diff --git a/.github/ISSUE_TEMPLATE/bug_report.yml b/.github/ISSUE_TEMPLATE/bug_report.yml
new file mode 100644
index 0000000..7c38e6d
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/bug_report.yml
@@ -0,0 +1,98 @@
+name: Bug Report
+description: Report a bug or unexpected behavior
+title: "[Bug]: "
+labels: ["bug", "triage"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to report a bug! Please fill out the form below.
+
+  - type: textarea
+    id: description
+    attributes:
+      label: Bug Description
+      description: A clear and concise description of what the bug is.
+      placeholder: Describe the bug...
+    validations:
+      required: true
+
+  - type: textarea
+    id: reproduction
+    attributes:
+      label: Steps to Reproduce
+      description: Steps to reproduce the behavior.
+      placeholder: |
+        1. Run command '...'
+        2. Upload image '...'
+        3. See error
+    validations:
+      required: true
+
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected Behavior
+      description: What did you expect to happen?
+    validations:
+      required: true
+
+  - type: textarea
+    id: actual
+    attributes:
+      label: Actual Behavior
+      description: What actually happened?
+    validations:
+      required: true
+
+  - type: dropdown
+    id: interface
+    attributes:
+      label: Interface
+      description: Which interface are you using?
+      options:
+        - CLI
+        - Web UI
+        - REST API
+        - Python Library
+    validations:
+      required: true
+
+  - type: input
+    id: version
+    attributes:
+      label: Stegasoo Version
+      description: Run `stegasoo --version` or check the web UI footer
+      placeholder: "4.0.1"
+    validations:
+      required: true
+
+  - type: input
+    id: python-version
+    attributes:
+      label: Python Version
+      description: Run `python --version`
+      placeholder: "3.11.0"
+    validations:
+      required: true
+
+  - type: input
+    id: os
+    attributes:
+      label: Operating System
+      placeholder: "Ubuntu 22.04 / Windows 11 / macOS 14"
+    validations:
+      required: true
+
+  - type: textarea
+    id: logs
+    attributes:
+      label: Error Logs
+      description: Paste any relevant error messages or tracebacks.
+      render: shell
+
+  - type: textarea
+    id: additional
+    attributes:
+      label: Additional Context
+      description: Add any other context, screenshots, or files here.
diff --git a/.github/ISSUE_TEMPLATE/config.yml b/.github/ISSUE_TEMPLATE/config.yml
new file mode 100644
index 0000000..324397a
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/config.yml
@@ -0,0 +1,8 @@
+blank_issues_enabled: true
+contact_links:
+  - name: Security Vulnerability
+    url: https://github.com/adlee-was-taken/stegasoo/security/advisories/new
+    about: Report security vulnerabilities privately
+  - name: Documentation
+    url: https://github.com/adlee-was-taken/stegasoo#readme
+    about: Check the documentation before opening an issue
diff --git a/.github/ISSUE_TEMPLATE/feature_request.yml b/.github/ISSUE_TEMPLATE/feature_request.yml
new file mode 100644
index 0000000..d1d994e
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/feature_request.yml
@@ -0,0 +1,62 @@
+name: Feature Request
+description: Suggest a new feature or enhancement
+title: "[Feature]: "
+labels: ["enhancement"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for suggesting a feature! Please fill out the form below.
+
+  - type: textarea
+    id: problem
+    attributes:
+      label: Problem Statement
+      description: Is your feature request related to a problem? Describe it.
+      placeholder: I'm always frustrated when...
+    validations:
+      required: true
+
+  - type: textarea
+    id: solution
+    attributes:
+      label: Proposed Solution
+      description: Describe the solution you'd like.
+      placeholder: I would like to be able to...
+    validations:
+      required: true
+
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Alternatives Considered
+      description: Describe any alternative solutions or features you've considered.
+
+  - type: dropdown
+    id: interface
+    attributes:
+      label: Affected Interface(s)
+      description: Which interface(s) would this feature affect?
+      multiple: true
+      options:
+        - CLI
+        - Web UI
+        - REST API
+        - Python Library
+        - Core Library
+
+  - type: dropdown
+    id: priority
+    attributes:
+      label: Priority
+      description: How important is this feature to you?
