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Library Cloud is a metadata service that provides open, programmatic access to the metadata available within the Harvard Library ecosystem. It normalizes metadata so that it can be found across silos, and enriches it with connections to information within the Library’s collection and beyond.

LibraryCloud offers item and collection APIs that provide search access to Harvard collections metadata:

The item API searches over 20 million aggregated metadata records sourced from Harvard Library's main catalog (Alma), JSTOR Forum (for visual information components), and ArchivesSpace (for archival finding aid components). When digitized content is available, these metadata records are enriched with information from Harvard Library's digital repository (DRS).
The collection API provides access to metadata about groupings or sets of these items created for administrative and discovery purposes by Harvard staff.

Need help? If you have questions or need to report a problem when using LibraryCloud APIs, please contact LTS Support.

About the Collections API

The base URI for the collections API is http://api.lib.harvard.edu/v2/collections. Use this API to:

Retrieve a list of all existing collections (sets), with full set metadata including set name, abbreviation (setSpec), set identifier, size, and description:
https://api.lib.harvard.edu/v2/collections?limit=100 (include a limit parameter, otherwise this query returns the first 10 sets only).
Retrieve collection metadata for a single set, by set identifier:
https://api.lib.harvard.edu/v2/collections/57203/
Retrieve a list of items in a specific set, by set identifier:
https://api.lib.harvard.edu/v2/collections/57203/items (returns a simple list of record identifiers for items in the set)

Note: The Items API supports querying full item records by associated set metadata. For example, the following items API queries use set metadata to return items in the English Crime and Execution Broadsides set:

Retrieve items by collectionID:
https://api.lib.harvard.edu/v2/items?collectionId=57203
Retrieve items by collectionTitle:
https://api.lib.harvard.edu/v2/items?collectionTitle=English Crime and Execution Broadsides
Retrieve items by setName:
https://api.lib.harvard.edu/v2/items?setName=English Crime and Execution Broadsides
Retrieve items by setSpec:
https://api.lib.harvard.edu/v2/items?setSpec=crimes

About the Items API

The base URI for items is https://api.lib.harvard.edu/v2/items.

Simple Keyword Query

The simplest query to the API includes only a search term:
https://api.lib.harvard.edu/v2/items?q=peanuts
The response will include all items where any field contains the text “peanuts”.

Multiple terms may be used in a simple query:
https://api.lib.harvard.edu/v2/items?q=Schulz peanuts
https://api.lib.harvard.edu/v2/items?q=Schulz+peanuts
https://api.lib.harvard.edu/v2/items?q=Schulz AND peanuts
All the above queries will return items where any field contains the text “Schulz” AND “peanuts”.

https://api.lib.harvard.edu/v2/items?q=Schulz OR peanuts
The response will include all items where any field contains the text “Schulz” OR “peanuts.

https://api.lib.harvard.edu/v2/items?q=Schulz NOT peanuts
The response will include all items where any field contains the text "Schulz" but NOT "peanuts".

Simple Response

The response to any query contains the total number of matching records, the number of records included within this response, the page number of this response, and the matching records.

Sample XML response:
https://api.lib.harvard.edu/v2/items?q=peanuts

Sample JSON response:
https://api.lib.harvard.edu/v2/items.json?q=peanuts

Searching by Field

See the Field Reference for a list of field-based queries.

A query can be limited to a particular field:
https://api.lib.harvard.edu/v2/items?title=peanuts
This query returns all items with the text “peanuts” in the title field.

Field-based queries support combining or excluding terms with AND, OR, NOT:
https://api.lib.harvard.edu/v2/items?subject=schulz charles
https://api.lib.harvard.edu/v2/items?subject=schulz+charles
https://api.lib.harvard.edu/v2/items?subject=schulz AND charles
All the above queries will return items where any subject field contains the text “schulz” AND “charles”.

https://api.lib.harvard.edu/v2/items?title=archaeology OR archeology
This query returns all items containing the text "archaeology" OR archeology in a title field.

https://api.lib.harvard.edu/v2/items?name=updike NOT john
This query returns all items where any name field contains the text "updike" but NOT "john".

