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APIs for Scholarly Resources

A list of commonly-used APIs for scholarly resources

CrossRef API

Provides access to metadata submitted by Crossref members such as bibliographic data, funding data, license information, full-text links, ORCID iDs, abstracts, and Crossmark updates.


No API key or authentication needed, but Crossref encourages you to include your contact information on each call. As mentioned in the documentation (under "Etiquette" section), any API queries that use HTTPS and have appropriate contact information will be directed to a special pool of API machines that are reserved for polite users.

How to get added to the "polite users" pool:

You can do one of the following:

  • Include a mailto parameter in your query. For example:
  • Include a mailto in your User-Agent HTTP header. For example: GroovyBib/1.1 (; BasedOnFunkyLib/1.4

Return Format

The API is generally RESTFUL and returns results in JSON.


No request limit specified, but it's good to keep it within a reasonable amount. From time to time, Crossref may impose a rate limit to ensure a good uptime. Check the status page to see if it's currently operational.

Useful links

API Wrappers