[sverweij]

Use '\n' for line breaks, like so:

a => b [label="POST /echo\nHello, it's me"];

(You might like https://mscgen.js.org b.t.w.)

[maffydub]

Sorry, I meant I couldn't find a way to do the same thing as that in Mermaid - I realize my message wasn't very clear, but thanks for replying!