==================
 Protocol Methods
==================

blockchain.block.header
=======================

Return the block header at the given height.

**Signature**

  .. function:: blockchain.block.header(height, cp_height=0)
  .. versionadded:: 1.3
  .. versionchanged:: 1.4
     *cp_height* parameter added
  .. versionchanged:: 1.4.1

  *height*

    The height of the block, a non-negative integer.

  *cp_height*

    Checkpoint height, a non-negative integer.  Ignored if zero,
    otherwise the following must hold:

      *height* <= *cp_height*

**Result**

  If *cp_height* is zero, the raw block header as a hexadecimal
  string.

  Otherwise a dictionary with the following keys.  This provides a
  proof that the given header is present in the blockchain; presumably
  the client has the merkle root hard-coded as a checkpoint.

  * *branch*

    The merkle branch of *header* up to *root*, deepest pairing first.

  * *header*

    The raw block header as a hexadecimal string.  Starting with version 1.4.1,
    AuxPoW data (if present in the original header) is truncated.

  * *root*

    The merkle root of all blockchain headers up to and including
    *cp_height*.


**Example Result**

With *height* 5 and *cp_height* 0 on the Bitcoin chain:

::

   "0100000085144a84488ea88d221c8bd6c059da090e88f8a2c99690ee55dbba4e00000000e11c48fecdd9e72510ca84f023370c9a38bf91ac5cae88019bee94d24528526344c36649ffff001d1d03e477"

.. _cp_height example:

With *cp_height* 8::

  {
    "branch": [
       "000000004ebadb55ee9096c9a2f8880e09da59c0d68b1c228da88e48844a1485",
       "96cbbc84783888e4cc971ae8acf86dd3c1a419370336bb3c634c97695a8c5ac9",
       "965ac94082cebbcffe458075651e9cc33ce703ab0115c72d9e8b1a9906b2b636",
       "89e5daa6950b895190716dd26054432b564ccdc2868188ba1da76de8e1dc7591"
       ],
    "header": "0100000085144a84488ea88d221c8bd6c059da090e88f8a2c99690ee55dbba4e00000000e11c48fecdd9e72510ca84f023370c9a38bf91ac5cae88019bee94d24528526344c36649ffff001d1d03e477",
    "root": "e347b1c43fd9b5415bf0d92708db8284b78daf4d0e24f9c3405f45feb85e25db"
  }

blockchain.block.headers
========================

Return a chunk of block headers from the main chain.

**Signature**

  .. function:: blockchain.block.headers(start_height, count, cp_height=0)
  .. versionadded:: 1.2
  .. versionchanged:: 1.4
     *cp_height* parameter added
  .. versionchanged:: 1.4.1
  .. versionchanged:: 1.6
     response contains *headers* field instead of *hex*

  *start_height*

    The height of the first header requested, a non-negative integer.

  *count*

    The number of headers requested, a non-negative integer.

  *cp_height*

    Checkpoint height, a non-negative integer.  Ignored if zero,
    otherwise the following must hold:

      *start_height* + (*count* - 1) <= *cp_height*

**Result**

  A dictionary with the following members:

  * *count*
    The number of headers returned, between zero and the number
    requested.  If the chain has not extended sufficiently far, only
    the available headers will be returned.  If more headers than
    *max* were requested at most *max* will be returned.

  * *headers*

    An array containing the binary block headers in-order; each header is a
    hexadecimal string.  AuxPoW data (if present in the original header) is
    truncated if *cp_height* is nonzero.

  * *max*

    The maximum number of headers the server will return in a single
    request.  (Recommended to be at least one difficulty retarget period,
    i.e. 2016)

  The dictionary additionally has the following keys if *count* and
  *cp_height* are not zero.  This provides a proof that all the given
  headers are present in the blockchain; presumably the client has the
  merkle root hard-coded as a checkpoint.

  * *root*

    The merkle root of all blockchain headers up to and including
    *cp_height*.

  * *branch*

    The merkle branch of the last returned header up to *root*,
    deepest pairing first.


**Example Response**

See :ref:`here <cp_height example>` for an example of *root* and
*branch* keys.

::

  {
    "count": 2,
    "headers":
    [
      "0100000000000000000000000000000000000000000000000000000000000000000000003ba3edfd7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4a29ab5f49ffff001d1dac2b7c",
      "010000006fe28c0ab6f1b372c1a6a246ae63f74f931e8365e15a089c68d6190000000000982051fd1e4ba744bbbe680e1fee14677ba1a3c3540bf7b1cdb606e857233e0e61bc6649ffff001d01e36299"
    ],
    "max": 2016
  }

blockchain.estimatefee
======================

Return the estimated transaction fee per kilobyte for a transaction to
be confirmed within a certain number of blocks.

**Signature**

  .. function:: blockchain.estimatefee(number, mode=None)
  .. versionchanged:: 1.6
     *mode* argument added

  *number*

    The number of blocks to target for confirmation.

