Item and Resource Responses

JSON Response Objects

Item and Resource Responses

The API will respond to a query to the item or resource endpoint with a JSON response object containing the following attributes:

{
    "views": Object,
    "timestamp": Number,
    "locations": Array,
    "fulltext_service": String,
    "next_issue": String,
    "newspaper_holdings_url": String,
    "title_url": String,
    "page": Array,
    "pagination": Object,
    "resource": Object,
    "cite_this": Object,
    "calendar_url": String,
    "previous_issue": String,
    "segments": List,
    "related_items": List,
    "word_coordinates_query": Object,
    "more_like_this": List,
    "articles_and_essays": List,
    "traditional_knowledge_labels": List,
    "item": Object,
    "word_coordinates_pages": Object,
    "type": String,
    "options": Object,
    "resources": List
}

Of these many attributes in the response object returned by the item endpoint, we will focus on two: the item attribute of the response, and the resources attribute of the response.

Description of the Item Attribute Object

Of these elements the one of most interest is item. The item object has the following structure:

{
    "place_of_publication": String,
    "source_collection": Array,
    "display_offsite": Boolean,
    "contributors": Array,
    "location_county": Array,
    "access_restricted": Boolean,
    "site": Array,
    "original_format": Array,
    "partof_title": Array,
    "date": String,
    "item_type": String,
    "url": String,
    "subject_headings": Array,
    "newspaper_title": Array,
    "created_published": Array,
    "extract_urls": Array,
    "partof_division": Array,
    "contents": Array,
    "subject": Array,
    "index": Number,
    "digital_id": Array,
    "call_number": Array,
    "group": Array,
    "score": Number,
    "location_country": Array,
    "title": String,
    "numeric_shelf_id": Number,
    "description": Array,
    "related_items": Array,
    "id": String,
    "online_format": Array,
    "subjects": Array,
    "location": Array,
    "_version_": Number,
    "mime_type": Array,
    "type": Array,
    "other_formats": Array,
    "library_of_congress_control_number": String,
    "rights_advisory": Array,
    "medium": String,
    "reproduction_number": Array,
    "repository": Array,
    "format": Array,
    "partof": Array,
    "timestamp": String,
    "date_issued": String,
    "reel_numbers": Array,
    "campaigns": Array,
    "raw_lccn": String,
    "number_edition": Array,
    "extract_timestamp": String,
    "genre": Array,
    "number": Array,
    "dates_of_publication": String,
    "partof_collection": Array,
    "other_title": Array,
    "hassegments": Boolean,
    "dates": Array,
    "composite_location": Array,
    "number_lccn": Array,
    "language": Array,
    "rights": Array,
    "locations": Array,
    "notes": Array,
    "shelf_id": String,
    "batch": Array,
    "summary": Array,
    "digitized": Boolean,
    "publication_frequency": Array,
    "resources": Array,
    "aka": Array,
    "contributor_names": Array,
    "image_url": Array,
    "access_advisory": Array
}

This table provides a description of the important fields in the item attribute object accessed using at=item from an item endpoint. Fields that are included in the item summary in the search results attribute are indicated. Fields that are only used for the web site are not described.

Item Field Object

One of the attributes of the Item Response Object is an "item" field object, which provides a variety of fields that can be used to describe the item. The fields in this object will differ from collection to collection, depending upon the practices of the collecting division.

These fields are used by the loc.gov website to provide additional bibliographical data for the item, or to simplify display or other aspects of presentation. In some cases, the fields replicate or summarize the fields in the item response object, while in other cases they provide information specific to the collection or format of the item. Because this field varies in contents and structure, it is best not to depend upon the existence, datatype, or values of the fields in this object. If you have questions about the meaning of a particular subfield in the item field object, please contact Ask a Librarian, who will be able to route your question to the appropriate people.

• access_advisory
• call_number
• contributors
• control_number
• created
• created_published
• created_published_date
• creator
• creators
• contributor_names
• date
• digital_id
• display_offsite
• format
• formats
• genre
• id
• language
• link
• location
• marc
• medium
• medium_brief
• mediums
• modified
• number_former_id
• notes
• other_control_numbers
• other_title
• place
• raw_collections
• repository
• reproduction_number
• resource_links
• restriction
• rights_advisory
• rights_information
• service_low
• service_medium
• stmt_of_responsibility
• sort_date
• source_created
• source_collection
• source_modified
• subject_headings
• subjects
• summary
• thumb_gallery
• title

Description of the Resource Attribute Object

    
    "files": [
        [
            {
                "captions": Array, [image]
                "duration" Integer, [audio or video]
                "format": Object, [iiif or audio or video]
                "height": Integer, [image or video]
                "info": Url, [iiif]
                "levels": Integer, [maps, manuscripts]
                "mimetype": String,
                "other_name": String, [book?]
                "profile": Array, [iiif]
                "protocol": Uri, [iiif ?]
                "size": Integer, [image, manuscript, video]
                "streams": Array, [audio or video]
                "tiles": Array, [audio at least]
                "type": String,
                "url": Url, [usually the URL of the file, but for web archives, the url captured]
                "use": String, [newspaper?]
                "width": Integer [image or video]
              },
        ]
    ],
    "audio": Url, [audio]
    "background": Url, [video?]
    "begin": String [Time], [audio or video]
    "caption": String, [image, audio, or video]
    "capture_range": Array {of dates}, [web archives]
    "djvu_text_file": Url, [book]
    "download_restricted": Boolean, [audio or video]
    "duration": Integer, [audio or video]
    "end": String [Time], [audio or video]
    "fulltext_derivative": Url, [book]
    "fulltext_file": Url, [book]
    "height": Integer, [image or video]
    "id": String,
    "info": Url, [iiif]
    "image": Url,
    "paprika_resource_path": String, [book]
    "pdf": Url, [book]
    "representative_index": Integer, [book]
    "type": String,
    "url": Url,
    "uuid": String, [audio or video]
    "version": Integer, [book]
    "video_stream": Url, [video]
    "video": Url, [video]
    "width": Integer, [image or video]
    "word_coordinates": Url, [OCRed book or newspaper]