stagewise: Browser-Powered Agent for Production Codebases

Tired of copy-pasting element selectors and folder paths into AI chatbots? stagewise eliminates that friction entirely. This revolutionary frontend coding agent lives inside your browser, sees what you see, and modifies your local codebase in real-time. No context switching. No guesswork. Just pure development magic.

In this deep dive, you'll discover how stagewise transforms frontend development workflows, explore its powerful plugin architecture, and learn step-by-step implementation strategies. We'll unpack real code examples, compare it against alternatives, and reveal why production teams are adopting this open-source powerhouse. Whether you're debugging legacy React components or building modern Vue applications, stagewise delivers framework-agnostic intelligence that actually understands your codebase.

What Is stagewise?

stagewise is the world's first frontend coding agent designed specifically for existing production-grade web applications. Developed by stagewise GmbH and released under the AGPLv3 license, this open-source tool represents a fundamental shift in how developers interact with AI assistants. Unlike traditional chatbots that operate in isolated windows, stagewise embeds directly into your browser, establishing a live connection between what you see and what you code.

The tool functions as a sophisticated bridge: you click on any element in your running application, describe the change you want, and stagewise intelligently maps that visual context to the exact files and code locations requiring modification. It works out of the box with zero configuration for most projects, supporting everything from legacy jQuery monoliths to modern micro-frontend architectures built with React, Vue, Angular, Svelte, or vanilla JavaScript.

What makes stagewise genuinely revolutionary is its browser-powered context system. When you select an element, the agent captures not just the DOM structure but also component hierarchies, CSS cascades, state management patterns, and even framework-specific metadata. This rich contextual understanding eliminates the ambiguity that plagues traditional AI coding assistants. The project has rapidly gained traction among developers frustrated with the copy-paste dance between browser DevTools and AI chat interfaces, amassing significant GitHub stars and an active Discord community.

Key Features That Make stagewise Essential

Zero-Configuration Deployment stagewise works immediately after installation. No webpack plugins, no Babel configurations, no intrusive code modifications. Simply run npx stagewise@latest in your project root while your development server runs. The CLI intelligently detects your framework, build system, and project structure automatically.

Visual Element Targeting The core innovation lies in its click-to-select mechanism. Instead of manually describing UI elements in text prompts, you visually indicate targets. stagewise captures the element's XPath, React component tree, Vue parent chain, CSS selectors, and even source map coordinates. This multi-dimensional context produces remarkably accurate code modifications.

Universal Framework Compatibility stagewise operates at the browser level, making it framework-agnostic. It doesn't care if you're using Next.js, Nuxt, Create React App, Vite, Angular CLI, or a custom rollup configuration. The agent interfaces with your running application through standard browser APIs, then maps changes back to your source files using source maps and intelligent path resolution.

Open Agent Interface While stagewise ships with its own optimized frontend agent, the architecture supports any MCP-compatible AI assistant. The tool seamlessly integrates with Cursor, GitHub Copilot, Windsurf, Cline, Roo Code, Kilo Code, and Trae. This flexibility means you can leverage your existing AI subscriptions while gaining stagewise's superior context delivery.

Plugin Extensibility The plugin system allows teams to customize behavior for specific codebase patterns. Write plugins to enforce design system rules, auto-generate tests for modified components, or integrate with internal APIs. Plugins can hook into the context gathering phase, the code generation phase, or the file writing phase, providing surgical control over the entire pipeline.

Real-Time Local Development All changes happen on your local machine. stagewise never uploads your source code to external servers. The browser extension communicates with a local CLI process, maintaining complete data privacy while delivering instant feedback loops.

Real-World Use Cases Where stagewise Shines

1. Legacy React Refactoring Without Documentation

You're tasked with updating a five-year-old React component library with zero documentation. The CSS uses unpredictable class naming conventions, state management mixes Redux with local state, and prop drilling runs five levels deep. With stagewise, you click the problematic button, type "convert this to a design system Button component with proper TypeScript props," and watch as the agent traces the component hierarchy, identifies all prop dependencies, updates parent components, and migrates styling to your design tokens automatically.

