.. This file is licensed under the MIT License (MIT) available on
   http://opensource.org/licenses/MIT.

getblocktemplate
================

``getblocktemplate "template_request"``

If the request parameters include a 'mode' key, that is used to explicitly select between the default 'template' request or a 'proposal'.

It returns data needed to construct a block to work on.

For full specification, see BIPs 22, 23, 9, and 145:

    https://github.com/bitcoin/bips/blob/master/bip-0022.mediawiki
    https://github.com/bitcoin/bips/blob/master/bip-0023.mediawiki
    https://github.com/bitcoin/bips/blob/master/bip-0009.mediawiki#getblocktemplate_changes
    https://github.com/bitcoin/bips/blob/master/bip-0145.mediawiki

Argument #1 - template_request
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

**Type:** json object, required

A json object in the following spec
       "rules": [           (json array, required) A list of strings
       "support",         (string) client side supported softfork deployment
       ...
       ],
       }

::

     {
       "mode": "str",       (string, optional) This must be set to "template", "proposal" (see BIP 23), or omitted
       "capabilities": [    (json array, optional) A list of strings
         "support",         (string) client side supported feature, 'longpoll', 'coinbasetxn', 'coinbasevalue', 'proposal', 'serverlist', 'workid'
         ...
       ],

Result
~~~~~~

::

  {
    "version" : n,                    (numeric) The preferred block version
    "rules" : [ "rulename", ... ],    (array of strings) specific block rules that are to be enforced
    "vbavailable" : {                 (json object) set of pending, supported versionbit (BIP 9) softfork deployments
        "rulename" : bitnumber          (numeric) identifies the bit number as indicating acceptance and readiness for the named softfork rule
        ,...
    },
    "vbrequired" : n,                 (numeric) bit mask of versionbits the server requires set in submissions
    "previousblockhash" : "xxxx",     (string) The hash of current highest block
    "transactions" : [                (array) contents of non-coinbase transactions that should be included in the next block
        {
           "data" : "xxxx",             (string) transaction data encoded in hexadecimal (byte-for-byte)
           "txid" : "xxxx",             (string) transaction id encoded in little-endian hexadecimal
           "hash" : "xxxx",             (string) hash encoded in little-endian hexadecimal (including witness data)
           "depends" : [                (array) array of numbers
               n                          (numeric) transactions before this one (by 1-based index in 'transactions' list) that must be present in the final block if this one is
               ,...
           ],
           "fee": n,                    (numeric) difference in value between transaction inputs and outputs (in satoshis); for coinbase transactions, this is a negative Number of the total collected block fees (ie, not including the block subsidy); if key is not present, fee is unknown and clients MUST NOT assume there isn't one
           "sigops" : n,                (numeric) total SigOps cost, as counted for purposes of block limits; if key is not present, sigop cost is unknown and clients MUST NOT assume it is zero
           "weight" : n,                (numeric) total transaction weight, as counted for purposes of block limits
        }
        ,...
    ],
    "coinbaseaux" : {                 (json object) data that should be included in the coinbase's scriptSig content
        "flags" : "xx"                  (string) key name is to be ignored, and value included in scriptSig
    },
    "coinbasevalue" : n,              (numeric) maximum allowable input to coinbase transaction, including the generation award and transaction fees (in satoshis)
    "coinbasetxn" : { ... },          (json object) information for coinbase transaction
    "target" : "xxxx",                (string) The hash target
    "mintime" : xxx,                  (numeric) The minimum timestamp appropriate for next block time in seconds since epoch (Jan 1 1970 GMT)
    "mutable" : [                     (array of string) list of ways the block template may be changed
       "value"                          (string) A way the block template may be changed, e.g. 'time', 'transactions', 'prevblock'
       ,...
    ],
    "noncerange" : "00000000ffffffff",(string) A range of valid nonces
    "sigoplimit" : n,                 (numeric) limit of sigops in blocks
    "sizelimit" : n,                  (numeric) limit of block size
    "weightlimit" : n,                (numeric) limit of block weight
    "curtime" : ttt,                  (numeric) current timestamp in seconds since epoch (Jan 1 1970 GMT)
    "bits" : "xxxxxxxx",              (string) compressed target of next block
    "height" : n                      (numeric) The height of the next block
  }

Examples
~~~~~~~~


.. highlight:: shell

::

  bitcoin-cli getblocktemplate {"rules": ["segwit"]}

::

  curl --user myusername --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "getblocktemplate", "params": [{"rules": ["segwit"]}] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/