mcp-server-s3

Manage AWS S3 buckets and objects from your AI assistant. Browse files, upload and download content, and generate presigned URLs.

npx mcp-server-s3

Works with Claude Desktop, Cursor, VS Code Copilot, and any MCP client. Uses your existing AWS credentials (~/.aws/credentials or environment variables).

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Why

S3 is the most widely used cloud storage service, but managing it from the command line means remembering aws s3 ls, aws s3 cp, presigned URL syntax, and various flags. Google has an official MCP for GCS, Cloudflare has one for R2, but AWS S3 doesn't have a polished standalone MCP server on npm. This one lets you ask your assistant to list buckets, download a config file, upload content, or generate a temporary sharing link. It uses the standard AWS credential chain, so if your CLI already works, this works too.

Tools

Tool	What it does
list_buckets	List all S3 buckets in your AWS account.
list_objects	List objects in a bucket, with optional prefix filter.
get_object	Download and read an object's content as text.
put_object	Upload text content to an S3 object.
delete_object	Delete an object from a bucket.
presigned_url	Generate a temporary presigned URL for an object.
bucket_info	Check if a bucket exists and get basic info.

Quick Start

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "s3": {
      "command": "npx",
      "args": ["mcp-server-s3"],
      "env": {
        "AWS_REGION": "us-east-1",
        "AWS_ACCESS_KEY_ID": "your-access-key",
        "AWS_SECRET_ACCESS_KEY": "your-secret-key"
      }
    }
  }
}

Claude Desktop

Add to claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "s3": {
      "command": "npx",
      "args": ["mcp-server-s3"],
      "env": {
        "AWS_REGION": "us-east-1",
        "AWS_ACCESS_KEY_ID": "your-access-key",
        "AWS_SECRET_ACCESS_KEY": "your-secret-key"
      }
    }
  }
}

VS Code

Configure the MCP server to run npx mcp-server-s3 with AWS_REGION, AWS_ACCESS_KEY_ID, and AWS_SECRET_ACCESS_KEY in the environment.

Authentication

The server uses the standard AWS credential chain:

1. Environment variables: AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_REGION
2. Shared credentials file: ~/.aws/credentials
3. IAM roles: when running on EC2, ECS, Lambda, or similar

Set AWS_REGION (defaults to us-east-1) and make sure your credentials have the necessary S3 permissions: s3:ListBuckets, s3:ListBucket, s3:GetObject, s3:PutObject, s3:DeleteObject, s3:HeadBucket.

Example prompts

• "List all my S3 buckets"
• "Show me the files in my-bucket/uploads/"
• "Download the config.json from my-bucket"
• "Upload this content to my-bucket/notes.txt"
• "Generate a presigned URL for this file that expires in 1 hour"

Development

npm install
npm run typecheck
npm run build
npm test
npm run format
npm run lint

See also

More MCP servers and developer tools on my portfolio.

Author

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License

MIT © 2026 Ofer Shapira