Autowrap

sequenceDiagram Merchant->>Customer: foo Note left of Person:One row for the a Note right of Person: Bob thinks a long long time, so long that the text does not fit In a row. Bob thinks a long long time, so long that the text does not fit In a row. Bob thinks a long long time, so long that the text does not fit In a row. Bob thinks a long long time, so long that the text does not fit In a row. Person-->>Customer: bar Note left of Person: Foo checks up on him
sequenceDiagram Alice->>Bob: Hello Bob, how are you? Bob-->>John: How about you John? Bob--xAlice: I am good thanks! Bob-xJohn: I am good thanks! Note right of John: Bob thinks a long long time, so long that the text does not fit In a row. Bob thinks a long long time, so long that the text does not fit In a row. Bob thinks a long long time, so long that the text does not fit In a row. Bob thinks a long long time, so long that the text does not fit In a row. Bob-->Alice: Checking with John... Alice->John: Yes... John, how are you?

No line breaks

sequenceDiagram;Alice->>Bob: Hello Bob, how are you?;Bob-->Bob: Hmmm?;Bob-->Alice: Ok;
sequenceDiagram;loop Daily query;Alice->>Bob: Hello Bob, how are you?;alt is sick;Bob->>Alice: Not so good :(;else is well;Bob->>Alice: Feeling fresh like a daisy;end;opt Extra response;Bob->>Alice: Thanks for asking;end;end;

Message types

sequenceDiagram Alice->>Bob: Hello Bob, how are you? Bob-->>John: How about you John? Bob--xAlice: I am good thanks! Bob-xJohn: I am good thanks! Note right of John: Bob thinks a long
long time, so long
that the text does
not fit on a row. Bob-->Alice: Checking with John... Alice->John: Yes... John, how are you?

Loops, alt and opt

sequenceDiagram loop Daily query Alice->>Bob: Hello Bob, how are you? alt is sick Bob->>Alice: Not so good :( else is well Bob->>Alice: Feeling fresh like a daisy end opt Extra response Bob->>Alice: Thanks for asking end end

Message to self in loop

sequenceDiagram participant Alice participant Bob Alice->>John: Hello John, how are you? loop Healthcheck John->>John: Fight against hypochondria end Note right of John: Rational thoughts
prevail... John-->>Alice: Great! John->>Bob: How about you? Bob-->>John: Jolly good!

Bounding test & async message to self

sequenceDiagram participant Alice participant Bob participant John the Long Alice->Bob: Hello Bob, how are you? loop Outer loop Note left of Alice: Bob thinks about
things
to think about Bob-xBob: I am good thanks! loop Inner loop Bob->>John the Long: How about you John? Note right of John the Long: Bob thinks a long
long time, so long
that the text does
not fit. end end Bob-->>Alice: Checking with John... Alice->>John the Long: Yes... John, how are you? John the Long-->>Alice: Super!