Sequence view

The sequence view draws a scenario as a sequence diagram: one column per node, one arrow per step, time running down the page. It suits readers who think in lifelines, and it is the quickest way to see who talks to whom, and in what order.

Pick Sequence on the bar to switch any scenario to it, or open a scenario that way:

scenarios:
  pay:
    title: Pay with a card
    mode: sequence

<Diagram name="payments" scenario="pay" mode="sequence" />

How it is drawn

Columns are the nodes the scenario uses, left to right in the order they first appear. Each is headed by its icon, title and sub, and a dotted lifeline hangs from the middle of the header, which is where the arrows begin and end.
Arrows are flow steps, drawn from the sender to the receiver with the step’s label above the line. The line style follows the step’s kind: solid for requests, dashed green for responses, red for errors, dotted grey for lookups and amber for events. A planned step is dashed.
Self steps are drawn as a small labelled box in the node’s column.
Phases become labelled bands across the diagram, such as “I · Record it”. Click one to fold its rows away, and again to show them; the timeline and the story fold the same phases.
Numbers at the left match the numbers in the timeline.

A step that crosses several nodes is drawn as one arrow from the first node to the last. The nodes in between do not get arrows of their own, because the sequence diagram shows what the scenario says, not the route a packet takes. Use the flow view to see the hops.

Playing it

The bar and the list of steps work the same way in every view. Click a row to play that step, press Play to run the scenario, or use the scrubber. The row in progress is highlighted.

When to use it

You want to	Use
Show the architecture and how a request moves through it	Flow
Show who talks to whom, and in what order	Sequence
Walk a newcomer through what happens, in words	Story

All three come from the same steps, so there is nothing to keep in sync.