mcp-sed-awk by William12556 - MCP Server

MCP sed/awk Server

Secure sed, awk, and diff text processing capabilities for Model Context Protocol servers.

Overview

This FastMCP server provides LLMs with efficient file editing and analysis through controlled execution of Unix text processing utilities. Token-efficient operations complement grep functionality while enforcing strict security controls through input validation, directory whitelisting, and resource limits.

Features

Pattern substitution via sed with regex support
Text transformation using awk field extraction and processing
File comparison with unified diff output
Preview operations for change verification before application
Directory whitelist access control
Comprehensive validation preventing command injection, path traversal, ReDoS attacks
Resource enforcement (file size limits, timeouts, memory caps)
Audit logging for security-relevant operations
Cross-platform support (Linux GNU tools, macOS BSD tools)

Requirements

Python 3.10 or higher
FastMCP 2.0+
System binaries: sed, awk, diff (standard on Linux/macOS)
Write permissions in target directories for sed operations

Installation

From GitHub:

git clone https://github.com/username/mcp-sed-awk.git
cd mcp-sed-awk
pip install -e .

Configure in Claude Desktop:

Edit ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "sed-awk": {
      "command": "mcp-sed-awk",
      "args": [
        "--allowed-directory", "/Users/username/Documents",
        "--allowed-directory", "/Users/username/Projects"
      ]
    }
  }
}

Restart Claude Desktop to activate the server.

Available Tools

sed_substitute - Pattern-based find-and-replace with automatic backup
preview_sed - Non-destructive change preview
awk_transform - Field extraction and text transformation
diff_files - File comparison with unified diff output
list_allowed_directories - Display accessible paths

Documentation

- Installation, configuration, usage examples, and troubleshooting

Project Status

Version 1.0.0 - Initial release

Completed:

Design baseline (15 functional requirements, 15 non-functional requirements)
Full test suite (100% pass rate: 51% unit test coverage, 19/19 integration tests)
Security architecture (validation, path control, resource limits, audit logging)
Platform abstraction (GNU/BSD compatibility layer)
FastMCP integration (decorator-based tool definitions)

Important Notice

Actual fitness for purpose is not guaranteed.

This project represents exploration of AI-supported software development using Claude Desktop and Claude Code from Anthropic, using an orchestration framework for systematic software development.

Development

Setup development environment:

git clone https://github.com/username/mcp-sed-awk.git
cd mcp-sed-awk
python3 -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate
pip install -e ".[dev]"

Run tests:

# Unit tests with coverage
pytest tests/ --cov=src/sed_awk_mcp --cov-report=term-missing

# Integration tests only
pytest tests/integration/

# All tests with output capture
pytest tests/ -v

Test artifacts: Results piped to workspace/test/result/pytest-result.txt

William12556/mcp-sed-awk