DCAT-US Schema v3.0 DataService fields

Overview

Field-level reference for the DCAT-US v3.0 DataService class. DataService is new in v3.0 and describes an API or other service that provides programmatic access to one or more datasets.

Source

data.gov

Keywords

data schema,

open data,

DCAT,

DCAT-US,

metadata standard,

data inventory,

API

Details

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Overview

New in v3.0. DataService describes a collection of operations accessible through an interface — such as a REST API, a SPARQL endpoint, or an OGC web service — that provides access to one or more datasets. In v1.1, APIs were documented as Distributions within a Dataset record. In v3.0, a DataService can be documented at the Catalog level as a first-class resource, separate from any individual dataset’s distribution list. This is particularly useful for services that provide access to many datasets, or for services that are not tied to a single dataset. When to use DataService vs Distribution: Use a Distribution when an API is the primary access method for a specific single dataset. Use a DataService when an API serves multiple datasets, is not tied to a single dataset, or when you want to describe the service itself as a catalog-level resource with its own metadata, contact information, and documentation. Required fields in v3.0: endpointURL, contactPoint, publisher, title —

Core fields

Field	Required	Type	Description
`title`	Mandatory	string	A human-readable name for the service. Example: `"Agency Open Data REST API"`
`endpointURL`	Mandatory	array of strings (IRI)	The root location(s) or primary endpoint URL(s) of the service. Must be web-resolvable IRIs. This is an array — a service can expose multiple endpoints simultaneously, for example both a v1 and v2 API. Example: `["https://api.agency.gov/v1/"]` or `["https://api.agency.gov/v1/", "https://api.agency.gov/v2/"]`
`contactPoint`	Mandatory	array of Kind objects	Contact information for questions about the service. Must include an email address that is continuously monitored. References the Kind class. Example: `[{"fn": "API Support Team", "hasEmail": "mailto:api-support@agency.gov"}]`
`publisher`	Mandatory	Agent object	The person or organization responsible for publishing and making the service available. References the Agent class. Example: `{"name": "Example Federal Agency"}`
`description`	Optional	string	A plain-language description of the service and what data it provides access to.
`endpointDescription`	Recommended	array of strings	URLs pointing to documentation that describes the service endpoint, its operations, and parameters. Typically a URL to an OpenAPI specification, WSDL document, or similar service description. Example: `["https://api.agency.gov/v1/openapi.json"]`
`servesDataset`	Recommended	array of Dataset objects	The datasets this service provides access to. Each Dataset must include at minimum `title`, `description`, `identifier`, `publisher`, and `contactPoint`. Use this to link the service to the datasets it serves. A DataService does not need to serve a specific dataset — for general-purpose APIs this field can be omitted.
`keyword`	Optional	array of strings	Keywords or tags describing the service. Include both technical and non-technical terms. Example: `["climate", "weather", "API", "REST"]`
`identifier`	Optional	Identifier object or string	A unique identifier for the service in the context of the catalog. A persistent URI is recommended. Example: `"https://agency.gov/services/open-data-api"`
`otherIdentifier`	Optional	array of Identifier objects	Additional identifiers for the service beyond the main identifier.
`created`	Optional	string (ISO 8601)	Date the service was first created. Distinct from a public launch date.
`modified`	Optional	string (ISO 8601)	Most recent date the service was changed or updated. Accepts date, datetime, year (YYYY), or year-month (YYYY-MM). Example: `"2024-03-20"`

Access and rights

Field	Required	Type	Description
`license`	Recommended	string (URL)	The license under which the service is made available. Provide as a URL. Example: `"https://creativecommons.org/publicdomain/zero/1.0/"`
`accessRights`	Optional	string	Information about who can access the service and under what conditions. Example: `"Public access with no restrictions."`
`rights`	Optional	array of strings	Rights statements not already covered by `license` or `accessRights`, such as copyright or attribution requirements. Example: `["Data provided by the National Climate Data Center is in the public domain."]`
`rightsHolder`	Optional	array of Organization objects	Organizations holding rights on the service. References the Organization class.
`creator`	Optional	array of Agent objects	Agents primarily responsible for producing the service, if different from publisher.

