File Watching

pm3 can watch your source files and automatically restart a process when changes are detected — perfect for development workflows.

Configuration

Watch the Working Directory

[web]
command = "node server.js"
watch = true

When watch = true, pm3 watches the process's working directory (cwd, or the directory containing pm3.toml).

Watch a Specific Path

[web]
command = "node server.js"
watch = "./src"

You can specify a relative path to watch only a subdirectory.

Ignore Patterns

[web]
command = "node server.js"
watch = "./src"
watch_ignore = ["node_modules", ".git", "dist", "*.log"]

Debounce Duration

[web]
command = "node server.js"
watch = "./src"
watch_debounce = 1000

Type: integer (milliseconds) | Default: 500

Controls how long pm3 waits after detecting a file change before triggering a restart. Increase this if rapid successive saves cause too many restarts.

Type: array of strings

Patterns in watch_ignore are matched against directory names and path suffixes. Common patterns to ignore:

• "node_modules" — Node.js dependencies
• ".git" — Git internals
• "dist" or "build" — build output
• "*.log" — log files

Behavior

• Debounce: File change events are debounced (default: 500ms, configurable via watch_debounce). Multiple rapid changes trigger only one restart.
• Restart: When a change is detected, pm3 performs a graceful restart of the process (sends kill_signal, waits kill_timeout, then respawns).
• Restart counter: File-watch restarts do not count toward max_restarts.

Example

[frontend]
command = "npm run dev"
cwd = "./frontend"
watch = "./src"
watch_ignore = ["node_modules", ".git"]
watch_debounce = 1000

[api]
command = "cargo run"
cwd = "./api"
watch = "./src"