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The /domains endpoints expose Hexagraph’s taxonomy of broad research domains. Each domain record contains descriptive metadata, scholarly output metrics, citation counts, and relationships to related fields and sibling domains. Domains are identified using the OA: prefix system.

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List domains

Retrieve a paginated list of research domains.

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Query Parameters

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page (number)

Page number for paginated results. Starts at 1.

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per_page (number)

Number of results returned per page. Maximum value is 200.

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sort (number)

Sort results by scholarly output count. Available values:
ValueDescription
1Sort by outputs ascending
-1Sort by outputs descending

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filter (string)

Filter results using one or more key-value expressions. Multiple filters may be combined using commas.

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group_by (string)

Group results by a specified field for aggregation and analysis.

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Example Request

curl "https://hexagraph-core.onrender.com/domains"

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Example Response

[
  {
      "id": "OA:3",
      "name": "Physical Sciences",
      "description": "branch of natural science that studies non-living systems",
      "outputs": 161993094,
      "citations": 1122314664,
      "urls": {
        "wikidata": "https://www.wikidata.org/wiki/Q14632398",
        "wikipedia": "https://en.wikipedia.org/wiki/Outline_of_physical_science"
      },
      "fields": [
        "Chemical Engineering",
        "Chemistry",
        "Computer Science",
        "Earth and Planetary Sciences",
        "Energy",
        "Engineering",
        "Environmental Science",
        "Materials Science",
        "Mathematics",
        "Physics and Astronomy"
      ],
      "siblings": [
        "Life Sciences",
        "Social Sciences",
        "Health Sciences"
      ]
    },
    {
      "id": "OA:2",
      "name": "Social Sciences",
      "description": "branch of science focused on societies and the relationships among individuals within those societies",
      "outputs": 116669682,
      "citations": 492101199,
      "urls": {
        "wikidata": "https://www.wikidata.org/wiki/Q34749",
        "wikipedia": "https://en.wikipedia.org/wiki/Social_science"
      },
      "fields": [
        "Arts and Humanities",
        "Business, Management and Accounting",
        "Decision Sciences",
        "Economics, Econometrics and Finance",
        "Psychology",
        "Social Sciences"
      ],
      "siblings": [
        "Life Sciences",
        "Physical Sciences",
        "Health Sciences"
      ]
    }
]

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Get a single domain

Fetch a specific domain by its OA: identifier.

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Example Request

curl "https://hexagraph-core.onrender.com/domains/OA:3"

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Example Response

{
  "id": "OA:3",
  "name": "Physical Sciences",
  "description": "branch of natural science that studies non-living systems",
  "outputs": 161993094,
  "citations": 1122314664,
  "urls": {
    "wikidata": "https://www.wikidata.org/wiki/Q14632398",
    "wikipedia": "https://en.wikipedia.org/wiki/Outline_of_physical_science"
  },
  "fields": [
    {
      "id": "OA:15",
      "name": "Chemical Engineering"
    }
  ],
  "siblings": [
    {
      "id": "OA:1",
      "name": "Life Sciences"
    }
  ]
}

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Response Fields

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id

Unique identifier for the domain. Uses the OA: prefix system (e.g. OA:3).

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name

Display name of the research domain (e.g. "Physical Sciences").

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description

Short description defining the scope of the domain.

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outputs

Total number of scholarly outputs associated with the domain.

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citations

Aggregate citation count across all works associated with the domain.

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urls

External reference links related to the domain.

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urls.wikidata

Link to the domain’s Wikidata entry.

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urls.wikipedia

Link to the corresponding Wikipedia article.

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fields

Research fields that belong to the domain. In the list endpoint, fields are returned as an array of field names. In the single-domain endpoint, fields are returned as objects containing:

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fields[].id

Unique identifier of the field.

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fields[].name

Display name of the field.

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siblings

Other top-level domains that exist alongside the current domain. In the list endpoint, siblings are returned as an array of names. In the single-domain endpoint, siblings are returned as objects containing:

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siblings[].id

Unique identifier of the sibling domain.

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siblings[].name

Display name of the sibling domain.