Related keyword object
2 endpoints on 2 platforms return the Related keyword object with the same 7 fields, so code written for one platform reads the others unchanged. A call costs $0.0020 to $0.0400. It is a preview structure and may still change.
A Related keyword is one word linked to the keyword asked about, with how it is linked (relation), its rank and its search index. On Douyin it is a word searched together with the keyword or seen with it in content; on Xiaohongshu, what people search before and after it.
related_to is the keyword asked about. A related word can go straight back in as the keyword of Keyword index history on the same platform.
Fields
A field the platform cannot give is left out of the item and named in meta.unavailable. It is never filled with a guess or a zero.
The related keyword
The keyword it is related to: the one asked about
How it is related: query (searched together with the keyword asked about), posts (appears together with it in content), prior (searched before it), after (searched after it): query posts prior after
Position by relevance among the keywords of the same relation, from 1
How closely it is related to the keyword asked about, 0 to 1
Search index of the related keyword: the platform's index, not a count of searches; null where the platform gives no figure for the word
Composite index of the related keyword: the platform's index of how much attention content about it drew, not a count
Where each number comes from
The same field name does not always mean the same act on every platform. This table says which of the platform's own numbers goes into the field.
rankThe platform's own place by relevance; places may have gaps between themDouyinWhat a platform cannot give
A platform stands against a field when none of its endpoints gives it.
relevanceXiaohongshu (RedNote)composite_indexXiaohongshu (RedNote)meta.unavailable.Endpoints that return Related keyword
The number beside each platform is how many of its endpoints return it.
Example
One item from douyin.index.keywords.related, as recorded 2026-10-12 21:52 UTC. Names, text, IDs and links are examples; the figures are as recorded.
{
"keyword": "露营车",
"related_to": "露营",
"relation": "query",
"rank": 2,
"relevance": 0.07604021617112115,
"search_index": 669384,
"composite_index": 190809
}