diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..0100bb9
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,72 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Added
+- CONTRIBUTING.md with contribution guidelines
+- CHANGELOG.md for tracking version history
+- CODE_OF_CONDUCT.md for community standards
+- SECURITY.md with security policy and vulnerability reporting
+
+## [0.5.0]
+
+### Added
+- I/O Mode with built-in WebSocket connection support via `cdp.connection` module
+- WebSocket management with async context managers
+- JSON-RPC message framing and multiplexing
+- Event handling via async iterators
+- Comprehensive error handling with typed exceptions
+- Optional websockets dependency via `[io]` extra
+
+### Changed
+- Enhanced README with I/O mode documentation
+- Improved examples demonstrating both Sans-I/O and I/O modes
+
+## [0.4.0]
+
+### Changed
+- Updated to latest Chrome DevTools Protocol specification
+- Improved type hints and mypy compliance
+- Enhanced documentation
+
+## [0.3.0]
+
+### Added
+- Initial Sans-I/O implementation
+- Automatic code generation from CDP specification
+- Type wrappers for all CDP types, commands, and events
+- Comprehensive test suite
+
+### Changed
+- Improved project structure
+- Enhanced type safety
+
+## [0.2.0]
+
+### Added
+- Enhanced type definitions
+- Additional protocol domains
+
+### Fixed
+- Various type annotation improvements
+- Bug fixes in code generation
+
+## [0.1.0]
+
+### Added
+- Initial release
+- Basic type wrappers for Chrome DevTools Protocol
+- Code generator from CDP specification
+- MIT License
+
+[Unreleased]: https://github.com/HyperionGray/python-chrome-devtools-protocol/compare/v0.5.0...HEAD
+[0.5.0]: https://github.com/HyperionGray/python-chrome-devtools-protocol/compare/v0.4.0...v0.5.0
+[0.4.0]: https://github.com/HyperionGray/python-chrome-devtools-protocol/compare/v0.3.0...v0.4.0
+[0.3.0]: https://github.com/HyperionGray/python-chrome-devtools-protocol/compare/v0.2.0...v0.3.0
+[0.2.0]: https://github.com/HyperionGray/python-chrome-devtools-protocol/compare/v0.1.0...v0.2.0
+[0.1.0]: https://github.com/HyperionGray/python-chrome-devtools-protocol/releases/tag/v0.1.0
diff --git a/CODE_OF_CONDUCT.md b/CODE_OF_CONDUCT.md
new file mode 100644
index 0000000..6bf31a2
--- /dev/null
+++ b/CODE_OF_CONDUCT.md
@@ -0,0 +1,127 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to make participation in our
+community a harassment-free experience for everyone, regardless of age, body
+size, visible or invisible disability, ethnicity, sex characteristics, gender
+identity and expression, level of experience, education, socio-economic status,
+nationality, personal appearance, race, religion, or sexual identity
+and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming,
+diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our
+community include:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes,
+  and learning from the experience
+* Focusing on what is best not just for us as individuals, but for the
+  overall community
+
+Examples of unacceptable behavior include:
+
+* The use of sexualized language or imagery, and sexual attention or
+  advances of any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or email
+  address, without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of
+acceptable behavior and will take appropriate and fair corrective action in
+response to any behavior that they deem inappropriate, threatening, offensive,
+or harmful.
+
+Community leaders have the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct, and will communicate reasons for moderation
+decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when
+an individual is officially representing the community in public spaces.
+Examples of representing our community include using an official e-mail address,
+posting via an official social media account, or acting as an appointed
+representative at an online or offline event.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported to the community leaders responsible for enforcement via GitHub issues.
+All complaints will be reviewed and investigated promptly and fairly.
+
+All community leaders are obligated to respect the privacy and security of the
+reporter of any incident.
+
+## Enforcement Guidelines
+
+Community leaders will follow these Community Impact Guidelines in determining
+the consequences for any action they deem in violation of this Code of Conduct:
+
+### 1. Correction
+
+**Community Impact**: Use of inappropriate language or other behavior deemed
+unprofessional or unwelcome in the community.
