Editor MCP

🚀 Text Editor MCP User Guide

Text Editor MCP implements a powerful text editing server through FastMCP. It allows AI assistants to edit code and other text files in a structured way.

📚 Table of Contents

• Environment Variables
  • Maximum Selectable Lines
  • Enable Usage Statistics Collection
  • Disable ID Verification
• Server Implementation Details
  • Initialization
  • File Integrity Verification System
  • Registered Tools
• Best Practices for System Prompts
• Usage Statistics
  • Data Collection
  • Recorded Information
  • Storage Location
  • Privacy Considerations
• Troubleshooting
  • Common Issues
• Inspiration Sources

📦 Environment Variables

MCP supports configuration through environment variables. Here are some key environment variables:

Maximum Selectable Lines

max_select_lines: Limits the maximum number of lines that can be selected in an overwrite operation. The default value is 50. For example:

export max_select_lines=100

Enable Usage Statistics Collection

DUCKDB_USAGE_STATS: When enabled, MCP will collect usage statistics into a DuckDB database.

Disable ID Verification

DISABLE_ID_VERIFICATION: Set it to true to disable the integrity verification of file contents. For example:

export DISABLE_ID_VERIFICATION=true

🔧 Server Implementation Details

Initialization

The main class TextEditorServer receives a FastMCP instance named "text-editor" during initialization.

File Integrity Verification System

This system uses SHA-256 to generate a unique identifier for the file content or the selected line range. For example, for a modification operation on specific lines, the ID will include a line range prefix (e.g., "L10-15-[hash value]") to ensure that the editing operation is applied to the expected content.

Registered Tools

The server registers the following main tools through FastMCP:

• set_file: Used to set the path of the file to be edited.
• skim: Reads the entire file content and returns a dictionary of line numbers to line texts.
• read: Reads content according to the specified line range and returns a structured dictionary.
• select: Selects specific lines (up to 50) involved in the subsequent overwrite operation.
• overwrite: Receives a new list of lines and generates a diff-format preview to show the changes to be made.
• confirm: Applies the changes prepared by the overwrite tool.
• cancel: Discards the pending changes in the overwrite tool.
• delete_file: Deletes the current file.
• new_file: Creates a new file.
• find_line: Finds lines containing specific text.
• find_function: Finds function definitions in Python and JavaScript/JSX files.
• Other tools...

💡 Best Practices for System Prompts

To optimize the behavior of AI assistants, it is recommended to use system prompts. For example:

mcp_server.set_system_prompt("As an experienced software engineer, you should perform editing operations in a strict and secure manner.")

This ensures that the assistant is more cautious when modifying files and follows best programming practices.

📊 Usage Statistics

Data Collection

MCP provides the function of collecting data using DuckDB to record users' usage of the server.

Recorded Information

Including but not limited to:

• User ID
• Operation type (read, write, etc.)
• Operation timestamp
• File size change
• Error log

Storage Location

Usage statistics are stored in the mcp_usage.db database file in the current working directory.

Privacy Considerations

All collected data is anonymized and is only used to improve service quality and analyze system performance.

🛠️ Troubleshooting

Common Issues

• Issue: Unable to connect to the MCP server

  • Solution: Check if the server is running and confirm that the network configuration is correct.

• Issue: Receive an error indicating ID verification failure

  • Solution: Either enable ID verification (enabled by default) or disable this function.

💡 Inspiration Sources

This project is inspired by the open-source community, especially the successful experiences of FastMCP and similar tools.