  *mode*

    A string to pass to the bitcoind *estimatesmartfee* RPC as the
    *estimate_mode* parameter. Optional. If omitted, the corresponding
    parameter to the bitcoind RPC is also omitted, i.e. the default
    value is determined by bitcoind.

**Result**

  The estimated transaction fee in whole coin units per kilobyte, as a
  floating point number.  If the daemon does not have enough
  information to make an estimate, the integer ``-1`` is returned.

**Example Result**

::

  0.00101079

.. note:: This estimate typically comes from the Bitcoin daemon, which only updates
  its estimate when new blocks are mined. The server is free to cache this internally
  for performance reasons, however it SHOULD avoid sending stale estimates
  by e.g. invalidating the cache before notifying clients of a new block header.


blockchain.headers.subscribe
============================

Subscribe to receive block headers when a new block is found.

**Signature**

  .. function:: blockchain.headers.subscribe()

**Result**

  The header of the current block chain tip.  The result is a dictionary with two members:

  * *hex*

    The binary header as a hexadecimal string.

  * *height*

    The height of the header, an integer.

**Example Result**

::

   {
     "height": 520481,
     "hex": "00000020890208a0ae3a3892aa047c5468725846577cfcd9b512b50000000000000000005dc2b02f2d297a9064ee103036c14d678f9afc7e3d9409cf53fd58b82e938e8ecbeca05a2d2103188ce804c4"
   }

**Notifications**

  As this is a subscription, the client will receive a notification
  when a new block is found.  The notification's signature is:

    .. function:: blockchain.headers.subscribe(header)
       :noindex:

    * *header*

      See **Result** above.

.. note:: should a new block arrive quickly, perhaps while the server
  is still processing prior blocks, the server may only notify of the
  most recent chain tip.  The protocol does not guarantee notification
  of all intermediate block headers.

  In a similar way the client must be prepared to handle chain
  reorganisations.  Should a re-org happen the new chain tip will not
  sit directly on top of the prior chain tip.  The client must be able
  to figure out the common ancestor block and request any missing
  block headers to acquire a consistent view of the chain state.


blockchain.scripthash.get_balance
=================================

Return the confirmed and unconfirmed balances of a :ref:`script hash
<script hashes>`.

**Signature**

  .. function:: blockchain.scripthash.get_balance(scripthash)
  .. versionadded:: 1.1

  *scripthash*

    The script hash as a hexadecimal string.

**Result**

  A dictionary with keys `confirmed` and `unconfirmed`.  The value of
  each is the appropriate balance in minimum coin units (satoshis).
  The `confirmed` balance is the sum of UTXO values at the current chaintip.
  The value for `unconfirmed` is the mempool delta (compared to `confirmed`),
  so note that it can also be negative.

**Result Example**

::

  {
    "confirmed": 103873966,
    "unconfirmed": 23684400
  }

blockchain.scripthash.get_history
=================================

Return the confirmed and unconfirmed history of a :ref:`script hash
<script hashes>`.

**Signature**

  .. function:: blockchain.scripthash.get_history(scripthash)
  .. versionadded:: 1.1

  *scripthash*

    The script hash as a hexadecimal string.

**Result**

  A list of confirmed transactions in blockchain order, with the
  output of :func:`blockchain.scripthash.get_mempool` appended to the
  list.  Each confirmed transaction is a dictionary with the following
  keys:

  * *height*

    The integer height of the block the transaction was confirmed in.

  * *tx_hash*

    The transaction hash in hexadecimal.

  See :func:`blockchain.scripthash.get_mempool` for how mempool
  transactions are returned.

**Result Examples**

::

  [
    {
      "height": 200004,
      "tx_hash": "acc3758bd2a26f869fcc67d48ff30b96464d476bca82c1cd6656e7d506816412"
    },
    {
      "height": 215008,
      "tx_hash": "f3e1bf48975b8d6060a9de8884296abb80be618dc00ae3cb2f6cee3085e09403"
    }
  ]

::

  [
    {
      "fee": 20000,
      "height": 0,
      "tx_hash": "9fbed79a1e970343fcd39f4a2d830a6bde6de0754ed2da70f489d0303ed558ec"
    }
  ]

blockchain.scripthash.get_mempool
=================================

Return the unconfirmed transactions of a :ref:`script hash <script
hashes>`.

**Signature**

  .. function:: blockchain.scripthash.get_mempool(scripthash)
  .. versionadded:: 1.1
  .. versionchanged:: 1.6
     results must be sorted (previously undefined order)

  *scripthash*

    The script hash as a hexadecimal string.

**Result**

  A list of mempool transactions. The order is the same as when computing the
  :ref:`status <status>` of the script hash.
  Each mempool transaction is a dictionary with the following keys:

  * *height*

    ``0`` if all inputs are confirmed, and ``-1`` otherwise.

