A web based interface to the Bitcoin API JSON-RPC

Command: getbestblockhash

The getbestblockhash RPC returns the header hash of the most recent block on the best block chain.

Parameters: none
Result—hash of the tip from the best block chain

	"result": "00000000000000000021b8a6638a0f05ca3bf904404b612620d5b755abd3daf0",
	"error": null,
	"id": null

Returns the hash of the best (tip) block in the longest blockchain.

"hex"      (string) the block hash hex encoded

> bitcoin-cli getbestblockhash 
> curl --user myusername --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "getbestblockhash", "params": [] }' -H 'content-type: text/plain;'