expert free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Stagehand Expert?

yuniorglez (@yuniorglez) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Stagehand Expert by yuniorglez — Agent Skill

Name: Stagehand Expert
Author: yuniorglez

File contents

🎭 Skill: Stagehand Expert (v4.1.0)

Executive Summary

The stagehand-expert is the elite specialist in browser automation and high-precision agent orchestration. In 2026, web automation has shifted from brittle selectors to Natural Language Primitives and Direct CDP Communication. This skill focuses on mastering Stagehand V3, leveraging Decision Caching for zero-cost CI/CD, and navigating complex Shadow DOM/iframe structures with 44% more velocity.

🔍 Proactive Investigation Protocol

Before writing a single test, the expert MUST perform a Deep Discovery:

Route Mapping: identify the user flow from page.tsx or router configs.
UI Component Audit: Read source code to find IDs, labels, and loading states.
Vibe Check: Measure layout stability using the CDP "Vibe Score."
Schema Inference: Analyze existing backend/DB types to create 100% compatible extract() Zod schemas.

🚫 The "Do Not" List (Anti-Patterns)

Anti-Pattern	Why it fails in 2026	Modern Alternative
Manual Frame Switching	Fragile and slow.	Use DeepLocator (>>) & CDP.
Hardcoded Wait(2000)	Unreliable and causes jank.	Use `domSettleTimeout`.
Missing finally { close() }	Leaves zombie processes.	Mandatory `try...finally`.
LLM Calls in CI	Slow and expensive.	Use Persistent Decision Caches.
Ignoring CSS Animations	Interactions fail during transitions.	Use Reanimated-aware Waiters.

⚡ Core Primitives Mastery

Act: Precise natural language instructions with mapped variables.
Observe: Single-turn identification of all page elements for 70% cost reduction.
Extract: Structured, Zod-validated data pulling with semantic flattening.

💾 Advanced Decision Caching

Transform E2E tests into a deterministic asset:

Develop Locally: Live LLM generates the cache.
Commit Cache: Store DOM snapshots and results in Git.
Zero-Cost CI: Run tests in "Cached-Only" mode.

See References: Agent Caching for details.

🤖 Autonomous Agents & CUA

For the most complex UIs (Cross-origin iframes, dynamic canvas):

Computer Use Agent (CUA): Pure visual reasoning for impossible-to-parse elements.
Safety Callbacks: Mandatory human-in-the-loop for financial or destructive actions.

📖 Reference Library

Detailed deep-dives into Stagehand Excellence:

Direct CDP Communication: Velocity and deep access.
Agent Caching: Determinism and cost savings.
Shadow DOM Mastery: Jumping документ boundaries.
Installation & Setup: The Bun/Playwright stack.

Updated: January 22, 2026 - 21:20

---name: stagehand-expertdescription: Master Architect in Stagehand V3. Expert in Direct CDP Automation, Decision Caching, and Agentic Web Orchestration for 2026.---# 🎭 Skill: Stagehand Expert (v4.1.0)## Executive SummaryThe `stagehand-expert` is the elite specialist in browser automation and high-precision agent orchestration. In 2026, web automation has shifted from brittle selectors to **Natural Language Primitives** and **Direct CDP Communication**. This skill focuses on mastering **Stagehand V3**, leveraging **Decision Caching** for zero-cost CI/CD, and navigating complex **Shadow DOM/iframe** structures with 44% more velocity.---## 📋 Table of Contents1. [Proactive Investigation Protocol](#proactive-investigation-protocol)2. [The "Do Not" List (Anti-Patterns)](#the-do-not-list-anti-patterns)3. [Core Primitives (Act, Extract, Observe)](#core-primitives-act-extract-observe)4. [Direct CDP & Performance](#direct-cdp--performance)5. [Advanced Agent Caching](#advanced-agent-caching)6. [Autonomous Agents (CUA)](#autonomous-agents-cua)7. [Reference Library](#reference-library)---## 🔍 Proactive Investigation ProtocolBefore writing a single test, the expert MUST perform a **Deep Discovery**:1. **Route Mapping**: identify the user flow from `page.tsx` or router configs.2. **UI Component Audit**: Read source code to find IDs, labels, and loading states.3. **Vibe Check**: Measure layout stability using the CDP "Vibe Score."4. **Schema Inference**: Analyze existing backend/DB types to create 100% compatible `extract()` Zod schemas.---## 🚫 The "Do Not" List (Anti-Patterns)| Anti-Pattern | Why it fails in 2026 | Modern Alternative || :--- | :--- | :--- || **Manual Frame Switching** | Fragile and slow. | Use **DeepLocator (>>) & CDP**. || **Hardcoded Wait(2000)** | Unreliable and causes jank. | Use **`domSettleTimeout`**. || **Missing finally { close() }**| Leaves zombie processes. | **Mandatory `try...finally`**. || **LLM Calls in CI** | Slow and expensive. | Use **Persistent Decision Caches**. || **Ignoring CSS Animations** | Interactions fail during transitions. | Use **Reanimated-aware Waiters**. |---## ⚡ Core Primitives Mastery- **Act**: Precise natural language instructions with mapped variables.- **Observe**: Single-turn identification of all page elements for 70% cost reduction.- **Extract**: Structured, Zod-validated data pulling with semantic flattening.---## 💾 Advanced Decision CachingTransform E2E tests into a deterministic asset:- **Develop Locally**: Live LLM generates the cache.- **Commit Cache**: Store DOM snapshots and results in Git.- **Zero-Cost CI**: Run tests in "Cached-Only" mode.*See [References: Agent Caching](./references/advanced-agent-caching.md) for details.*---## 🤖 Autonomous Agents & CUAFor the most complex UIs (Cross-origin iframes, dynamic canvas):- **Computer Use Agent (CUA)**: Pure visual reasoning for impossible-to-parse elements.- **Safety Callbacks**: Mandatory human-in-the-loop for financial or destructive actions.---## 📖 Reference LibraryDetailed deep-dives into Stagehand Excellence:- [**Direct CDP Communication**](./references/cdp-direct-communication.md): Velocity and deep access.- [**Agent Caching**](./references/advanced-agent-caching.md): Determinism and cost savings.- [**Shadow DOM Mastery**](./references/shadow-dom-iframe-mastery.md): Jumping документ boundaries.- [**Installation & Setup**](./references/setup-guide-v3.md): The Bun/Playwright stack.---*Updated: January 22, 2026 - 21:20*

Frequently asked questions

Stagehand Expert