📂 MCP File Server

MCP File Server is a secure, sandboxed file server providing controlled access to filesystem operations via the Model Control Protocol (MCP). It supports reading, writing, listing, creating, and deleting files and directories within a configurable working directory while enforcing strict security checks. Git operations are also available for repositories in the working directory.

Table of Contents

• Features
• Installation & Quick Start
• Command‑Line Options
• Integration with LM Studio
• MCP API Overview
  • initialize
  • tools/list
  • tools/call
• Available Tools
  • File Operations
    • read_file
    • write_file
    • list_files
    • create_directory
    • delete_file
    • delete_directory
    • search_in_file
  • Git Operations
    • git_status
    • git_log
    • git_checkout
    • git_branch_create
    • git_branch_delete
    • git_branch_list
    • git_add
    • git_commit
    • git_push
    • git_pull
    • git_diff
    • git_clone
    • git_submodule_add
    • git_submodule_update
    • git_submodule_list
• Security Features

🎯 Features

• Sandboxed operations – all paths are confined to a user‑specified working directory.
• Path traversal protection, file‑size limits, and blocked extensions.
• Binary support via Base64 encoding for safe transport of non‑text data.
• Git operations (status, log, branches, commit/push/pull) for repositories in the working directory.
• Simple line‑delimited JSON‑RPC protocol suitable for stdin/stdout integration.
• Ready‑to‑use with LM Studio through a minimal mcp.json configuration.

📦 Installation & Quick Start

# Clone the repository (if not already done)
git clone https://github.com/undici77/MCPFileServer.git
cd MCPFileServer

# Ensure git is installed on your system (required for git operations)
git --version

# Run the startup script – it creates a virtual environment,
# installs dependencies, and starts the server.
./run.sh -d /path/to/working/directory

The script will:

• Verify that Python 3 is available.
• Create a .venv virtual environment (if missing).
• Install required packages (aiofiles).
• Start main.py with the supplied working directory.

📌 Note for Git Operations: The git operations use Python's subprocess to call the system git CLI. Git must be installed and available in your PATH.

📌 Tip: Ensure the script has execution permission: chmod +x run.sh

⚙️ Command‑Line Options

Option	Description
-d, --directory	Path to the working directory. If omitted, the server uses the current process directory. The directory must exist and be readable/writable.

🤝 Integration with LM Studio

Add an entry for the file server in your project's mcp.json:

{
  "mcpServers": {
    "file-server": {
      "command": "/absolute/path/to/MCPFileServer/run.sh",
      "args": [
        "-d",
        "/absolute/path/to/working/directory"
      ],
      "env": {
        "WORKING_DIR": "."
      }
    }
  }
}

• Replace the paths with absolute locations on your machine.
• Ensure run.sh is executable (chmod +x run.sh) and dependencies are installed.

📡 MCP API Overview

All communication follows JSON‑RPC 2.0 over stdin/stdout.

initialize

Sent by the client to obtain server capabilities.

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "initialize",
  "params": {}
}

The server responds with protocol version, capabilities, and its name/version.

tools/list

Retrieves a machine‑readable list of supported tools.

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/list",
  "params": {}
}

The response contains an array of tool definitions (name, description, input schema).

tools/call

Invokes a specific tool.

{
  "jsonrpc": "2.0",
  "id": 3,
  "method": "tools/call",
  "params": {
    "name": "<tool_name>",
    "arguments": { … }
  }
}

Note: The key for the tool name is **name**, not tool. This matches the server implementation.

🛠️ Available Tools

File Operations

Tool	Description
read_file	Read a file's contents (text or binary).
write_file	Write text or Base64‑encoded binary data to a file.
list_files	List files and directories with optional filtering.
create_directory	Create a new sub‑directory (parents created as needed).
delete_file	Delete a single file.
delete_directory	Remove a directory; optionally force deletion of non‑empty trees.
search_in_file	Search for a string in a file or recursively in a directory, returning contextual excerpts.

read_file

Read the contents of a file inside the working directory. Parameters

Name	Type	Required	Description
path	string	✅	Relative path to the target file.
binary	boolean	❌ (default: false)	Set to true to read the file as binary; the result is Base64‑encoded.

Example

{
  "method": "tools/call",
  "params": {
    "name": "read_file",
    "arguments": {
      "path": "example.txt",
      "binary": false
    }
  }
}

write_file

Write content to a file (creating intermediate directories if needed). Parameters

Name	Type	Required	Description
path	string	✅	Relative path of the target file.
content	string	✅	Text to write, or Base64‑encoded binary data when binary=true.
binary	boolean	❌ (default: false)	Set to true to treat content as Base64‑encoded binary.