Multiple queries can be combined:
https://api.lib.harvard.edu/v2/items?title=peanuts&q=snack
This query returns all items with the text “peanuts” in a title field and “snack” anywhere in the record.

https://api.lib.harvard.edu/v2/items?title=peanuts&name=Schulz
This query returns all items with the text “peanuts” in the title field and “Schulz” in the name field.

Case-sensitive exact-match queries can be done on specific fields by appending _exact to the field name:
https://api.lib.harvard.edu/v2/items?title_exact=Peanuts
This query returns all items with a title of exactly “Peanuts”. In the Field Reference list, the "Exact Match Search" column indicates if a field supports an exact match query. Note that an exact query can match on contents of a single MODS field only. In the conversion to LibraryCloud MODS, a single field may be split up – for example, a MARC subject heading and its subdivisions will each be fielded separately. In this case, there isn't an item API fielded query that will return only matches on the full subject heading and its subdivisions.

Accented Characters and Punctuation

If your query terms contain accented characters, include these in the search:
https://api.lib.harvard.edu/v2/items?name=Saint-Exupéry, Antoine de
https://api.lib.harvard.edu/v2/items?name=Molière

If your query includes an ampersand, the ampersand must be replaced by the URL-encoded equivalent (%26). For example, to search the title Saxo Grammaticus & the life of Hamlet:
https://api.lib.harvard.edu/v2/items?title_exact=Saxo+Grammaticus+%26+the+life+of+Hamlet

At this time, LibraryCloud queries can be sensitive to the presence of punctuation. Some MODS fields (e.g. Genre) include supplied punctuation (e.g., a terminal period or comma) that must be included in the query or it will fail.

Stemming, Stopwords and Wildcards

LibraryCloud uses standard Solr index stemming and stopword lists. The stemming algorithm is based on the Porter stemming algorithm.

Keywords may be wild-carded with an asterisk:
https://api.lib.harvard.edu/v2/items?title=peanut*
https://api.lib.harvard.edu/v2/items?title=p*nut

Paging

By default, each response will include the first 10 records available. A query can request more records in a response (up to 250), and page through the results.
https://api.lib.harvard.edu/v2/items?title=peanuts?start=100&limit=50
Return the results for the query starting at item 100, with a page size of 50 (e.g. records 100 through 149).

Parameter	Description
start	The row number to start returning results from. If omitted, will default to 1.
limit	The number of results to return. Default is 10. May be between 0 and 250.

Sorting

In some cases, query responses can be sorted in ascending or descending order. See the "Can Sort" column in the Field Reference for an indication of which fields are sortable.

This query returns results sorted in ascending order by source of item:
https://api.lib.harvard.edu/v2/items?q=university AND choir&sort=source

This query returns results sorted in descending order by recordIdentifier of item:
https://api.lib.harvard.edu/v2/items?title=peanuts&sort.desc=recordIdentifier

Parameter	Description
sort.asc OR sort	The field to use for sorting, in ascending order
sort.desc	The field to use for sorting, in descending order

Facets are attributes of an item (name, genre, type of resource, language, date, etc.) that can be used to power a faceted search or browse option in a discovery system. The items API supports a facets parameter that will return a list of facet values present in the query results. Many item API fields are available for faceting – see the Field Reference "Can Facet" column for an indication of which fields can be faceted.

For example, this query will return items that contain "peanuts" in a title followed by a list of facet values (and counts) for the “name” and “resourceType” fields that are present in the query results:
https://api.lib.harvard.edu/v2/items.json?title=peanuts&facets=name,resourceType

Parameter	Description
facets	A comma-separated list of facets to return
facet_size	The maximum number of facets to be returned for each faceted field. Default is 10. May be between 1 and 100.