  * *tx_hash*

    The transaction hash in hexadecimal.

  * *fee*

    The transaction fee in minimum coin units (satoshis).

**Result Example**

::

  [
    {
      "tx_hash": "45381031132c57b2ff1cbe8d8d3920cf9ed25efd9a0beb764bdb2f24c7d1c7e3",
      "height": 0,
      "fee": 24310
    }
  ]


blockchain.scripthash.listunspent
=================================

Return an ordered list of UTXOs sent to a script hash.

**Signature**

  .. function:: blockchain.scripthash.listunspent(scripthash)
  .. versionadded:: 1.1

  *scripthash*

    The script hash as a hexadecimal string.

**Result**

  A list of unspent outputs in blockchain order.  This function takes
  the mempool into account.  Mempool transactions paying to the
  address are included at the end of the list in an undefined order.
  Any output that is spent in the mempool does not appear.  Each
  output is a dictionary with the following keys:

  * *height*

    The integer height of the block the transaction was confirmed in.
    ``0`` if the transaction is in the mempool.

  * *tx_pos*

    The zero-based index of the output in the transaction's list of
    outputs.

  * *tx_hash*

    The output's transaction hash as a hexadecimal string.

  * *value*

    The output's value in minimum coin units (satoshis).


**Warning**

  In the case of pre-segwit legacy UTXOs, the satoshi value claimed by a server should be
  verified by the client by requesting the full funding transaction and parsing it
  to look for the output amount corresponding to ``tx_hash:tx_pos``.
  This is necessary as the pre-segwit legacy sighash does not commit to the input amount, so
  the server could try to trick a client into burning their coins as fees.
  Note that it is not necessary to SPV-verify ``tx_hash``, as the sighash commits to the txid,
  and the txid commits to the raw tx, from which we read out the satoshi amount.


**Result Example**

::

  [
    {
      "tx_pos": 0,
      "value": 45318048,
      "tx_hash": "9f2c45a12db0144909b5db269415f7319179105982ac70ed80d76ea79d923ebf",
      "height": 437146
    },
    {
      "tx_pos": 0,
      "value": 919195,
      "tx_hash": "3d2290c93436a3e964cfc2f0950174d8847b1fbe3946432c4784e168da0f019f",
      "height": 441696
    }
  ]

.. _subscribed:

blockchain.scripthash.subscribe
===============================

Subscribe to a script hash.

**Signature**

  .. function:: blockchain.scripthash.subscribe(scripthash)
  .. versionadded:: 1.1

  *scripthash*

    The script hash as a hexadecimal string.

**Result**

  The :ref:`status <status>` of the script hash.

**Notifications**

  The client will receive a notification when the :ref:`status <status>` of the script
  hash changes.  Its signature is

    .. function:: blockchain.scripthash.subscribe(scripthash, status)
       :noindex:

blockchain.scripthash.unsubscribe
=================================

Unsubscribe from a script hash, preventing future notifications if its :ref:`status
<status>` changes.

**Signature**

  .. function:: blockchain.scripthash.unsubscribe(scripthash)
  .. versionadded:: 1.4.2

  *scripthash*

    The script hash as a hexadecimal string.

**Result**

  Returns :const:`True` if the scripthash was subscribed to, otherwise :const:`False`.
  Note that :const:`False` might be returned even for something subscribed to earlier,
  because the server can drop subscriptions in rare circumstances.

blockchain.transaction.broadcast
================================

Broadcast a transaction to the network.

**Signature**

  .. function:: blockchain.transaction.broadcast(raw_tx)
  .. versionchanged:: 1.1
     errors returned as JSON RPC errors rather than as a result.

  *raw_tx*

    The raw transaction as a hexadecimal string.

**Result**

  The transaction hash as a hexadecimal string.

  **Note** protocol version 1.0 (only) does not respond according to
  the JSON RPC specification if an error occurs.  If the daemon
  rejects the transaction, the result is the error message string from
  the daemon, as if the call were successful.  The client needs to
  determine if an error occurred by comparing the result to the
  expected transaction hash.

**Result Examples**

::

   "a76242fce5753b4212f903ff33ac6fe66f2780f34bdb4b33b175a7815a11a98e"

Protocol version 1.0 returning an error as the result:

::

  "258: txn-mempool-conflict"

blockchain.transaction.broadcast_package
========================================

Broadcast a package of transactions to the network (submitpackage). The package must consist of a child with its parents,
and none of the parents may depend on one another. The package must be topologically sorted,
with the child being the last element in the array.

**Signature**

  .. function:: blockchain.transaction.broadcast_package(raw_txs, verbose=false)
  .. versionadded:: 1.6

  *raw_txs*

    An array of raw transactions, each as a hexadecimal string.

  *verbose*

    Whether a verbose coin-specific response is required.

