> ## 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.

# Sources API — Overview

> Overview of Hexagraph's global registry of journals, conferences, repositories, and publication venues.

The `/sources` endpoints expose Hexagraph's global registry of scholarly journals, conference proceedings, preprint servers, repositories, and book series. Sources host or index scholarly [Outputs](/api-reference/outputs) and are identified by the `HX_S` prefix system.

***

## Filter and Sort Fields

The `/sources` API supports filtering and sorting on specific source attributes:

| Field            | Sort | Filter |
| ---------------- | :--: | :----: |
| `name`           |   ✓  |        |
| `issn`           |   ✓  |    ✓   |
| `is_oa`          |   ✓  |    ✓   |
| `outputs_count`  |   ✓  |    ✓   |
| `cited_by_count` |   ✓  |    ✓   |