The Annotation API is an extension to the Europeana REST API which allows you to create, retrieve and manage annotations on Europeana objects. Annotations are user-contributed or system-generated enhancements, additions or corrections to (or a selection of) metadata or media. We adopted the Web Annotation Data Model as a base model for the representation of annotations and as a format for exchanging annotations between client applications and the API, but also the Web Annotation Protocol as base HTTP protocol for the API.

Please note that this API is in an Alpha state, you can use your regular API key for GET requests in this API Using the PUT/POST/DELETE methods for this API is currently not publicly available.. You can request access to the write methods by emailing us with your use case

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The Annotation Data Model

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annotationdatamodel annotationdatamodel

What are annotations?

Annotations (in the Europeana context) are user-contributed or system-generated enhancements to (a selection of) metadata or media. The most well-known type of annotation is the "tag", a short textual depiction of something. Annotations allow for the creation of meaningful connections across Europeana and will also offer up new ways to explore or find the content you're looking for.

The Annotations API adopted the Web Annotation Data Model (WA) as a base model for exchanging annotations between client applications and the API. It is a W3C recommendation that describes a model and format to share annotations across different platforms.

Please note that, even though we have adopted WA as underlying data model for this API, it is not expected that we support the full extent of the model. We thus advise to look at the EDM Annotations Profile which describes the basics of our implementation and, in particular, the section on Annotation Scenarios for a comprehensive list of the different kinds of annotations that we support.

Basics of the model

In the Web Annotation Data Model an annotation is essentially a reified relation between two or more resources, typically a body and a target, and conveys that the body reflects what is intended to be said about the target. A body can also be absent to describe situations where a target is simply bookmarked. A target can represent a resource or just a part of it that is being annotated.

Being reified as a class enables an annotation to be further described with a motivation which expresses the reason why the annotation was created but also some provenance information such as the user that created the annotation and the software application that was used, as well as the times when it was initially created and sent to the API.

Representation in JSON-LD

Annotations

Agent

An Agent can be either a Person or a Software. Typically the Person corresponds to the user that created the annotation while the Software reflects the client application that was used to create it. A Software can also create annotations if they result from an automatic process.

Semantic Resource

A Semantic Resource is used whenever an external resource needs to be referenced as the body of the annotation. It is mostly used for Semantic Tagging.

Media Resource

Annotations that refer to a media resource require that an oa:SpecificResource object is defined so that the context in which the annotation was made is captured by the annotation. Besides context, a Specific Resource can be used to capture any additional information about how a target is used in the Annotation. The following table lists the properties supported by this class.

Optional and mandatory fields

{
  "@context": “http://www.w3.org/ns/anno.jsonld”
  "id": "http://data.europeana.eu/annotations/1",
  "type": "Annotation",
  "created": "2015-03-10T14:08:07Z",
  "creator": {
    "type": "Person",
    "name": "John Smith"
  },
  "generated": "2015-04-01T09:00:00Z",
  "generator": {
      "type": "Software",
      "name": "HistoryPin",
      "homepage": "https://www.historypin.org/"
  },
  "motivation": "tagging",
  "bodyValue": "MyBeautifulTag",
  "target": "http://data.europeana.eu/item/92062/BibliographicResource_1000126189360"
}

Annotation Scenarios

The Annotations API supports different types of annotations. This page explains the types of annotations that are currently supported, providing examples on how to represent them in the API.

The examples used in this Section are shortened versions of the Annotation Model, you can find an example of a complete Annotation Data Model implementation here.

Simple tags (without language)

A simple tag is a short textual description of a resource. This scenario only applies when the language of the tag is not known, otherwise see the scenario described in the next Section.

{
  "motivation": "tagging",
  "bodyValue": "painting",
  "target": "http://data.europeana.eu/item/92062/BibliographicResource_1000126189360"
}

Simple tags (with language)

A simple tag is a short textual description of a resource.

{
  "motivation": "tagging",
  "body": {
    "type": "TextualBody",
    "value": "painting",
    "language": "en"
 },
  "target": "http://data.europeana.eu/item/92062/BibliographicResource_1000126189360"
}

Semantic tags

A semantic tag is a tag to a resource from a controlled vocabulary, making it machine-interpretable.

