How to Fix OpenClaw 502 Bad Gateway Errors

# Check if OpenClaw is running:
systemctl status openclaw
ps aux | grep openclaw

# Test direct access (bypassing proxy):
curl http://localhost:3000/health
# If this fails, OpenClaw isn't running
# If this works, the problem is in the proxy config

# Check which port OpenClaw is using:
netstat -tuln | grep LISTEN | grep openclaw
# Or:
lsof -i -P | grep openclaw
# Note the port (e.g., :3000)

# Check nginx config:
sudo nano /etc/nginx/sites-available/openclaw
# Verify this line matches OpenClaw port:
proxy_pass http://localhost:3000;

# Check Caddy config:
sudo nano /etc/caddy/Caddyfile
# Verify:
reverse_proxy localhost:3000

# Nginx error log:
sudo tail -f /var/log/nginx/error.log
# Look for:
# - "Connection refused" (wrong port or process down)
# - "upstream timed out" (timeout too short)
# - "no live upstreams" (all backends dead)

# Caddy error log:
sudo journalctl -u caddy -f --no-pager

# Apache error log:
sudo tail -f /var/log/apache2/error.log

# For nginx, edit site config:
sudo nano /etc/nginx/sites-available/openclaw
# Add these to location block:
proxy_read_timeout 300s;
proxy_connect_timeout 75s;
proxy_send_timeout 300s;

# For Caddy, add to reverse_proxy directive:
reverse_proxy localhost:3000 {
  transport http {
    read_timeout 300s
    write_timeout 300s
  }
}

# Reload config:
sudo systemctl reload nginx
# or:
sudo systemctl reload caddy

# Nginx SSL proxy config should include:
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;

# For websockets (if OpenClaw uses them):
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";

# Verify SSL cert is valid:
sudo certbot certificates
# Renew if expired:
sudo certbot renew

# SSH tunnel to access OpenClaw directly:
ssh -L 3000:localhost:3000 user@your-server.com
# Then browse to http://localhost:3000

# Or temporarily allow direct access:
sudo ufw allow 3000/tcp
curl http://your-server-ip:3000/health

# If direct access works:
# - Problem is proxy config
# If direct access fails:
# - Problem is OpenClaw itself (see not-responding guide)

# Close firewall after testing:
sudo ufw delete allow 3000/tcp