+      options:
+        - Nice to have
+        - Would improve my workflow
+        - Critical for my use case
+
+  - type: textarea
+    id: context
+    attributes:
+      label: Additional Context
+      description: Add any other context, mockups, or examples here.
diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
new file mode 100644
index 0000000..a8cefc0
--- /dev/null
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -0,0 +1,46 @@
+## Description
+
+<!-- Describe your changes in detail -->
+
+## Type of Change
+
+<!-- Mark the relevant option with an 'x' -->
+
+- [ ] Bug fix (non-breaking change that fixes an issue)
+- [ ] New feature (non-breaking change that adds functionality)
+- [ ] Breaking change (fix or feature that would cause existing functionality to change)
+- [ ] Documentation update
+- [ ] Refactoring (no functional changes)
+- [ ] CI/CD or build changes
+
+## Related Issues
+
+<!-- Link any related issues here -->
+
+Fixes #
+
+## Testing
+
+<!-- Describe how you tested your changes -->
+
+- [ ] I have added tests that prove my fix/feature works
+- [ ] Existing tests pass locally with my changes
+- [ ] I have tested manually (describe below)
+
+### Manual Testing Steps
+
+<!-- If applicable, describe manual testing performed -->
+
+## Checklist
+
+- [ ] My code follows the project's style guidelines
+- [ ] I have performed a self-review of my code
+- [ ] I have commented my code, particularly in hard-to-understand areas
+- [ ] I have updated the documentation accordingly
+- [ ] I have updated CHANGELOG.md (if user-facing changes)
+- [ ] My changes generate no new warnings
+- [ ] Any dependent changes have been merged and published
+
+## Screenshots
+
+<!-- If applicable, add screenshots to help explain your changes -->
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..bb5738b
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,96 @@
+# Changelog
+
+All notable changes to Stegasoo will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org).
+
+## [4.0.1] - 2025-01-02
+
+### Fixed
+- Fixed numpy binary incompatibility on Python 3.10 (jpegio/scipy)
+- Fixed BatchCredentials test failures with missing `reference_photo` parameter
+- Graceful handling when DCT dependencies have version mismatches
+
+### Changed
+- Applied `ruff` linter fixes across entire codebase (~400 issues)
+- Applied `black` formatter to all Python files
+- Modernized type hints: `Optional[X]` → `X | None`
+- Updated ruff config to use `[tool.ruff.lint]` section
+- Moved documentation files to repository root
+
+### Removed
+- Removed obsolete debug/diagnostic scripts
+- Cleaned up backup files and dev scripts
+
+## [4.0.0] - 2024-12-29
+
+### Added
+- Refreshed Web UI with modern, snazzy interface
+- Improved user experience across all pages
+
+### Changed
+- Major version bump for breaking API changes
+- Simplified passphrase handling (single passphrase instead of day-based)
+- Removed date_str parameter from encoding
+
+### Fixed
+- Various bug fixes for Web UI
+- CLI updates and improvements
+
+## [3.2.0] - 2024-12-28
+
+### Added
+- Big revamp of the encoding system
+- Home and about page improvements
+- UNDER_THE_HOOD.md documentation
+
+### Changed
+- Renamed `phrase` → `passphrase` in API
+- Updated Web UI styling
+
+## [3.0.2] - 2024-12-27
+
+### Added
+- Full experimental DCT steganography support
+- jpegio integration for better JPEG manipulation
+- DCT/LSB mode selector in Web UI
+
+## [3.0.0] - 2024-12-25
+
+### Added
+- DCT (Discrete Cosine Transform) steganography mode
+- Support for JPEG carriers without quality loss
+- Channel key feature for private messaging
+
+### Changed
+- Complete rewrite of steganography engine
+- New hybrid authentication system
+
+## [2.0.0] - 2024-12-20
+
+### Added
+- Web UI frontend
+- REST API (FastAPI)
+- Batch processing support
+- RSA key authentication option
+
+### Changed
+- Migrated to hybrid photo + passphrase + PIN authentication
+
+## [1.0.0] - 2024-12-15
+
+### Added
+- Initial release
+- LSB steganography
+- AES-256-GCM encryption
+- CLI interface
+- Basic PIN authentication
+
+[4.0.1]: https://github.com/adlee-was-taken/stegasoo/compare/v4.0.0...v4.0.1
+[4.0.0]: https://github.com/adlee-was-taken/stegasoo/compare/v3.2.0...v4.0.0
+[3.2.0]: https://github.com/adlee-was-taken/stegasoo/compare/v3.0.2...v3.2.0
+[3.0.2]: https://github.com/adlee-was-taken/stegasoo/compare/v3.0.0...v3.0.2
+[3.0.0]: https://github.com/adlee-was-taken/stegasoo/compare/v2.0.0...v3.0.0
+[2.0.0]: https://github.com/adlee-was-taken/stegasoo/compare/v1.0.0...v2.0.0
+[1.0.0]: https://github.com/adlee-was-taken/stegasoo/releases/tag/v1.0.0
diff --git a/CODE_OF_CONDUCT.md b/CODE_OF_CONDUCT.md
new file mode 100644
index 0000000..011af5d
--- /dev/null
+++ b/CODE_OF_CONDUCT.md
@@ -0,0 +1,54 @@
+# 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:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior:
+
+* The use of sexualized language or imagery, and sexual attention or advances
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information without explicit permission
+* Other conduct which could reasonably be considered inappropriate
+
+## Enforcement Responsibilities
+
+Project maintainers 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.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when
+an individual is officially representing the community in public spaces.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported to the project maintainers. All complaints will be reviewed and
+investigated promptly and fairly.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant](https://www.contributor-covenant.org),
+version 2.0.
