S3 MCP Server

Python module to download objects in an S3 bucket.

Local serverstdioPython

What is the S3 MCP server?

Most file and storage access work still happens through a UI a human drives. S3 MCP server moves it into the conversation instead. Python module to download objects in an S3 bucket.

The short version

Styling conventions: PEP 8

The tools it exposes

The server publishes 2 tools. What each one is for:

  • Installation — The Installation tool exposed by this server
  • Usage — The Usage tool exposed by this server

What it needs from you

Configuration is passed through the environment: AWS_DEFAULT_REGION, AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY. Treat anything key-shaped as a real credential — scope it to the minimum the server needs, and rotate it if it ever lands in a shared config.

Getting it running

The server ships on PyPI as s3-downloader, so your MCP client can launch it on demand — there is no separate build step. Add the server block to your client's configuration, restart it, and the tools register themselves.

How it compares

This sits in the file and storage access group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. S3's toolset — Installation, Usage — is a fair guide to whether it matches your workflow.

We check each listing at SyncDev against the project's documentation before it goes live — if something here drifts out of date, it is a bug worth reporting.

Things to watch

  • It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
  • Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
  • Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.

Available tools

ToolWhat it does
InstallationThe Installation tool exposed by this server.
UsageThe Usage tool exposed by this server.

How to install the S3 MCP server

{
  "mcpServers": {
    "s3-downloader": {
      "command": "uvx",
      "args": ["s3-downloader"],
      "env": {
        "AWS_DEFAULT_REGION": "your-value",
        "AWS_ACCESS_KEY_ID": "your-value",
        "AWS_SECRET_ACCESS_KEY": "your-value"
      }
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Configuration

VariableDescriptionRequired
AWS_DEFAULT_REGIONConfiguration value read at startup.Optional
AWS_ACCESS_KEY_IDCredential the server authenticates with.Yes
AWS_SECRET_ACCESS_KEYCredential the server authenticates with.Yes

Example prompts to try

  • Use S3 to Installation.
  • Use S3 to Usage.

Frequently asked questions

It connects S3 to MCP-compatible AI assistants such as Claude and Cursor, exposing 2 tools (Installation, Usage) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with S3 directly.