# Douyin trend-index related keywords API

The Douyin trend-index related keywords API returns the keywords related to a keyword on Douyin in one week, from the platform's own keyword tool. One call costs 2 credits ($0.004 to $0.0067 depending on the pack); failed calls are free. Call it over HTTP or from your AI client over MCP. Last tested 2026-10-17.

- Page: https://socialtoai.com/douyin-keyword-related-api/
- Last updated: 2026-10-17
- Last tested: 2026-10-17

| Request | Price key | Credits |
| --- | --- | --- |
| `POST /v1/call/douyin.keyword_related` | `douyin.keyword_related` | 2 |

Preview: this interface is not marked stable yet, so its parameters and fields may still change. It is charged like any other call, and a failed call is not charged.

## Request

```bash
curl https://api.socialtoai.com/v1/call/douyin.keyword_related \
  -H "Authorization: Bearer $SOCIALTOAI_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "keyword": "露营",
    "until": "2026-10-04T00:00:00Z"
  }'
```

```python
import os
import requests

response = requests.post(
    "https://api.socialtoai.com/v1/call/douyin.keyword_related",
    headers={"Authorization": f"Bearer {os.environ['SOCIALTOAI_KEY']}"},
    json={
        "keyword": "露营",
        "until": "2026-10-04T00:00:00Z",
    },
)
print(response.json())
```

## Parameters

| Name | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| `keyword` | string | Required | — | One keyword; letter case does not matter |
| `until` | datetime | Required | — | Which week: relations are computed by the week (Monday to Sunday, China time), and the week returned is the last whole one ending on or before this day. The latest week is published early in the next; before that the result is empty |

First page only: up to 250 items, with no cursor parameter and no next page.

## Response fields

| Field | Type | Meaning | Given |
| --- | --- | --- | --- |
| `items[].title` | string | The entry's title or name. | yes |
| `items[].url` | string | A link that opens it; null where the platform's list has none. | yes |
| `items[].rank` | integer | Position on a board, from 1. | yes |
| `items[].heat` | integer | The platform's heat score. | yes |
| `items[].fields.related_to` | string | The keyword you asked about. | yes |
| `items[].fields.relation` | string | How it is related: query (searched together with your keyword), posts (appears with it in content), prior (searched before it), after (searched after it). | yes |
| `items[].fields.relevance` | number | How closely it is related to your keyword, from 0 to 1. | yes |
| `items[].fields.search_index` | integer | The related keyword's search index: the platform's own index, not a count of searches. null where the platform gives no figure for the word. | yes |
| `items[].fields.composite_index` | integer | The related keyword's composite index: the platform's own index of how much attention content about it drew, not a count. | yes |

Every item also has platform, id, ref, approx and type; the response around the items is the same on every call. [Response format](https://socialtoai.com/docs/api/response.md)

## Sample response

```json
{
  "request_id": "req_00000000-0000-4000-8000-000000000001",
  "schema_version": "v1",
  "fetched_at": "2026-10-12T21:52:26.000Z",
  "action": "call",
  "op": "douyin.keyword_related",
  "platform": "douyin",
  "status": "ok",
  "items": [
    {
      "platform": "douyin",
      "id": "露营车",
      "ref": "露营车",
      "approx": [],
      "type": "entry",
      "entry_type": "keyword_related",
      "title": "露营车",
      "url": null,
      "rank": 2,
      "heat": null,
      "fields": {
        "related_to": "露营",
        "relation": "query",
        "relevance": 0.07604021617112115,
        "search_index": 669384,
        "composite_index": 190809
      }
    }
  ],
  "unavailable": [],
  "page": {
    "has_more": false
  },
  "warnings": [],
  "applied_params": {
    "keyword": "露营",
    "until": "2026-10-04T00:00:00Z"
  },
  "cost_credits": 2,
  "billing": {
    "cost_credits": 2,
    "balance_credits": 98,
    "today_spend_credits": 2,
    "daily_limit_credits": null,
    "daily_remaining_credits": null,
    "display": "This call: 2 credits. Balance: 98 credits."
  },
  "replayed": false
}
```

## Paging and failures

- One call returns the first page only, up to 250 items, with no cursor, for 2 credits.
- A call that runs and finds nothing is a successful call: status is "empty", items is empty, and it costs 2 credits.
- On this call Douyin cannot tell a video that does not exist from one with no data: both come back as empty, and both are charged.
- 1 call per second per key, 5 after a purchase; going over is not charged. [Rate limits](https://socialtoai.com/docs/credits-and-billing.md#rate-limits)
- A failed call costs 0 credits and is never retried on its own. [Error codes](https://socialtoai.com/docs/api/errors.md)

## Ask your AI

- Get the keywords related to a keyword on Douyin in one week, from the platform's own keyword tool (keyword: 露营, until: 2026-10-04T00:00:00Z). → `call {"op":"douyin.keyword_related","keyword":"露营","until":"2026-10-04T00:00:00Z"}`, 2 credits

## More on Douyin

| Interface | What it does | Price key | Credits | Page |
| --- | --- | --- | --- | --- |
| `brand_radar` | Get the daily averages of a brand's search, content and spread indexes on Douyin over a date range, from the platform's own index tool, with the averages of every brand in its industry and of the industry's top 3, 5, 10, 15 and 30 to hold them against. | `douyin.brand_radar` | 2 | https://socialtoai.com/douyin-brand-radar-api.md |
| `keyword_audience` | Get who is behind a keyword on Douyin over a date range, from the platform's own keyword tool. | `douyin.keyword_audience` | 2 | https://socialtoai.com/douyin-keyword-audience-api.md |
| `keyword_history` | Get the day-by-day search index and composite index of a keyword on Douyin over a date range, from 巨量算数 (the Douyin index), with the daily averages of the period, of the one before and of a year earlier. | `douyin.keyword_history` | 4 | https://socialtoai.com/douyin-keyword-history-api.md |
| `brand_history` | Get a brand's day-by-day search, content and spread indexes on Douyin over a date range, from the platform's own index tool. | `douyin.brand_history` | 2 | https://socialtoai.com/douyin-brand-history-api.md |
| `keyword_videos` | Get the roughly 20 high-index videos Douyin's index tool puts forward for a keyword. | `douyin.keyword_videos` | 2 | https://socialtoai.com/douyin-keyword-videos-api.md |
| `index_topics` | Get the live topic board or the fastest-rising topic board of Douyin's index tool, about 30 entries each. | `douyin.index_topics` | 2 | https://socialtoai.com/douyin-index-topics-api.md |
| `search` | Find videos by keyword: text, author, likes, comment count and publish time. | `douyin.search` | 12 | https://socialtoai.com/douyin-search-api.md |
| `trending` | What is trending now: title, rank and heat. | `douyin.trending` | 2 | https://socialtoai.com/douyin-trending-api.md |
| `detail` | One video by ID or link: text, author, likes, comment count and publish time. | `douyin.detail` | 2 | https://socialtoai.com/douyin-detail-api.md |
| `comments` | The comments under one video: text, likes, reply count and time. | `douyin.comments` | 2 | https://socialtoai.com/douyin-comments-api.md |

## FAQ

**Do I need a Douyin account or Douyin's own API access?**

No. You only need a SocialToAI key. The call returns content and account information publicly visible on Douyin; you never sign in to Douyin or apply for anything there.

**Can I get the next page?**

No. On Douyin this interface gives its first page only (up to 250 items): the response carries no cursor, and page.has_more is always false.

**What does “Preview” mean here?**

Preview: this interface is not marked stable yet, so its parameters and fields may still change. It is charged like any other call, and a failed call is not charged.