Per-App Options

Each app is defined as a TOML table with the hostname as the key:

["myapp.example.com"]
address = "127.0.0.1:3001"
command = "node server.js"
health_check = "/"

Options Reference

Field	Default	Description
`address`	required	Address the backend listens on (e.g. `127.0.0.1:3001`)
`command`	required	Shell command to start the app (see below)
`health_check`	required	HTTP path to check if the app is ready (e.g. `/` or `/health`)
`wait_period`	`10m`	How long to wait after the last request before killing the process
`adaptive_wait`	`false`	Enable adaptive idle timeout based on traffic patterns
`min_wait_period`	`5m`	Minimum idle timeout when `adaptive_wait` is enabled
`max_wait_period`	`30m`	Maximum idle timeout when `adaptive_wait` is enabled
`low_req_per_hour`	`12`	Request rate below which idle timeout stays at `min_wait_period`
`high_req_per_hour`	`300`	Request rate above which idle timeout stays at `max_wait_period`
`start_timeout`	`30s`	Max time to wait for the app to become healthy
`stop_timeout`	`30s`	Max time to wait for the app to stop
`cold_start_page`	`false`	Show a loading page to browser users during cold starts
`cold_start_page_path`	—	Path to a custom HTML file for the cold start page
`also_warm`	`[]`	List of other app hostnames to pre-warm when this app receives traffic
`health_check_initial_backoff_ms`	`10`	Initial retry delay for health checks (milliseconds)
`health_check_max_backoff_secs`	`2`	Maximum retry delay for health checks (seconds)

By default, command is a single string. Penny starts the process when a request arrives and kills it (SIGKILL) when the idle timeout expires:

["myapp.example.com"]
command = "node server.js"

If your app needs a graceful shutdown — for example a Docker container or a database — you can provide separate start and stop commands:

["myapp.example.com".command]
start = "docker start myapp"
end = "docker stop myapp"

When using the table form, Penny runs the end command on shutdown instead of killing the process.

Duration fields like wait_period, start_timeout, and stop_timeout accept values like: