Semantic Artefact Catalogue (SAC) providers were invited to apply to join this support action to implement an API based on the Metadata for Ontology Description and Publication (MOD) ontology to promote interoperability and enhance access to SACs. This API enables a uniform interface to semantic artefacts (SA), enabling seamless querying by stakeholders, regardless ofdomain. This open call was an opportunity for SACs to participate in a community-driven effort to improve the FAIRness of their resources through the adoption of this API. As part of the work of WP4 on Metadata and Ontologies FAIR-IMPACT has established a draft specification of a candidate shared/standard API for SACs. The first version of this draft API is described in D4.3 Specification of shared metadata description of semantic artefacts and their catalogues including common reference API1. In this specification, the Metadata for OntologyDescription and Publication (MOD) ontology, provides a reference vocabulary to semantically describe SAs and their catalogues, including the list of objects (extended from DCAT2) and their properties. MOD is itself the subject of another deliverable, M4.3 Specification of semantic artefact description2. The MOD-API for SACs3 is designed to provide unified access to the catalogue content (i.e., the artefacts, their distribution and their records), enabling seamless querying and use by stakeholders independent of domain. The MOD-API is formalised by means of an OpenAPI template designed to guide the implementation of Web REST APIs. This support offer was a call for implementations of the MOD-API by existing SACs. FAIR-IMPACT offered to support to relevant labs, institutions or infrastructure already providing (some kind of) SAC and who were willing to implement the MOD-API on top of their catalogues to ease the use of their services and enable a better interoperability between all SACs.