Show HN: We turned Codex Into In-browser AI Agent

An In-Browser AI Agent for Web Automation

Codex for Chrome is a privacy-preserving, general-purpose AI agent implemented as a Chrome extension. The agent operates entirely within the user's local browser environment, interpreting natural language commands and autonomously interacting with web pages to fulfill user requests. All large language model inference occurs client-side, ensuring that sensitive data never leaves the user's machine and eliminating the need for backend infrastructure.

AI Republic is a Seattle-based artificial intelligence startup developing an AI agents marketplace designed specifically for small and medium-sized businesses (SMBs). Our mission is to democratize access to intelligent automation technologies, empowering organizations to enhance productivity and operational efficiency while maintaining full control over their proprietary data and workflows.

This project is derived from OpenAI's open-source Codex reference implementation, available at github.com/openai/codex. We express our profound gratitude to the OpenAI team (@openai) for releasing codex under an open-source license, which has enabled our development of this privacy-focused, browser-native AI agent implementations.

Current Status: Alpha Testing

Codex for Chrome is currently in active alpha development and is intended exclusively for personal evaluation or internal organizational use. At this time, we do NOT authorize the use of this codebase to create derivative works for public distribution, including but not limited to publishing extensions to the Chrome Web Store or other browser extension marketplaces.

Important Notice: Any unauthorized commercial redistribution or publication of extensions based on this codebase is strictly prohibited during the alpha phase.

We are committed to releasing this project under the Apache License 2.0—maintaining consistency with the upstream Codex licensing framework. This transition to a fully permissive open-source license will enable unrestricted use, modification, and distribution, including the creation and publication of derivative extensions.

Current Considerations:

Before finalizing the Apache 2.0 license adoption, we are working to resolve potential trademark considerations regarding the "Codex" name with OpenAI. Depending on the outcome of these discussions, the project may undergo a rebranding to ensure clear distinction from OpenAI's offerings.

Potential Rebranding:

We are evaluating BrowserX (or browserx) as a candidate name for the project should rebranding become necessary. This naming convention better reflects the project's browser-centric architecture and cross-platform agent capabilities while avoiding potential trademark conflicts. The name emphasizes the extension's role as a powerful, extensible ("X") browser automation framework.

Stay tuned for updates on licensing finalization and any naming changes through our GitHub repository and official communication channels.

Currently Supported:

• OpenAI GPT-5 (via OpenAI API endpoints)

In Development:

• Anthropic Claude
• Google Gemini
• DeepSeek

We are actively working to expand model provider support to offer users greater flexibility and choice in their AI backend infrastructure.

Challenge: Complex Web Applications

Modern web applications, particularly Single-Page Applications (SPAs), present significant challenges for AI agent automation. These applications feature dynamically generated DOM structures, shadow DOM elements, framework-specific rendering patterns (React, Vue, Angular), and complex state management systems that make reliable element identification and interaction difficult for language models.

Our Ongoing Efforts:

We are continuously enhancing our browser tool suite to handle increasingly sophisticated web interactions, including:

• Improved element selection strategies for dynamic and framework-rendered content
• Enhanced DOM traversal algorithms to handle shadow DOM and nested iframe contexts
• Robust state detection mechanisms for asynchronous UI updates and lazy-loaded content
• Intelligent retry and fallback logic for handling transient DOM states
• Advanced selector generation using accessibility attributes, data attributes, and semantic markup

Community Contribution Opportunity:

This area of the project requires substantial open-source community support. The diversity and complexity of modern web applications make it impossible for a single team to address all edge cases and framework-specific patterns. We welcome contributions from developers who have:

• Experience with specific JavaScript frameworks and their DOM manipulation patterns
• Expertise in web accessibility and ARIA attribute usage for reliable element targeting
• Knowledge of browser automation testing tools and best practices
• Interest in AI agent reliability and robustness improvements

How You Can Help:

• Report challenging websites or SPAs where the agent struggles
• Contribute improved tool implementations for specific use cases
• Submit test cases and fixtures for complex web application scenarios
• Propose and implement new DOM interaction strategies

Together, we can build a more capable and reliable browser automation agent that handles the full spectrum of modern web applications.

Follow these steps to build and run Codex for Chrome in your local development environment:

• Node.js (v16 or higher recommended)
• npm package manager
• Google Chrome browser
• OpenAI API key (obtain here)

1. Clone the repository:

   git clone [email protected]:The-AI-Republic/browserx.git

2. Navigate to the project directory:

3. Install dependencies:

4. Build the extension:

   This generates the production-ready extension in the dist/ directory.

5. Load the extension in Chrome:

   • Navigate to chrome://extensions/ in your browser
   • Enable Developer Mode (toggle in the top-right corner)
   • Click Load unpacked
   • Select the dist/ directory from your project

6. Configure API credentials:

   • Open the extension side panel
   • Navigate to the Settings page
   • Enter your OpenAI API key
   • Click Test Connection to verify API connectivity

7. Verify installation:

   • Once the connection test succeeds, the agent is ready for use
   • Begin issuing natural language commands through the side panel interface

You're all set! The agent can now interact with web pages on your behalf.

For developers working on browser tool integrations, we provide a standalone testing extension that simulates LLM function calling to individual browser tools.

1. Build the testing extension:

2. Load the test extension:

   • Navigate to chrome://extensions/
   • Ensure Developer Mode is enabled
   • Click Load unpacked
   • Select the tests/tools/e2e directory

3. Execute tool tests:

   • Use the testing extension interface to simulate function calls to specific browser tools
   • Validate tool behavior, response formats, and error handling
   • This allows isolated testing without requiring full LLM integration

We welcome collaboration from the developer community and business partners interested in advancing privacy-preserving AI agent technologies.

• Investment opportunities: Strategic partnerships and funding discussions
• Enterprise adoption: Integrating Codex for Chrome into organizational workflows
• Open-source contributions: Code improvements, bug fixes, documentation enhancements, and feature development

For all collaboration inquiries, please contact:

Richard Miao Email: [email protected] LinkedIn: linkedin.com/in/rcmiao

We look forward to building the future of in-browser AI agents together.

Pending Apache License 2.0 adoption (see Licensing section above)

This software is provided "as is" during the alpha testing phase. Use at your own risk. AI Republic and contributors are not liable for any damages, data loss, or security issues arising from the use of this software.