Response Format

By default, all responses are in MODS format. Dublin Core (DC) can be requested by adding .dc to the base URI
https://api.lib.harvard.edu/v2/items.dc?title=peanuts

Response Serialization

By default, all responses are returned as XML. Responses can be returned as JSON either by adding “.json” to the base URI, or by setting the “Accept” HTTP header in the request to “application/json”. When specifying both the response format and serialization, the format should be added first.
https://api.lib.harvard.edu/v2/items.json?title=peanuts
https://api.lib.harvard.edu/v2/items.dc.json?title=peanuts

Cross-Domain Queries

The API sets the necessary CORS header to allow cross-domain requests in supported browsers. Cross-domain queries can also use JSONP by specifying a callback function name in a “callback” parameter.
https://api.lib.harvard.edu/v2/items.json?title=peanuts&callback=myfunction

Parameter	Description
calback	Javascript function name. The response data will enclosed in a javascript function call with this name.

API Versioning

The version number of the API is specified in the base URL (e.g. “v2”). A version number is always required when accessing the API. The version number will be incremented whenever breaking (non backwards-compatible) changes are made to the API.

Field Reference

This section describes the fields available for searching through the API. In some cases, fields available through the API aggregate multiple fields within the MODS records. When applicable, this is identified in the MODS field mapping column.

