Gemini CLI

Gemini CLI is Google's open-source terminal agent. It uses a standard mcpServers configuration identical to Claude Desktop.

Prerequisites

• Gemini CLI installed. For more information, see the Gemini CLI repository
• The ionoscloud-mcp binary built and available. For more information, see Quick Start
• An IONOS CLOUD API token. For least-privilege access, see Authentication to scope the token to only the tools you need.

Add the MCP server

Open or create the Gemini CLI settings file:

• macOS / Linux: ~/.gemini/settings.json
• Windows: %USERPROFILE%\.gemini\settings.json

For a project-scoped config, use .gemini/settings.json in your project root.

Add the following entry to the mcpServers object:

{
  "mcpServers": {
    "ionoscloud": {
      "command": "/usr/local/bin/ionoscloud-mcp",
      "env": {
        "IONOS_TOKEN": "your-api-token"
      }
    }
  }
}

To also enable Object Storage tools:

{
  "mcpServers": {
    "ionoscloud": {
      "command": "/usr/local/bin/ionoscloud-mcp",
      "env": {
        "IONOS_TOKEN": "your-api-token",
        "IONOS_S3_ACCESS_KEY": "your-access-key",
        "IONOS_S3_SECRET_KEY": "your-secret-key"
      }
    }
  }
}

Note: Gemini CLI only passes environment variables that are explicitly listed in the env block to the MCP server process; Gemini CLI does not inherit system environment variables automatically.

Verify the connection

1

Start Gemini CLI

gemini

2

Test the connection

Type: List my IONOS CLOUD data centers.

Result: Gemini CLI calls list_datacenters and returns your data centers.

Note: All tools are registered at startup by default, so Compute Engine and Object Storage tools appear immediately. To reduce the startup tool count (for example, on clients with a tool-count cap), set IONOS_MCP_LOAD_MODE=lazy in the env block and call the ionos_load_compute_tools or ionos_load_objectstorage_tools sentinels on demand. For more information, see Selective Tool Loading.

For full Gemini CLI MCP documentation, see MCP servers with the Gemini CLI.