
The Python library pycoin (http://github.com/richardkiss/pycoin), originally written and maintained by Richard Kiss, is a Python-based library that supports manipulation of bitcoin keys and transactions, even supporting the scripting language enough to properly deal with non-standard transactions. As of June, 2014, the latest released version is 0.42, and all examples here are based on that version; be warned that it is still under active development, so later versions may have differences in API or command-line tools.

The pycoin library supports both Python 2 (2.7.x) and Python 3 (after 3.3), and comes with some handy command-line utilities, ku and tx.


To install:

$ python3 -m venv /tmp/pycoin
$ . /tmp/pycoin/bin/activate
$ pip install pycoin==0.42
Downloading/unpacking pycoin==0.42
  Downloading pycoin-0.42.tar.gz (66kB): 66kB downloaded
  Running setup.py (path:/tmp/pycoin/build/pycoin/setup.py) egg_info for package pycoin
    
Installing collected packages: pycoin
  Running setup.py install for pycoin
    
    Installing tx script to /tmp/pycoin/bin
    Installing cache_tx script to /tmp/pycoin/bin
    Installing bu script to /tmp/pycoin/bin
    Installing fetch_unspent script to /tmp/pycoin/bin
    Installing block script to /tmp/pycoin/bin
    Installing spend script to /tmp/pycoin/bin
    Installing ku script to /tmp/pycoin/bin
    Installing genwallet script to /tmp/pycoin/bin
Successfully installed pycoin
Cleaning up...
$

KU and TX
=========

KU
--

The command-line utility ```ku``` ("key utility") is Swiss Army knife for manipulating keys. It supports BIP32 keys, WIF, and address (bitcoin and alt coins). Here are some examples.

Create a BIP32 Key using the default entropy sources of GPG and /dev/random:

    $ ku create

    input           : create
    network         : Bitcoin
    wallet key      : xprv9s21ZrQH143K3LU5ctPZTBnb9kTjA5Su9DcWHvXJemiJBsY7VqXUG7hipgdWaU
                        m2nhnzdvxJf5KJo9vjP2nABX65c5sFsWsV8oXcbpehtJi
    public version  : xpub661MyMwAqRbcFpYYiuvZpKjKhnJDZYAkWSY76JvvD7FH4fsG3Nqiov2CfxzxY8
                        DGcpfT56AMFeo8M8KPkFMfLUtvwjwb6WPv8rY65L2q8Hz
    tree depth      : 0
    fingerprint     : 9d9c6092
    parent f'print  : 00000000
    child index     : 0
    chain code      : 80574fb260edaa4905bc86c9a47d30c697c50047ed466c0d4a5167f6821e8f3c
    private key     : yes
    secret exponent : 112471538590155650688604752840386134637231974546906847202389294096567806844862
     hex            : f8a8a28b28a916e1043cc0aca52033a18a13cab1638d544006469bc171fddfbe
    wif             : L5Z54xi6qJusQT42JHA44mfPVZGjyb4XBRWfxAzUWwRiGx1kV4sP
     uncompressed   : 5KhoEavGNNH4GHKoy2Ptu4KfdNp4r56L5B5un8FP6RZnbsz5Nmb
    public pair x   : 76460638240546478364843397478278468101877117767873462127021560368290114016034
    public pair y   : 59807879657469774102040120298272207730921291736633247737077406753676825777701
     x as hex       : a90b3008792432060fa04365941e09a8e4adf928bdbdb9dad41131274e379322
     y as hex       : 843a0f6ed9c0eb1962c74533795406914fe3f1957c5238951f4fe245a4fcd625
    y parity        : odd
    key pair as sec : 03a90b3008792432060fa04365941e09a8e4adf928bdbdb9dad41131274e379322
     uncompressed   : 04a90b3008792432060fa04365941e09a8e4adf928bdbdb9dad41131274e379322
                        843a0f6ed9c0eb1962c74533795406914fe3f1957c5238951f4fe245a4fcd625
    hash160         : 9d9c609247174ae323acfc96c852753fe3c8819d
     uncompressed   : 8870d869800c9b91ce1eb460f4c60540f87c15d7
    Bitcoin address : 1FNNRQ5fSv1wBi5gyfVBs2rkNheMGt86sp
     uncompressed   : 1DSS5isnH4FsVaLVjeVXewVSpfqktdiQAM


