filter-concepts.md

Filter concepts

{% hint style="warning" %} These are the original OpenAlex Concepts, which are being deprecated in favor of Topics. We will continue to provide these Concepts for Works, but we will not be actively maintaining, updating, or providing support for these concepts. Unless you have a good reason to be relying on them, we encourage you to look into Topics instead. {% endhint %}

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
• summary_stats.2yr_mean_citedness (accepts float, null, !null, can use range queries such as < >)
• summary_stats.h_index (accepts integer, null, !null, can use range queries)
• summary_stats.i10_index (accepts integer, null, !null, can use range queries)
• works_count

/concepts convenience filters

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

default.search

Value: a search string

This works the same as using the search parameter for Concepts.

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