Understanding commands

EventCatalog supports different message types, this includes commands, events (and soon queries).

Commands are messages that represent intent, commands can be rejected in distributed systems.

Example of a command

An example of a command would be PlaceOrder message over HTTP.

• This message is used to place an order in a system
• Commands can be rejected, the PlaceOrder may be rejected by the service that processes it.

Commands in EventCatalog

• Commands in EventCatalog can be accepted by services or invoked by services.
• Commands in EventCatalog are blue (following EventStorming conventions)
• Commands live in the /commands folder.