The Crossref Curriculum

Using HTTPS to query

Most queries sent to our XML API will use HTTPS. HTTPS querying requires either a member or registered query services account email address. Use a DOI-to-metadata query when you know the DOI and want to find its associated metadata.

HTTPS query examples

DOI-to-metadata query example

https://0-doi-crossref-org.lib.rivier.edu/servlet/query?pid={email@address.com}&id=10.1577/H02-043

DOI-to-metadata query requesting UNIXSD results

https://0-doi-crossref-org.lib.rivier.edu/servlet/query?pid={username:password}&format=unixsd**&id=10.1577/H02-043

DOI-to-metadata queries may also be supplied using this format

https://0-doi-crossref-org.lib.rivier.edu/search/doi?pid={email or username:password}&doi=10.1577/H02-043

XML query

https://0-doi-crossref-org.lib.rivier.edu/servlet/query?usr={username&pwd=password}&format=unixref&qdata=<?xml version="1.0"?><query_batch version="2.0"...

where:

  • usr is your Crossref account username
  • pwd is your Crossref account password
  • pid is your Crossref account username and password (included as username:password) or a registered query services account email address.
  • format is the desired results format
  • qdata is the query data (XML is the recommended format)
  • id is a Crossref DOI

XML querying

An XML query must contain complete and valid query XML. Multiple queries may be included in a single XML file, but the <query> element is repeatable. For best results, do not exceed 5 queries per HTTPS XML query request.

Multiple queries in a single request

https://0-doi-crossref-org.lib.rivier.edu/servlet/query?usr=username&pwd=password&qdata=<?xml version = "1.0" encoding="UTF-8"?>  
<query_batch xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.0" xmlns="http://0-www.crossref.org.lib.rivier.edu/qschema/2.0"  xsi:schemaLocation="http://0-www.crossref.org.lib.rivier.edu/qschema/2.0 http://0-www.crossref.org.lib.rivier.edu/qschema/crossref_query_input2.0.xsd"><head><email_address>support@crossref.org</email_address><doi_batch_id>ABC_123_fff</doi_batch_id> </head> <body> <query key="query1" enable-multiple-hits="true" forward-match="false"><issn match="optional">15360075</issn><journal_title match="exact">American Journal of Bioethics</journal_title><author match="fuzzy" search-all-authors="false">Agich</author><volume match="fuzzy">1</volume><issue>1</issue><first_page>50</first_page><year>2001</year><article_title>The Salience of Narrative for Bioethics</article_title></query><query key="query2" enable-multiple-hits="true"><unstructured_citation>Hungate, B. A., &amp; Hampton, H. M. (2012). Ecosystem services: Valuing ecosystems for climate. Nature Climate Change, 2(3), 151-152.</unstructured_citation></query></body></query_batch>

HTTPS XML query example

https://0-doi-crossref-org.lib.rivier.edu/servlet/query?usr=username&pwd=password&qdata=<?xml version = "1.0" encoding="UTF-8"?>  
<query_batch xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.0" xmlns="http://0-www.crossref.org.lib.rivier.edu/qschema/2.0"  xsi:schemaLocation="http://0-www.crossref.org.lib.rivier.edu/qschema/2.0 http://0-www.crossref.org.lib.rivier.edu/qschema/crossref_query_input2.0.xsd"><head><email_address>support@crossref.org</email_address><doi_batch_id>ABC_123_fff</doi_batch_id> </head> <body> <query key="1178517" enable-multiple-hits="false" forward-match="false"><issn match="optional">15360075</issn><journal_title match="exact">American Journal of Bioethics</journal_title><author match="fuzzy" search-all-authors="false">Agich</author><volume match="fuzzy">1</volume><issue>1</issue><first_page>50</first_page><year>2001</year><article_title>The Salience of Narrative for Bioethics</article_title></query></body></query_batch>

HTTPS XML query with an unstructured (formatted) citation

Learn more about querying with an unstructured (formatted) citation

https://0-doi-crossref-org.lib.rivier.edu/servlet/query?usr=<USERNAME>&pwd=<PASSWORD>&format=unixref&qdata=<?xml version = "1.0" encoding="UTF-8"?><query_batch xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.0" xmlns="http://0-www.crossref.org.lib.rivier.edu/qschema/2.0" xsi:schemaLocation="http://0-www.crossref.org.lib.rivier.edu/qschema/2.0 http://0-www.crossref.org.lib.rivier.edu/qschema/crossref_query_input2.0.xsd"><head><email_address>your@email.org</email_address><doi_batch_id>01032012</doi_batch_id></head><body><query key="q1" enable-multiple-hits="true"><unstructured_citation>Hungate, B. A., &amp; Hampton, H. M. (2012). Ecosystem services: Valuing ecosystems for climate. Nature Climate Change, 2(3), 151-152.</unstructured_citation></query></body></query_batch>

HTTPS XML query with URL encoding

https://0-doi-crossref-org.lib.rivier.edu/servlet/query?usr=username&pwd=password&qdata=%3C?xml%20version=%221.0%22?%3E%3Cquery_batch%20version=%222.0%22%20xsi:schemaLocation=%22https://0-www-crossref-org.lib.rivier.edu/qschema/2.0%20https://0-www-crossref-org.lib.rivier.edu/qschema/crossref_query_input2.0.xsd%22%20xmlns=%22https://0-www-crossref-org.lib.rivier.edu/qschema/2.0%22%20xmlns:xsi=%22http://www.w3.org/2001/XMLSchema-instance%22%3E%3Chead%3E%3Cemail_address%3Esupport@crossref.org%3C/email_address%3E%3Cdoi_batch_id%3EABC_123_fff%3C/doi_batch_id%3E%20%3C/head%3E%20%3Cbody%3E%20%3Cquery%20key=%221178517%22%20enable-multiple-hits=%22false%22%20forward-match=%22false%22%3E%3Cissn%20match=%22optional%22%3E15360075%3Cissn%3Cjournal_title%20match=%22exact%22%3EAmerican%20Journal%20of%20Bioethics%3C/journal_title%3E%3Cauthor%20match=%22fuzzy%22%20search-all-authors=%22false%22%3EAgich%3C/author%3E%3Cvolume%20match=%22fuzzy%22%3E1%3C/volume%3E%3Cissue%3E1%3C/issue%3E%3Cfirst_page%3E50%3C/first_page%3E%3Cyear%3E2001%3C/year%3E%3Carticle_title%3EThe%20Salience%20of%20Narrative%20for%20Bioethics%3C/article_title%3E%3C/query%3E%3C/body%3E%3C/query_batch%

Note that some characters must be URL-encoded:

Character Name URL code
; Semi-colon %3B
/ Slash, virgule, separatrix, or solidus %2F
? Question mark %3F
: Colon %3A
@ At sign, arobase %40
= Equals sign %3D
& Ampersand %26
lf line feed %0A

Last Updated: 2020 April 8 by Laura J. Wilkinson