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..6d47370
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,165 @@
+# Contributing to Stegasoo
+
+Thank you for your interest in contributing to Stegasoo! This document provides guidelines and information for contributors.
+
+## Getting Started
+
+### Prerequisites
+
+- Python 3.10 or higher
+- Git
+- Docker (optional, for container testing)
+
+### Development Setup
+
+1. **Clone the repository**
+   ```bash
+   git clone https://github.com/adlee-was-taken/stegasoo.git
+   cd stegasoo
+   ```
+
+2. **Create a virtual environment**
+   ```bash
+   python -m venv venv
+   source venv/bin/activate  # On Windows: venv\Scripts\activate
+   ```
+
+3. **Install development dependencies**
+   ```bash
+   pip install -e ".[dev]"
+   ```
+
+4. **Install pre-commit hooks**
+   ```bash
+   pre-commit install
+   ```
+
+## Development Workflow
+
+### Code Style
+
+We use the following tools to maintain code quality:
+
+- **Black** - Code formatting (line length: 100)
+- **Ruff** - Linting
+- **MyPy** - Type checking
+
+Run all checks before committing:
+```bash
+black src/ tests/ frontends/
+ruff check src/ tests/ frontends/
+mypy src/
+```
+
+### Running Tests
+
+```bash
+# Run all tests
+pytest
+
+# Run with coverage
+pytest --cov=stegasoo --cov-report=term-missing
+
+# Run specific test file
+pytest tests/test_stegasoo.py
+```
+
+### Type Hints
+
+All new code should include type hints:
+
+```python
+def encode_message(
+    message: str,
+    carrier_image: bytes,
+    passphrase: str,
+    pin: str = "",
+) -> EncodeResult:
+    ...
+```
+
+## Making Changes
+
+### Branch Naming
+
+- `feature/description` - New features
+- `fix/description` - Bug fixes
+- `docs/description` - Documentation updates
+- `refactor/description` - Code refactoring
+
+### Commit Messages
+
+Write clear, concise commit messages:
+
+```
+Add channel key validation for private messaging
+
+- Implement validate_channel_key() function
+- Add tests for valid/invalid key formats
+- Update CLI to support --channel-key flag
+```
+
+### Pull Request Process
+
+1. **Create a feature branch** from `main`
+2. **Make your changes** with appropriate tests
+3. **Ensure all checks pass** (tests, linting, formatting)
+4. **Submit a PR** with a clear description
+5. **Address review feedback** promptly
+
+### PR Checklist
+
+- [ ] Tests added/updated for changes
+- [ ] Documentation updated if needed
+- [ ] CHANGELOG.md updated for user-facing changes
+- [ ] All CI checks passing
+- [ ] No merge conflicts with `main`
+
+## Project Structure
+
+```
+stegasoo/
+├── src/stegasoo/       # Core library
+│   ├── crypto.py       # Encryption/decryption
+│   ├── steganography.py # LSB embedding
+│   ├── dct_steganography.py # DCT embedding
+│   └── ...
+├── frontends/
+│   ├── cli/            # Command-line interface
+│   ├── web/            # Flask web UI
+│   └── api/            # FastAPI REST API
+├── tests/              # Test suite
+└── examples/           # Usage examples
+```
+
+## Reporting Issues
+
+### Bug Reports
+
+Please include:
+- Python version and OS
+- Stegasoo version (`stegasoo --version`)
+- Minimal reproduction steps
+- Expected vs actual behavior
+- Error messages/tracebacks
+
+### Feature Requests
+
+Please include:
+- Use case description
+- Proposed solution (if any)
+- Alternatives considered
+
+## Security
+
+If you discover a security vulnerability, please see [SECURITY.md](SECURITY.md) for responsible disclosure guidelines. **Do not open a public issue for security vulnerabilities.**
+
+## License
+
+By contributing, you agree that your contributions will be licensed under the MIT License.
+
+## Questions?
+
+Feel free to open a discussion or issue if you have questions about contributing.