Name	Exact Match Search	Can Sort	Can Facet	MODS Field Mapping	Examples/Notes
abstractTOC	No	No	No	abstract tableOfContents	This query returns items with the keyword "justinian" in an abstract or table of contents field: https://api.lib.harvard.edu/v2/items?abstractTOC=Justinian
classification	Yes	No	Yes	classification Physical organization code. Includes bibliographic-level classification but not holdings. See shelfLocator for holdings-level classification.	https://api.lib.harvard.edu/v2/items?classification=F1435.3 Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?classification_exact=PR2825.A2 I8
collectionId	Yes	No	Yes	extension.sets.systemId Query by the set/collection ID assigned to items that have been grouped together for delivery via Harvard Digital Collections.	This query returns items associated with a specific set by its identifier: https://api.lib.harvard.edu/v2/items?collectionId=84560 Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?collectionId_exact=84560
collectionTitle	Yes	No	Yes	extension.sets.setName extension.sets.setSpec Query by the set/collection title assigned to items that have been grouped together for delivery via Harvard Digital Collections.	This query returns items associated with a specific set by set title: https://api.lib.harvard.edu/v2/items?collectionTitle=Chinese Rare Books Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?collectionTitle_exact=Chinese Rare Books
copyrightDate	Yes	No	Yes	originInfo.copyrightDate Use YYYY format to search.	https://api.lib.harvard.edu/v2/items?copyrightDate=2010
dateCaptured	Yes	No	Yes	originInfo.dateCaptured	https://api.lib.harvard.edu/v2/items?dateCaptured=2016&genre=performed+music Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?dateCaptured_exact=201502--
dateCreated	Yes	No	Yes	originInfo.dateCreated	https://api.lib.harvard.edu/v2/items?q=daguerreotypes&dateCreated=1806 Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?dateCreated_exact=late 18th-early 19th century
dateIssued	Yes	No	Yes	originInfo.dateIssued	https://api.lib.harvard.edu/v2/items?name=asimov isaac&dateIssued=1961 Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?name=asimov isaac&dateIssued_exact=[1961]
dateRange (future)
dates.start	No	No	No	originInfo.dateIssued originInfo.dateCreated Use YYYY format to search.	This query returns all works by Molière published from 1990 forward: https://api.lib.harvard.edu/v2/items?name=Molière&dates.start=1990 This query returns all works by Molière published from 1990 backward: https://api.lib.harvard.edu/v2/items?name=Molière&dates.end=1990 This query returns all works by Molière published from 1990 to 2000: https://api.lib.harvard.edu/v2/items?name=Molière&dates.start=1990&dates.end=2000
dates.end	No	No	No
edition	Yes	No	Yes	originInfo.edition	https://api.lib.harvard.edu/v2/items?name=Molière&edition=7th. ed. Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?name=wordsworth&edition_exact=[1st ed.]
genre	Yes	No	Yes	genre	https://api.lib.harvard.edu/v2/items?q=fish+watercolor&genre=Drawings Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?genre_exact=pendants (jewelry)
identifier	Yes	No	No	identifier (Identifier of an item in another system)	This query returns an item by it's ISBN: https://api.lib.harvard.edu/v2/items?identifier=9789601426440
isCollection	Yes	No	Yes	typeOfResource (where collection="yes") Values are “true” or “false”. Indicates whether or not a record describes a collection of items.	https://api.lib.harvard.edu/v2/items?q=colonial+north+america&isCollection=true
isManuscript	Yes	No	Yes	typeOfResource (where manuscript="yes") Values are “true” or “false”. Indicates whether or not a record describes manuscript or archival material.	https://api.lib.harvard.edu/v2/items?q=colonial+north+america&isManuscript=true
isOnline	No	Yes†	Yes	"true" if location.url[@access = 'raw object'] exists, "false" otherwise Indicates whether or not an item is available in digital form; values are "true" or "false". See also inDRS.	https://api.lib.harvard.edu/v2/items?q=earhart amelia&isOnline=true †Will sort all @access=raw object items together in a result set.
issuance	Yes	No	Yes	originInfo.issuance	This query returns items with subject "astronomy" issued as a serial: https://api.lib.harvard.edu/v2/items?subject=astronomy&issuance=serial
languageCode	Yes	No	Yes	language.languageTerm (where languageTerm type="code") Search is based on language ISO code.	This query returns items of Shakespeare in Chinese: https://api.lib.harvard.edu/v2/items?name=shakespeare&languageCode=chi
languageText	Yes	No	Yes	language.languageTerm (where languageTerm type="text") Facet as "language" rather than "languageText". Search is based on language name text.	This query returns items by or about Laozi in Chinese: https://api.lib.harvard.edu/v2/items?title=laozi&language=Chinese
name	Not available	No	Yes	name.namePart e.g. "Greenblatt, Stephen"	Will find term in any name field: https://api.lib.harvard.edu/v2/items?name=shakespeare
