2.5 -- Node.js and PM2

Context

OpenClaw is written in Node.js. PM2 is a process manager that keeps OpenClaw running, manages logs, and automatically restarts on crash.

Install Node.js via nvm (Node Version Manager), not via apt. Why: apt often provides an outdated version, and nvm allows you to switch versions easily.

Step 1: Install nvm

$ curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/master/install.sh | bash

Reload the shell:

$ source ~/.bashrc

Verify:

$ nvm --version

Step 2: Install Node.js

Install the LTS (Long Term Support) version:

$ nvm install --lts
$ nvm alias default lts/*

Verify:

$ node --version
$ npm --version

Expected version: Node.js 22.x or higher (LTS at the time of writing).

Step 3: Install PM2

$ npm install -g pm2

Verify:

$ pm2 --version

Step 4: Configure PM2 for automatic startup

PM2 can restart automatically when the server reboots:

$ pm2 startup

This command displays a line to copy and paste (it starts with sudo env PATH=...). Execute it.

Then save the current list of processes (empty for now):

$ pm2 save

Why PM2 and not systemd directly?

PM2 provides features specific to Node.js:

• Automatic restart on crash with exponential backoff
• Built-in log management (pm2 logs)
• Memory/CPU monitoring (pm2 monit)
• Cluster mode to use all CPUs
• Zero-downtime reload (pm2 reload)
• Configuration ecosystem via ecosystem.config.js

systemd will be used for the gateway (section 15), but PM2 manages Node.js application processes.

Common errors

• Installing Node.js via apt: The version will be too old. Uninstall it (sudo apt remove nodejs) and use nvm.
• "nvm: command not found" after installation: You didn't reload the shell. Run source ~/.bashrc or open a new terminal.
• PM2 installed locally instead of globally: Make sure you use npm install -g pm2 (with the -g).
• PM2 startup doesn't work: Make sure to execute the sudo command displayed by pm2 startup, don't just run pm2 startup with sudo.

Verification

$ node --version
$ npm --version
$ pm2 --version
$ pm2 list

Expected results: - Node.js v22.x+ - npm v10.x+ - PM2 v5.x+ - PM2 list empty (no processes yet)

Estimated time

10 minutes.