# Workers and cron jobs A worker is an app that runs one command as its process and has no address. A cron app runs one command on a schedule. Both are apps: Astris builds them from a Git repository, like a web app. For the other app commands, see [Apps](/docs/apps). ## Create a worker The MCP tool `deploy` takes `kind` set to `worker` and a `command`. With the CLI, add these flags to `astris deploy`: - `--kind worker` - `--command ` ``` astris deploy --project --name --git-url --branch --kind worker --command ``` A worker has no address. ## Create a cron app The MCP tool `deploy` takes `kind` set to `cron`, a `command` and a `schedule`. With the CLI, add `--kind cron`, `--command ` and `--schedule `. ``` astris deploy --project --name --git-url --branch --kind cron --command --schedule ``` The schedule has five fields, separated by one space, for example `0 3 * * *`. A cron app keeps running, and the schedule runs the command inside it. ## Rules - A command has 1 to 512 characters, with no line break. - A schedule has at most 100 characters. Each field holds only digits and the characters `*`, `,`, `-` and `/`. - A worker needs a command and takes no schedule. A cron app needs both. - A worker or a cron app cannot use `--build static`. - The kind, the command and the schedule are set when you create the app. - A worker or a cron app has no address. Adding a domain to it is refused with [bad_request](/docs/errors/bad_request): `This app does not serve a website, so it cannot have a domain.` The CLI refuses a call that breaks a rule and sends nothing. The API refuses it with [bad_request](/docs/errors/bad_request). ## Your plan's pool A worker or a cron app counts against your plan's pool like any app: the memory it is given, and the same share of CPU and disk. See [Usage](/docs/usage). A new app that does not fit is refused with [upgrade_required](/docs/errors/upgrade_required).