**Result**

  If *verbose* is :const:`false`:

    A dictionary with the following keys:

    * `success`
        * Type: bool
        * Value: Indicating the result of the package submission
    * `errors`
        * Type: Optional[List[Dict]]
        * Value: Error message and txid (NOT wtxid) of transactions that were not accepted

  If *verbose* is :const:`true`:

    The result is a bitcoind-specific dictionary -- whatever bitcoind
    returns as response to the submitpackage (or equivalent) RPC.
    (`example docs <https://bitcoincore.org/en/doc/30.0.0/rpc/rawtransactions/submitpackage/>`_ for Bitcoin Core)

    As the exact structure and semantics depend on the bitcoind version (or alternative bitcoind, e.g. btcd),
    the electrum protocol can make no guarantees about it.
    Unlike the `verbose=False` result, which is guaranteed to be stable and can be relied upon,
    the `verbose=True` result should be considered experimental and better-suited for debugging.

.. note:: The exact relay behaviour might depend on the bitcoind version of the server.

.. note:: Server implementations should verify (e.g. by enforcing a minimum bitcoind version at runtime)
  that the backing bitcoind supports relay of transaction packages. For example, note that Bitcoin Core 26.0
  already exposes the `submitpackage` RPC however it is effectively non-functional until Bitcoin Core 28.0.

**Result Example**

When *verbose* is :const:`false`:

    Successful broadcast::

        {
          "success": true
        }

    With errors::

        {
          "success": false,
          "errors":
          [
            {
              "txid": "ec6f295cd4b1b91f59cabb0ab8fdc7c76580db08be6426e465f75a69d82b9659",
              "error": "bad-txns-inputs-missingorspent"
            }
          ]
        }

When *verbose* is :const:`true` (exact structure depends on bitcoind impl and version, and should not be relied upon)::

    {                                   (json object)
      "package_msg" : "str",            (string) The transaction package result message. "success" indicates all transactions were accepted into or are already in the mempool.
      "tx-results" : {                  (json object) transaction results keyed by wtxid
        "wtxid" : {                     (json object) transaction wtxid
          "txid" : "hex",               (string) The transaction hash in hex
          "other-wtxid" : "hex",        (string, optional) The wtxid of a different transaction with the same txid but different witness found in the mempool. This means the submitted transaction was ignored.
          "vsize" : n,                  (numeric, optional) Sigops-adjusted virtual transaction size.
          "fees" : {                    (json object, optional) Transaction fees
            "base" : n,                 (numeric) transaction fee in BTC
            "effective-feerate" : n,    (numeric, optional) if the transaction was not already in the mempool, the effective feerate in BTC per KvB. For example, the package feerate and/or feerate with modified fees from prioritisetransaction.
            "effective-includes" : [    (json array, optional) if effective-feerate is provided, the wtxids of the transactions whose fees and vsizes are included in effective-feerate.
              "hex",                    (string) transaction wtxid in hex
              ...
            ]
          },
          "error" : "str"               (string, optional) The transaction error string, if it was rejected by the mempool
        },
        ...
      },
      "replaced-transactions" : [       (json array, optional) List of txids of replaced transactions
        "hex",                          (string) The transaction id
        ...
      ]
    }

.. note:: If the input is malformed, notably if `raw_txs` is not a well-formed package,
  errors will be sent back as JSON RPC ERROR, as usual.
  Ultimately the distinction can depend on bitcoind.
  Compare examples (id=3 gets JSON RPC ERROR, but id=4 gets success=false with errors array)::

    <- {"id": 3, "method": "blockchain.transaction.broadcast_package", "params": [["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", "02000000000101ab93b5c11c9a591b441de4228c942603a0479fa0d33a1a2bee72e75bd301c25e0000000000fdffffff01640c03000000000016001446116f48b60ad5b22377dcf951643e2e1aa3957a0247304402206002cc311d16b5cef7349bcd4174d3ae14d5741680ab81d7e24bc31c89634fd6022072d0d6b72c4ddbe62c527ebc5955677793cc13fe801ec22604d93bbc1b1f3291012102fb265cce2019e555fe23fb45e4cbc3d966bb399a52b2e93b808ad7961b426de1a4090000"]]}
    -> {"jsonrpc":"2.0","error":{"code":1,"message":"the tx package was rejected by network rules.\n\npackage topology disallowed. not child-with-parents or parents depend on each other.."},"id":3}