{
  "motivation": "tagging",
  "body": "http://sws.geonames.org/2988507",
  "target": "http://data.europeana.eu/item/09102/_UEDIN_214"
}

Object links

An object link is a relationship between two (Europeana) objects. This relationship can be any.

{
  "motivation": "linking",
  "target": [
      "http://data.europeana.eu/item/92062/BibliographicResource_1000126189360",
      "http://data.europeana.eu/item/92062/BibliographicResource_1000126189361"
  ]
}

Geo Tags

A geo-tag adds a geographical location to an item.

{
  "motivation": "tagging",
  "body": {
    "@context": "http://www.europeana.eu/schemas/context/entity.jsonld",
    "type": "Place",
    "lat": "52.081131",
    "long": "4.324053"
  },
  "target": "http://data.europeana.eu/item/92034/GVNRC_NFA03_kop_6_3"
}

Annotating media resources

Annotating a media resource means that the target of the annotation is not the Europeana item but instead a specific media resource within that item.

{
  "motivation": "tagging",
  "bodyValue": "Folk Music",
  "target": {
    "type": "SpecificResource",
    "scope": "http://data.europeana.eu/item/2059207/data_sounds_T471_5",
    "source": "http://comhaltasarchive.ie/tracks/12535"
  }
}

Transcriptions

A transcription is typically an annotation expressing a relation between an image and the text that is represented on that image. Besides the text, the annotation can also refer to a page where the text is displayed, like in the example below.

{
  "motivation": "transcribing",
  "body": {
    "id": "https://europeana.transcribathon.eu/documents/story/item/?item=39378387",
    "language": "de",
    "format": "text/html"
  },
  "target": {
    "scope": "http://data.europeana.eu/item/743/_nhp5sXg",
    "source": 
    "https://glam.uni.wroc.pl/iiif/image-api/RKP_HAASE_371_62468_0001/full/full/0/default.jpg"
  }
}

Getting Started

Access keys

While this API is in an Alpha state you will need to use a separate API key (other than for the main Europeana REST API) to start using it. You can use the following keys:

Creating annotations in the production (live) environment is currently limited to only selected partners, this will be opened up as part of the Beta release.

Request

Every Annotations API call is an HTTP request in a specified format that is sent to the Annotations API service. The API root URLs for the two environments are located at:

https://test-annotations.europeana.eu/annotation (test)
https://www.europeana.eu/api/annotations (production)

Response

This API only supports the JSON-LD format, which is the Linked Open Data version of JSON (with the same syntax as JSON). The request and response format does not need to be passed along to the API, if not provided it will fallback to the default. You can provide the format either via the URL (extension) or via the "Accept" header. To specify the request and response format you can either do:

/search.jsonld?wskey=xxxxx&query=*:*

Or:

Request header: "Accept: application/ld+json"
/search?wskey=xxxxx&query=*:*

Authentication

For reading requests (GET) you need to authenticate by passing along your API key as the wskey parameter. Example (replace YOUR_KEY with your API key):

/search?wskey=YOUR_KEY&query=*:*

For writing requests (POST/PUT/DELETE) on behalf of a user you need to pass along your API key as the wskey parameter along with a user token as the userToken parameter. Example (replace YOUR_KEY with your API key and YOUR_TOKEN with the user token):

/create?wskey=YOUR_KEY&userToken=YOUR_TOKEN&query=*:*

Error Codes

An error during processing of an API method is reported by (1) a relevant HTTP status code, (2) a value of the success field and (3) a meaningful error message in the error field.

The following HTTP status codes are returned:

Annotation API Methods

Search

Search for annotations.

GET /search

Request

Search and Facet fields

The following table shows the fields that can be used for searching annotations and the ones that can be used for faceting:

Response

{
  "@context": "http://www.w3.org/ns/anno.jsonld",
  "id": "http://annotations.europeana.eu/annotation/search?wskey=xxxxx&query=*:*&page=0&pageSize=10",
  "items": [
    "http://data.europeana.eu/annotation/base/1",
    "http://data.europeana.eu/annotation/base/2",
    [..]
  ],
  "next": "http://annotations.europeana.eu/annotation/search?wskey=xxxxx&query=*:*&page=1&pageSize=10",
  "partOf": {
     "id": "http://annotations.europeana.eu/annotation/search?wskey=xxxxx&query=*:*",
     "total": 135610
  },
  "total": 10,
  "type": "AnnotationPage"
}

Create

The API has a generic method available for the creation of annotations. The creation method expects a body payload in the request with the full annotation. Alternatively you can provide this information as part of the body parameter.

