Error rule

One entry of a task’s on_error.

Field	Type	Required	Description
case	string		Extra condition on the matched error, checked alongside code. A false case falls to the next rule.
code	string[]		Error code patterns. ’%’ is the only wildcard; every other character is literal. Empty = catch-all.
goto	string		Task to route to when retries are exhausted. ‘$task-id’ or ‘end’. Omit to fail the instance.
not_reached	boolean		Assert this code means the remote was never reached, so an only_once task may retry it.
panic	Fault		Terminate as ‘failed’ with this code and message — a defect. Nothing can catch a panic.
raise	Fault		Terminate as ‘raised’ with this code and message — a condition a parent can catch.
retry	Retry		Retry policy applied before the rule routes. Omit for no retries.

Retry

The value of a rule’s retry.

integer

Shorthand for ‘retries’, on the default backoff curve (1s, doubling, capped at 5m).

object

The long form: retry count plus any part of the backoff curve. Every slot takes a $: expression.

Field	Type	Required	Description
delay	string | number		Wait before the first retry: ”30s”, a number of milliseconds, or a $: expression. Defaults to 1s.
factor	number | string		Multiplier applied to the wait after each attempt. 1 keeps it constant. Defaults to 2.
max_delay	string | number		Ceiling the growing wait is clamped to. Defaults to 5m, or to ‘delay’ when that is longer.
retries	integer | string		Number of retries before following goto or failing. 0 = no retries.

Fault

The value of a rule’s raise or panic.

Field	Type	Required	Description
code	string	yes	Error code, lower_snake_case with no dots. A literal — never an expression.
message	string	yes	Human-readable message. A template: ${ } renders when the clause fires.
data	Shape		Structured payload this fault carries, evaluated when the clause fires. Lands on error.data.