The get settings API allows to retrieve settings of index/indices:

GET /twitter/_settings

Multiple Indices and Types

The get settings API can be used to get settings for more than one index with a single call. General usage of the API follows the following syntax: host:port/{index}/_settings where {index} can stand for comma-separated list of index names and aliases. To get settings for all indices you can use _all for {index}. Wildcard expressions are also supported. The following are some examples:

GET /twitter,kimchy/_settings

GET /_all/_settings

GET /log_2013_*/_settings

Filtering settings by name

The settings that are returned can be filtered with wildcard matching as follows:

GET /log_2013_-*/_settings/index.number_*