Sketch mode

A file with no workspace block is a sketch: bare statements are implicitly wrapped in workspace { model { ... } }, and any identifier that’s used but never declared is auto-created as a placeholder software system (tagged Placeholder).

customer -> shop "buys things"
shop -> billing "somehow charges" ?
billing -> erp

This is a complete, valid model — it parses, validates, and renders a single landscape view with everything in it. Placeholders participate in all standard views like any other software system; there’s nothing special you need to do to “finish” one later — just declare it properly (shop = softwareSystem "Shop" { ... }) under the same identifier and it picks up wherever the placeholder left off.

? — marking uncertainty

A trailing ? on a relationship marks it explicitly uncertain, distinct from merely undetailed:

shop -> billing "somehow charges" ?

? is meaningful, not just decorative: structurizrx validate --strict and auto lint both surface ?-marked items as findings, so an agent (or a human) can grep a large model for “things I said I wasn’t sure about.”

Opting a full workspace into sketch leniency

Inside a full workspace { ... } block, strictness is the default: an undeclared identifier is a parse error, same as any other unknown-keyword error. Add !sketch at the top of the file to opt that workspace into the same auto-vivification bare sketch files get:

!sketch
workspace "Shop" {
    model {
        customer -> shop "buys things"   // shop auto-created, no error
    }
}

Dotted identifiers (port references like api.rest) must always resolve to a declared element, even in sketch mode — auto-vivification only applies to bare identifiers.

Next: Element extras — status, lifecycle, ports, and the other optional annotations available on any element.