+
+**Consequence**: A private, written warning from community leaders, providing
+clarity around the nature of the violation and an explanation of why the
+behavior was inappropriate. A public apology may be requested.
+
+### 2. Warning
+
+**Community Impact**: A violation through a single incident or series
+of actions.
+
+**Consequence**: A warning with consequences for continued behavior. No
+interaction with the people involved, including unsolicited interaction with
+those enforcing the Code of Conduct, for a specified period of time. This
+includes avoiding interactions in community spaces as well as external channels
+like social media. Violating these terms may lead to a temporary or
+permanent ban.
+
+### 3. Temporary Ban
+
+**Community Impact**: A serious violation of community standards, including
+sustained inappropriate behavior.
+
+**Consequence**: A temporary ban from any sort of interaction or public
+communication with the community for a specified period of time. No public or
+private interaction with the people involved, including unsolicited interaction
+with those enforcing the Code of Conduct, is allowed during this period.
+Violating these terms may lead to a permanent ban.
+
+### 4. Permanent Ban
+
+**Community Impact**: Demonstrating a pattern of violation of community
+standards, including sustained inappropriate behavior, harassment of an
+individual, or aggression toward or disparagement of classes of individuals.
+
+**Consequence**: A permanent ban from any sort of public interaction within
+the community.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage],
+version 2.0, available at
+https://www.contributor-covenant.org/version/2/0/code_of_conduct.html.
+
+Community Impact Guidelines were inspired by [Mozilla's code of conduct
+enforcement ladder](https://github.com/mozilla/diversity).
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see the FAQ at
+https://www.contributor-covenant.org/faq. Translations are available at
+https://www.contributor-covenant.org/translations.
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..6b73d26
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,138 @@
+# Contributing to PyCDP
+
+Thank you for your interest in contributing to Python Chrome DevTools Protocol (PyCDP)! We welcome contributions from the community.
+
+## Getting Started
+
+### Prerequisites
+
+- Python 3.7 or higher
+- Poetry for dependency management
+- Git for version control
+
+### Setting Up Development Environment
+
+1. Fork and clone the repository:
+   ```bash
+   git clone https://github.com/YOUR_USERNAME/python-chrome-devtools-protocol.git
+   cd python-chrome-devtools-protocol
+   ```
+
+2. Install dependencies:
+   ```bash
+   pip install poetry
+   poetry install
+   ```
+
+## Development Workflow
+
+### Code Generation
+
+This project automatically generates Python wrappers from the Chrome DevTools Protocol specification:
+
+```bash
+poetry run python generator/generate.py
+```
+
+### Running Tests
+
+Run the test suite:
+```bash
+poetry run pytest test/
+poetry run pytest generator/
+```
+
+### Type Checking
+
+We use mypy for static type checking:
+```bash
+poetry run mypy cdp/
+poetry run mypy generator/
+```
+
+### Complete Build
+
+Run all checks (type checking, tests, and generation):
+```bash
+poetry run make default
+```
+
+## Submitting Changes
+
+### Pull Request Process
+
+1. Create a new branch for your feature or bugfix:
+   ```bash
+   git checkout -b feature/your-feature-name
+   ```
+
+2. Make your changes and ensure:
+   - All tests pass
+   - Code passes type checking
+   - Code follows the existing style
+   - Documentation is updated if needed
+
+3. Commit your changes with clear, descriptive messages:
+   ```bash
+   git commit -m "Add feature: brief description"
+   ```
+
+4. Push to your fork and submit a pull request:
+   ```bash
+   git push origin feature/your-feature-name
+   ```
+
+5. In your pull request description:
+   - Describe what changes you made and why
+   - Reference any related issues
+   - Include any relevant context
+
+### Code Review
+
+- Maintainers will review your pull request
+- Address any feedback or requested changes
+- Once approved, a maintainer will merge your PR
+
+## Reporting Issues
+
+### Bug Reports
+
+When reporting bugs, please include:
+- A clear, descriptive title
+- Steps to reproduce the issue
+- Expected behavior vs. actual behavior
+- Python version and environment details
+- Any relevant error messages or logs
+
+### Feature Requests
+
+For feature requests, please:
+- Clearly describe the feature and its use case
+- Explain why it would be valuable
+- Provide examples if possible
+
+## Code Style
+
+- Follow PEP 8 style guidelines
+- Use type hints for function parameters and return values
+- Write clear, descriptive variable and function names
+- Add docstrings for public APIs
+- Keep functions focused and modular
+
+## Documentation
+
+- Update README.md if you add new features
+- Update docstrings for any modified functions or classes
+- Add examples for new functionality when appropriate
+
+## License
+
+By contributing, you agree that your contributions will be licensed under the MIT License.
