--- type: api title: Get the field capabilities description: **All methods and paths for this operation:** url: https://www.elastic.co/elastic/docs-builder/docs/4371/api/doc/elasticsearch/v8/operation/operation-field-caps resource: https://www.elastic.co/elastic/docs-builder/docs/4371/api/doc/elasticsearch/v8/operation/operation-field-caps products: - Elasticsearch --- # Get the field capabilities Availability: 5.4+ ## Paths - `POST` (also `GET`) `/{index}/_field_caps` - `POST` (also `GET`) `/_field_caps` - [Api key auth](/elastic/docs-builder/docs/4371/api/doc/elasticsearch/v8/authentication#apikeyauth) - [Basic auth](/elastic/docs-builder/docs/4371/api/doc/elasticsearch/v8/authentication#basicauth) - [Bearer auth](/elastic/docs-builder/docs/4371/api/doc/elasticsearch/v8/authentication#bearerauth) #### Path Parameters - `index` (union IndexName | [] IndexName) — optional, leave it out to use `/_field_caps` A comma-separated list of data streams, indices, and aliases used to limit the request. Supports wildcards (*). To target all data streams and indices, omit this parameter or use * or _all. ## Description Get information about the capabilities of fields among multiple indices. For data streams, the API returns field capabilities among the stream’s backing indices. It returns runtime fields like any other field. For example, a runtime field with a type of keyword is returned the same as any other field that belongs to the `keyword` family. ## Required authorization * Index privileges: `view_index_metadata`,`read` ## Query String Parameters - `allow_no_indices` (boolean · default: true) If false, the request returns an error if any wildcard expression, index alias, or `_all` value targets only missing or closed indices. This behavior applies even if the request targets other open indices. For example, a request targeting `foo*,bar*` returns an error if an index starts with foo but no index starts with bar. - `expand_wildcards` (string ExpandWildcards · default: open) The type of index that wildcard patterns can match. If the request can target data streams, this argument determines whether wildcard expressions match hidden data streams. Supports comma-separated values, such as `open,hidden`. Supported values include: - `all`: Match any data stream or index, including hidden ones. - `open`: Match open, non-hidden indices. Also matches any non-hidden data stream. - `closed`: Match closed, non-hidden indices. Also matches any non-hidden data stream. Data streams cannot be closed. - `hidden`: Match hidden data streams and hidden indices. Must be combined with `open`, `closed`, or `both`. - `none`: Wildcard expressions are not accepted. Values: `all`, `open`, `closed`, `hidden`, `none` - `fields` (union Fields) A comma-separated list of fields to retrieve capabilities for. Wildcard (`*`) expressions are supported. One of: `Field` or `Field[]` - `ignore_unavailable` (boolean · default: false) If `true`, missing or closed indices are not included in the response. - `include_unmapped` (boolean · default: false) If true, unmapped fields are included in the response. - `filters` (string) A comma-separated list of filters to apply to the response. - `types` ([] string) A comma-separated list of field types to include. Any fields that do not match one of these types will be excluded from the results. It defaults to empty, meaning that all field types are returned. - `include_empty_fields` (boolean · default: true) If false, empty fields are not included in the response. ## Request Body `application/json` - `fields` (string Fields) — optional A list of fields to retrieve capabilities for. Wildcard (`*`) expressions are supported. - `index_filter` ({} QueryContainer) — optional Filter indices if the provided query rewrites to `match_none` on every shard. IMPORTANT: The filtering is done on a best-effort basis, it uses index statistics and mappings to rewrite queries to `match_none` instead of fully running the request. For instance a range query over a date field can rewrite to `match_none` if all documents within a shard (including deleted documents) are outside of the provided range. However, not all queries can rewrite to `match_none` so this API may return an index even if the provided filter matches no document. See [QueryContainer](https://www.elastic.co/elastic/docs-builder/docs/4371/api/doc/elasticsearch/v8/types/_types-query_dsl-querycontainer) - `runtime_mappings` (RuntimeFields) — optional Define ad-hoc runtime fields in the request similar to the way it is done in search requests. These fields exist only as part of the query and take precedence over fields defined with the same name in the index mappings. ## Response `application/json` - `indices` (string Indices) The list of indices where this field has the same type family, or null if all indices have the same type family for the field. - `fields` (map string to string to FieldCapability) ## Code Examples #### Console ```console POST my-index-*/_field_caps?fields=rating { "index_filter": { "range": { "@timestamp": { "gte": "2018" } } } } ``` #### JavaScript ```javascript const response = await client.fieldCaps({ index: "my-index-*", fields: "rating", index_filter: { range: { "@timestamp": { gte: "2018", }, }, }, }); ``` #### Python ```python resp = client.field_caps( index="my-index-*", fields="rating", index_filter={ "range": { "@timestamp": { "gte": "2018" } } }, ) ``` #### curl ```curl curl -X POST "$ELASTICSEARCH_URL/my-index-*/_field_caps?fields=rating" \ -H "Authorization: ApiKey $ELASTIC_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "index_filter": { "range": { "@timestamp": { "gte": "2018" } } } }' ``` #### C# ```c# var response = await client .FieldCapsAsync(d1 => d1 .Indices(new[] { "my-index-*" }) .IndexFilter(d2 => d2 .Range(new UntypedRangeQuery() { Field = global::Elastic.Clients.Elasticsearch.Infer.Field(x => x.Timestamp), Gte = "2018" }) ) ); ``` #### PHP ```php $resp = $client->fieldCaps([ "index" => "my-index-*", "fields" => "rating", "body" => [ "index_filter" => [ "range" => [ "@timestamp" => [ "gte" => "2018", ], ], ], ], ]); ``` #### Ruby ```ruby response = client.field_caps( index: "my-index-*", fields: "rating", body: { "index_filter": { "range": { "@timestamp": { "gte": "2018" } } } } ) ``` ## Response Examples #### Get two fields A successful response from `GET _field_caps?fields=rating,title`. The field `rating` is defined as a long in `index1` and `index2` and as a `keyword` in `index3` and `index4`. The field `rating` is not aggregatable in `index1`. The field `rating` is not searchable in `index4`. The field `title` is defined as text in all indices. ```json { "indices": [ "index1", "index2", "index3", "index4", "index5" ], "fields": { "rating": { "long": { "metadata_field": false, "searchable": true, "aggregatable": false, "indices": [ "index1", "index2" ], "non_aggregatable_indices": [ "index1" ] }, "keyword": { "metadata_field": false, "searchable": false, "aggregatable": true, "indices": [ "index3", "index4" ], "non_searchable_indices": [ "index4" ] } }, "title": { "text": { "metadata_field": false, "searchable": true, "aggregatable": false } } } } ``` #### Get unmapped fields A successful response from `GET _field_caps?fields=rating,title&include_unmapped`. The response contains an entry for each field that is present in some indices but not all. For example, the `rating` and `title` fields are unmapped in `index5`. ```json { "indices": [ "index1", "index2", "index3", "index4", "index5" ], "fields": { "rating": { "long": { "metadata_field": false, "searchable": true, "aggregatable": false, "indices": [ "index1", "index2" ], "non_aggregatable_indices": [ "index1" ] }, "keyword": { "metadata_field": false, "searchable": false, "aggregatable": true, "indices": [ "index3", "index4" ], "non_searchable_indices": [ "index4" ] } }, "title": { "text": { "metadata_field": false, "searchable": true, "aggregatable": false } } } } ```