Sequence diagram

Sequence diagrams show the order messages pass between participants over time — the standard way to document an API call, an auth handshake, or a distributed-systems trace. zombie-mermaid supports actors, activation boxes, and every Mermaid arrow type.

An authenticated API call, message by message.

sequenceDiagram
  Alice->>Bob: Hello Bob!
  Bob-->>Alice: Hi Alice!

Where sequence diagrams come from, and how the syntax works.

Sequence diagrams show messages passing between participants in the order they happen — the standard way software teams document an API call, an authentication handshake, or a trace across several services. Mermaid’s syntax defines participants as plain actors or typed as a boundary, database, or queue, then connects them with more than half a dozen arrow styles — solid, dotted, or crossed, synchronous or async — to encode exactly what kind of message is being sent. Activation bars mark how long a participant is doing work, and blocks like `alt`, `par`, and `loop` group messages into conditional, parallel, or repeated flows.

Every Sequence diagram example, on its own page.

Explore the other diagram types.