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3: Getting to know the domain

We will be building a simple service, where we can register book authors, let them write books and eventually publish them. The publishers though will not be part of our bounded context, and we will need to retrieve any information about them from an external publisher API (https://github.com/MaikKingma/publisher-service).

In our domain model we have identified two aggregates: Author and Book. A publisher is information from another bounded context. It might change over time, and we have no control over it as such. That is why we make it an immutable value object in our context, that is not persisted to our database. The only thing we need to know from a publisher, is the identifier of the publisher. We will need it in order to identify the publisher of a book.

Domain Diagram​

domain-model.png

The API​

POST /authors/commands/register
POST /authors/{id}/commands/writeBook
GET /authors

GET /books?title
POST /books/{id}/commands/publish

If there are any questions about the domain model or the API definition feel free to ask me or your neighbour.