Large File MCP

Large File MCP Server

MCP server for intelligent handling of large files — smart chunking, search, navigation, and streaming.

🔗 Live Demo / Landing Page — install with npx @willianpinho/large-file-mcp

📚 Full Documentation | API Reference | Examples

Features

• Smart Chunking - Automatically determines optimal chunk size based on file type
• Intelligent Navigation - Jump to specific lines with surrounding context
• Powerful Search - Regex support with context lines before/after matches
• File Analysis - Comprehensive metadata and statistical analysis
• Memory Efficient - Stream files of any size without loading into memory
• Performance Optimized - Built-in LRU caching for frequently accessed chunks
• Type Safe - Written in TypeScript with strict typing
• Cross-Platform - Works on Windows, macOS, and Linux

Installation

npm install -g @willianpinho/large-file-mcp

Or use directly with npx:

npx @willianpinho/large-file-mcp

Quick Start

Claude Code CLI

Add the MCP server using the CLI:

# Add for current project only (local scope)
claude mcp add --transport stdio --scope local large-file-mcp -- npx -y @willianpinho/large-file-mcp

# Add globally for all projects (user scope)
claude mcp add --transport stdio --scope user large-file-mcp -- npx -y @willianpinho/large-file-mcp

Verify installation:

claude mcp list
claude mcp get large-file-mcp

Remove if needed:

# Remove from local scope
claude mcp remove large-file-mcp -s local

# Remove from user scope
claude mcp remove large-file-mcp -s user

MCP Scopes:

• local - Available only in the current project directory
• user - Available globally for all projects
• project - Defined in .mcp.json for team sharing

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "large-file": {
      "command": "npx",
      "args": ["-y", "@willianpinho/large-file-mcp"]
    }
  }
}

Config file locations:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Restart Claude Desktop after editing.

Other AI Platforms

Gemini:

{
  "tools": [
    {
      "name": "large-file-mcp",
      "command": "npx @willianpinho/large-file-mcp",
      "protocol": "mcp"
    }
  ]
}

Usage

Once configured, you can use natural language to interact with large files:

Read the first chunk of /var/log/system.log

Find all ERROR messages in /var/log/app.log

Show me line 1234 of /code/app.ts with context

Get the structure of /data/sales.csv

Available Tools

read_large_file_chunk

Read a specific chunk of a large file with intelligent chunking.

Parameters:

• filePath (required): Absolute path to the file
• chunkIndex (optional): Zero-based chunk index (default: 0)
• linesPerChunk (optional): Lines per chunk (auto-detected if not provided)
• includeLineNumbers (optional): Include line numbers (default: false)

Example:

{
  "filePath": "/var/log/system.log",
  "chunkIndex": 0,
  "includeLineNumbers": true
}

search_in_large_file

Search for patterns in large files with context.

Parameters:

• filePath (required): Absolute path to the file
• pattern (required): Search pattern
• caseSensitive (optional): Case sensitive search (default: false)
• regex (optional): Use regex pattern (default: false)
• maxResults (optional): Maximum results (default: 100)
• contextBefore (optional): Context lines before match (default: 2)
• contextAfter (optional): Context lines after match (default: 2)

Example:

{
  "filePath": "/var/log/error.log",
  "pattern": "ERROR.*database",
  "regex": true,
  "maxResults": 50
}

get_file_structure

Analyze file structure and get comprehensive metadata.

Parameters:

• filePath (required): Absolute path to the file

Returns: File metadata, line statistics, recommended chunk size, and sample lines.

navigate_to_line

Jump to a specific line with surrounding context.

Parameters:

• filePath (required): Absolute path to the file
• lineNumber (required): Line number to navigate to (1-indexed)
• contextLines (optional): Context lines before/after (default: 5)

get_file_summary

Get comprehensive statistical summary of a file.

Parameters:

• filePath (required): Absolute path to the file

Returns: File metadata, line statistics, character statistics, and word count.

stream_large_file

Stream a file in chunks for processing very large files.

Parameters:

• filePath (required): Absolute path to the file
• chunkSize (optional): Chunk size in bytes (default: 64KB)
• startOffset (optional): Starting byte offset (default: 0)
• maxChunks (optional): Maximum chunks to return (default: 10)

Supported File Types

The server intelligently detects and optimizes for:

• Text files (.txt) - 500 lines/chunk
• Log files (.log) - 500 lines/chunk
• Code files (.ts, .js, .py, .java, .cpp, .go, .rs, etc.) - 300 lines/chunk
• CSV files (.csv) - 1000 lines/chunk
• JSON files (.json) - 100 lines/chunk
• XML files (.xml) - 200 lines/chunk
• Markdown files (.md) - 500 lines/chunk
• Configuration files (.yml, .yaml, .sh, .bash) - 300 lines/chunk

Configuration

Customize behavior using environment variables:

Example with custom settings (Claude Desktop):

{
  "mcpServers": {
    "large-file": {
      "command": "npx",
      "args": ["-y", "@willianpinho/large-file-mcp"],
      "env": {
        "CHUNK_SIZE": "1000",
        "CACHE_ENABLED": "true"
      }
    }
  }
}

Example with custom settings (Claude Code CLI):

claude mcp add --transport stdio --scope user large-file-mcp \
  --env CHUNK_SIZE=1000 \
  --env CACHE_ENABLED=true \
  -- npx -y @willianpinho/large-file-mcp

Examples

Analyzing Log Files

Analyze /var/log/nginx/access.log and find all 404 errors

The AI will use the search tool to find patterns and provide context around each match.

Code Navigation

Find all function definitions in /project/src/main.py

Uses regex search to locate function definitions with surrounding code context.

CSV Data Exploration

Show me the structure of /data/sales.csv

Returns metadata, line count, sample rows, and recommended chunk size.

Large File Processing

Stream the first 100MB of /data/huge_dataset.json

Uses streaming mode to handle very large files efficiently.

Performance

Caching

• LRU Cache with configurable size (default 100MB)
• TTL-based expiration (default 5 minutes)
• Speeds up repeated access to the same file chunk or structure lookup

Cache hit-rate depends entirely on your access pattern (how often you re-request the same chunk), so there's no single universal number — run pnpm run benchmark to measure it against a documented, repeatable "hot chunk" workload. On that workload it currently measures 95% (95/100 accesses hit the cache).

Memory Management

• Streaming architecture - files are read line-by-line, never fully loaded
• Configurable chunk sizes - adjust based on your use case
• Smart buffering - minimal memory footprint for search operations

Read Latency (measured)

Uncached readChunk() latency from scripts/benchmark.mjs, generated fixtures, Apple M1 Pro laptop — re-run the script on your own hardware for your own numbers: