Backblaze B2 MCP Server

A Model Context Protocol (MCP) server that provides seamless integration with Backblaze B2 cloud storage. Built as a wrapper around the backblaze-b2 npm package, this server enables MCP clients like Claude Desktop, VS Code, and Cursor to interact with your B2 buckets and files.

Features

Bucket Management - Create, delete, list, and update buckets
File Operations - Upload, list, hide, and delete files
Large File Support - Multipart uploads for files >100MB
Key Management - Manage application keys and permissions
Simple Setup - Just configure your B2 credentials in MCP config

Configuration

Get B2 Credentials

Sign up at Backblaze B2
Go to App Keys in your account
Create a new application key
Copy the keyID and applicationKey

MCP Client Setup

Add this configuration to your MCP client:

Claude Desktop (~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "backblaze-b2": {
      "command": "npx",
      "args": ["backblaze-mcp"],
      "env": {
        "B2_APPLICATION_KEY_ID": "your_key_id_here",
        "B2_APPLICATION_KEY": "your_application_key_here"
      }
    }
  }
}

VS Code/Cursor (.vscode/mcp.json):

{
  "servers": {
    "backblaze-b2": {
      "command": "npx",
      "args": ["backblaze-mcp"],
      "env": {
        "B2_APPLICATION_KEY_ID": "your_key_id_here",
        "B2_APPLICATION_KEY": "your_application_key_here"
      }
    }
  }
}

Available Tools

Bucket Management (5 tools)

createBucket - Create a new bucket
deleteBucket - Delete a bucket
listBuckets - List all buckets
getBucket - Get bucket info
updateBucket - Change bucket type (public/private)

File Operations (7 tools)

getUploadUrl - Get upload URL
uploadFile - Upload a file (base64-encoded)
listFileNames - List files in a bucket
listFileVersions - List all file versions
hideFile - Hide a file from listings
getFileInfo - Get file metadata
deleteFileVersion - Delete a file version
getDownloadAuthorization - Get download auth token

Large File Operations (5 tools)

For files >100MB:

startLargeFile - Start large file upload
getUploadPartUrl - Get part upload URL
uploadPart - Upload a file part
listParts - List uploaded parts
finishLargeFile - Complete the upload
cancelLargeFile - Cancel the upload

Key Management (3 tools)

createKey - Create application keys
deleteKey - Delete a key
listKeys - List all keys

Usage Examples

Upload a File

1. Call getUploadUrl with your bucketId
2. Encode your file to base64
3. Call uploadFile with the URL, token, filename, and base64 data

Large File Upload

1. Call startLargeFile to get a fileId
2. Split file into parts and upload each with uploadPart
3. Call finishLargeFile with SHA1 hashes of all parts

Development

Build from Source

git clone https://github.com/braveram/backblaze-mcp.git
cd backblaze-mcp
npm install
npm run build

Binary Data

File uploads use base64 encoding:

Encode your file to base64 before calling uploadFile or uploadPart
The server handles the conversion to binary for B2

Troubleshooting

Server won't start

Check that B2_APPLICATION_KEY_ID and B2_APPLICATION_KEY are set in your MCP config
Verify credentials are valid in the B2 console

Upload fails

Ensure data is properly base64-encoded
Check bucket permissions
Use large file operations for files >100MB

Built With

backblaze-b2 - Backblaze B2 client
@modelcontextprotocol/sdk - MCP SDK

License

MIT