originDate	Yes	No	Yes	originInfo.dateIssued originInfo.dateCreated originInfo.dateCaptured originInfo.copyrightDate originInfo.dateOther	https://api.lib.harvard.edu/v2/items?name=asimov+isaac&originDate=1961 Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?name=asimov+isaac&originDate_exact=[1961]
originPlace	Yes	No	Yes	originInfo.place.placeTerm	https://api.lib.harvard.edu/v2/items?q=colonial+north+america&originPlace=Boston Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?originPlace_exact=New-England
physicalDescription		No	No	physicalDescription.form physicalDescription.note	This query returns items in print form with "peanut" in the title: https://api.lib.harvard.edu/v2/items?title=peanut&physicalDescription=print
physicalLocation	No	No	Yes	location.physicalLocation Includes Harvard repository names but also non-Harvard locations, especially for artworks.	https://api.lib.harvard.edu/v2/items?physicalLocation=tozzer&subject=cylinder seals
publisher	Yes	No	Yes	originInfo.publisher	https://api.lib.harvard.edu/v2/items?q=shakespeare&publisher=Arden Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?q=shakespeare&publisher_exact=Arden Shakespeare
recordIdentifier	Yes	No	No	recordInfo.recordIdentifier at the top level only priorrecordids.recordIdentifier e.g. recordIdentifier=sch00443c00117 (for finding aids), recordIdentifier=S26791_olvsurrogate827653 (for images), recordIdentifier=012956251 (for Aleph) Internal recordInfo.recordIdentifier elements in finding aid components and image records can be searched as keywords.	https://api.lib.harvard.edu/v2/items?recordIdentifier=990148733450203941 (for Alma) https://api.lib.harvard.edu/v2/items?recordIdentifier=014873345 (for Aleph) https://api.lib.harvard.edu/v2/items?recordIdentifier=sch00227c00197 (for finding aids) https://api.lib.harvard.edu/v2/items?recordIdentifier=W42143_urn-3:FHCL:1176307 (for images) Use a keyword query to retrieve items based on record ID in finding aid components and image records: https://api.lib.harvard.edu/v2/items?q=olvsurrogate717044
repository	Yes	No	Yes	Search: location.physicalLocation (where @type="repository") Facet: extension.librarycloud.HarvardRepositories.HarvardRepository Includes Harvard repositories only. A search will query the long form repository name (e.g.Eda Kuhn Loeb Music Library); faceting will return the short form repository name (e.g. Loeb Music).	https://api.lib.harvard.edu/v2/items?q=peanuts&repository=Oakes Ames
resourceType (4/11/19: not working correctly)	Yes	No	Yes	typeOfResource	https://api.lib.harvard.edu/v2/items?name=shakespeare&resourceType=three dimensional object
role	Yes	No	Yes	name.namePart.role.roleTerm	https://api.lib.harvard.edu/v2/items?name=shakespeare&role=publisher
seriesTitle	Yes	No	Yes	In relatedItem[@type='series']: titleInfo.title titleInfo.subtitle titleInfo.partName titleInfo.partNumber facet as "relatedItem" rather than "seriesTitle"	https://api.lib.harvard.edu/v2/items?seriesTitle=Harvard-Yenching Institute Monograph Series
shelfLocator	Yes	No	Yes	location.shelfLocator	https://api.lib.harvard.edu/v2/items?q=peanuts&shelfLocator=Film Mas Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?q=peanuts&shelfLocator_exact=Film%20Mas%2025860
source	No	Yes	Yes	recordInfo.recordIdentifier source attribute Sources are currently MH:ALMA (from Alma), MH:VIA (image items from JSTOR forum), or MH:OASIS (finding aid components from ArchivesSpace). Attribute occurs only on top-level recordInfo.recordIdentifier elements	https://api.lib.harvard.edu/v2/items?q=earhart amelia&source=MH:ALMA
subject	Yes	No	Yes	subject.topic subject.geographic subject.temporal subject.titleInfo subject.name subject.genre subject.hierarchicalGeographic.continent subject.hierarchicalGeographic.country subject.hierarchicalGeographic.province subject.hierarchicalGeographic.region subject.hierarchicalGeographic.state subject.hierarchicalGeographic.territory subject.hierarchicalGeographic.county subject.hierarchicalGeographic.city subject.hierarchicalGeographic.island subject.hierarchicalGeographic.area subject.hierarchicalGeographic.extraterrestrialArea subject.hierarchicalGeographic.citySection	https://api.lib.harvard.edu/v2/items?subject=perseus Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?subject_exact=cylinder seals Note: An exact query can match on contents of a single field only. In LibraryCloud MODS, a subject heading and its subdivision(s) are split into separate fields, e.g. the subject heading "Older people -- Services for" appears in the LibCloud MODS record as these fields: <mods:topic>Older people</mods:topic> <mods:topic>Services for</mods:topic>
subject.genre	Yes	No	Yes	subject.genre	https://api.lib.harvard.edu/v2/items?subject.genre=folklore Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?subject.genre_exact=Folklore
subject.geographic	Yes	No	Yes	subject.geographic	https://api.lib.harvard.edu/v2/items?subject.geographic=giza Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?subject.geographic_exact=Giza, Egypt