2. Rapid UI Iteration in Vue Prototypes

Your product manager needs three different versions of a dashboard widget by end-of-day. Instead of manually duplicating Vue files and hunting down scoped CSS, you launch stagewise, click the widget, and prompt "create two variants: one with a dark theme and compact layout, another with data visualization cards." The agent clones the component, adjusts the template structure, modifies the scoped styles, and even suggests composable functions for shared logic.

3. Cross-Browser CSS Bug Squashing

A flexbox layout breaks spectacularly in Safari but works perfectly in Chrome. Traditional debugging requires adding console logs, inspecting computed styles, and manually transcribing findings to an AI. With stagewise, you open Safari, click the broken container, and say "fix flexbox compatibility for Safari while maintaining the Chrome layout." The agent sees the computed styles, understands the browser discrepancy, and generates vendor-specific fixes with fallbacks.

4. Accessibility Audit Remediation

Your accessibility audit flagged 47 contrast violations and 23 missing ARIA labels across a sprawling Angular application. Rather than fixing each manually, you run stagewise, click the first offending element, and prompt "fix all contrast issues and add appropriate ARIA labels throughout this component tree." The agent propagates changes across child components, updates CSS custom properties for color values, and adds semantic attributes based on component roles.

5. Micro-Frontend Component Migration

Your organization is splitting a monolithic Next.js app into micro-frontends. You need to extract a complex user profile section into a standalone module. stagewise lets you click the root profile component and instruct "extract this into a separate Vite-based micro-frontend with its own package.json, maintaining all current props and state contracts." The agent handles file restructuring, dependency analysis, build configuration generation, and inter-app communication setup.

Step-by-Step Installation & Setup Guide

Prerequisites

Before installing stagewise, ensure your system meets these requirements:

• Node.js 16+ and npm/pnpm installed
• Git repository initialized for your project (stagewise tracks changes)
• Development server that provides source maps (standard for most modern frameworks)
• Modern browser (Chrome, Firefox, Edge, or Safari 14+)

Installation Process

Step 1: Start Your Application

Begin by running your web application in development mode as you normally would:

# For React/Vite projects
npm run dev

# For Next.js projects
npm run dev

# For Angular projects
ng serve

# For Vue projects
npm run dev

Ensure your dev server is fully running and accessible at localhost (typically port 3000, 5173, or 4200).

Step 2: Launch stagewise

Open a new terminal window in the root directory of your project. Execute one of these commands:

# Using npm (recommended)
npx stagewise@latest

# Using pnpm
pnpm dlx stagewise@latest

The CLI will automatically:

• Detect your framework and build tool
• Install the browser extension (if not already present)
• Generate a .stagewise.config.json file
• Prompt you to authenticate or create a free account

Step 3: Initial Configuration

The interactive setup asks three questions:

1. Project name: Defaults to your package.json name
2. Agent preference: Choose stagewise agent or connect your existing Cursor/Copilot
3. Plugin activation: Enable recommended plugins for your framework

The entire process takes under 60 seconds. Once complete, stagewise opens a new browser tab with your application and the stagewise overlay active.

Step 4: Verify Installation

You should see a small stagewise icon in the bottom-right corner of your browser. Click it to open the command palette. Click any element on your page to confirm the selection overlay appears. You're now ready to start coding with AI-powered precision.

REAL Code Examples from stagewise

Example 1: Basic Element Selection and Modification

This example demonstrates the core workflow: selecting a button element and requesting a style change. stagewise generates framework-specific code based on visual context.

