Options

All options at a glance. Each links to the guide that explains it.

Scheduler options

new Scheduler(options). backend is required: no store is assumed. Guide: Scheduler options.

Option	Type	Default	Meaning
backend	Backend	required	Where runs are claimed and recorded
instanceId	string	hostname:pid	Name of this instance in history
name	string	none	Name decorated jobs choose this scheduler by
data	value or function	none	Data for the runs of every job, read as ctx.data
jitterMs	number	2000	Default maximum random delay before claiming
maxLateMs	number	60000	Default lateness limit
historySize	number	1000	Default runs kept per job
historyTtlMs	number	none	Default maximum age of history
timezone	string	the server’s	Default time zone for cron jobs
leaseMs	number	30000	How long a lease lasts without a heartbeat
heartbeatMs	number	5000 or leaseMs / 6	How often the lease is renewed and backups check
log	boolean	false	One log line per start, finish, failure, skip and lost run
logger	Logger	console	Where logs and unhandled errors go
unrefTimers	boolean	false	Let the process exit while timers are pending

Job options

The last argument of every(), cron() and at(). Guide: Job options.

Option	Type	Default	Lease backend only	Meaning
jitterMs	number	scheduler’s, or interval / 4 if smaller		Maximum random delay before claiming
maxLateMs	number	scheduler’s		Skip a run reached later than this
timeoutMs	number	none		Abort ctx.signal and fail the run after this long
overlap	'skip' | 'allow'	'skip'	yes	Skip a run while the previous one is going, or allow both
maxAttempts	number (1 to 100)	3	yes	Times a run may be started when runners die
catchUpMs	number	300000	yes	On start, run the latest slot if missed and due less than this ago. 0 = never
historySize	number	scheduler’s		Runs kept for this job
historyTtlMs	number	scheduler’s		Maximum age of this job’s history
data	value or function	none		Data for this job’s runs, read as ctx.data. On top of the scheduler’s
offsetMs	number	0		every() only: shifts the grid
timezone	string	scheduler’s		cron() only: IANA time zone

Constraints

Constraint	Checked when
jitterMs < half the time between runs	The job is added
maxLateMs > jitterMs	The job is added
jitterMs + maxLateMs < how long the backend remembers a run	The job is added
heartbeatMs < half of leaseMs	The scheduler is created
Interval of every() at least 1 second	The job is added

Decorator options

The options of @Every, @Cron and @At are the job options above, plus these. Guide: Decorators.

Option	Type	Default	Meaning
name	string	Class-method	The job’s name, when it isn’t the first argument
scheduler	string or Scheduler	the default scheduler	The scheduler the job goes to. A named one is created from its settings if it doesn’t exist

register() options

scheduler.register(object, options).

Option	Type	Default	Meaning
prefix	string	none	Put in front of every job name of the object
defaults	job options, with timezone	none	Job options for every job of the object. A decorator’s own options win

Scheduler.configure() options

The scheduler options above, with these differences. Reference: Decorators.

Option	Type	Default	Meaning
backend	Backend or (name) => Backend	required	The backend, or a function that returns one for a scheduler’s name
autoStart	boolean	false	Start the scheduler when it is created

stop() options

Option	Type	Default	Meaning
timeoutMs	number	30000	How long to wait for running jobs before returning

Redis backend

new RedisBackend(options). Guide: Redis and Valkey. new ValkeyBackend(options) takes the same, with valkey in place of redis and no 'idmp' strategy. A strategy is a name, or { name, ...settings } with the settings of that strategy only.

Option	Type	Default	Meaning
redis	URL, { host, port, username, password, db }, or a client	localhost:6379	Connection
strategy	'lease' | 'stream-id' | 'idmp' | 'script', or { name, ...settings }	'lease'	How one winner is picked
prefix	string	'cron:'	Key prefix
strategy.durationSec	number (1 to 86400)	300	{ name: 'idmp' } only: how long a run’s ID is remembered
strategy.maxSize	number (1 to 10000)	1000	{ name: 'idmp' } only: how many run IDs are kept per job
strategy.windowMs	number	300000	{ name: 'script' } only: how long a claimed run is remembered

PostgreSQL backend

new PostgresBackend(options). Guide: PostgreSQL.

Option	Type	Default	Meaning
connection	connection string, pg Pool or Client, postgres.js instance, or { all, transaction }	postgres://localhost:5432/postgres	Connection
table	string	'anarchon_runs'	Table name, may include a schema

SQLite backend

new SqliteBackend(options). Guide: SQLite and libSQL.

Option	Type	Default	Meaning
database	file path, node:sqlite or better-sqlite3 database, @libsql/client client, or { all, transaction }	'./anarchon.db'	Database
table	string	'anarchon_runs'	Table name
busyTimeoutMs	number	5000	How long a write waits for another process

RabbitMQ backend

new RabbitMQBackend(options). Guide: RabbitMQ.

Option	Type	Default	Meaning
url	string	'amqp://localhost'	AMQP URL
connection	amqplib connection		Your own connection
prefix	string	'cron.'	Queue name prefix
slotTtlMs	number	300000	How long a run is remembered

NATS backend

new NatsBackend(options). Guide: NATS.

Option	Type	Default	Meaning
servers	string | string[]	'nats://localhost:4222'	Server URL or URLs
connection	NATS connection		Your own connection
stream	string	'CRON'	JetStream stream name
prefix	string	'cron.'	Subject prefix
duplicateWindowMs	number	300000	How long a run is remembered
historySize	number	1000	Messages kept per subject
replicas	number	1	Stream replicas

Durations

Wherever an interval is accepted as a string:

Unit	Meaning	Example
ms	milliseconds	'500ms'
s	seconds	'10s'
m	minutes	'35m'
h	hours	'1h30m'
d	days	'2d'

Units combine ('1h30m') and accept decimals ('1.5h'). A plain number, or a string of digits, is milliseconds.

All the other options ending in Ms take a number of milliseconds.