subject.hierarchicalGeographic	Yes	No	No	subject.hierarchicalGeographic.continent subject.hierarchicalGeographic.country subject.hierarchicalGeographic.province subject.hierarchicalGeographic.region subject.hierarchicalGeographic.state subject.hierarchicalGeographic.territory subject.hierarchicalGeographic.county subject.hierarchicalGeographic.city subject.hierarchicalGeographic.island subject.hierarchicalGeographic.area subject.hierarchicalGeographic.extraterrestrialArea subject.hierarchicalGeographic.citySection	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic=Boston
subject.hierarchicalGeographic.area	Yes	No	Yes	subject.hierarchicalGeographic.area	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic.area=galicia
subject.hierarchicalGeographic.city	Yes	No	Yes	subject.hierarchicalGeographic.city	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic.city=Cochituate&q=maps
subject.hierarchicalGeographic.citySection	Yes	No	Yes	subject.hierarchicalGeographic.citySection	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic.citySection=charlestown
subject.hierarchicalGeographic.continent	Yes	No	Yes	subject.hierarchicalGeographic.continent	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic.continent=africa
subject.hierarchicalGeographic.country	Yes	No	Yes	subject.hierarchicalGeographic.country	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic.country=canada
subject.hierarchicalGeographic.county	Yes	No	Yes	subject.hierarchicalGeographic.county	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic.county=middlesex
subject.hierarchicalGeographic.extraterrestrialArea	Yes	No	Yes	subject.hierarchicalGeographic.extraterrestrialArea	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic.extraterrestrialArea=*
subject.hierarchicalGeographic.island	Yes	No	Yes	subject.hierarchicalGeographic.island	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic.island=*
subject.hierarchicalGeographic.province	Yes	No	Yes	subject.hierarchicalGeographic.province	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic.province=quebec
subject.hierarchicalGeographic.region	Yes	No	Yes	subject.hierarchicalGeographic.region	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic.region=nile
subject.hierarchicalGeographic.state	Yes	No	Yes	subject.hierarchicalGeographic.state	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic.state=massachusetts&q=maps
subject.hierarchicalGeographic.territory	Yes	No	Yes	subject.hierarchicalGeographic.territory	https://api.lib.harvard.edu/v2/items?subject.hierarchicalGeographic.territory=*
subject.name	Yes	No	Yes	subject.name subject.name.namePart	https://api.lib.harvard.edu/v2/items?subject.name=kubrick stanley Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?subject.name=Kubrick, Stanley
subject.name.role	Yes	No	Yes	subject.name.role.roleTerm Terms may be expressed as a word (photographer.) or abbreviation ("cmp" for composer).	https://api.lib.harvard.edu/v2/items?subject.name.role=cmp Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?subject.name.role_exact=photographer.
subject.temporal	Yes	No	Yes	subject.temporal	https://api.lib.harvard.edu/v2/items?q=samurai&subject.temporal=edo Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?q=samurai&subject.temporal_exact=Edo period, 1600-1868
subject.titleInfo	Yes	No	Yes	subject.titleInfo.title subject.titleInfo.subTitle subject.titleInfo.partNumber subject.titleInfo.partName	https://api.lib.harvard.edu/v2/items?subject.titleInfo=Middlemarch Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?subject.titleInfo_exact=Gospel%20of%20Mary
subject.topic	Yes	No	Yes	subject.topic	https://api.lib.harvard.edu/v2/items?subject.topic=mochica pottery Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?subject.topic_exact=Mochica pottery
title	Yes	No	No	titleInfo.title titleInfo.subTitle titleInfo.partNumber titleInfo.partName	https://api.lib.harvard.edu/v2/items?title=complete motown singles Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?title_exact=Labour Party
url	Yes	No	No	location.url Can be URLs or URNs; includes links to digital content and catalog records.	https://api.lib.harvard.edu/v2/items?q=earhart amelia&url=RAD.SCHL Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?q=earhart amelia&url_exact=https://nrs.harvard.edu/urn-3:RAD.SCHL:29639951
url.access	Yes	No	Yes	location.url.access (range = <preview, raw object>) facet as url.access.preview or url.access.raw_object Query for records containing a url field with a specific @access attribute. Values are: "preview"= indicates link to image thumbnail "raw object"= indicates link to full online content	This query returns items containing a url with the attribute access="preview" (i.e., an image thumbnail link is present): https://api.lib.harvard.edu/v2/items?q=earhart amelia&url.access=preview **At this time, only url.access=preview works.
urn	No	No	No	location.url Queries an item by its NRS URN (the URN only e.g., " urn-3:FHCL:1155043" minus the actionable URL components).	https://api.lib.harvard.edu/v2/items?urn=urn-3:FHCL:1155043
DRS Extensions
accessFlag (valid if inDRS=true)	Yes	No	Yes	extension.HarvardDRS.accessFlag (range = <P, R, N, B>) P (publicly accessible), R (restricted to Harvard), N (not available for delivery), B (bypass, access handled differently) See also: availableTo to query human-readable version of DRS accessFlags.	https://api.lib.harvard.edu/v2/items?genre=daguerreotype&accessFlag=P