    <- {"id": 4, "method": "blockchain.transaction.broadcast_package", "params": [["0200000000010148d372010d796a89f12864b5c86495d67bce98cb9ac3ba652bf811aa6b82c36c0000000000fdffffff01d20c030000000000160014e437538b7f13871562066babd1fbab72b4fba958024730440220662e4d917c0af3b37dd0bad65c9b46ba2a1504cd4f1346f35c0020f6d0edbd0e02207b44f98612bd3f58164385f4a572af2a2f471c924f6569aa6f3ddcaaa0e57753012103c3172a9f8820681c62b8bf28961988a4642b33f4920b9da14b06965c7fff83fd68090000", "02000000000101ab93b5c11c9a591b441de4228c942603a0479fa0d33a1a2bee72e75bd301c25e0000000000fdffffff014e0c03000000000016001446116f48b60ad5b22377dcf951643e2e1aa3957a0247304402202850349c76c41b801c429feaee96d773788b478c1cf051e967824fe504e5948902204bbede1252490c06c38feb206266aaf126937f6a3bc0a16d038fabde9781c6fd012102fb265cce2019e555fe23fb45e4cbc3d966bb399a52b2e93b808ad7961b426de1a4090000"]]}
    -> {"jsonrpc":"2.0","result":{"success":false,"errors":[{"txid":"c13d8d63284853d3417a150cfddcfc62d31cab4b311c9322cb43f979a518ac3a","error":"insufficient fee, rejecting replacement c13d8d63284853d3417a150cfddcfc62d31cab4b311c9322cb43f979a518ac3a, not enough additional fees to relay; 0.00000022 < 0.0000011"}]},"id":4}


blockchain.transaction.get
==========================

Return a raw transaction.

**Signature**

  .. function:: blockchain.transaction.get(tx_hash, verbose=false)
  .. versionchanged:: 1.1
     ignored argument *height* removed
  .. versionchanged:: 1.2
     *verbose* argument added

  *tx_hash*

    The transaction hash as a hexadecimal string.

  *verbose*

    Whether the verbose bitcoind response is required.

**Result**

    If *verbose* is :const:`false`:

       The raw transaction as a hexadecimal string.

    If *verbose* is :const:`true`:

       The result is a bitcoind-specific dictionary -- whatever bitcoind
       returns when asked for a verbose form of the raw transaction.

**Example Results**

When *verbose* is :const:`false`::

  "01000000015bb9142c960a838329694d3fe9ba08c2a6421c5158d8f7044cb7c48006c1b48"
  "4000000006a4730440220229ea5359a63c2b83a713fcc20d8c41b20d48fe639a639d2a824"
  "6a137f29d0fc02201de12de9c056912a4e581a62d12fb5f43ee6c08ed0238c32a1ee76921"
  "3ca8b8b412103bcf9a004f1f7a9a8d8acce7b51c983233d107329ff7c4fb53e44c855dbe1"
  "f6a4feffffff02c6b68200000000001976a9141041fb024bd7a1338ef1959026bbba86006"
  "4fe5f88ac50a8cf00000000001976a91445dac110239a7a3814535c15858b939211f85298"
  "88ac61ee0700"

When *verbose* is :const:`true`::

 {
   "blockhash": "0000000000000000015a4f37ece911e5e3549f988e855548ce7494a0a08b2ad6",
   "blocktime": 1520074861,
   "confirmations": 679,
   "hash": "36a3692a41a8ac60b73f7f41ee23f5c917413e5b2fad9e44b34865bd0d601a3d",
   "hex": "01000000015bb9142c960a838329694d3fe9ba08c2a6421c5158d8f7044cb7c48006c1b484000000006a4730440220229ea5359a63c2b83a713fcc20d8c41b20d48fe639a639d2a8246a137f29d0fc02201de12de9c056912a4e581a62d12fb5f43ee6c08ed0238c32a1ee769213ca8b8b412103bcf9a004f1f7a9a8d8acce7b51c983233d107329ff7c4fb53e44c855dbe1f6a4feffffff02c6b68200000000001976a9141041fb024bd7a1338ef1959026bbba860064fe5f88ac50a8cf00000000001976a91445dac110239a7a3814535c15858b939211f8529888ac61ee0700",
   "locktime": 519777,
   "size": 225,
   "time": 1520074861,
   "txid": "36a3692a41a8ac60b73f7f41ee23f5c917413e5b2fad9e44b34865bd0d601a3d",
   "version": 1,
   "vin": [ {
     "scriptSig": {
       "asm": "30440220229ea5359a63c2b83a713fcc20d8c41b20d48fe639a639d2a8246a137f29d0fc02201de12de9c056912a4e581a62d12fb5f43ee6c08ed0238c32a1ee769213ca8b8b[ALL|FORKID] 03bcf9a004f1f7a9a8d8acce7b51c983233d107329ff7c4fb53e44c855dbe1f6a4",
       "hex": "4730440220229ea5359a63c2b83a713fcc20d8c41b20d48fe639a639d2a8246a137f29d0fc02201de12de9c056912a4e581a62d12fb5f43ee6c08ed0238c32a1ee769213ca8b8b412103bcf9a004f1f7a9a8d8acce7b51c983233d107329ff7c4fb53e44c855dbe1f6a4"
     },
     "sequence": 4294967294,
     "txid": "84b4c10680c4b74c04f7d858511c42a6c208bae93f4d692983830a962c14b95b",
     "vout": 0}],
   "vout": [ { "n": 0,
              "scriptPubKey": { "addresses": [ "12UxrUZ6tyTLoR1rT1N4nuCgS9DDURTJgP"],
                                "asm": "OP_DUP OP_HASH160 1041fb024bd7a1338ef1959026bbba860064fe5f OP_EQUALVERIFY OP_CHECKSIG",
                                "hex": "76a9141041fb024bd7a1338ef1959026bbba860064fe5f88ac",
                                "reqSigs": 1,
                                "type": "pubkeyhash"},
              "value": 0.0856647},
            { "n": 1,
              "scriptPubKey": { "addresses": [ "17NMgYPrguizvpJmB1Sz62ZHeeFydBYbZJ"],
                                "asm": "OP_DUP OP_HASH160 45dac110239a7a3814535c15858b939211f85298 OP_EQUALVERIFY OP_CHECKSIG",
                                "hex": "76a91445dac110239a7a3814535c15858b939211f8529888ac",
                                "reqSigs": 1,
                                "type": "pubkeyhash"},
              "value": 0.1360904}]}

