A web based interface to the Bitcoin API JSON-RPC

Command: getblockhash

The getblockhash RPC returns the header hash of a block at the given height in the local best block chain.

Parameter—a block height
Result—the block header hash

The height of the block whose header hash should be returned. The height of the hardcoded genesis block is 0.
null
getblockhash height

Returns hash of block in best-block-chain at height provided.

Arguments:
1. height         (numeric, required) The height index

Result:
"hash"         (string) The block hash

Examples:
> bitcoin-cli getblockhash 1000
> curl --user myusername --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "getblockhash", "params": [1000] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/