// stagewise automatically generates this context object when you click a button
const elementContext = {
  // DOM information captured from browser
  selector: "button[data-testid='submit-form']",
  xpath: "/html/body/div[1]/main/form/button[2]",
  
  // Framework-specific metadata (React example)
  react: {
    componentName: "CheckoutForm",
    filePath: "src/components/CheckoutForm.tsx",
    props: ["onSubmit", "isDisabled", "children"],
    hooks: ["useState", "useCallback"]
  },
  
  // CSS context
  styles: {
    computed: { backgroundColor: "#3b82f6", padding: "8px 16px" },
    sourceFiles: ["src/styles/components.css", "src/theme/variables.css"],
    classNames: ["btn", "btn-primary", "mt-4"]
  },
  
  // State and data flow
  state: {
    managedBy: "useState",
    variableName: "isSubmitting",
    initialValue: false
  }
};

// After you prompt: "Change this button to a green success style"
stagewise.generateCode({
  context: elementContext,
  prompt: "Convert to green success style with darker hover state",
  agent: "stagewise-agent"
}).then(modifications => {
  // Returns an array of file changes
  console.log(modifications);
  /*
  [
    {
      filePath: "src/components/CheckoutForm.tsx",
      changes: [
        {
          line: 42,
          original: 'className="btn btn-primary mt-4"',
          modified: 'className="btn btn-success mt-4"'
        }
      ]
    },
    {
      filePath: "src/styles/components.css",
      changes: [
        {
          line: 156,
          original: ".btn-success { background-color: #10b981; }",
          modified: ".btn-success { background-color: #10b981; }\n.btn-success:hover { background-color: #059669; }"
        }
      ]
    }
  ]
  */
});

Explanation: This code shows how stagewise captures rich contextual data beyond simple selectors. The elementContext object contains framework-specific metadata, CSS provenance, and state management details. When you request a change, the agent uses this context to generate precise modifications across multiple files, understanding that changing a button's appearance might require updates to both the component markup and the stylesheet.

Example 2: Creating a Custom Plugin for Design System Enforcement

Plugins extend stagewise's core functionality. This example creates a plugin that automatically adds TypeScript interfaces for component props when modifying UI elements.

// .stagewise/plugins/design-system-enforcement.js
module.exports = {
  name: "design-system-enforcement",
  version: "1.0.0",
  
  // Hook into the code generation phase
  onCodeGenerate: async ({ context, generatedCode, framework }) => {
    // Only apply to React TypeScript projects
    if (framework !== 'react-ts') return generatedCode;
    
    // Check if the modified component lacks a typed interface
    const hasInterface = /interface\s+\w+Props/.test(
      context.react.componentSource
    );
    
    if (!hasInterface && generatedCode.includes('props.')) {
      // Generate TypeScript interface based on prop usage
      const propNames = [...generatedCode.matchAll(/props\.(\w+)/g)]
        .map(match => match[1]);
      const uniqueProps = [...new Set(propNames)];
      
      const interfaceCode = `
// Auto-generated by stagewise design-system plugin
interface ${context.react.componentName}Props {
${uniqueProps.map(prop => `  ${prop}: any;`).join('\n')}
}
`;
      
      // Prepend interface to the component file
      return {
        ...generatedCode,
        modifications: [
          {
            filePath: context.react.filePath,
            operation: "prepend",
            code: interfaceCode
          },
          ...generatedCode.modifications
        ]
      };
    }
    
    return generatedCode;
  },
  
  // Hook into the post-write phase to run ESLint
  onWriteComplete: async ({ modifiedFiles }) => {
    const { execSync } = require('child_process');
    
    // Auto-fix linting issues in modified files
    modifiedFiles.forEach(file => {
      try {
        execSync(`npx eslint --fix "${file}"`, { stdio: 'ignore' });
      } catch (error) {
        console.warn(`ESLint fix failed for ${file}`);
      }
    });
  }
};

Explanation: This plugin demonstrates stagewise's extensibility. The onCodeGenerate hook intercepts AI-generated code, analyzes it for TypeScript best practices, and automatically adds type interfaces when missing. The onWriteComplete hook runs ESLint auto-fix on modified files, ensuring code quality. Teams can create plugins for custom design tokens, test generation, or integration with internal APIs, making stagewise adapt to any codebase's standards.