Create a BIP32 key from a passphrase:

*THE PASSPHRASE IN THIS EXAMPLE IS WAY TOO EASY TO GUESS.*

      $ ku P:foo

      input           : P:foo
      network         : Bitcoin
      wallet key      : xprv9s21ZrQH143K31AgNK5pyVvW23gHnkBq2wh5aEk6g1s496M8ZMjxncCKZKgb5j
                          ZoY5eSJMJ2Vbyvi2hbmQnCuHBujZ2WXGTux1X2k9Krdtq
      public version  : xpub661MyMwAqRbcFVF9ULcqLdsEa5WnCCugQAcgNd9iEMQ31tgH6u4DLQWoQayvtS
                          VYFvXz2vPPpbXE1qpjoUFidhjFj82pVShWu9curWmb2zy
      tree depth      : 0
      fingerprint     : 5d353a2e
      parent f'print  : 00000000
      child index     : 0
      chain code      : 5eeb1023fd6dd1ae52a005ce0e73420821e1d90e08be980a85e9111fd7646bbc
      private key     : yes
      secret exponent : 65825730547097305716057160437970790220123864299761908948746835886007793998275
       hex            : 91880b0e3017ba586b735fe7d04f1790f3c46b818a2151fb2def5f14dd2fd9c3
      wif             : L26c3H6jEPVSqAr1usXUp9qtQJw6NHgApq6Ls4ncyqtsvcq2MwKH
       uncompressed   : 5JvNzA5vXDoKYJdw8SwwLHxUxaWvn9mDea6k1vRPCX7KLUVWa7W
      public pair x   : 81821982719381104061777349269130419024493616650993589394553404347774393168191
      public pair y   : 58994218069605424278320703250689780154785099509277691723126325051200459038290
       x as hex       : b4e599dfa44555a4ed38bcfff0071d5af676a86abf123c5b4b4e8e67a0b0b13f
       y as hex       : 826d8b4d3010aea16ff4c1c1d3ae68541d9a04df54a2c48cc241c2983544de52
      y parity        : even
      key pair as sec : 02b4e599dfa44555a4ed38bcfff0071d5af676a86abf123c5b4b4e8e67a0b0b13f
       uncompressed   : 04b4e599dfa44555a4ed38bcfff0071d5af676a86abf123c5b4b4e8e67a0b0b13f
                          826d8b4d3010aea16ff4c1c1d3ae68541d9a04df54a2c48cc241c2983544de52
      hash160         : 5d353a2ecdb262477172852d57a3f11de0c19286
       uncompressed   : e5bd3a7e6cb62b4c820e51200fb1c148d79e67da
      Bitcoin address : 19Vqc8uLTfUonmxUEZac7fz1M5c5ZZbAii
       uncompressed   : 1MwkRkogzBRMehBntgcq2aJhXCXStJTXHT

Get info as JSON:

