---
title: "Get a single domain"
method: GET
path: "/domains/{id}"
tags: ["Domains"]
---

# Get a single domain

`GET /domains/{id}`

Retrieve a single domain by its ID (1-4).

## Path parameters

- `id` string, required

## Query parameters

- `select` string
- `api_key` string, required

## Response `200`

Successful response

- Domain — Top-level category in the topic hierarchy (4 total)
  - `id` string — The OpenAlex ID for this domain.
  - `display_name` string — The English-language label of the domain.
  - `description` string — A description of this domain.
  - `display_name_alternatives` string[] — Alternate names for this domain.
  - `fields` object[] — The fields within this domain. Each object has `id` and `display_name`.
    - `id` string
    - `display_name` string
  - `siblings` object[] — Other domains at the same level. Each object has `id` and `display_name`.
    - `id` string
    - `display_name` string
  - `ids` object — External identifiers:
    - `openalex` string
    - `wikidata` string
    - `wikipedia` string
  - `works_count` integer — The number of works tagged with topics in this domain.
  - `cited_by_count` integer — Total citations to works in this domain.
  - `works_api_url` string — A URL that returns all works tagged with this domain.
  - `created_date` string, date — When this domain was added to OpenAlex (ISO 8601 date).
  - `updated_date` string, date-time — When this domain was last updated (ISO 8601 datetime).

## Other responses

- `404` — Entity not found
- `429` — Rate limit exceeded

---

[API](https://skmtc.net/openalex/apis/openalex-api.md) · [All operations](https://skmtc.net/openalex/apis/openalex-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/openalex/openalex-api/revisions/60b6c8bd0799/schema)