Example

{
  "method": "tools/call",
  "params": {
    "name": "write_file",
    "arguments": {
      "path": "output.txt",
      "content": "Hello, world!",
      "binary": false
    }
  }
}

list_files

List files and directories under the working directory. Parameters

Name	Type	Required	Description
extensions	array of strings	❌	Filter by file extensions (e.g., [".py", ".txt"]). If omitted, all files are listed.
recursive	boolean	❌ (default: true)	Search sub‑directories recursively when true.
show_empty_dirs	boolean	❌ (default: true)	Include directories that contain no matching files.

Example

{
  "method": "tools/call",
  "params": {
    "name": "list_files",
    "arguments": {
      "extensions": [".py", ".txt"],
      "recursive": true,
      "show_empty_dirs": false
    }
  }
}

create_directory

Create a new directory (including any missing parent directories). Parameters

Name	Type	Required	Description
path	string	✅	Relative path of the directory to create.

Example

{
  "method": "tools/call",
  "params": {
    "name": "create_directory",
    "arguments": { "path": "new_folder/subfolder" }
  }
}

delete_file

Delete a file inside the working directory. Parameters

Name	Type	Required	Description
path	string	✅	Relative path of the file to delete.

Example

{
  "method": "tools/call",
  "params": {
    "name": "delete_file",
    "arguments": { "path": "temp.txt" }
  }
}

delete_directory

Delete a directory, optionally forcing removal of its contents. Parameters

Name	Type	Required	Description
path	string	✅	Relative path of the directory to delete.
force	boolean	❌ (default: false)	When true, deletes non‑empty directories recursively.

Example

{
  "method": "tools/call",
  "params": {
    "name": "delete_directory",
    "arguments": { "path": "old_folder", "force": true }
  }
}

search_in_file

Search for a string in a file or recursively in all files within a directory, returning contextual excerpts. Parameters

Name	Type	Required	Description
path	string	✅	Relative path to a file or directory.
search_string	string	✅	Text to search for.
context_lines	integer	❌ (default: 3)	Number of lines before and after each match to include.
case_sensitive	boolean	❌ (default: false)	Perform a case‑sensitive search when true.
max_matches	integer	❌ (default: 50)	Maximum matches returned per file.

Example

{
  "method": "tools/call",
  "params": {
    "name": "search_in_file",
    "arguments": {
      "path": "log.txt",
      "search_string": "ERROR",
      "context_lines": 2,
      "case_sensitive": false,
      "max_matches": 10
    }
  }
}

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Git Operations

All git operations work on the working directory by default. To operate on a nested repository, use the repo_path parameter.

Tool	Description
git_status	Show the working tree status.
git_log	Show commit log history.
git_checkout	Switch to a different branch or commit.
git_branch_create	Create a new branch.
git_branch_delete	Delete a branch.
git_branch_list	List all branches in the repository.
git_add	Add file contents to the staging area.
git_commit	Record changes to the repository.
git_push	Push changes to a remote repository.
git_pull	Fetch from and integrate with a remote repository.
git_diff	Show changes between commits, commit and working tree.
git_clone	Clone a repository into a new directory.
git_submodule_add	Add a submodule to the repository.
git_submodule_update	Update existing submodules.
git_submodule_list	List all submodules in the repository.

Note: All git tools support an optional repo_path parameter to operate on a repository in a subdirectory (e.g., "repo_path": "vendor/my-repo"). When omitted, operations target the working directory directly.

git_status

Show the working tree status. Parameters

Name	Type	Required	Description
short	boolean	❌ (default: true)	Use short format output.
repo_path	string	❌	Path to repository relative to working directory (uses working directory if omitted).

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_status",
    "arguments": { 
      "short": true,
      "repo_path": "vendor/my-repo"
    }
  }
}

git_log

Show commit log history. Parameters

Name	Type	Required	Description
max_count	integer	❌ (default: 20)	Maximum number of commits to show.
oneline	boolean	❌ (default: true)	Show compact one-line format.
repo_path	string	❌	Path to repository relative to working directory (uses working directory if omitted).

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_log",
    "arguments": { 
      "max_count": 10, 
      "oneline": true,
      "repo_path": "vendor/my-repo"
    }
  }
}

git_checkout

Switch to a different branch or commit. Parameters

Name	Type	Required	Description
branch	string	✅	Branch name or commit hash to checkout.
repo_path	string	❌	Path to repository relative to working directory (uses working directory if omitted).