Example 3: Integration with Cursor for Enhanced Context

stagewise can feed its rich browser context into Cursor, giving your existing AI assistant superpowers. This configuration example shows how to connect the two tools.

// .stagewise.config.json
{
  "project": {
    "name": "my-production-app",
    "framework": "react",
    "typescript": true
  },
  
  "agent": {
    "provider": "cursor",
    "apiKey": "${CURSOR_API_KEY}",
    "model": "claude-3.5-sonnet",
    "contextEnrichment": {
      "enabled": true,
      "includeDomSnapshot": true,
      "includeComponentTree": true,
      "maxCssRules": 100
    }
  },
  
  "cursor": {
    "integration": {
      "enabled": true,
      "forwardContext": true,
      "autoApplySuggestions": false,
      "showDiffPreview": true
    }
  },
  
  "plugins": ["design-system-enforcement", "test-generator"]
}

Explanation: This configuration file directs stagewise to use Cursor as its AI backend while enriching prompts with browser context. The contextEnrichment object controls what data gets sent: full DOM snapshots, component hierarchies, and relevant CSS rules. When you click an element, stagewise packages this context and forwards it to Cursor, which then generates code with unprecedented accuracy. The showDiffPreview setting ensures you review changes before application, maintaining developer control.

Example 4: Framework-Agnostic Component Conversion

This advanced example shows stagewise converting a React component to Vue syntax, demonstrating its cross-framework intelligence.

// Original React component (selected in browser)
function UserCard({ user, onEdit }) {
  const [isHovered, setIsHovered] = useState(false);
  
  return (
    <div 
      className="user-card"
      onMouseEnter={() => setIsHovered(true)}
      onMouseLeave={() => setIsHovered(false)}
    >
      <img src={user.avatar} alt={user.name} />
      <h3>{user.name}</h3>
      {isHovered && (
        <button onClick={() => onEdit(user.id)}>
          Edit Profile
        </button>
      )}
    </div>
  );
}

// stagewise generates this Vue 3 equivalent
<template>
  <div 
    class="user-card"
    @mouseenter="isHovered = true"
    @mouseleave="isHovered = false"
  >
    <img :src="user.avatar" :alt="user.name" />
    <h3>{{ user.name }}</h3>
    <button v-if="isHovered" @click="$emit('edit', user.id)">
      Edit Profile
    </button>
  </div>
</template>

<script setup>
import { ref } from 'vue';

const props = defineProps({
  user: {
    type: Object,
    required: true
  }
});

const emit = defineEmits(['edit']);
const isHovered = ref(false);
</script>

<style scoped>
.user-card {
  /* Preserved styles from original component */
  transition: all 0.3s ease;
}
</style>

Explanation: This showcases stagewise's deep understanding of framework paradigms. It doesn't just translate syntax—it restructures the entire component to follow Vue 3's composition API conventions, converts React's onClick to Vue's $emit pattern, and preserves the reactive hover state logic. The agent maintains styling and accessibility attributes while adapting to the target framework's best practices.

Advanced Usage & Best Practices

Master the Selection Combo Click elements while holding modifier keys for advanced selection modes. Ctrl+Click selects the entire component tree. Shift+Click selects all similar elements on the page. Alt+Click isolates the exact DOM node without framework context. These combos dramatically improve precision for bulk operations.

Chain Multiple Commands stagewise supports command chaining for complex workflows. After generating code, immediately follow up with "write unit tests for these changes" or "update the Storybook stories." The agent maintains context across commands, creating cohesive modifications.

Leverage Git Integration Always commit before major stagewise operations. The tool automatically creates pre-modification snapshots, but manual commits provide better rollback points. Use descriptive commit messages like chore: snapshot before stagewise button refactor for easy navigation.

