How to Give Google Antigravity Direct SSH Access to Remote Servers (Proxmox & Linux)

Figure 1: Architectural flow — Antigravity Agent communicating over the Model Context Protocol to execute privileged remote operations with masked credentials.

1. The Architecture of AI Agent Remote Access

Before deploying remote execution capabilities, software engineers must understand the underlying trust boundaries. Traditional interactive terminal sessions require a human engineer to authenticate via biometrics, passphrase-protected keys, or two-factor hardware tokens. In contrast, an AI agent operates autonomously in request-response cycles.

2. Step 1: Generate a Dedicated Ed25519 Key Pair

Open a terminal on your host machine (macOS / Linux). We generate an elliptic-curve Ed25519 key pair with zero passphrase (-N ""), enabling non-interactive authentication for the MCP background process:

# Generate dedicated, passphrase-less Ed25519 key for Antigravity
ssh-keygen -t ed25519 -N "" -f ~/.ssh/ag_proxmox -C "ag_proxmox"

# Enforce strict local filesystem permissions (Owner Read/Write only)
chmod 600 ~/.ssh/ag_proxmox
chmod 644 ~/.ssh/ag_proxmox.pub

This command creates two discrete files within your local ~/.ssh/ directory:

• ~/.ssh/ag_proxmox: The private key that stays securely stored on your local machine and is referenced only by the MCP configuration.
• ~/.ssh/ag_proxmox.pub: The public key that will be authorized on the target remote server.

3. Step 2: Authorize the Public Key on Your Remote Server

Next, append the public key to the remote server's authorized_keys list. If your workstation has direct network connectivity to the remote target (e.g., a local Proxmox VE node at 192.168.0.***), use ssh-copy-id:

# Install the public key directly to your remote server
ssh-copy-id -i ~/.ssh/ag_proxmox.pub [email protected].***

Alternatively, if you are logged into your remote server's web shell or serial console, append the public key string manually and ensure strict permissions:

# On the remote server (e.g. Proxmox / Ubuntu)
mkdir -p ~/.ssh
chmod 700 ~/.ssh

# Append your masked public key
echo "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAI...[REDACTED_PUBLIC_KEY]... ag_proxmox" >> ~/.ssh/authorized_keys
chmod 600 ~/.ssh/authorized_keys

4. Step 3: Configure the SSH MCP Server (`ssh-mcp-config.json`)

To bridge Google Antigravity to the remote server, we deploy the open-source @uarlouski/ssh-mcp-server daemon. Create a dedicated configuration file at ~/.gemini/config/ssh-mcp-config.json:

{
  "servers": {
    "proxmox": {
      "host": "192.168.0.***",
      "port": 22,
      "username": "root",
      "privateKeyPath": "~/.ssh/ag_proxmox"
    },
    "vps-production": {
      "host": "10.0.0.***",
      "port": 2222,
      "username": "deploy",
      "privateKeyPath": "~/.ssh/ag_proxmox",
      "allowedCommands": [
        "uptime",
        "free -m",
        "df -h",
        "docker ps",
        "systemctl status nginx"
      ]
    }
  },
  "commandTimeout": 30000
}

5. Step 4: Register the MCP in Google Antigravity (`mcp_config.json`)

Now, register the server inside Antigravity's master Model Context Protocol configuration located at ~/.gemini/config/mcp_config.json:

{
  "mcpServers": {
    "ssh": {
      "command": "npx",
      "args": [
        "-y",
        "@uarlouski/ssh-mcp-server@latest",
        "--configPath=/Users/<USERNAME>/.gemini/config/ssh-mcp-config.json"
      ]
    }
  }
}

6. Step 5: Real-World Execution Scenarios

With the bridge established, Antigravity has native tool calls to query and administer remote servers directly from the chat window.

E: Failed to fetch https://enterprise.proxmox.com/debian/pve/... 401 Unauthorized [IP: 192.168.0.***]

7. Production Hardening & Security Checklist

Before deploying agentic SSH capabilities across mission-critical corporate infrastructure, review the following security guidelines:

• Dedicated Service User: Create an isolated user account (e.g., antigravity) rather than authorizing keys directly for root. Grant selective sudoers permissions in /etc/sudoers.d/antigravity.
• Network Isolation: Restrict inbound SSH traffic to your administrative VPN or private overlay network (Tailscale / WireGuard), ensuring port 22 is never exposed directly to the public internet.
• Session Audit Logging: Configure system-wide auditd or shell command logging (pam_tty_audit.so) to maintain an immutable record of every instruction executed by the AI agent.
• Data Redaction: When reviewing AI transcripts, ensure public IP addresses, private subnets, and customer tokens are masked.