| Term | Definition |
|---|---|
| routemaster | A state machine service |
| label | A single named entity moving through a single state machine. Note the primary key is (state_machine, label), i.e. labels have no meaning between separate state machines. |
| metadata | Arbitrary metadata associated with a label, used to decide how that label should progress through a state machine. The exit condition DSL can access this through the metadata prefix. |
| feed | A dynamic data source, retrieved lazily, and accessible through the feed prefix. |
| system | The prefix for injected constants in the exit condition DSL. |
| context | The context in which exit condition programs run. |
| state | A single node in the state machine. |
| action | A type of state that triggers a side-effect in an external service upon a label entering it. A label remaining here implies that routemaster has been unable to successfully trigger the side-effect. |
| gate | A type of state that restricts a label from continuing, based on an exit condition. |
| exit condition | A conditional statement that resolves to either true or false, deciding whether a label can leave the associated state. Can be dependent on the context, external data feeds, the current time, or the duration that a label has been in the state |