contentModel (valid if inDRS=true)	Yes	No	Yes	extension.HarvardDRS.contentModel (range = <AUDIO, DOCUMENT, PDS DOCUMENT, PDS DOCUMENT LIST, STILL IMAGE, TEXT, VIDEO>) Use _exact query to find "DOCUMENT". See also: digitalFormat to query by human-readable value derived from the contentModel for an object in Harvard's Digital Repository Service (DRS).	https://api.lib.harvard.edu/v2/items?title=biodiversity&limit=100&contentModel=PDS DOCUMENT Use the case-sensitive exact match query to find "DOCUMENT": https://api.lib.harvard.edu/v2/items?contentModel_exact=DOCUMENT
fileDeliveryURL (valid if inDRS=true)	Yes	No	No	extension.HarvardDRS.fileDeliveryURL, eg. "http://nrs.harvard.edu/urn-3:FHCL.HOUGH:1090399" Query an item by its full delivery URL.	https://api.lib.harvard.edu/v2/items?title=annual+report&fileDeliveryURL=https://nrs.harvard.edu/urn-3:HMS.COUNT:22923642
inDRS	Yes	No	Yes	extension.HarvardDRS.inDRS (range = <"true", "false">) Query for items in Harvard Library's digital repository service. See also isOnline.	https://api.lib.harvard.edu/v2/items?genre=daguerreotype&inDRS=true
maxImageDeliveryDimension (future)	Future	No	Future	extension.HarvardDRS.maxImageDeliveryDimension - e.g., "600". Value is in pixels.
metsLabel (valid if inDRS=true)	Yes	No	No	extension.HarvardDRS.metsLabel eg. Any text string Query for items by keywords in the descriptive METS label - if defined in DRS metadata.	https://api.lib.harvard.edu/v2/items?metsLabel=seward Case-sensitive exact match: https://api.lib.harvard.edu/v2/items?metsLabel_exact=The Italians in Chicago. Washington: G.P.O., 1897.
modified.after (valid if inDRS=true)	Yes	No	No	extension.HarvardDRS.lastModifiedDate - eg. "2016-05-03 Query items by the "last modified" date of a linked digital object in DRS (in YYYY-MM-DD format).	This query returns items in DRS last modified after 2016-01-05: https://api.lib.harvard.edu/v2/items?q=&modified.after=2016-01-05 This query returns items in DRS last modified before a specific date: https://api.lib.harvard.edu/v2/items?q=&modified.before=2016-01-05 This query returns items in DRS last modified on 2016-01-05: https://api.lib.harvard.edu/v2/items?q=*&modified.after=2016-01-04&modified.before=2016-01-06
modified.before (valid if inDRS=true)		No	No
ownerCode (valid if inDRS=true)	Yes	No	Yes	extension.HarvardDRS.ownerCode, eg. "FHCL.HOUGH"	https://api.lib.harvard.edu/v2/items?q=cookbook*&ownerCode=RAD.SCHL
ownerCodeDisplayName (valid if inDRS=true)	Yes	No	Yes	extension.HarvardDRS.ownerCodeDisplayName, eg. "Houghton Library"	https://api.lib.harvard.edu/v2/items?q=daguerreotype&ownerCodeDisplayName=Schlesinger
uriType (valid if inDRS=true)	Yes	No	Yes	extension.HarvardDRS.uriType (range = <FDS, IDS, PDS, PDS_LIST, SDS, SDS_VIDEO>) Query for items by type of delivery urn, which is a proxy for type of delivery service. Delivery service types: FDS (text documents), IDS (images), PDS (page-turned objects), PDS_LIST (list of page-turned objects), SDS (streaming audio), (SDS_VIDEO (streaming video)	https://api.lib.harvard.edu/v2/items?subject=jazz&uriType=SDS
LibraryCloud Extensions
availableTo	Yes	No	Yes	extension.librarycloud.availableTo Human-readable values for access to digital content in Harvard's Digital Repository Service (DRS). Values are "Everyone" (corresponds to accessFlag=P) and "Harvard only" (corresponds to accessFlag=R). See also: availableTo to query by DRS accessFlag.	https://api.lib.harvard.edu/v2/items?q=colonialism&availableTo=Everyone
digitalFormat		No	Yes	extension.librarycloud.digitalFormats.digitalFormat Human readable values derived from the contentModel for an object in Harvard's Digital Repository Service (DRS). Values are audio, books and documents, images, and video. See also: contentModel to query by the DRS content model of an object in Harvard's Digital Repository Service (DRS).	https://api.lib.harvard.edu/v2/items?subject=poetry&digitalFormat=audio
processed.after	Yes	No	No	extension.librarycloud.processingDate Use YYYY-MM-DD format to search. This processing date indicates the most recent re-ingest of a metadata record (an "item") into LibraryCloud from its source catalog.	This query returns items processed after the date specified: https://api.lib.harvard.edu/v2/items?processed.after=2019-01-01 This query returns items processed before the date specified: https://api.lib.harvard.edu/v2/items?processed.before=2019-01-02 This query returns items processed between the specified dates: https://api.lib.harvard.edu/v2/items?processed.after=2018-07-01&processed.before=2019-01-01
processed.before	Yes	No	No
Sets Extensions
setName		No	Yes	extension.sets.set.setName Human-readable names that identify a set of materials selected by, for example, a curator for administrative or discovery purposes or for harvesting via OAI-PMH.	https://api.lib.harvard.edu/v2/items?setName=chinese rare books
setSpec		No	Yes	extension.sets.set.setSpec Codes used to identify a set of materials selected by, for example, a curator for administrative or discovery purposes or for harvesting via OAI-PMH.	https://api.lib.harvard.edu/v2/items?setSpec=crb