+
+## Questions?
+
+If you have questions, feel free to:
+- Open an issue for discussion
+- Reach out to the maintainers
+
+Thank you for contributing to PyCDP!
diff --git a/README.md b/README.md
index 70504e3..e81be19 100644
--- a/README.md
+++ b/README.md
@@ -79,10 +79,6 @@ See the [examples directory](examples/) for more usage patterns.
 
 For users who prefer to manage their own I/O:
 
-## Sans-I/O Mode (Original)
-
-For users who prefer to manage their own I/O:
-
 ```python
 from cdp import page
 
@@ -90,6 +86,33 @@ frame_id = page.FrameId('my id')
 assert repr(frame_id) == "FrameId('my id')"
 ```
 
-For more information, see the [complete documentation](https://py-cdp.readthedocs.io).
+## API Documentation
+
+For detailed API documentation, see:
+
+- **[Complete Documentation](https://py-cdp.readthedocs.io)** - Full API reference on Read the Docs
+- **[Chrome DevTools Protocol](https://chromedevtools.github.io/devtools-protocol/)** - Official CDP specification
+- **[Examples](examples/)** - Code examples demonstrating usage patterns
+
+### Key Modules
+
+- `cdp.connection` - WebSocket I/O and connection management (I/O mode)
+- `cdp.<domain>` - Type wrappers for each CDP domain (e.g., `cdp.page`, `cdp.network`, `cdp.runtime`)
+- Each domain module provides types, commands, and events for that CDP domain
+
+## Contributing
+
+We welcome contributions! Please see our [Contributing Guide](CONTRIBUTING.md) for details on:
+
+- Setting up your development environment
+- Running tests and type checking
+- Submitting pull requests
+- Reporting issues
+
+Please also read our [Code of Conduct](CODE_OF_CONDUCT.md) before contributing.
+
+## Security
+
+For information about reporting security vulnerabilities, please see our [Security Policy](SECURITY.md).
 
 <a href="https://www.hyperiongray.com/?pk_campaign=github&pk_kwd=pycdp"><img alt="define hyperion gray" width="500px" src="https://hyperiongray.s3.amazonaws.com/define-hg.svg"></a>
diff --git a/SECURITY.md b/SECURITY.md
new file mode 100644
index 0000000..b6d758e
--- /dev/null
+++ b/SECURITY.md
@@ -0,0 +1,139 @@
+# Security Policy
+
+## Supported Versions
+
+We take security seriously and provide security updates for the following versions:
+
+| Version | Supported          |
+| ------- | ------------------ |
+| 0.5.x   | :white_check_mark: |
+| 0.4.x   | :white_check_mark: |
+| < 0.4   | :x:                |
+
+## Reporting a Vulnerability
+
+If you discover a security vulnerability in PyCDP, please help us by responsibly disclosing it to us.
