By Bella Ratmelia, Librarian, Data Services
On 3 January 2022, OpenAlex announced their official launch on Twitter. This also includes the launch of their API and its documentation.
What is OpenAlex?
When the beta version was first announced in 2021, it positioned itself as a drop-in replacement of the now deprecated MAG, but it has since evolved to be beyond just a replacement.
OpenAlex is a free and open source “index of hundreds of millions of interconnected entities across the global research system”. It aggregates and standardize data from primarily Microsoft Academic Graph (MAG) and Crossref, as well as ORCID, Unpaywall, institutional repositories, etc.
The OpenAlex API
The API is free with a very user-friendly documentation. It is built around what they call as “five-entity models”: authors, works, venues (i.e., journals or repositories), institutions, and concepts. These five entities are inter-connected with each other while also having their own API endpoints, making it easy and intuitive to use (at least compared to other similar APIs out there).
There is some interesting information that can be retrieved by the API, such as a paper’s retraction status, open access status, concepts (i.e., topics) and abstract.
The abstracts, however, are not provided in plain text form due to legal constraints. It is provided in inverted index format which encodes information about the abstract's words and their positions within the text. Some extra clean-ups will be necessary if you plan to use this API to retrieve abstracts.
Even though it has no rate limit, OpenAlex encouraged that the requests are kept under 100,000 per day. There is also a “polite pool” that users can join by simply providing their email address inside the API calls. Users in this pool will receive much faster and more consistent response times compared to the “common pool”.
API usage examples
Here are some examples that can give a better overview of what the API can retrieve. Simply click on the API URL to view the results in your browser (you can also paste the JSON result to an online JSON formatter that will make it more readable)
Example #1
Get the number of scholarly works produced in SMU grouped by their open access status (green, bronze, gold, hybrid, or closed):
https://api.openalex.org/works?filter=institutions.ror:https://ror.org/050qmg959&group_by=oa_status
Example #2
Get some basic information on SMU, including the number works and number of citations that SMU has collected:
https://api.openalex.org/institutions/ror:050qmg959
Example #3
Get some basic information on an author, including number of publications and citations each year:
http://api.openalex.org/authors/orcid:0000-0003-1613-5981
Example #4
Get the number of retracted papers by SMU:
https://api.openalex.org/works?filter=institutions.ror:https://ror.org/050qmg959&group_by=is_retracted
Have fun exploring the API! As always, if you have any questions or comments that you would like to share about OpenAlex or bibliometrics in general, drop us an email at library@smu.edu.sg.