The getindexinfo RPC returns the status of one or all available indices currently running in the node
getindexinfo ( "index_name" )
*bitcoin-cli help getindexinfo
getindexinfo ( "index_name" ) Returns the status of one or all available indices currently running in the node. Arguments: 1. index_name (string, optional) Filter results for an index with a specific name. Result: { (json object) "name" : { (json object) The name of the index "synced" : true|false, (boolean) Whether the index is synced or not "best_block_height" : n (numeric) The block height to which the index is synced } } Examples: > bitcoin-cli getindexinfo > curl --user myusername --data-binary '{"jsonrpc": "1.0", "id": "curltest", "method": "getindexinfo", "params": []}' -H 'content-type: text/plain;' http://127.0.0.1:8332/ > bitcoin-cli getindexinfo txindex > curl --user myusername --data-binary '{"jsonrpc": "1.0", "id": "curltest", "method": "getindexinfo", "params": [txindex]}' -H 'content-type: text/plain;' http://127.0.0.1:8332/