zw

This MCP server implements a zero-width character steganography toolkit designed for solving CTF challenges. It exposes multiple tools that can analyze, decode, encode, and export data hidden in zero-width or invisible characters. Key capabilities include zw_analyze for character distribution analysis, zw_decode which tries multiple decoding schemes (with automatic brute-force across schemes and character sets), zw_encode to embed a message into zero-width text, zw_dump_raw to export the raw zero-width sequence for debugging, zw_list_chars to enumerate all known zero-width/invisible characters, and zw_list_presets to show all encoding presets. You can invoke these tools through MCP requests, and the server will route the request to the appropriate function, e.g., analyze a text segment and then decode any hidden payload found within it. The workflow typically involves sending a request to analyze input, followed by a decode operation to recover any hidden message, optionally using a specific encoding preset or a combination of schemes. The tooling supports a wide range of encoding schemes, including binary mapping, positional numeral systems, Steganographr, Unicode Tag mappings, StegCloak, segmented encoding, and brute-force exploration of character arrangements, making it suitable for complex hidden-message challenges.

Prerequisites:

• Rust toolchain (rustc and cargo) installed on your system
• Git to clone the repository

Step-by-step installation:

1. Clone the repository: git clone https://github.com/your-organization/zw-mcp-server.git
2. Change into the project directory: cd zw-mcp-server
3. Build the release binary: cargo build --release
4. The executable will be located at: target/release/zw-mcp-server (Linux/macOS) or target/release/zw-mcp-server.exe (Windows)
5. Optional: move the binary to a directory in your PATH for ease of use, e.g.: mv target/release/zw-mcp-server /usr/local/bin/zw-mcp-server
6. Verify installation: zw-mcp-server --help

Notes:

• The server is ready to be wired into MCP clients via the mcp.json configuration as shown in the example.
• If you want to run it directly for testing, you can invoke the binary with appropriate MCP requests using the CLI or by integrating with your MCP client.

Tips and common issues:

• Ensure you have the correct permissions to execute the binary after building (chmod +x on Unix-like systems).
• If you are deploying on Windows, use zw-mcp-server.exe and ensure the path is properly quoted in JSON configurations.
• The server supports a broad set of zero-width / invisible character schemes; if a decode attempt fails, consider enabling a broader preset list or using zw_dump_raw to inspect the exact sequence.
• When configuring clients (VS Code, Claude Desktop, etc.), make sure the command path points to the compiled binary and that the client can access any required runtime dependencies.
• For debugging, zw_dump_raw can help you verify the exact zero-width character sequence being processed before attempting decoding.