
Advanced filesystem operations for Claude Desktop with large file handling capabilities and Claude-optimized features.
Quick Start
Add to your Claude Desktop config.
{
"mcpServers": {
"fast-filesystem": {
"command": "npx",
"args": ["-y", "fast-filesystem-mcp"]
}
}
}
- With backup files enabled
{
"mcpServers": {
"fast-filesystem": {
"command": "npx",
"args": ["-y", "fast-filesystem-mcp"],
"env": {
"CREATE_BACKUP_FILES": "true"
}
}
}
}
Backup Configuration
Control backup file creation behavior.
CREATE_BACKUP_FILES=false (default): Disables backup file creation to reduce clutter
CREATE_BACKUP_FILES=true: Creates backup files before modifications
Note: Backup files are created with timestamps (e.g., file.txt.backup.1755485284402) to prevent data loss during edits.
Debug and Logging Configuration
The MCP server uses a safe logging system that prevents JSON-RPC communication errors.
DEBUG_MCP=true or MCP_DEBUG=true: Enable debug logging to stderr
MCP_LOG_FILE=/path/to/log.txt: Write logs to file instead of stderr
MCP_SILENT_ERRORS=true or SILENT_ERRORS=true: Suppress error messages in responses
Note: Debug output is automatically suppressed by default to prevent JSON parsing errors in Claude Desktop.
New Version Update
To update to the latest version, follow these steps.
- Uninstall previous version
npm uninstall -g fast-filesystem-mcp
- Clean cache and dependencies
npm cache clean --force
pnpm store prune
- Install latest version
npm install -g fast-filesystem-mcp
- Verify installation
npm list -g fast-filesystem-mcp
fast-filesystem-mcp --version
Features
Core File Operations
- Fast File Reading/Writing: Optimized for Claude Desktop with chunking support
- Sequential Reading: Read large files completely with continuation token support
- Large File Handling: Stream-based writing for files of any size
- Directory Operations: Comprehensive directory listing, creation, and management
- File Search: Name and content-based file searching with filtering
Advanced Capabilities
- Pagination Support: Handle large directories efficiently
- Chunked Reading: Read large files in manageable chunks
- Streaming Writes: Memory-efficient writing for large files
- Backup & Recovery: Automatic backup creation and error recovery
- Retry Logic: Built-in retry mechanism for reliable operations
- Claude-Optimized: Response sizes and formats optimized for Claude
- Memory Efficient: Streaming operations prevent memory overflow
- Smart Exclusions: Automatically excludes system files and directories
- Progress Tracking: Real-time progress monitoring for large operations
File Operations
Complex File Management
Archive Management
Directory Synchronization
Directory Operations
Search Operations
System Operations
Precise File Editing
The fast-filesystem MCP now includes powerful editing tools for source code and text files.
fast_edit_file - Single Block Editing
Supports multiple editing modes.
- replace: Replace text or entire lines
- replace_range: Replace multiple lines at once
- insert_before: Insert content before specified line
- insert_after: Insert content after specified line
- delete_line: Delete specific lines
{
"tool": "fast_edit_file",
"arguments": {
"path": "/path/to/file.js",
"mode": "replace",
"line_number": 10,
"new_text": "const newVariable = 'updated value';",
"backup": true
}
}
fast_edit_multiple_blocks - Batch Editing
Edit multiple parts of a file in a single operation.
{
"tool": "fast_edit_multiple_blocks",
"arguments": {
"path": "/path/to/file.js",
"edits": [
{
"mode": "replace",
"old_text": "oldFunction()",
"new_text": "newFunction()"
},
{
"mode": "insert_after",
"line_number": 5,
"new_text": "// Added comment"
}
],
"backup": true
}
}
Extract specific lines by number, range, or pattern.
{
"tool": "fast_extract_lines",
"arguments": {
"path": "/path/to/file.js",
"pattern": "function.*",
"context_lines": 2
}
}
fast_search_and_replace - Advanced Replace
Powerful search and replace with regex support.
{
"tool": "fast_search_and_replace",
"arguments": {
"path": "/path/to/file.js",
"search_pattern": "console\\.log\\(.*\\)",
"replace_text": "logger.info($1)",
"use_regex": true,
"max_replacements": 10,
"backup": true
}
}
Editing Features
- Automatic Backup: Creates backups before modifications
- Error Recovery: Restores from backup on failure
- Line-based Operations: Precise control over specific lines
- Pattern Matching: Regular expression support
- Batch Operations: Multiple edits in single transaction
- Context Extraction: Extract lines with surrounding context
Large File Writing
fast_large_write_file
- Streaming: Writes files in chunks to prevent memory issues
- Backup: Automatically creates backups before overwriting
- Verification: Verifies file integrity after writing
- Retry Logic: Automatic retry on failure with exponential backoff
- Progress Tracking: Real-time monitoring of write progress
License
Apache 2.0
Copyright 2025 efforthye
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Repository
https://github.com/efforthye/fast-filesystem-mcp