    $ ku P:foo -P -j
    {
       "y_parity": "even", 
       "public_pair_y_hex": "826d8b4d3010aea16ff4c1c1d3ae68541d9a04df54a2c48cc241c2983544de52", 
       "private_key": "no", 
       "parent_fingerprint": "00000000", 
       "tree_depth": "0", 
       "network": "Bitcoin", 
       "btc_address_uncompressed": "1MwkRkogzBRMehBntgcq2aJhXCXStJTXHT", 
       "key_pair_as_sec_uncompressed": "04b4e599dfa44555a4ed38bcfff0071d5af676a86abf123c5b4b4e8e67a0b0b13f826d8b4d3010aea16ff4c1c1d3ae68541d9a04df54a2c48cc241c2983544de52", 
       "public_pair_x_hex": "b4e599dfa44555a4ed38bcfff0071d5af676a86abf123c5b4b4e8e67a0b0b13f", 
       "wallet_key": "xpub661MyMwAqRbcFVF9ULcqLdsEa5WnCCugQAcgNd9iEMQ31tgH6u4DLQWoQayvtSVYFvXz2vPPpbXE1qpjoUFidhjFj82pVShWu9curWmb2zy", 
       "chain_code": "5eeb1023fd6dd1ae52a005ce0e73420821e1d90e08be980a85e9111fd7646bbc", 
       "child_index": "0", 
       "hash160_uncompressed": "e5bd3a7e6cb62b4c820e51200fb1c148d79e67da", 
       "btc_address": "19Vqc8uLTfUonmxUEZac7fz1M5c5ZZbAii", 
       "fingerprint": "5d353a2e", 
       "hash160": "5d353a2ecdb262477172852d57a3f11de0c19286", 
       "input": "P:foo", 
       "public_pair_x": "81821982719381104061777349269130419024493616650993589394553404347774393168191", 
       "public_pair_y": "58994218069605424278320703250689780154785099509277691723126325051200459038290", 
       "key_pair_as_sec": "02b4e599dfa44555a4ed38bcfff0071d5af676a86abf123c5b4b4e8e67a0b0b13f"
    }

Public BIP32 Key:

    $ ku -w -P P:foo
    xpub661MyMwAqRbcFVF9ULcqLdsEa5WnCCugQAcgNd9iEMQ31tgH6u4DLQWoQayvtSVYFvXz2vPPpbXE1qpjoUFidhjFj82pVShWu9curWmb2zy

Generate a subkey:

    $ ku -w -s3/2 P:foo
    xprv9wTErTSkjVyJa1v4cUTFMFkWMe5eu8ErbQcs9xajnsUzCBT7ykHAwdrxvG3g3f6BFk7ms5hHBvmbdutNmyg6iogWKxx6mefEw4M8EroLgKj

Hardened subkey:

    $ ku -w -s3/2H P:foo
    xprv9wTErTSu5AWGkDeUPmqBcbZWX1xq85ZNX9iQRQW9DXwygFp7iRGJo79dsVctcsCHsnZ3XU3DhsuaGZbDh8iDkBN45k67UKsJUXM1JfRCdn1

WIF:

    $ ku -W P:foo
    L26c3H6jEPVSqAr1usXUp9qtQJw6NHgApq6Ls4ncyqtsvcq2MwKH

Address:

    $ ku -a P:foo
    19Vqc8uLTfUonmxUEZac7fz1M5c5ZZbAii

Generate a bunch of subkeys:

    $ ku P:foo -s 0/0-5 -w
    xprv9xWkBDfyBXmZjBG9EiXBpy67KK72fphUp9utJokEBFtjsjiuKUUDF5V3TU8U8cDzytqYnSekc8bYuJS8G3bhXxKWB89Ggn2dzLcoJsuEdRK
    xprv9xWkBDfyBXmZnzKf3bAGifK593gT7WJZPnYAmvc77gUQVej5QHckc5Adtwxa28ACmANi9XhCrRvtFqQcUxt8rUgFz3souMiDdWxJDZnQxzx
    xprv9xWkBDfyBXmZqdXA8y4SWqfBdy71gSW9sjx9JpCiJEiBwSMQyRxan6srXUPBtj3PTxQFkZJAiwoUpmvtrxKZu4zfsnr3pqyy2vthpkwuoVq
    xprv9xWkBDfyBXmZsA85GyWj9uYPyoQv826YAadKWMaaEosNrFBKgj2TqWuiWY3zuqxYGpHfv9cnGj5P7e8EskpzKL1Y8Gk9aX6QbryA5raK73p
    xprv9xWkBDfyBXmZv2q3N66hhZ8DAcEnQDnXML1J62krJAcf7Xb1HJwuW2VMJQrCofY2jtFXdiEY8UsRNJfqK6DAdyZXoMvtaLHyWQx3FS4A9zw
    xprv9xWkBDfyBXmZw4jEYXUHYc9fT25k9irP87n2RqfJ5bqbjKdT84Mm7Wtc2xmzFuKg7iYf7XFHKkSsaYKWKJbR54bnyAD9GzjUYbAYTtN4ruo

