Get a single work

It's easy to get a work from from the API with: /works/<entity_id> Here's an example:
That will return a Work object, describing everything OpenAlex knows about the work with that ID.
{
"id": "https://openalex.org/W2741809807",
"doi": "https://doi.org/10.7717/peerj.4375",
"title": "The state of OA: a large-scale analysis of the prevalence and impact of Open Access articles",
"display_name": "The state of OA: a large-scale analysis of the prevalence and impact of Open Access articles",
"publication_year": 2018,
"publication_date": "2018-02-13",
// other fields removed for brevity
}
You can make up to 50 of these queries at once by requesting a list of entities and filtering on IDs using OR syntax (tutorial).

External IDs

You can look up works using external IDs such as a DOI:
You can use the full ID or a shorter Uniform Resource Name (URN) format like so:
Available external IDs for works are:
External ID
URN
DOI
doi
Microsoft Academic Graph (MAG)
mag
PubMed ID (PMID)
pmid
PubMed Central ID (PMCID)
pmcid