blockchain.transaction.get_merkle
=================================

Return the merkle branch to a confirmed transaction given its hash
and height.

**Signature**

  .. function:: blockchain.transaction.get_merkle(tx_hash, height)

  *tx_hash*

    The transaction hash as a hexadecimal string.

  *height*

    The height at which it was confirmed, an integer.

**Result**

  A dictionary with the following keys:

  * *block_height*

    The height of the block the transaction was confirmed in.

  * *merkle*

    A list of transaction hashes the current hash is paired with,
    recursively, in order to trace up to obtain merkle root of the
    block, deepest pairing first.

  * *pos*

    The 0-based index of the position of the transaction in the
    ordered list of transactions in the block.

**Result Example**

::

  {
    "merkle":
    [
      "713d6c7e6ce7bbea708d61162231eaa8ecb31c4c5dd84f81c20409a90069cb24",
      "03dbaec78d4a52fbaf3c7aa5d3fccd9d8654f323940716ddf5ee2e4bda458fde",
      "e670224b23f156c27993ac3071940c0ff865b812e21e0a162fe7a005d6e57851",
      "369a1619a67c3108a8850118602e3669455c70cdcdb89248b64cc6325575b885",
      "4756688678644dcb27d62931f04013254a62aeee5dec139d1aac9f7b1f318112",
      "7b97e73abc043836fd890555bfce54757d387943a6860e5450525e8e9ab46be5",
      "61505055e8b639b7c64fd58bce6fc5c2378b92e025a02583303f69930091b1c3",
      "27a654ff1895385ac14a574a0415d3bbba9ec23a8774f22ec20d53dd0b5386ff",
      "5312ed87933075e60a9511857d23d460a085f3b6e9e5e565ad2443d223cfccdc",
      "94f60b14a9f106440a197054936e6fb92abbd69d6059b38fdf79b33fc864fca0",
      "2d64851151550e8c4d337f335ee28874401d55b358a66f1bafab2c3e9f48773d"
    ],
    "block_height": 450538,
    "pos": 710
  }

blockchain.transaction.id_from_pos
==================================

Return a transaction hash and optionally a merkle proof,
given a block height and a position in the block.

**Signature**

  .. function:: blockchain.transaction.id_from_pos(height, tx_pos, merkle=false)
  .. versionadded:: 1.4

  *height*

    The main chain block height, a non-negative integer.

  *tx_pos*

    A zero-based index of the transaction in the given block, an integer.

  *merkle*

    Whether a merkle proof should also be returned, a boolean.

**Result**

  If *merkle* is :const:`false`, the transaction hash as a hexadecimal string.
  If :const:`true`, a dictionary with the following keys:

  * *tx_hash*

    The transaction hash as a hexadecimal string.

  * *merkle*

    A list of transaction hashes the current hash is paired with,
    recursively, in order to trace up to obtain merkle root of the
    block, deepest pairing first.