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_checkout",
    "arguments": { 
      "branch": "main",
      "repo_path": "vendor/my-repo"
    }
  }
}

git_branch_create

Create a new branch. Parameters

Name	Type	Required	Description
branch	string	✅	Name of the new branch.
start_point	string	❌	Starting point (branch or commit) for the new branch.

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_branch_create",
    "arguments": { 
      "branch": "feature/new-ui",
      "start_point": "main"
    }
  }
}

git_branch_delete

Delete a branch. Parameters

Name	Type	Required	Description
branch	string	✅	Name of the branch to delete.
force	boolean	❌ (default: false)	Force deletion even if branch has unmerged changes.

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_branch_delete",
    "arguments": { 
      "branch": "old-branch",
      "force": true
    }
  }
}

git_branch_list

List all branches in the repository. Parameters

Name	Type	Required	Description
all	boolean	❌ (default: false)	List both local and remote branches.

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_branch_list",
    "arguments": { "all": true }
  }
}

git_add

Add file contents to the staging area. Parameters

Name	Type	Required	Description
paths	array of strings	✅	List of file paths to add.

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_add",
    "arguments": { 
      "paths": ["src/main.py", "tests/test_main.py"] 
    }
  }
}

git_commit

Record changes to the repository. Parameters

Name	Type	Required	Description
message	string	✅	Commit message.
all	boolean	❌ (default: false)	Automatically stage all modified and deleted files.

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_commit",
    "arguments": { 
      "message": "Add new feature",
      "all": true
    }
  }
}

git_push

Push changes to a remote repository. Parameters

Name	Type	Required	Description
remote	string	❌ (default: origin)	Remote repository name.
branch	string	❌	Branch to push (defaults to current branch).

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_push",
    "arguments": { 
      "remote": "origin",
      "branch": "main"
    }
  }
}

git_pull

Fetch from and integrate with a remote repository. Parameters

Name	Type	Required	Description
remote	string	❌ (default: origin)	Remote repository name.
branch	string	❌	Branch to pull (defaults to current branch).

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_pull",
    "arguments": { 
      "remote": "origin",
      "branch": "main"
    }
  }
}

git_diff

Show changes between commits, commit and working tree. Parameters

Name	Type	Required	Description
path	string	❌	Specific file or directory to show diff for.

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_diff",
    "arguments": {
      "path": "src/main.py"
    }
  }
}

git_clone

Clone a repository into a new directory. Parameters

Name	Type	Required	Description
url	string	✅	URL of the repository to clone (HTTPS or SSH).
path	string	✅	Directory name where the repository will be cloned (relative to working directory).
branch	string	❌	Specific branch to checkout after cloning.
recursive	boolean	❌ (default: false)	Clone submodules recursively.

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_clone",
    "arguments": {
      "url": "https://github.com/owner/repo.git",
      "path": "vendor/repo",
      "branch": "main"
    }
  }
}

git_submodule_add

Add a submodule to the repository. Parameters

Name	Type	Required	Description
url	string	✅	URL of the repository to add as submodule.
path	string	✅	Path where the submodule will be placed.
name	string	❌	Name for the submodule (optional, defaults to path).

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_submodule_add",
    "arguments": {
      "url": "https://github.com/owner/lib.git",
      "path": "vendor/lib"
    }
  }
}

git_submodule_update

Update existing submodules. Parameters

Name	Type	Required	Description
init	boolean	❌ (default: true)	Initialize submodules before updating.
recursive	boolean	❌ (default: true)	Update submodules recursively.

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_submodule_update",
    "arguments": {
      "init": true,
      "recursive": true
    }
  }
}

git_submodule_list

List all submodules in the repository. Parameters

Name	Type	Required	Description
summary	boolean	❌ (default: true)	Show summary of submodule status.

Example

{
  "method": "tools/call",
  "params": {
    "name": "git_submodule_list",
    "arguments": { "summary": true }
  }
}

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🔐 Security Features

• Path traversal protection – all paths are resolved against the working directory; attempts to escape result in an error.
• Blocked extensions & sensitive filenames – files such as .exe, .bat, passwd, etc., are rejected.
• File‑size limits – reads/writes exceeding 100 MiB (MAX_FILE_SIZE) are denied.
• Null byte and dangerous pattern checks – prevent malformed input attacks.
• Git command validation – branch names and paths are validated to prevent injection attacks.

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