> ## 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 Quickstart: First REST and GraphQL Request

> Learn how to make your first Hexagraph API call and run a GraphQL query to retrieve enriched scholarly metadata in under 5 minutes.

This guide walks you through your first REST and GraphQL requests against the Hexagraph API. No authentication is required — you can start querying live scholarly metadata immediately. By the end of this guide you'll have fetched a scholarly output by ID, run a filtered search, and executed a GraphQL query from the playground.

<Steps>
  <Step title="Check the API">
    Before making data requests, confirm the Hexagraph service is up and reachable by calling the health endpoint.

    ```bash theme={null}
    curl https://api.hexagraph.in/health
    ```

    A healthy service returns:

    ```json theme={null}
    {
      "status": "ok"
    }
    ```

    If you receive a non-`200` response or a network error, the service may be temporarily unavailable. Try again after a few moments.
  </Step>

  <Step title="Fetch a scholarly output">
    Retrieve a single scholarly work by its `HX_ID`. Hexagraph uses the `HX_` prefix for all entity identifiers, derived from the primary catalog identifier.

    ```bash theme={null}
    curl https://api.hexagraph.in/outputs/HX_W2107277218
    ```

    Example response (trimmed):

    ```json theme={null}
    {
      "id": "HX_W2107277218",
      "doi": "https://doi.org/10.1038/nature12373",
      "title": "Human-level control through deep reinforcement learning",
      "year": 2015,
      "citations": 18423,
      "authors": [
        { "id": "HX_A5086208034", "name": "Volodymyr Mnih" },
        { "id": "HX_A5010412141", "name": "Koray Kavukcuoglu" },
        { "id": "HX_A5025753558", "name": "David Silver" }
      ]
    }
    ```

    Use the `id` values returned in the `authors` array to resolve individual author records via the `/authors/{id}` endpoint.
  </Step>

  <Step title="Search publications">
    Use the `/outputs` endpoint with query parameters to search across millions of scholarly works. Combine `search` with `filter` to narrow results, and use `page` and `per_page` for pagination.

    ```bash theme={null}
    curl "https://api.hexagraph.in/outputs?search=artificial+intelligence&filter=has_doi:true&page=1&per_page=3"
    ```

    Key query parameters:

    | Parameter  | Type    | Description                                              |
    | ---------- | ------- | -------------------------------------------------------- |
    | `search`   | string  | Full-text search term across titles and abstracts        |
    | `filter`   | string  | Comma-separated filter expressions (e.g. `has_doi:true`) |
    | `page`     | integer | Page number for paginated results (default: `1`)         |
    | `per_page` | integer | Number of results per page (default: `10`, max: `50`)    |

    The response includes a `meta` object with total result counts and pagination details alongside the `results` array.
  </Step>

  <Step title="Try GraphQL">
    Hexagraph exposes a full GraphQL API for flexible, nested queries. The interactive playground is available at:

    **[https://api.hexagraph.in/graphql](https://api.hexagraph.in/graphql)**

    Paste the following query into the playground to retrieve the same scholarly output you fetched in Step 2:

    ```graphql theme={null}
    query GetScholarlyOutput {
      output(id: "HX_W2107277218") {
        id
        doi
        title
        year
        date
        citations
        authors {
          name
        }
      }
    }
    ```

    GraphQL lets you request exactly the fields you need — no more, no less — and compose nested queries across related entities (e.g. fetching an author's affiliated institutions in the same request). See the [GraphQL Overview](/api-reference/graphql/overview) for the full schema reference.
  </Step>
</Steps>

<Note>
  Hexagraph enforces rate limits of **30 requests per minute** and **1,000 requests per day** per IP address. If you exceed these limits, you'll receive an HTTP `429 Too Many Requests` response. See [Rate Limits & Authentication](/authentication) for guidance on handling limit errors gracefully.
</Note>

<CardGroup cols={2}>
  <Card title="API Reference" icon="code" href="/api-reference/overview">
    Explore the full REST endpoint catalog, parameters, and response schemas.
  </Card>

  <Card title="Rate Limits" icon="gauge" href="/authentication">
    Understand how rate limiting works and how to avoid hitting your quota.
  </Card>
</CardGroup>