DSL Grammar

A DSL document is { name: string, steps: Step[] }. Every step has an action plus a subset of these fields, validated by packages/dsl/src/dsl.schema.ts:

Field	Type	Meaning
selector	string	CSS selector
value	string	Navigation URL, fill value, or wait duration depending on the action
outputKey	string	Key under which the result is stored in the run's artefact
attr	string	Attribute name, for extractAttr
condition	string	contains | notContains | exists | notExists, for assert
timeoutMs	number	Per-step timeout override

Base actions

Action	Required fields
goto	value (the URL)
click	selector
fill	selector, value
waitFor	selector
wait	value (duration)
extractText	selector, outputKey
extractHtml	selector, outputKey
extractAttr	selector, outputKey, attr
extract	selector, outputKey
screenshot	outputKey
saveSource	outputKey
assert	selector, condition; value also required when condition is contains or notContains

This set is fixed and intentionally use-case agnostic — it never grows a site-specific verb. A Challenger extension can register additional actions; the compiler unions each extension's schema into the step type, and the registry rejects any name that collides with a base action or another extension's action.

See Write DSL Flows for a complete working example.