An Endpoint in the sequence diagram

[yamada-wacul]

Proposal

I want to put Endpoints in sequence diagram in some cases.

An Endpoint is used in Interaction diagrams (Sequence, Timing, Communication or Interaction Overview) to reflect a lost or found Message in sequence.

https://sparxsystems.com/enterprise_architect_user_guide/16.1/modeling_languages/endpoint.html

Example

sequenceDiagram
    participant Alice
    Alice --x : foo
    --> Alice : bar

Loading

If there's no recipient after the arrow or sender before the arrow, it will be a line to/from the endpoint.

Screenshots

[jayaprabhakar]

I would love this feature too. Besides indicating lost message, it is helpful to show, a trigger from an external system that is not modeled. Or similarly a message to some external actor. (Or it could be response message for the request from the external system)