More Query Examples

#Search all of LibraryCloud for “peanuts” in the title:
https://api.lib.harvard.edu/v2/items?title=peanuts

#Search finding aid components for “peanuts” in the title:
https://api.lib.harvard.edu/v2/items?title=peanuts&source=MH:OASIS (can use MH:OASIS, MH:VIA, or MH:ALMA)

#Search for a specific component identifier in a finding aid:
https://api.lib.harvard.edu/v2/items?source=MH:OASIS&recordIdentifier=sch00443c00072

#Search for a specific image component identifier in JSTOR Forum (the identifier actually has the form "<viaRecordId>_<URN>", but the wildcard matches the URN portion if not known:
https://api.lib.harvard.edu/v2/items?recordIdentifier=W188002*

#Search for all components in an OASIS record:
https://api.lib.harvard.edu/v2/items?recordIdentifier=sch00443*

#Look up the MODS for a PDS object given its URN:
https://api.lib.harvard.edu/v2/items?urn=urn-3:FHCL.HOUGH:25620083

#Search all of library cloud for VIA records that are public and have “peanuts” in the title:
https://api.lib.harvard.edu/v2/items?title=peanuts&source=MH:VIA&accessFlag=P

#Get the facet counts for collections with various collection titles:
https://api.lib.harvard.edu/v2/items?facets=collectionTitle

#Get all manuscripts from Schlesinger Library that contain either the string "electronic finding aid available" OR "electronic container list available":
https://api.lib.harvard.edu/v2/items?physicalLocation=sch&isManuscript=true&q=(electronic finding aid available) OR (electronic container list available)