String Le

What the string-le MCP server does

The string-le MCP server gives MCP-compatible agents a way to collect string values from configuration files, data files, and source code. Its main use is extracting text for localization preparation, configuration review, or inspection of values in a document without returning keys, numbers, booleans, or other non-string values from parsed formats.

Supported structured formats include JSON and JSONC-style content, YAML, CSV and TSV, TOML, INI, and dotenv or environment files. It also understands string constructs in Python, Rust, Go, shell, PHP, Ruby, Perl, C#, JavaScript, and TypeScript. Markdown and unrecognized formats use a quoted-string fallback.

How it works

The string-le MCP server exposes one tool, extract_strings:

extract_strings(content, format?, filename?, dedupe?, multiline?, maxResults?)

The caller supplies the content rather than a path. The optional format selects a parser, while filename can provide context for format detection or reporting. Results preserve document order unless deduplication is requested. Empty values are removed, and results are limited to 500 by default; when the limit is reached, the response includes meta.truncated.

CSV extraction supports optional header handling, selected columns, and streaming behavior for large input. YAML supports plain and block or folded scalars, including multiple documents. Source-language readers handle constructs such as Python docstrings, Rust raw strings, Go backtick strings, shell heredocs, and JavaScript or TypeScript template literals.

Setup and configuration

Install and run the package with Node.js and npx:

npx -y string-le-mcp

An MCP host can register it with a stdio configuration:

{
  "mcpServers": {
    "string-le": {
      "command": "npx",
      "args": ["-y", "string-le-mcp"]
    }
  }
}

You can also install the package globally and invoke string-le-mcp directly. The server needs no environment variables, API key, or server-specific configuration. It is available to Claude Code, Cursor, Windsurf, and other hosts that accept stdio MCP servers. VS Code 1.101 and later can use the related extension's agent-mode registration instead.

Tools and capabilities

The string-le MCP server provides:

• String extraction from parsed data formats and programming languages
• Optional deduplication and multiline handling
• A configurable maximum result count
• Document-order output
• A fallback scan for quoted strings in unsupported formats
• CSV column selection and large-file streaming support

Limitations and notes

The server does not read files from disk and does not make network requests. The host or agent must provide the document content. Parsed formats exclude keys and typed non-string values, while INI values are treated as strings because INI is untyped. The fallback parser only recognizes quoted strings, so it cannot extract unquoted text. Parse errors are silent in the underlying extraction behavior unless the surrounding String-LE tooling enables parse-error reporting. Unrecognized formats fall back to quoted-string extraction.