Workflow

For every notification sent by a client Repository, the COAR Notify server:

1. authenticates the call

2. checks some simple properties: is the payload structurally valid, is it a type of notification we’re able to handle?

3. stores the notification object in a database

4. sends a 201 HTTP response to the client

5. process the notification depending on its type

6. stores raw extrinsic metadata to the storage

   1. a dedicated indexer converts the notification to the CodeMeta format

   2. this metadata is now stored and associated to a proper SWHID / origin URL

7. sends a COAR Notification indicating the result of the ingestion.

Graphically:

        sequenceDiagram
    participant Repository
    participant inbox as SWH COAR Notify Server
    participant handler as Notification handler
    participant rawstorage as Raw Metadata Storage
    participant storage as Metadata Storage
    Repository->>inbox: Send Announce RelationshipAction Notification
    inbox->>inbox: Authenticate sender with token
    opt Invalid auth
        inbox->>Repository: HTTP 401 response
    end
    inbox->>inbox: Validate Notification
    opt Invalid payload
        inbox->>Repository: HTTP 400 response
    end
    inbox->>Database: Store notification
    inbox->>handler: process the notification
    opt Unprocessable
        inbox->>Repository: Unprocessable COAR Notification
    end
    opt Reject
        inbox->>Repository: Reject COAR Notification
    end
    inbox->>Repository: HTTP 201 response
    handler->>rawstorage: Store metadata
    indexer-->rawstorage: fetch and process raw metadata
    indexer->>storage: store CodeMeta metadata
    handler->>inbox: send the processing result
    inbox->>Database: Prepare & store Accept Notification
    inbox->>Repository: Accept COAR Notification