# kitsu.categories

**stable** **Advanced**

Kitsu anime/manga categories (genres/themes).

`GET /v1/kitsu/categories`

## What you get

A list of Kitsu results in Onekey's unified shape, in `data` (an array). An empty array is a normal, successful answer and is charged like any other; a source that reports "nothing found" as an error returns a free `404 not_found` instead.

## What it costs

- **Advanced · 5 credits** for a fresh fetch, charged only when it succeeds.
- **Free when served from cache (0.2 credit for a cached response over 100 KB).**
- **Free** if the request is invalid (never charged) or the source fails or reports not found (refunded).

## Parameters

This endpoint takes no parameters.

## Request

```bash
curl "https://api.onekey.dev/v1/kitsu/categories" \
  -H "x-api-key: YOUR_API_KEY"
```

```python
import requests

res = requests.get(
    "https://api.onekey.dev/v1/kitsu/categories",
    params={},
    headers={"x-api-key": "YOUR_API_KEY"},
)
body = res.json()

if body["success"]:
    print(body["data"])
else:
    print(body["error"]["code"], body["error"]["message"])
```

```javascript
const params = new URLSearchParams({});
const res = await fetch(`https://api.onekey.dev/v1/kitsu/categories?${params}`, {
  headers: { "x-api-key": "YOUR_API_KEY" },
});
const body = await res.json();

if (body.success) console.log(body.data);
else console.error(body.error.code, body.error.message);
```

## Recorded response

A real Kitsu response, recorded and returned in Onekey's shape. Fields the platform does not provide are `null`.

```json
{
  "success": true,
  "data": [
    {
      "entity": {
        "id": "164",
        "name": "Romance",
        "description": "Romance describes a story that deals with love between two or more characters typically also having an optimistic ending. Romance is also a difficulty encountered when creating a harem."
      },
      "ext": {
        "mediaCount": 27855
      }
    },
    {
      "entity": {
        "id": "156",
        "name": "Fantasy",
        "description": "Fantasy is a genre of fiction that uses magic and other supernatural phenomena as a primary element of plot, theme, or setting. Many works within the genre take place in fictional worlds where magic is common. Fantasy is generally distinguished from science fiction and horror by the expectation that it steers clear of (pseudo-)scientific and macabre themes, respectively, though there is a great deal of overlap between the three (which are subgenres of speculative fiction).\n\nIn popular culture, t"
      },
      "ext": {
        "mediaCount": 26539
      }
    }
  ],
  "metadata": {
    "platform": "kitsu",
    "endpoint": "categories",
    "cached": false,
    "stale": false,
    "age_s": 0,
    "fetched_at": "2026-01-01T12:00:00+00:00",
    "credits_charged": 5,
    "request_id": "7f3a9c2e5b1d4c8fa2e6d0b9c4f18e37"
  },
  "error": null
}
```

## Field mapping

How this endpoint's source fields become Onekey's [unified schema](https://onekey.dev/docs/schema.md). Fields the source lacks come back as `null`.

| Source path | Onekey field | Transform |
| --- | --- | --- |
| `id` | `entity.id` | - |
| `attributes.title` | `entity.name` | - |
| `attributes.description` | `entity.description` | - |
| `attributes.totalMediaCount` | `ext.mediaCount` | `toNumber` |

## Caching and freshness

- Fresh for about 1 hour. Repeat calls in that window are served from cache and are free.
- Between 1 hour and 1 day the cached copy is still served instantly and marked `stale: true` while Onekey refreshes it in the background.
- If the source is down when a refresh is needed, the last copy can be served for up to 3 days more (marked stale).
- A "not found" is remembered for 5 minutes and is free.
- The cache is shared across all customers, which is what keeps repeat calls cheap.

## What can go wrong

| Status | Code | What to do |
| --- | --- | --- |
| 401 | `unauthorized` | Check the `x-api-key` header. |
| 402 | `insufficient_credits` | [Add credits](https://onekey.dev/pricing); your balance must cover the price. |
| 404 | `not_found` | Unknown endpoint path. |
| 422 | `invalid_params` | Fix the parameters using the table above. Free. |
| 429 | `rate_limited` | Wait `Retry-After` seconds, then retry. |
| 502 | `upstream_error` | The source failed. Refunded; retry with backoff. |

See [Errors](https://onekey.dev/docs/errors.md) for the full list and retry guidance.

Status: stable (verified against the live source).