Backblaze B2 MCP Server

What the code does

We read the source, 5 d ago · rules 995398eba69f

What this server is able to do. For an MCP server this is often the job itself — a terminal server runs commands because that is what it is for. Listed so you know what you are plugging in, not as an accusation.

  const at = (name: string) => (pinnedDir ? atDirFd(pinnedDir.fd, name) : path.join(dir, name));

Found in continuous integration, deployment or infrastructure files, or in a neighbouring package of the same monorepo. None of this is installed when you add the server: it describes how the project is built and released. We list it because a leaked key in a build pipeline is still a real problem, but it is not something this server does on your machine.

  const credentialEnvPresent = Object.entries(process.env).some(

Is this your server and something here is wrong? Tell us — corrections are free and do not require a plan.

Connect this server

This server runs on your own machine — install it with the package manager and the client starts it for you. Package name taken from the official registry entry.

claude mcp add b2-mcp -e 'B2_APPLICATION_KEY_ID=<B2_APPLICATION_KEY_ID>' -e 'B2_APPLICATION_KEY=<B2_APPLICATION_KEY>' -- npx -y @backblaze-labs/b2-mcp

{
  "mcpServers": {
    "b2-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@backblaze-labs/b2-mcp"
      ],
      "env": {
        "B2_APPLICATION_KEY": "<B2_APPLICATION_KEY>",
        "B2_APPLICATION_KEY_ID": "<B2_APPLICATION_KEY_ID>"
      }
    }
  }
}

[mcp_servers.b2-mcp]
command = "npx"
args = ["-y", "@backblaze-labs/b2-mcp"]
env = { B2_APPLICATION_KEY_ID = "<B2_APPLICATION_KEY_ID>", B2_APPLICATION_KEY = "<B2_APPLICATION_KEY>" }

{
  "mcpServers": {
    "b2-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@backblaze-labs/b2-mcp"
      ],
      "env": {
        "B2_APPLICATION_KEY": "<B2_APPLICATION_KEY>",
        "B2_APPLICATION_KEY_ID": "<B2_APPLICATION_KEY_ID>"
      }
    }
  }
}

{
  "servers": {
    "b2-mcp": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@backblaze-labs/b2-mcp"
      ],
      "env": {
        "B2_APPLICATION_KEY": "<B2_APPLICATION_KEY>",
        "B2_APPLICATION_KEY_ID": "<B2_APPLICATION_KEY_ID>"
      }
    }
  }
}

Put your own values in place of <B2_APPLICATION_KEY_ID> (Backblaze B2 application key ID for native B2 and S3-compatible tools), <B2_APPLICATION_KEY> (Backblaze B2 application key secret). The author’s registry entry marks them as required.

Optional settings from the registry entry, left out of the block above: B2_REGION (Optional fallback S3-compatible region used before authorization), B2_MASTER_KEY_ID (Optional master key ID for Partner/Groups API tools), B2_MASTER_KEY (Optional master key secret for Partner/Groups API tools).