**Example Results**

When *merkle* is :const:`false`::

  "fc12dfcb4723715a456c6984e298e00c479706067da81be969e8085544b0ba08"

When *merkle* is :const:`true`::

  {
    "tx_hash": "fc12dfcb4723715a456c6984e298e00c479706067da81be969e8085544b0ba08",
    "merkle":
    [
      "928c4275dfd6270349e76aa5a49b355eefeb9e31ffbe95dd75fed81d219a23f8",
      "5f35bfb3d5ef2ba19e105dcd976928e675945b9b82d98a93d71cbad0e714d04e",
      "f136bcffeeed8844d54f90fc3ce79ce827cd8f019cf1d18470f72e4680f99207",
      "6539b8ab33cedf98c31d4e5addfe40995ff96c4ea5257620dfbf86b34ce005ab",
      "7ecc598708186b0b5bd10404f5aeb8a1a35fd91d1febbb2aac2d018954885b1e",
      "a263aae6c470b9cde03b90675998ff6116f3132163911fafbeeb7843095d3b41",
      "c203983baffe527edb4da836bc46e3607b9a36fa2c6cb60c1027f0964d971b29",
      "306d89790df94c4632d652d142207f53746729a7809caa1c294b895a76ce34a9",
      "c0b4eff21eea5e7974fe93c62b5aab51ed8f8d3adad4583c7a84a98f9e428f04",
      "f0bd9d2d4c4cf00a1dd7ab3b48bbbb4218477313591284dcc2d7ca0aaa444e8d",
      "503d3349648b985c1b571f59059e4da55a57b0163b08cc50379d73be80c4c8f3"
    ]
  }

mempool.get_fee_histogram
=========================

Return a histogram of the fee rates paid by transactions in the memory
pool, weighted by transaction size.

**Signature**

  .. function:: mempool.get_fee_histogram()
  .. versionadded:: 1.2

**Result**

  The histogram is an array of [*fee*, *vsize*] pairs, where |vsize_n|
  is the cumulative virtual size of mempool transactions with a fee rate
  in the interval [|fee_n1|, |fee_n|], and |fee_n1| > |fee_n|.

  .. |vsize_n| replace:: vsize\ :sub:`n`
  .. |fee_n| replace:: fee\ :sub:`n`
  .. |fee_n1| replace:: fee\ :sub:`n-1`

  Fee intervals may have variable size.  The choice of appropriate
  intervals is currently not part of the protocol.

  *fee* uses sat/vbyte as unit, and must be a non-negative integer or float.

  *vsize* uses vbyte as unit, and must be a non-negative integer.

**Example Results**

::

    [[12, 128812], [4, 92524], [2, 6478638], [1, 22890421]]

::

   [[59.5, 30324], [40.1, 34305], [35.0, 38459], [29.3, 41270], [27.0, 45167], [24.3, 53512], [22.9, 53488], [21.8, 70279], [20.0, 65328], [18.2, 72180], [18.1, 5254], [18.0, 191579], [16.5, 103640], [15.7, 106715], [15.1, 141776], [14.0, 183261], [13.5, 166496], [11.8, 166050], [11.1, 242436], [9.2, 184043], [7.1, 202137], [5.2, 222011], [4.8, 344788], [4.6, 17101], [4.5, 1696864], [4.1, 598001], [4.0, 32688687], [3.9, 505192], [3.8, 38417], [3.7, 2944970], [3.3, 693364], [3.2, 726373], [3.1, 308878], [3.0, 11884957], [2.6, 996967], [2.3, 822802], [2.2, 9075547], [2.1, 12149801], [2.0, 16387874], [1.4, 873120], [1.3, 3493364], [1.1, 2302460], [1.0, 23204633]]


mempool.get_info
================

Returns details on the active state of the TX memory pool.

**Signature**

  .. function:: mempool.get_info()
  .. versionadded:: 1.6

**Result**

  A dictionary with the following keys:

    * `mempoolminfee`
        * Type: floating point number
        * Value:
            Dynamic minimum fee rate in BTC/kvB for tx to be accepted given current conditions.
            The maximum of minrelaytxfee and minimum mempool fee, in BTC/kvB.
    * `minrelaytxfee`
        * Type: floating point number
        * Value: Static operator-configurable minimum relay fee for transactions, in BTC/kvB.
    * `incrementalrelayfee`
        * Type: floating point number
        * Value: Static operator-configurable minimum fee rate increment for mempool limiting or replacement, in BTC/kvB.

**Example Result**

::

  {
      "mempoolminfee": 0.00001000,
      "minrelaytxfee": 0.00001000,
      "incrementalrelayfee": 0.00001000
  }


server.add_peer
===============

A newly-started server uses this call to get itself into other servers'
peers lists.  It should not be used by wallet clients.

**Signature**

  .. function:: server.add_peer(features)

  .. versionadded:: 1.1

  * *features*

    The same information that a call to the sender's
    :func:`server.features` RPC call would return.

**Result**

  A boolean indicating whether the request was tentatively accepted.
  The requesting server will appear in :func:`server.peers.subscribe`
  when further sanity checks complete successfully.


server.banner
=============

Return a banner to be shown in the Electrum console.

**Signature**

  .. function:: server.banner()

**Result**

  A string.

**Example Result**

  ::

     "Welcome to Electrum!"


server.donation_address
=======================

Return a server donation address.

**Signature**

  .. function:: server.donation_address()

**Result**

  A string.

