Sequence Diagram Generator

Generate sequence diagrams free online — visualize API flows, authentication, and system interactions using code or AI.

What is a Sequence Diagram?

A sequence diagram shows how different objects or systems interact with each other over time, in a specific sequence. They are essential for documenting API interactions, authentication flows, and microservice communication.

When to Use Sequence Diagrams

• API Documentation: Show how your REST or GraphQL API handles requests and authentication.
• Authentication Flows: Document OAuth2, SAML, JWT, or session-based auth flows.
• Microservice Communication: Map which services call which, in what order.
• Bug Investigation: Reconstruct the sequence of events that led to a bug or race condition.

Mermaid Sequence Diagram Syntax

Use sequenceDiagram keyword. Solid arrows: A->>B: Message. Dashed arrows (returns): A-->>B: Response. Actors: actor User. Activation boxes: activate B / deactivate B.