FC-Service

FC-Service is the federated catalogue of the dataLOFT platform. It is a modified version of the Eclipse FC Service adapted for the HealthX dataspace and implements the Gaia-X Federation Services Lot 5 specification (core catalogue features).

Purpose

FC-Service makes provider self-descriptions and service offerings available to consumers and other platform components. Providers register their offerings in the catalogue when they join the data space. Consumers query the catalogue to discover available datasets and providers before initiating a contract negotiation.

Architecture

FC-Service uses a Neo4j graph database as its backend. Self-descriptions and verifiable presentations are stored as graph nodes, which enables flexible querying via Cypher.

Interfaces

Endpoint	Method	Description
/participants	GET	Return all registered participant verifiable credentials.
/participants	POST	Register a new participant.
/query	POST	Execute a Cypher query against the catalogue graph. Payload: { "statement": "<cypher>" }

The /query endpoint gives full access to the Neo4j graph via Cypher. This is the primary way to retrieve service offerings. The graph follows the Gaia-X ontology, so nodes and relationships use the gx__ prefix.

Example — retrieve all connector endpoint URLs that carry the cloud-processing keyword:

curl --request POST \
  --url https://fed-cat.dataspace.fun/query \
  --header 'content-type: application/json' \
  --data '{
  "statement": "MATCH (p) <-[:gx__providedBy]- (n:gx__ServiceOffering) -[:gx__endpoint]-> (m:gx__Endpoint) -[:gx__standardConformity]-> (s:gx__StandardConformity) WHERE apoc.coll.contains(n.gx__keyword, '\''cloud-processing'\'') RETURN m.gx__endpointURL as url, s.gx__standardReference as standard"
}'

Example response:

[
  {
    "url": ["test.sva.de"],
    "standard": ["https://docs.internationaldataspaces.org/ids-knowledgebase/dataspace-protocol"]
  }
]

Portal

The portal is the web UI for FC-Service. It ships as part of the FC-Service deployment and provides two main functions:

• Browse: view participant credentials and service offerings registered in the catalogue.
• Publish: add credentials to the catalogue without calling the API directly. The portal provides templates for the supported verifiable credential types (e.g. participant VC, service offering VC), handles VC creation, and submits the result to FC-Service.

To publish a service offering, you select an issuer by DID, provide the corresponding private key, choose a template, and fill in the required fields. The portal signs and submits the VC on your behalf.

The portal is accessible at the FC-Service domain (e.g. https://loire-portal.dataspace.fun).

Usage in the platform

• Signature-Auth-Handler queries /participants to verify that a requesting participant is registered.
• Consumer applications query /query or /participants to discover providers and their offerings.
• Providers register via the portal or directly via /participants when joining the dataspace.