POST http://annotations.europeana.eu/annotation/

Request

POST  http://annotations.europeana.eu/annotation/?wskey=YOUR_KEY&userToken=YOUR_TOKEN HTTP/1.1
Accept: application/ld+json
Content-Type: application/ld+json
Content-Length: 999
{
  "motivation": "tagging",
  "bodyValue": "Trombone",
  "target": "http://data.europeana.eu/item/09102/_UEDIN_214"
}

Response

Content-Type: application/ld+json
ETag: "_87e52ce126126"
Link: <http://www.w3.org/ns/ldp#Resource>l; rel="type"
Allow: POST,GET,OPTIONS,HEAD
Vary: Accept
Content-Length: 999
{
  "@context": "http://www.w3.org/ns/anno.jsonld",
  "id": "http://data.europeana.eu/annotation/base/1",
  "type": "Annotation",
  "created": "2016-01-31T12:03:45Z",
  "creator": "http://data.europeana.eu/user/55376",
  "generated": "2016-01-31T12:04:00Z",
  "generator": "http://data.europeana.eu/provider/historypin",
  "bodyValue": "Trombone",
  "motivation": "tagging",
  "target": "http://data.europeana.eu/item/09102/_UEDIN_214"
}

For more examples and information on the data model for an annotation, see data model.

Read

Retrieve annotations by their identifier.

GET /{provider}/{identifier}

Response

HTTP/1.1 200 OK
Content-Type: application/ld+json
{
  "@context": "http://www.w3.org/ns/anno.jsonld",
  "id": "http://data.europeana.eu/annotation/base/1",
  "type": "Annotation",
  "created": "2016-01-31T12:03:45Z",
  "generated": "2016-01-31T12:04:00Z",
  "generator": "http://www.europeana.eu",
  "bodyValue": "Trombone",
  "motivation": "tagging",
  "target": "http://data.europeana.eu/item/09102/_UEDIN_214"
}

See data model for more information on the representation of an annotation.

Update

Update the contents of an annotation. For this you can send a PUT request to the ID of the annotation. You can only update the annotations you have created yourself.

PUT /base/1

Request

You can provide the same content in the Update method as you’d provide for the Create method. Note that you have to provide the full annotation body, you currently cannot update parts of the annotation.

PUT /base/1 HTTP/1.1
Accept: application/ld+json
{
  "bodyValue": "Trombone",
  "motivation": "tagging",
  "target": "http://data.europeana.eu/item/09102/_UEDIN_214"
}

Response

HTTP/1.1 200 OK
Content-Type: application/ld+json
{
  "@context": "http://www.w3.org/ns/anno.jsonld",
  "id": "http://data.europeana.eu/annotation/base/1",
  "type": "Annotation",
  "created": "2016-01-31T12:03:45Z",
  "generated": "2016-01-31T12:04:00Z",
  "generator": "http://www.europeana.eu",
  "bodyValue": "Trombone",
  "motivation": "tagging",
  "target": "http://data.europeana.eu/item/09102/_UEDIN_214"
}

Delete

Delete an annotation. You can send a DELETE HTTP request using the ID of the annotation. You can only delete the annotations you have created yourself. Deletion means the annotation will not be available anymore for search, and only available for retrieval based on the ID of the annotation.

DELETE /base/1

Request

DELETE /collections/1 HTTP/1.1

Response

HTTP/1.1 204 NO CONTENT
Content-Length: 0

Console

Roadmap and Changelog

The current version of the Annotations API is 0.3.3 (August 2022). It is currently available as a Public Alpha, which is the first public version released primarily to get feedback from you. Do note that this means that changes can be introduced which could break backwards compatibility. It also means that to use this API you need a separate API key than for the other Europeana APIs. To see the changes made for the current version and also all previous releases, see the API changelog in the project GitHub.

Credits

This API was initially developed as part of the Europeana Sounds project. It's development has been carried out by the AIT Austrian Institute of Technology in cooperation with the Europeana Foundation.