+
+Thank you for helping make Stegasoo better!
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..d40f505
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024-2025 Aaron D. Lee
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
index e3fac78..98d8edb 100644
--- a/README.md
+++ b/README.md
@@ -2,8 +2,10 @@
 
 A secure steganography system for hiding encrypted messages in images using hybrid authentication.
 
+[![Tests](https://github.com/adlee-was-taken/stegasoo/actions/workflows/test.yml/badge.svg)](https://github.com/adlee-was-taken/stegasoo/actions/workflows/test.yml)
+[![Lint](https://github.com/adlee-was-taken/stegasoo/actions/workflows/lint.yml/badge.svg)](https://github.com/adlee-was-taken/stegasoo/actions/workflows/lint.yml)
 ![Python](https://img.shields.io/badge/Python-3.10--3.12-blue)
-![License](https://img.shields.io/badge/License-MIT-green)
+[![License: MIT](https://img.shields.io/badge/License-MIT-green.svg)](https://opensource.org/licenses/MIT)
 ![Security](https://img.shields.io/badge/Security-AES--256--GCM-red)
 ![Version](https://img.shields.io/badge/Version-4.0.1-purple)
 
diff --git a/examples/README.md b/examples/README.md
new file mode 100644
index 0000000..30f3396
--- /dev/null
+++ b/examples/README.md
@@ -0,0 +1,48 @@
+# Stegasoo Examples
+
+This directory contains example scripts demonstrating how to use Stegasoo.
+
+## Prerequisites
+
+Install Stegasoo first:
+
+```bash
+pip install stegasoo
+# Or for development:
+pip install -e ".[all]"
+```
+
+## Examples
+
+### basic_usage.py
+
+Basic encode/decode workflow with a text message.
+
+```bash
+python basic_usage.py
+```
+
+### embed_file.py
+
+Embed and extract files (documents, images, etc.) inside carrier images.
+
+```bash
+python embed_file.py
+```
+
+### channel_keys.py
+
+Use channel keys to create private communication channels for groups.
+
+```bash
+python channel_keys.py
+```
+
+## Test Images
+
+You'll need to provide your own images:
+
+- `my_secret_photo.png` - Your reference photo (keep this secret!)
+- `carrier.png` - The image that will carry your hidden message
+
+For testing, you can use any PNG or BMP image. JPEG carriers are supported with DCT mode.
diff --git a/examples/basic_usage.py b/examples/basic_usage.py
new file mode 100644
index 0000000..2cdd8c4
--- /dev/null
+++ b/examples/basic_usage.py
@@ -0,0 +1,59 @@
+#!/usr/bin/env python3
+"""
+Basic Stegasoo Usage Example
+
+This example demonstrates how to encode and decode a secret message
+using the Stegasoo library.
+"""
+
+from pathlib import Path
+
+import stegasoo
+
+
+def main():
+    # Load your images
+    # The reference photo is your "key" - keep it secret!
+    reference_photo = Path("my_secret_photo.png").read_bytes()
+    carrier_image = Path("carrier.png").read_bytes()
+
+    # Your secret message
+    message = "This is my secret message!"
+
+    # Your credentials
+    passphrase = "correct horse battery staple"  # Use 4+ words
+    pin = "123456"  # 6-9 digits
+
+    # === ENCODE ===
+    print("Encoding message...")
+    result = stegasoo.encode(
+        message=message,
+        reference_photo=reference_photo,
+        carrier_image=carrier_image,
+        passphrase=passphrase,
+        pin=pin,
+    )
+
+    # Save the stego image
+    output_path = Path(f"secret_{result.suggested_filename}")
+    output_path.write_bytes(result.stego_image)
+    print(f"Saved to: {output_path}")
+    print(f"Capacity used: {result.capacity_used_percent:.1f}%")
+
+    # === DECODE ===
+    print("\nDecoding message...")
+    stego_image = output_path.read_bytes()
+
+    decoded = stegasoo.decode(
+        stego_image=stego_image,
+        reference_photo=reference_photo,
+        passphrase=passphrase,
+        pin=pin,
+    )
+
+    print(f"Decoded message: {decoded.message}")
+    print(f"Message type: {decoded.payload_type}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/examples/channel_keys.py b/examples/channel_keys.py
new file mode 100644
index 0000000..af32cb9
--- /dev/null
+++ b/examples/channel_keys.py
@@ -0,0 +1,72 @@
+#!/usr/bin/env python3
+"""
+Channel Keys Example
+
+Channel keys allow you to create private communication channels.
+Only people with the same channel key can decode messages.