Plugin Composition Combine multiple plugins for powerful pipelines. Stack a TypeScript enforcement plugin with a test generator and a design token validator. The plugin system executes sequentially, allowing each plugin to build on previous transformations.

Performance Optimization For large codebases (>10,000 components), configure maxComponentDepth in your config to limit context gathering. Disable includeDomSnapshot for simple CSS changes. These tweaks reduce latency from seconds to milliseconds.

Security Hygiene Never commit your .stagewise/secrets.json file. Use environment variables for API keys. The AGPLv3 license ensures transparency, but review plugin sources before installation, especially community-contributed ones.

stagewise vs. Alternatives: Why It Wins

stagewise's unique advantage is its browser-native architecture. While Cursor and Copilot excel at generating new code within your IDE, they lack visual context. They can't see your running application, computed styles, or component interactions. stagewise fills this critical gap, making it the perfect complement rather than a replacement. Use stagewise for UI modifications and refactoring; use your IDE agent for backend logic and new feature development.

The open-source nature under AGPLv3 means you can audit the code, contribute improvements, and self-host for enterprise environments. The license requires you to share modifications, which builds a stronger ecosystem—perfect for teams wanting transparency without vendor lock-in.

Frequently Asked Questions

Is stagewise really free for commercial use? Yes, the core tool is free under AGPLv3. You can use it in commercial projects, but any modifications to stagewise itself must be open-sourced. For proprietary modifications or enterprise support, contact sales@stagewise.io for a commercial license.

Which frameworks are officially supported? All of them. stagewise works with React, Vue, Angular, Svelte, Solid, Qwik, Preact, and vanilla JavaScript. It also supports meta-frameworks like Next.js, Nuxt, SvelteKit, and Remix. If it runs in a browser with source maps, stagewise works.

How does stagewise access my local codebase securely? The browser extension communicates with a localhost WebSocket server started by the CLI. Your code never leaves your machine. The connection uses encrypted channels, and you can firewall the port for additional security. No cloud processing occurs unless you explicitly configure an external AI agent.

Can I use stagewise alongside my existing Cursor/Copilot subscription? Absolutely. stagewise is designed to enhance, not replace, your current tools. Configure your preferred agent in .stagewise.config.json and stagewise becomes a supercharged context provider for the AI you already trust.

What happens if stagewise generates incorrect code? All changes appear in a diff preview before application. You can accept, reject, or modify each suggestion. stagewise also creates a Git stash automatically, allowing instant reversion. The system learns from corrections to improve future suggestions.

How is this different from just taking a screenshot for Cursor? Screenshots are static and lose all semantic information. stagewise captures live component trees, state values, event listeners, CSS cascade origins, and source file mappings. It's the difference between describing a painting from memory versus having the original canvas with all paint layers intact.

Do plugins slow down the development process? Well-designed plugins add negligible overhead (10-50ms). The plugin system uses async execution and caches results. Disable plugins selectively for specific operations if needed. The performance impact is far outweighed by the time saved in manual code quality enforcement.

Conclusion: Why stagewise Belongs in Your Toolkit

stagewise fundamentally reimagines the AI-assisted development workflow. By embedding intelligence directly into the browser, it eliminates the friction that has long plagued frontend developers—no more context switching, no more ambiguous element descriptions, no more copy-paste errors. The tool's framework-agnostic design, robust plugin architecture, and commitment to open-source transparency make it a rare find: a developer tool that genuinely respects your existing workflow while dramatically enhancing it.

The ability to click any element and watch as an AI understands not just what it sees, but how it's built, represents a quantum leap over traditional AI coding assistants. Whether you're maintaining a decade-old jQuery application or architecting a cutting-edge micro-frontend system, stagewise adapts to your stack, not the other way around.

Ready to transform your frontend development? Install stagewise today with a single command: npx stagewise@latest. Join the growing community on Discord, explore the source code, and start building with the precision that only browser-powered context can provide. Your production codebase deserves an agent that truly understands it.