+
+### How to Report
+
+**Please do not report security vulnerabilities through public GitHub issues.**
+
+Instead, please report security vulnerabilities by:
+
+1. **Creating a private security advisory** on GitHub:
+   - Go to the [Security tab](https://github.com/HyperionGray/python-chrome-devtools-protocol/security)
+   - Click "Report a vulnerability"
+   - Provide detailed information about the vulnerability
+
+2. **Or by emailing** the maintainers directly:
+   - Include "SECURITY" in the subject line
+   - Provide a detailed description of the vulnerability
+   - Include steps to reproduce the issue
+   - Suggest a fix if possible
+
+### What to Include
+
+When reporting a vulnerability, please include:
+
+- Type of vulnerability (e.g., injection, XSS, authentication bypass)
+- Full paths of source file(s) related to the vulnerability
+- Location of the affected source code (tag/branch/commit or direct URL)
+- Step-by-step instructions to reproduce the issue
+- Proof-of-concept or exploit code (if possible)
+- Impact of the vulnerability and potential attack scenarios
+
+### What to Expect
+
+- **Initial Response**: We aim to acknowledge receipt within 48 hours
+- **Status Updates**: We'll keep you informed about our progress
+- **Disclosure Timeline**: We'll work with you to understand the issue and develop a fix
+- **Credit**: We'll acknowledge your contribution in release notes (unless you prefer to remain anonymous)
+
+## Security Best Practices
+
+When using PyCDP:
+
+### WebSocket Connections
+
+- **Always use TLS/SSL** for WebSocket connections in production (`wss://` not `ws://`)
+- **Validate endpoint URLs** before connecting
+- **Authenticate connections** properly to Chrome DevTools endpoints
+- **Limit exposure** of CDP endpoints (use `--remote-debugging-port` carefully)
+
+### Input Validation
+
+- **Sanitize inputs** when sending commands to Chrome DevTools
+- **Validate responses** from the browser
+- **Handle errors gracefully** to prevent information disclosure
+
+### Dependency Management
+
+- **Keep dependencies up to date** using `poetry update`
+- **Review security advisories** for dependencies
+- **Use the optional `[io]` extra** only when needed to minimize dependency surface
+
+### Access Control
+
+- **Restrict access** to CDP endpoints to trusted clients only
+- **Use proper authentication** when exposing CDP over a network
+- **Monitor connections** for suspicious activity
+
+## Security Considerations
+
+### Chrome DevTools Protocol
+
+The Chrome DevTools Protocol provides powerful control over browser instances:
+
+- **Full DOM access**: Can read and modify page content
+- **JavaScript execution**: Can execute arbitrary JavaScript in pages
+- **Network interception**: Can intercept and modify network requests
+- **Cookie access**: Can read and modify cookies
+- **Storage access**: Can read and modify localStorage, sessionStorage, etc.
+
+### Important Warnings
+
+⚠️ **Never expose CDP endpoints to untrusted networks without authentication**
+
+⚠️ **Be cautious when connecting to untrusted CDP endpoints**
+
+⚠️ **Validate all data received from CDP to prevent injection attacks**
+
+⚠️ **Do not store sensitive credentials in CDP commands or scripts**
+
+## Known Security Considerations
+
+### WebSocket Security
+
+- WebSocket connections do not follow same-origin policy
+- Ensure proper origin validation for CDP endpoints
+- Use secure WebSocket connections (WSS) in production
+
+### Code Execution
+
+- CDP allows arbitrary JavaScript execution
+- Validate and sanitize any user input before executing
+- Be aware of potential for remote code execution vulnerabilities
+
+## Updates and Patches
+
+Security updates will be released as:
+
+- **Patch versions** for critical security fixes
+- **GitHub Security Advisories** for documented vulnerabilities
+- **CHANGELOG.md** entries for all security-related changes
+
+Subscribe to repository notifications to stay informed about security updates.
+
+## Additional Resources
+
+- [Chrome DevTools Protocol Documentation](https://chromedevtools.github.io/devtools-protocol/)
+- [OWASP WebSocket Security](https://owasp.org/www-community/vulnerabilities/WebSocket_Security)
+- [Python Security Best Practices](https://python.readthedocs.io/en/stable/library/security_warnings.html)
+
+## Contact
+
+For non-security issues, please use GitHub issues.
+
+For security concerns, please use the private reporting methods described above.
+
+Thank you for helping keep PyCDP and its users safe!