> ## Documentation Index
> Fetch the complete documentation index at: https://hexagraph-docs.voyla.in/llms.txt
> Use this file to discover all available pages before exploring further.

# Hexagraph Data Model: Scholarly Entities Explained

> Understand the six core entity types in Hexagraph — outputs, authors, sources, institutions, publishers, and funders — and how they interrelate.

Hexagraph organizes scholarly metadata around six core entity types: **outputs**, **authors**, **sources**, **institutions**, **publishers**, and **funders**. Together, these entities form a connected knowledge graph — a work is authored by researchers affiliated with institutions, published in a source owned by a publisher, and funded by one or more funders. Every entity has a unique [HX\_ID](/concepts/id-system) and can be queried individually or traversed relationally via REST or GraphQL.

***

## Outputs

Outputs represent scholarly works — journal articles, preprints, books, datasets, and other academic publications. They are the central entity in Hexagraph and link to nearly every other entity type.

* **OA prefix:** `HX_W`
* **Example ID:** `HX_W2107277218`
* **Key fields:** `id`, `doi`, `title`, `year`, `date`, `citations`, `authors`, `source`

***

## Authors

Authors are the researchers and scholars who produce scholarly outputs. Each author record aggregates publication history, citation counts, and institutional affiliations over time.

* **OA prefix:** `HX_A`
* **Example ID:** `HX_A5086208034`
* **Key fields:** `id`, `orcid`, `name`, `citations`, `outputs_count`, `affiliations`

***

## Sources

Sources represent the venues in which outputs are published — journals, open-access repositories, conference proceedings, and preprint servers.

* **OA prefix:** `HX_S`
* **Example ID:** `HX_S137773608`
* **Key fields:** `id`, `name`, `issn`, `type`

***

## Institutions

Institutions are universities, national laboratories, research centers, hospitals, and other organizations with which authors are affiliated.

* **OA prefix:** `HX_I`
* **Example ID:** `HX_I1290206310`
* **Key fields:** `id`, `name`, `country`, `type`

***

## Publishers

Publishers are the organizations responsible for publishing and distributing scholarly sources. A publisher may own many journals or repositories.

* **OA prefix:** `HX_P`
* **Example ID:** `HX_P4310320595`
* **Key fields:** `id`, `name`

***

## Funders

Funders are the agencies and organizations that provide financial support for research. Outputs can be linked to one or more funders through grant records.

* **OA prefix:** `HX_F`
* **Example ID:** `HX_F4320306076`
* **Key fields:** `id`, `name`, `doi`

***

## Entity Relationships

Hexagraph entities are interconnected. An **output** links directly to its **authors**, the **source** it was published in, the **institutions** affiliated with its authors, and any **funders** that supported the research. **Authors** link to **institutions** through their affiliation history — an author may have been affiliated with multiple institutions at different points in their career.

This relational structure means you can traverse the graph starting from any entity. For example, from a single output you can reach its authors, then their institutions, then other outputs from those institutions — all through the REST or GraphQL API.

***

## Entity Summary

<CardGroup cols={2}>
  <Card title="Outputs" icon="file-lines" href="/api-reference/outputs">
    **Endpoint:** `/outputs/{id}`\
    **OA Prefix:** `HX_W`\
    **Example ID:** `HX_W2107277218`\
    Scholarly works: articles, preprints, books, datasets.
  </Card>

  <Card title="Authors" icon="user" href="/api-reference/authors">
    **Endpoint:** `/authors/{id}`\
    **OA Prefix:** `HX_A`\
    **Example ID:** `HX_A5086208034`\
    Researchers and scholars with publication histories.
  </Card>

  <Card title="Sources" icon="newspaper" href="/api-reference/sources">
    **Endpoint:** `/sources/{id}`\
    **OA Prefix:** `HX_S`\
    **Example ID:** `HX_S137773608`\
    Journals, repositories, and conference venues.
  </Card>

  <Card title="Institutions" icon="building-columns" href="/api-reference/institutions">
    **Endpoint:** `/institutions/{id}`\
    **OA Prefix:** `HX_I`\
    **Example ID:** `HX_I1290206310`\
    Universities, labs, and research centers.
  </Card>

  <Card title="Publishers" icon="print" href="/api-reference/publishers">
    **Endpoint:** `/publishers/{id}`\
    **OA Prefix:** `HX_P`\
    **Example ID:** `HX_P4310320595`\
    Organizations that publish scholarly sources.
  </Card>

  <Card title="Funders" icon="hand-holding-dollar" href="/api-reference/funders">
    **Endpoint:** `/funders/{id}`\
    **OA Prefix:** `HX_F`\
    **Example ID:** `HX_F4320306076`\
    Agencies and organizations funding research.
  </Card>
</CardGroup>