Coverage and scope

Field	Required	Type	Description
`spatial`	Optional	array of Location objects	Geographic region(s) covered by the data accessible through this service. References the Location class. Example: `[{"@type": "Location", "prefLabel": "United States"}]`
`temporal`	Optional	array of PeriodOfTime objects	Time period(s) covered by the data accessible through this service. References the PeriodOfTime class. Example: `[{"@type": "PeriodOfTime", "startDate": "2000-01-01", "endDate": "2024-12-31"}]`
`spatialResolutionInMeters`	Optional	string	The minimum spatial separation resolvable by this service, in meters. Expressed as a numeric string. Example: `"1000"` for 1 kilometre resolution.
`temporalResolution`	Optional	string (ISO 8601 duration)	The minimum time period resolvable by this service. Example: `"P1D"` for daily resolution.
`theme`	Optional	array of Concept objects	Thematic categories for the service. Each Concept requires a `prefLabel`. Example: `[{"prefLabel": "Climate Science"}]`
`category`	Optional	array of Concept objects	High-level categories for the service. Distinct from `theme`.
`language`	Optional	string or array of strings	ISO 639-1 two-letter language codes supported by the service. Example: `"en"` or `["en", "es"]`

Provenance and quality

Field	Required	Type	Description
`conformsTo`	Optional	array of Standard objects	Standards or specifications the service endpoints implement. References the Standard class. Example: `[{"@type": "Standard", "title": "OGC API - Features", "identifier": "https://ogcapi.ogc.org/features/"}]`
`qualifiedAttribution`	Optional	array of Attribution objects	Agents with specific named responsibilities for the service — for example, a service owner or technical lead. References the Attribution class.
`wasUsedBy`	Optional	array of Activity objects	Activities that used or tested the service. References the Activity class.
`hasQualityMeasurement`	Optional	array of QualityMeasurement objects	Quality measurements for the service — for example, availability percentage, average response time, or reliability metrics. References the QualityMeasurement class.

Example

A minimal DataService record meeting all v3.0 required fields:

{
  "@type": "DataService",
  "title": "Agency Open Data REST API",
  "endpointURL": ["https://api.agency.gov/v1/"],
  "contactPoint": [
    {
      "@type": "Kind",
      "fn": "API Support Team",
      "hasEmail": "mailto:api-support@agency.gov"
    }
  ],
  "publisher": {
    "@type": "Agent",
    "name": "Example Federal Agency"
  }
}

A more complete record showing recommended and commonly used fields:

{
  "@type": "DataService",
  "title": "Agency Open Data REST API",
  "description": "A REST API providing queryable access to agency datasets in JSON and CSV formats. Supports filtering by date range, geographic area, and dataset type.",
  "endpointURL": [
    "https://api.agency.gov/v1/",
    "https://api.agency.gov/v2/"
  ],
  "endpointDescription": [
    "https://api.agency.gov/v1/openapi.json",
    "https://api.agency.gov/v2/openapi.json"
  ],
  "contactPoint": [
    {
      "@type": "Kind",
      "fn": "API Support Team",
      "hasEmail": "mailto:api-support@agency.gov",
      "tel": "+1-202-555-0100"
    }
  ],
  "publisher": {
    "@type": "Agent",
    "name": "Example Federal Agency"
  },
  "identifier": "https://agency.gov/services/open-data-api",
  "keyword": ["open data", "API", "REST", "federal data"],
  "license": "https://creativecommons.org/publicdomain/zero/1.0/",
  "accessRights": "Public access with no restrictions.",
  "rights": ["Data provided by Example Federal Agency is in the public domain."],
  "modified": "2024-03-20",
  "language": ["en"],
  "spatial": [
    {
      "@type": "Location",
      "prefLabel": "United States"
    }
  ],
  "temporal": [
    {
      "@type": "PeriodOfTime",
      "startDate": "2000-01-01"
    }
  ],
  "theme": [
    {
      "prefLabel": "Open Government Data"
    }
  ],
  "conformsTo": [
    {
      "@type": "Standard",
      "title": "OpenAPI Specification 3.0",
      "identifier": "https://spec.openapis.org/oas/v3.0.0"
    }
  ],
  "servesDataset": [
    {
      "@type": "Dataset",
      "title": "Agency Travel Data FY2024",
      "description": "Records of official travel expenditures during fiscal year 2024.",
      "identifier": "https://agency.gov/data/travel-fy2024",
      "publisher": {
        "name": "Example Federal Agency"
      },
      "contactPoint": {
        "fn": "Jane Smith",
        "hasEmail": "mailto:jane.smith@agency.gov"
      }
    }
  ]
}

Source: jsonschema/definitions/DataService.json · Generated reference: jsonschema/docs/DataService.md

Overview

Source

Category

Keywords

Details

Overview

Core fields

Access and rights

Coverage and scope

Provenance and quality

Example

Glossary