Metadata Delivery

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The collective power of members’ metadata is available for use in a variety of tools and APIs that allow anybody to search and reuse our metadata in sophisticated ways.

Watch the introductory animation in your language: français; español; português do Brasil; 简体中文; 日本語; 한국어; العربية; Bahasa Indonesia; or English below.



Lots of people need to incorporate scholarly metadata into their software and services. For example:

  • Manuscript tracking systems
  • Hosting platforms
  • Bibliographic management software
  • Library systems
  • Author profiling tools
  • Specialist subject databases
  • Scholarly sharing networks
  • Metrics and analytics services
  • Collaborative authoring and reading tools
  • Annotation tools
  • Recommendation engines

The resulting dissemination of metadata enhances content discoverability. The widespread use of our APIs helps to ensure that the entire community can create robust, persistent and accurate citations of our members’ content, to the benefit of publishers, readers and the organizations that use our metadata delivery services.

How it works

There are two main approaches for getting metadata:

  1. User interfaces for people: there are a few options listed below but you may want to start with our newest, open, most comprehensive, and easiest-to-use human interface, Metadata Search.

  2. APIs for machines: we recommend you first look at our newest and most flexible one, our REST API. Take a look at a list of some of the organizations who rely on our REST API.

If you’re interested in using these tools or APIs for production services, we offer the Metadata Plus service with outputs in either/or JSON or XML, and with extra service and support guarantees. If you are interested in the Plus service please contact us.

This table summarizes your options. Please see links and text below for additional details. If you still have questions contact us for help.

REST API OAI-PMH Metadata Plus (OAI-PMH + REST API) OpenURL Simple Text Query Metadata (web) Search
For machine use?
For human use?
Low volume/occasional use
Citation matching?
Low volume
Volume downloads?
For regular use?
Low volume
For occasional use?
Free or fee? Free & fee
Full service has a fee. More options available Fee Free but requires an account Free Free
Includes all available metadata? Bibliographic only DOIs only In JSON only
For more information REST API OAI-PMH Metadata Plus (OAI-PMH + REST API) OpenURL Simple Text Query Metadata (web) Search

Note: Members have additional options for retrieving their own metadata (only)

Content negotiation

The APIs listed here provide metadata in a variety of representations (aka output formats). If you want to get access to our metadata in a particular representation (e.g. RDF, BibTex, XML, CSL), you can use content negotiation to retrieve the metadata for a DOI in the representation you want. Content negotiation is supported by a number of DOI registration agencies including Crossref, DataCite, and mEDRA.

How to participate - Machine interfaces (APIs) for accessing metadata

We have a number of APIs for accessing metadata. There is one general purpose API and several specialized ones. The specialized APIs are either designed for our members so that they can manage their metadata or they are APIs based on standards that are popular in the community.

API Name Description
REST API The REST API enables sophisticated, flexible machine and programmatic access to search and filter our metadata. It can be used for example to look up the metadata for a content item or submit a query on an author’s name or find retractions registered with us. It also allows users to search and filter on a number of elements, including a funder, or all content items with ORCID iDs. The REST API is open to all and it’s also included in the Plus service
OAI-PMH This API uses a standard popular with the library community that lets you harvest metadata. This API is included in the Plus service.
OpenURL This API lets you look up a Crossref DOI for a reference using a standard that is popular in the library community and particularly with link resolver services.

How to participate - user interfaces for accessing metadata

Crossref provides a number of user interfaces to access Crossref metadata. Some are general purpose, and others are more specialized.

Service Name Description
Metadata Search Metadata Search is our primary user interface for searching and filtering of our metadata. It allows users to quickly enter any term and users can search and filter on a number of elements, including ISSN, ORCIDs, funding data and more.It can be used to lookup the DOI for a reference or a partial reference or a set of references.
Simple text query Simple text query is a tool designed to allow members to easily link their references via DOIs. It allows a member to look up DOIs for multiple formatted references at a time and then deposit these in order to fulfill their reference linking obligations.

Watch the introductory animation in your language: français; español; português do Brasil; 简体中文; 日本語; 한국어로; العربي; Bahasa Indonesia; or English below.


Obligations & fees

All our metadata retrieval services are available publicly and at no charge to the community. If you’re using the Public REST API, please consider including your email address in header requests as we are able to prioritize these into a “Polite” pool of queries. And if you need extra service and support guarantees and are interested in the Metadata Plus service, there are fees that apply here.

Getting help

Not sure which option to retrieve metadata is best for you? Try our helpful solution finder.

Already using one of our solutions but having problems?

We offer help documentation for all metadata delivery services. And documentation about the REST API is available on Github. Our support team can help with any technical or troubleshooting questions.

Please contact our outreach team team with any questions or to get set up, or contact our technical support specialists for any technical or troubleshooting questions.

Last Updated: 2017 January 23 by Jennifer Kemp