HostLink Skill#

Execute commands on the host machine from inside this container.

Quick Reference#

bash

# Execute a command on the host
hostlink exec "ls /home/jebadiah"

# Ping the daemon (connection test)
hostlink ping

# With explicit socket/token (if env vars not set)
hostlink -s /run/hostlink/hostlink.sock -k $HOSTLINK_TOKEN exec "echo hello"

# Set working directory
hostlink -w /home/jebadiah exec "pwd"

# Set environment variables
hostlink -e MY_VAR=value exec "echo $MY_VAR"

# With timeout (ms)
hostlink -T 60000 exec "long-running-command"

# JSON output (machine-readable)
hostlink -j exec "ls -la" | python3 -c "import sys,json; d=json.load(sys.stdin); print(d['stdout'])"

# List configured targets
hostlink targets

Environment Variables#

Set these so you don't need to pass flags every time:

VariablePurposeDefaultHOSTLINK_SOCKETUnix socket path/run/hostlink/hostlink.sock``HOSTLINK_TOKENAuth token(required)HOSTLINK_TARGETTarget node name(optional)

Best place to set these: workspace/.env or openclaw.json env.vars section.

Connection Status#

Check if hostlinkd is reachable:

bash

hostlink ping
# Expected: [hostname] pong - uptime Xs
# If error: daemon not running or socket not mounted

Common Use Cases#

Access host filesystem#

bash

hostlink exec "ls /home/jebadiah/projects"
hostlink exec "cat /etc/hostname"

Run host-side GPU/ML tools#

bash

hostlink exec "nvidia-smi"
hostlink exec "ollama list"
hostlink exec "ls ~/.cache/huggingface/hub"

Access the Qwen3 merge project#

bash

hostlink exec "ls /path/to/qwen3-merge"
hostlink exec "cat /path/to/qwen3-merge/README.md"

Docker management on host#

bash

hostlink exec "docker ps"
hostlink exec "docker stats --no-stream"

Exit Codes#

CodeMeaning0Success1Remote command failed (check exit_code in JSON output)2Connection failed (daemon unreachable)3Authentication failed (wrong token)5Timeout7Client error (bad args, missing targets file)

Troubleshooting#

"Connection failed" / exit 2:

• hostlinkd not running on host: sudo systemctl start hostlinkd
• Socket not mounted: check docker-compose volume mount
• Wrong socket path: check HOSTLINK_SOCKET env var

"Authentication failed" / exit 3:

• Wrong HOSTLINK_TOKEN — must match auth_token in /etc/hostlink/hostlink.conf

"server busy" error:

• Host is at max_concurrent limit — retry shortly

Architecture#

text

Container (you are here)          Host machine
┌─────────────────────┐          ┌──────────────────────────┐
│  hostlink (client)  │◄────────►│  hostlinkd (daemon)      │
│  workspace/bin/     │  Unix    │  /etc/hostlink/           │
│                     │  socket  │  auth_token = <secret>    │
└─────────────────────┘          │  shell = /bin/bash        │
                                 └──────────────────────────┘

See references/setup.md for installation and docker-compose configuration.