# 3.6.7.聚合元数据(Aggregation Metadata)

您可以将一条元数据与请求时的各个聚合相关联，并一起返回。 考虑这个例子，我们想将颜色蓝色与我们的 **terms** 聚合相关联。

```
curl -XGET 'localhost:9200/twitter/tweet/_search?pretty' -H 'Content-Type: application/json' -d'
{
  "size": 0,
  "aggs": {
    "titles": {
      "terms": {
        "field": "title"
      },
      "meta": {
        "color": "blue"
      }
    }
  }
}
'
```

那么这个元数据将被返回到我们的标题术语聚合

```
{
    "aggregations": {
        "titles": {
            "meta": {
                "color" : "blue"
            },
            "doc_count_error_upper_bound" : 0,
            "sum_other_doc_count" : 0,
            "buckets": [
            ]
        }
    },
    ...
}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://xiaoxiami.gitbook.io/elasticsearch/ji-chu/36aggregationsju-he-fen-679029/367ju-he-yuan-shu-636e28-aggregation-metadata.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.