Generate the corresponding addresses:

    $ ku P:foo -s 0/0-5 -a
    1MrjE78H1R1rqdFrmkjdHnPUdLCJALbv3x
    1AnYyVEcuqeoVzH96zj1eYKwoWfwte2pxu
    1GXr1kZfxE1FcK6ZRD5sqqqs5YfvuzA1Lb
    116AXZc4bDVQrqmcinzu4aaPdrYqvuiBEK
    1Cz2rTLjRM6pMnxPNrRKp9ZSvRtj5dDUML
    1WstdwPnU6HEUPme1DQayN9nm6j7nDVEM

Generate the corresponding WIFS:

    $ ku P:foo -s 0/0-5 -W
    L5a4iE5k9gcJKGqX3FWmxzBYQc29PvZ6pgBaePLVqT5YByEnBomx
    Kyjgne6GZwPGB6G6kJEhoPbmyjMP7D5d3zRbHVjwcq4iQXD9QqKQ
    L4B3ygQxK6zH2NQGxLDee2H9v4Lvwg14cLJW7QwWPzCtKHdWMaQz
    L2L2PZdorybUqkPjrmhem4Ax5EJvP7ijmxbNoQKnmTDMrqemY8UF
    L2oD6vA4TUyqPF8QG4vhUFSgwCyuuvFZ3v8SKHYFDwkbM765Nrfd
    KzChTbc3kZFxUSJ3Kt54cxsogeFAD9CCM4zGB22si8nfKcThQn8C

Check that it works by choosing a BIP32 string (the one corresponding to subkey 0/3):

    $ ku -W xprv9xWkBDfyBXmZsA85GyWj9uYPyoQv826YAadKWMaaEosNrFBKgj2TqWuiWY3zuqxYGpHfv9cnGj5P7e8EskpzKL1Y8Gk9aX6QbryA5raK73p
    L2L2PZdorybUqkPjrmhem4Ax5EJvP7ijmxbNoQKnmTDMrqemY8UF
    $ ku -a xprv9xWkBDfyBXmZsA85GyWj9uYPyoQv826YAadKWMaaEosNrFBKgj2TqWuiWY3zuqxYGpHfv9cnGj5P7e8EskpzKL1Y8Gk9aX6QbryA5raK73p
    116AXZc4bDVQrqmcinzu4aaPdrYqvuiBEK

Yep, looks familiar.

From secret exponent:

    $ ku 1

    input           : 1
    network         : Bitcoin
    secret exponent : 1
     hex            : 1
    wif             : KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU73sVHnoWn
     uncompressed   : 5HpHagT65TZzG1PH3CSu63k8DbpvD8s5ip4nEB3kEsreAnchuDf
    public pair x   : 55066263022277343669578718895168534326250603453777594175500187360389116729240
    public pair y   : 32670510020758816978083085130507043184471273380659243275938904335757337482424
     x as hex       : 79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
     y as hex       : 483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8
    y parity        : even
    key pair as sec : 0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
     uncompressed   : 0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
                        483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8
    hash160         : 751e76e8199196d454941c45d1b3a323f1433bd6
     uncompressed   : 91b24bf9f5288532960ac687abb035127b1d28a5
    Bitcoin address : 1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH
     uncompressed   : 1EHNa6Q4Jz2uvNExL497mE43ikXhwF6kZm

Litecoin version:

