Bifrost

Persistent SSH connection plugin for OpenCode.

Bifrost maintains a single SSH connection using ControlMaster multiplexing, so every command reuses the same connection instead of reconnecting each time.

Installation

1. Register the plugin

Add to your ~/.config/opencode/opencode.json:

{
  "plugins": [
    "opencode-bifrost@latest"
  ]
}

2. Create the SSH config

Create ~/.config/opencode/bifrost.json:

{
  "host": "your-server-ip",
  "user": "root",
  "keyPath": "~/.ssh/id_rsa"
}

| Field | Required | Default | Description | |-------|----------|---------|-------------| | host | Yes | - | Server IP or hostname | | user | No | root | SSH username | | keyPath | Yes | - | Path to SSH private key | | port | No | 22 | SSH port |

Note: Password authentication is not supported. Use SSH keys only.

3. Restart OpenCode

The plugin is installed automatically on startup.

Usage

Once configured, the agent automatically uses Bifrost when you mention:

• "server", "remote", "deploy", "production", "staging"
• "check the server", "run on server", "server logs"

Available Tools

| Tool | Description | |------|-------------| | bifrost_connect | Establish SSH connection (called automatically) | | bifrost_exec | Run a command on the server | | bifrost_status | Check connection status | | bifrost_disconnect | Close the connection | | bifrost_upload | Upload a file to the server | | bifrost_download | Download a file from the server |

Example Prompts

"How's the server doing?"
"Show me the nginx logs"
"Restart the docker containers"
"Upload config.yaml to /etc/app/"
"What's using port 8080?"

How It Works

Bifrost uses SSH ControlMaster to maintain a persistent connection:

First command:  [Connect] -----> [Execute] -----> [Keep socket open]
Next commands:  [Reuse socket] -> [Execute] -----> [Still open]
Session ends:   [Auto-disconnect]

The control socket is stored at ~/.ssh/bifrost-control/.

Security

All inputs are validated before execution to prevent injection attacks:

• Path traversal (../) blocked
• Command injection (;, |, &, `, $()) blocked
• Shell expansion (*, ?, ~, {}) blocked
• Unicode bypass attempts detected and rejected
• Null bytes and control characters rejected

Requirements

• OpenCode with plugin support
• SSH key-based authentication

Development

# Run tests
bun test

# Type check
bun run typecheck

# Build
bun run build

License

MIT