**Example Result**

  ::

     "1BWwXJH3q6PRsizBkSGm2Uw4Sz1urZ5sCj"


server.features
===============

Return a list of features and services supported by the server.

**Signature**

  .. function:: server.features()

**Result**

  A dictionary of keys and values.  Each key represents a feature or
  service of the server, and the value gives additional information.

  The following features MUST be reported by the server.  Additional
  key-value pairs may be returned.

  * *hosts*

    A dictionary, keyed by host name, that this server can be reached
    at.  Normally this will only have a single entry; other entries
    can be used in case there are other connection routes (e.g. Tor).

    The value for a host is itself a dictionary, with the following
    optional keys:

    * *ssl_port*

      An integer.  Omit or set to :const:`null` if SSL connectivity
      is not provided.

    * *tcp_port*

      An integer.  Omit or set to :const:`null` if TCP connectivity is
      not provided.

    A server should ignore information provided about any host other
    than the one it connected to.

  * *genesis_hash*

    The hash of the genesis block.  This is used to detect if a peer
    is connected to one serving a different network.

  * *hash_function*

    The hash function the server uses for :ref:`script hashing
    <script hashes>`.  The client must use this function to hash
    pay-to-scripts to produce script hashes to send to the server.
    The default is "sha256".  "sha256" is currently the only
    acceptable value.

  * *server_version*

    A string that identifies the server software.  Should be the same
    as the first element of the result to the :func:`server.version` RPC call.

  * *protocol_max*
  * *protocol_min*

    Strings that are the minimum and maximum Electrum protocol
    versions this server speaks.  Example: "1.1".

  * *pruning*

    An integer, the pruning limit.  Omit or set to :const:`null` if
    there is no pruning limit.  Should be the same as what would
    suffix the letter ``p`` in the IRC real name.

**Example Result**

::

  {
      "genesis_hash": "000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943",
      "hosts": {"14.3.140.101": {"tcp_port": 51001, "ssl_port": 51002}},
      "protocol_max": "1.0",
      "protocol_min": "1.0",
      "pruning": null,
      "server_version": "ElectrumX 1.0.17",
      "hash_function": "sha256"
  }


server.peers.subscribe
======================

Return a list of peer servers.  Despite the name this is not a
subscription and the server must send no notifications.

**Signature**

  .. function:: server.peers.subscribe()

**Result**

  An array of peer servers, each returned as a 3-element array.  For
  example::

    ["107.150.45.210",
     "e.anonyhost.org",
     ["v1.0", "p10000", "t", "s995"]]

  The first element is the IP address, the second is the host name
  (which might also be an IP address), and the third is a list of
  server features.  Each feature and starts with a letter.  'v'
  indicates the server maximum protocol version, 'p' its pruning limit
  and is omitted if it does not prune, 't' is the TCP port number, and
  's' is the SSL port number.  If a port is not given for 's' or 't'
  the default port for the coin network is implied.  If 's' or 't' is
  missing then the server does not support that transport.

server.ping
===========

Ping the server to ensure it is responding, and to keep the session
alive.  The server may disconnect clients that have sent no requests
for roughly 10 minutes.

**Signature**

  .. function:: server.ping()
  .. versionadded:: 1.2

**Result**

  Returns :const:`null`.

server.version
==============

Identify the client to the server and negotiate the protocol version.
This must be the first message sent on the wire.
Only the first :func:`server.version` message is accepted.

**Signature**

  .. function:: server.version(client_name="", protocol_version="1.4")
  .. versionchanged:: 1.6
     server must tolerate and ignore extraneous args

  * *client_name*

    A string identifying the connecting client software.

  * *protocol_version*

    An array ``[protocol_min, protocol_max]``, each of which is a
    string.  If ``protocol_min`` and ``protocol_max`` are the same,
    they can be passed as a single string rather than as an array of
    two strings, as for the default value.

  Extraneous unknown args MUST be tolerated and ignored by the server,
  to allow for future extensions.

  The server should use the highest protocol version both support::

    version = min(client.protocol_max, server.protocol_max)

  If this is below the value::

    max(client.protocol_min, server.protocol_min)

  then there is no protocol version in common and the server must
  close the connection.  Otherwise it should send a response
  appropriate for that protocol version.

**Result**

  An array of 2 strings:

     ``[server_software_version, protocol_version]``

  identifying the server and the protocol version that will be used
  for future communication.

**Example**::

  server.version("Electrum 3.0.6", ["1.1", "1.2"])

**Example Result**::

  ["ElectrumX 1.2.1", "1.2"]

**Example**

  Redundant unknown arguments MUST be ignored and tolerated by the server::

    server.version("electrum/4.6.2", ["1.4", "1.6"], "trailing_garbage1", 9999.9, "dd": {})

**Example Result**::

  ["ElectrumX 1.18.0", "1.4"]


Some more stuff for altcoins
============================

:ref:`Protocol Methods for altcoins`