RO-Crate Overview

RO-Crate is a lightweight way to package research objects with machine-readable metadata. In OSCAR Hub we treat each service as a dataset whose metadata lives in ro-crate-metadata.json. The build script parses this file and renders the landing page content from it.

Key concepts we rely on

@graph

A list of all entities related to your service (dataset, software dependencies, authors, icons). Every node has an @id used for cross-references.

Dataset node (@id: "./")

This is the entry point for the catalog. The fields displayed on the landing page (name, description, service type, hardware/software requirements) all live here.

Linked entities

Objects such as the license, authors, or software requirements can be defined once and referenced via @id. The catalog flattens them for display while preserving their structure internally.

Assets and icons

Logos are referenced via the dataset logo property and stored next to the crate. The build process copies them into dist/assets/icons/<slug>/ so the catalog can render service cards.

Starter template

The repository ships with a ready-to-edit blueprint under template/. It includes a fully linked RO-Crate (ro-crate-metadata.json), placeholder assets (fdl.yml, script.sh, icon.png, sample-input.txt), and acceptance test nodes. Copy it to bootstrap new services and then trim the sections you do not need.

Minimal example

{
  "@context": "https://w3id.org/ro/crate/1.1/context",
  "@graph": [
    {
      "@id": "ro-crate-metadata.json",
      "@type": "CreativeWork",
      "conformsTo": { "@id": "https://w3id.org/ro/crate/1.1" },
      "about": { "@id": "./" }
    },
    {
      "@id": "./",
      "@type": "Dataset",
      "name": "YOLOv8 Object Detection",
      "description": "Perform GPU-accelerated YOLOv8 inference inside OSCAR.",
      "serviceType": "synchronous",
      "URL": "https://github.com/grycap/oscar-hub/tree/main/crates/yolov8",
      "author": { "@id": "#grycap" },
      "license": { "@id": "https://opensource.org/licenses/MIT" },
      "datePublished": "2024-05-16",
      "memoryRequirements": "8 GiB",
      "hasPart": [
        { "@id": "fdl.yml" },
        { "@id": "script.sh" }
      ]
    },
    { "@id": "#grycap", "@type": "Organization", "name": "GRyCAP" },
    {
      "@id": "fdl.yml",
      "@type": [ "File", "SoftwareSourceCode" ],
      "name": "Service Definition (FDL)",
      "url": "https://server/fdl.yml",
      "encodingFormat": "text/yaml"
    },
    {
      "@id": "script.sh",
      "@type": [ "File", "SoftwareSourceCode" ],
      "name": "Service Execution Script",
      "url": "https://server/script.sh",
      "encodingFormat": "text/x-shellscript"
    }
  ]
}

ℹ️ When you reference local files (like fdl.yml or script.sh) in hasPart, make sure the actual file is bundled alongside ro-crate-metadata.json. Validators will flag missing resources.

Use this page as the conceptual overview, then continue to the dedicated sections for detailed field requirements and validation tips.