+"""
+
+from pathlib import Path
+
+import stegasoo
+from stegasoo.channel import generate_channel_key, get_channel_fingerprint
+
+
+def main():
+    # Generate a channel key for your group
+    channel_key = generate_channel_key()
+    fingerprint = get_channel_fingerprint(channel_key)
+
+    print("=== Channel Key Generated ===")
+    print(f"Key: {channel_key}")
+    print(f"Fingerprint: {fingerprint}")
+    print("\nShare this key securely with your group members!")
+    print("-" * 40)
+
+    # Load images
+    reference_photo = Path("my_secret_photo.png").read_bytes()
+    carrier_image = Path("carrier.png").read_bytes()
+
+    # Encode with channel key
+    print("\nEncoding message with channel key...")
+    result = stegasoo.encode(
+        message="Secret group message!",
+        reference_photo=reference_photo,
+        carrier_image=carrier_image,
+        passphrase="correct horse battery staple",
+        pin="123456",
+        channel_key=channel_key,  # Add the channel key
+    )
+
+    stego_data = result.stego_image
+    print(f"Encoded successfully!")
+
+    # Decode with correct channel key
+    print("\nDecoding with correct channel key...")
+    decoded = stegasoo.decode(
+        stego_image=stego_data,
+        reference_photo=reference_photo,
+        passphrase="correct horse battery staple",
+        pin="123456",
+        channel_key=channel_key,  # Same channel key
+    )
+    print(f"Message: {decoded.message}")
+
+    # Try to decode with wrong channel key
+    print("\nTrying to decode with wrong channel key...")
+    wrong_key = generate_channel_key()
+    try:
+        stegasoo.decode(
+            stego_image=stego_data,
+            reference_photo=reference_photo,
+            passphrase="correct horse battery staple",
+            pin="123456",
+            channel_key=wrong_key,  # Different channel key
+        )
+        print("ERROR: Should have failed!")
+    except (stegasoo.DecryptionError, stegasoo.ExtractionError):
+        print("Correctly rejected - wrong channel key!")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/examples/embed_file.py b/examples/embed_file.py
new file mode 100644
index 0000000..c127ac8
--- /dev/null
+++ b/examples/embed_file.py
@@ -0,0 +1,78 @@
+#!/usr/bin/env python3
+"""
+File Embedding Example
+
+This example demonstrates how to embed a file (like a document or image)
+inside a carrier image using Stegasoo.
+"""
+
+from pathlib import Path
+
+import stegasoo
+from stegasoo.models import FilePayload
+
+
+def main():
+    # Load images
+    reference_photo = Path("my_secret_photo.png").read_bytes()
+    carrier_image = Path("carrier.png").read_bytes()
+
+    # Load the file to embed
+    secret_file = Path("secret_document.pdf")
+    file_data = secret_file.read_bytes()
+
+    # Create a FilePayload
+    payload = FilePayload(
+        filename=secret_file.name,
+        data=file_data,
+        mime_type="application/pdf",
+    )
+
+    # Credentials
+    passphrase = "correct horse battery staple"
+    pin = "123456"
+
+    # Check capacity first
+    capacity = stegasoo.calculate_capacity(carrier_image)
+    print(f"Carrier capacity: {capacity['capacity_bytes']:,} bytes")
+    print(f"File size: {len(file_data):,} bytes")
+
+    if len(file_data) > capacity["capacity_bytes"]:
+        print("Error: File too large for this carrier!")
+        return
+
+    # Encode the file
+    print("\nEmbedding file...")
+    result = stegasoo.encode(
+        file_payload=payload,
+        reference_photo=reference_photo,
+        carrier_image=carrier_image,
+        passphrase=passphrase,
+        pin=pin,
+    )
+
+    output_path = Path(f"contains_file_{result.suggested_filename}")
+    output_path.write_bytes(result.stego_image)
+    print(f"Saved to: {output_path}")
+
+    # Decode and extract the file
+    print("\nExtracting file...")
+    decoded = stegasoo.decode(
+        stego_image=output_path.read_bytes(),
+        reference_photo=reference_photo,
+        passphrase=passphrase,
+        pin=pin,
+    )
+
+    if decoded.payload_type == "file":
+        extracted_path = Path(f"extracted_{decoded.filename}")
+        extracted_path.write_bytes(decoded.file_data)
+        print(f"Extracted: {extracted_path}")
+        print(f"Original filename: {decoded.filename}")
+        print(f"MIME type: {decoded.mime_type}")
+    else:
+        print(f"Unexpected payload type: {decoded.payload_type}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/src/stegasoo/py.typed b/src/stegasoo/py.typed
new file mode 100644
index 0000000..e69de29