filter-concepts.md

Filter concepts

You can filter concepts with the filter parameter:

• Get concepts that are at level 0 (top level)
  https://api.openalex.org/concepts?filter=level:0

{% hint style="info" %} It's best to read about filters before trying these out. It will show you how to combine filters and build an AND, OR, or negation query {% endhint %}

/concepts attribute filters

You can filter using these attributes of the Concept object (click each one to view their documentation on the Concept object page):

• ancestors.id
• cited_by_count
• ids.openalex (alias: openalex)
• level
• works_count

/concepts convenience filters

These filters aren't attributes of the Concept object, but they're included to address some common use cases:

display_name.search

Value: a search string

Returns: concepts with a display_name containing the given string; see the search page for details.

• Get concepts with display_name containing "electrodynamics":
  https://api.openalex.org/concepts?filter=display_name.search:electrodynamics

{% hint style="info" %} In most cases, you should use the search parameter instead of this filter because it uses a better search algorithm. {% endhint %}

has_wikidata

Value: a Boolean (true or false)

Returns: concepts that have or lack a Wikidata ID, depending on the given value. For now, all concepts in OpenAlex do have Wikidata IDs.

• Get concepts without Wikidata IDs:
  https://api.openalex.org/concepts?filter=has_wikidata:false