agent-hanju/char-index-mcp

Overview

This tool is a Model Context Protocol (MCP) server that exposes character-level index-based string manipulation operations. It allows AI agents to perform actions such as substring extraction, character replacement, and length calculation using zero-based character positions. The server is written in Python and communicates via the MCP protocol.

Best for

Best for
Developers building MCP-based tools that require exact character-level text processing in AI agent workflows

Use cases

• Extracting substrings by character index range
• Replacing characters at specific positions
• Computing string length and character offsets

How to use

Install

uvx char-index-mcp --help

Tools exposed

• find_nth_char
• find_all_char_indices
• find_nth_substring
• find_all_substring_indices
• split_at_indices
• insert_at_index
• delete_range
• replace_range
• find_regex_matches
• extract_between_markers
• count_chars
• extract_substrings

Tested with

Claude Desktop, Claude Code, Cursor

Example client config

{\n  "mcpServers": {\n    "char-index": {\n      "command": "uvx",\n      "args": ["char-index-mcp"]\n    }\n  }\n}

Notes

This tool is a Model Context Protocol (MCP) server that exposes character-level index-based string manipulation operations. It allows AI agents to perform actions such as substring extraction, character replacement, and length calculation using zero-based character positions. The server is written in Python and communicates via the MCP protocol.

2 stars on GitHub. Last updated 2026-04-02. Licensed MIT.

Use cases

• Extracting substrings by character index range
• Replacing characters at specific positions
• Computing string length and character offsets

Pros

• Lightweight Python server with minimal dependencies
• Simple integer-based interface for precise string operations
• Integrates seamlessly with MCP-compatible AI agents and tools

Cons

• Very low community traction (only 2 GitHub stars)
• Limited documentation and example usage
• Only supports basic character-level operations, no regex or pattern matching

Indexed from awesome-mcp-servers-punkpeye and enriched against its public facts.