Topics Overview
Topics are research areas automatically assigned to works. Topics exist in a four-level hierarchy: domain > field > subfield > topic.
Filter, sort, and group_by fields
The API supports filtering, sorting, and grouping on topics fields. See Filtering, Sorting, and Grouping for syntax.
Fields marked (deprecated) are .search filters — use the search parameter instead.
| Field | Sort | Group_by | Filter |
|---|---|---|---|
cited_by_count |
✓ | ✓ | ✓ |
default.search (deprecated) |
✓ | ||
description.search (deprecated) |
✓ | ||
display_name |
✓ | ✓ | |
display_name.search (deprecated) |
✓ | ||
domain.id |
✓ | ✓ | ✓ |
field.id |
✓ | ✓ | ✓ |
from_created_date |
✓ | ✓ | |
id |
✓ | ✓ | ✓ |
ids.openalex |
✓ | ✓ | ✓ |
keywords.search (deprecated) |
✓ | ||
openalex |
✓ | ✓ | ✓ |
subfield.id |
✓ | ✓ | ✓ |
works_count |
✓ | ✓ | ✓ |