Running mcp-sim as a service

mcp-sim service installs mcp-sim as a native background service, managed by
whichever OS it runs on:

• macOS → launchd
• Linux → systemd (or SysV/Upstart as fallback)
• Windows → Windows Service

Install and manage

mcp-sim service install --listen :9090 --config ~/.config/mcp-sim/config.yaml
mcp-sim service start
mcp-sim service status
mcp-sim service stop
mcp-sim service restart
mcp-sim service uninstall

--listen and --config are only read at install time — they’re recorded
as the arguments the OS service manager passes to the hidden
mcp-sim service run entry point it invokes on every start.

Installing system-wide requires elevated privileges (sudo on macOS/Linux, an
elevated shell on Windows). To skip that on macOS/Linux, install a per-user
service instead (LaunchAgent / systemd --user, no root needed):

mcp-sim service install --user --listen :9090
mcp-sim service start

Windows Service install always needs elevation — there’s no per-user
equivalent on that OS.

Manual launchd customization (macOS)

If you’d rather manage the launchd plist yourself instead of using
mcp-sim service install, create
~/Library/LaunchAgents/com.espetro.mcp-sim.plist:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>
  <string>com.espetro.mcp-sim</string>
  <key>ProgramArguments</key>
  <array>
    <string>/usr/local/bin/mcp-sim</string>
    <string>serve</string>
    <string>--listen</string>
    <string>:9090</string>
  </array>
  <key>RunAtLoad</key>
  <true/>
  <key>KeepAlive</key>
  <true/>
  <key>StandardOutPath</key>
  <string>/usr/local/var/log/mcp-sim.log</string>
  <key>StandardErrorPath</key>
  <string>/usr/local/var/log/mcp-sim.log</string>
</dict>
</plist>

Load the service:

mkdir -p /usr/local/var/log
launchctl load ~/Library/LaunchAgents/com.espetro.mcp-sim.plist

Using Homebrew services

If installed via Homebrew:

brew services start mcp-sim
brew services stop mcp-sim
brew services restart mcp-sim

Logs: brew services log mcp-sim