Mermaid for
Sequence diagrams
Show exactly how your systems talk
Trace a request end to end, document an auth flow once instead of re-explaining it in every review, and see exactly where a handoff breaks down.
What is a sequence diagram?
A sequence diagram shows how processes, systems, or people interact over time, in the exact order those interactions occur. Each participant gets a vertical lifeline, and messages between them are drawn as horizontal arrows, top to bottom.
Originally developed as part of UML (Unified Modeling Language) in the 1990s, sequence diagrams became a standard tool for documenting software behavior and communication protocols. In Mermaid, they’re written in plain text, so they live in your repo, update with your code, and never go stale in a drawer.
What you can map
with a
sequence diagram
API request and response flows
Authentication and authorization sequences
Microservice communication
Event-driven architecture flows
Frontend-to-backend interactions
Third-party integration handshakes
Support ticket or incident escalation flows
API request and response flows
Authentication and authorization sequences
Microservice communication
Event-driven architecture flows
Frontend-to-backend interactions
Third-party integration handshakes
Support ticket or incident escalation flows
Who uses sequence diagrams
on Mermaid
Tech Leads
Show the exact flow of a system interaction in code reviews, architecture discussions, or incident retrospectives.
Business Analysts
Translate technical workflows into something stakeholders can follow without losing the detail that matters.
When a sequence diagram is
the right call
Fast, accurate, editable, and actionable.
Describe your idea and get a diagram you can refine, then share with your team instantly.
FAQ
Common questions about building sequence diagrams in Mermaid.
