GET /domains

openalex.org:openalex-api

Summary: List domains
Operation ID: listDomains
Auth: unknown
Description

Get a list of domains (top-level topic categories). There are only 4 domains: Life Sciences, Social Sciences, Physical Sciences, and Health Sciences.

Parameters (10)

api_key (string, query, required)

Your OpenAlex API key (required). Get a free key at https://openalex.org/settings/api

cursor (string, query, optional)

Cursor for deep pagination. Use `cursor=*` to start, then use the `next_cursor` from the response.

filter (string, query, optional)

Filter domains. Examples: `id:1`, `works_count:>10000000` See [all Domain fields](/api-reference/domains#available-filter-sort-and-group_by-fields).

group_by (string, query, optional)

Group results by a field and return counts. Available fields vary by entity type. See [all Domain fields](/api-reference/domains#available-filter-sort-and-group_by-fields).

page (integer, query, optional)

Page number for pagination. Use cursor for deep pagination beyond 10,000 results.

Constraints: {'minimum': 1}

per_page (integer, query, optional, default: 25)

Number of results per page (1-100, default 25)

Constraints: {'minimum': 1, 'maximum': 100}

sample (integer, query, optional)

Return a random sample of N results (max 10,000). Cannot be used with sort or page.

Constraints: {'maximum': 10000}

search (string, query, optional)

Full-text search across titles, abstracts, and other text fields. Example: `search=machine learning`

select (string, query, optional)

Comma-separated list of fields to return. Reduces response size. Example: `select=id,display_name,cited_by_count`

sort (string, query, optional)

Sort by: `works_count`, `cited_by_count`. Prefix with `-` for descending. See [all Domain fields](/api-reference/domains#available-filter-sort-and-group_by-fields).

Examples (3)

TitleTypeURLAction
List all domains curl https://api.openalex.org/domains
List domains with limited fields curl https://api.openalex.org/domains?select=id,display_name,works_count
List domains sorted by works count descending curl https://api.openalex.org/domains?sort=-works_count&per_page=4

Probe History

Latency

Status Codes

TimeStatusLatencySize
2026-03-23 11:09:17.703880 200 211ms
2026-03-23 10:16:14.221176 200 233ms
2026-03-23 09:21:33.241255 400 202ms

Response Changes

WhenOldNew
2026-03-23 10:16:14.221176 739af3d5fb6b b39dc05bd071
2026-03-23 11:09:17.703880 b39dc05bd071 8aaef7b99693