docs: add decision record about optional params in CatalogRequest (#4325

)

* docs: add decision record about optional params in CatalogRequest

* DEPENDENCIES

* pr remarks

* move scopes into root object

docs/developer/decision-records/2024-07-03-additional-catalogrequest-param/README.md

@@ -0,0 +1,51 @@
+# Adding an additional parameter to the `CatalogRequest` (Management API)
+
+## Decision
+
+The `POST /catalog/request` endpoint to request a catalog will receive a new optional field in the request body with
+which the requesting participant (=consumer) can insert additional scopes into the DCP interaction.
+
+## Rationale
+
+In typical DCP interactions, the consumer derives the required scopes from the current request (e.g. policies, or
+existing agreements). This does not work for a Catalog request, because there is no request context.
+
+Further, in many dataspaces there are "default scopes", i.e. scopes that must be present on every DSP interaction, but
+these are static - they can't be changed at runtime.
+
+So if a provider offers assets, that are only available is a special (non-default) credential is presented, the consumer
+must be able to attach the respective scope strings to the access token.
+
+_NB: the information which scopes must be added, has to be conveyed out-of-band._
+
+In other words, a consumer may know that a provider has certain assets available, but they have an access policy
+constraint on them, which makes them "invisible" unless a certain credential is presented.
+
+## Approach
+
+The `CatalogRequest` will receive a new nullable field `additionalScopes` which is a list of scope strings (as
+per [DCP Specification, Section 3.1](https://github.com/eclipse-tractusx/identity-trust/blob/main/specifications/verifiable.presentation.protocol.md#31-access-scopes)):
+
+```json
+{
+  "@type": "CatalogRequest",
+  "counterPartyAddress": "http://provider-address.com",
+  "counterPartyId": "providerId",
+  "protocol": "dataspace-protocol-http",
+  "querySpec": {
+    //...
+  },
+  "additionalScopes": [
+    "org.eclipse.edc.vc.type.AdditionalCredentialType1:read",
+    "org.eclipse.edc.vc.type.AdditionalCredentialType2:*"
+  ]
+}
+```
+
+Scope strings provided in that fashion will get added to the default scopes.
+
+NB: the `additionalScopes` entry is _OPTIONAL_.
+
+This feature will be added in an Alpha version of the Management API first, specifically of `3.1.0-alpha`. The
+respective URL path will be `/v3.1alpha/api/management/catalog/request` as per
+our [deprecation policy](https://github.com/eclipse-edc/docs/tree/main/developer/decision-records/2024-05-27-maturity-levels-deprecation-policy).

docs/developer/decision-records/README.md

@@ -57,3 +57,4 @@
 - [2024-01-12 Dynamic Constraint Functions](./2024-01-12-dynamic-constraint-functions/)
 - [2024-05-24 Dataplane Selection Improvements](./2024-05-24-dataplane-selection-improvements/)
 - [2024-06-24 Api Authentication Configuration](./2024-06-24-api-authentication-configuration/)
+- [2024-07-03 Additional CatalogRequest scope parameter](./2024-07-03-additional-catalogrequest-param/)