    $ ku -nL 1

    input            : 1
    network          : Litecoin
    secret exponent  : 1
     hex             : 1
    wif              : T33ydQRKp4FCW5LCLLUB7deioUMoveiwekdwUwyfRDeGZm76aUjV
     uncompressed    : 6u823ozcyt2rjPH8Z2ErsSXJB5PPQwK7VVTwwN4mxLBFrao69XQ
    public pair x    : 55066263022277343669578718895168534326250603453777594175500187360389116729240
    public pair y    : 32670510020758816978083085130507043184471273380659243275938904335757337482424
     x as hex        : 79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
     y as hex        : 483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8
    y parity         : even
    key pair as sec  : 0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
     uncompressed    : 0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
                         483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8
    hash160          : 751e76e8199196d454941c45d1b3a323f1433bd6
     uncompressed    : 91b24bf9f5288532960ac687abb035127b1d28a5
    Litecoin address : LVuDpNCSSj6pQ7t9Pv6d6sUkLKoqDEVUnJ
     uncompressed    : LYWKqJhtPeGyBAw7WC8R3F7ovxtzAiubdM

Dogecoin WIF:

    $ ku -nD -W 1
    QNcdLVw8fHkixm6NNyN6nVwxKek4u7qrioRbQmjxac5TVoTtZuot

From public pair (on Testnet):

    $ ku -nT 55066263022277343669578718895168534326250603453777594175500187360389116729240,even

    input                   : 550662630222773436695787188951685343262506034537775941755001873603
                                89116729240,even
    network                 : Bitcoin testnet
    public pair x           : 55066263022277343669578718895168534326250603453777594175500187360389116729240
    public pair y           : 32670510020758816978083085130507043184471273380659243275938904335757337482424
     x as hex               : 79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
     y as hex               : 483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8
    y parity                : even
    key pair as sec         : 0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
     uncompressed           : 0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
                                483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8
    hash160                 : 751e76e8199196d454941c45d1b3a323f1433bd6
     uncompressed           : 91b24bf9f5288532960ac687abb035127b1d28a5
    Bitcoin testnet address : mrCDrCybB6J1vRfbwM5hemdJz73FwDBC8r
     uncompressed           : mtoKs9V381UAhUia3d7Vb9GNak8Qvmcsme

From hash160:

    $ ku 751e76e8199196d454941c45d1b3a323f1433bd6

    input           : 751e76e8199196d454941c45d1b3a323f1433bd6
    network         : Bitcoin
    hash160         : 751e76e8199196d454941c45d1b3a323f1433bd6
    Bitcoin address : 1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH

As a Dogecoin address:

    $ ku -nD 751e76e8199196d454941c45d1b3a323f1433bd6

    input            : 751e76e8199196d454941c45d1b3a323f1433bd6
    network          : Dogecoin
    hash160          : 751e76e8199196d454941c45d1b3a323f1433bd6
    Dogecoin address : DFpN6QqFfUm3gKNaxN6tNcab1FArL9cZLE

tx
--

The command-line utility ```tx``` will display transactions in human-readable form, fetch base transactions from pycoin's transaction cache or from web services (blockchain.info, blockr.io, biteasy.com are currently supported), merge transactions, add or delete inputs or outputs, and sign transactions.

Examples:


View the famous "pizza" transaction [PIZZA]:

    $ tx 49d2adb6e476fa46d8357babf78b1b501fd39e177ac7833124b3f67b17c40c2a
    warning: consider setting environment variable PYCOIN_CACHE_DIR=~/.pycoin_cache to cache transactions fetched via web services
    warning: no service providers found for get_tx; consider setting environment variable PYCOIN_SERVICE_PROVIDERS=BLOCKR_IO:BLOCKCHAIN_INFO:BITEASY:BLOCKEXPLORER
    usage: tx [-h] [-t TRANSACTION_VERSION] [-l LOCK_TIME] [-n NETWORK] [-a]
              [-i address] [-f path-to-private-keys] [-g GPG_ARGUMENT]
              [--remove-tx-in tx_in_index_to_delete]
              [--remove-tx-out tx_out_index_to_delete] [-F transaction-fee] [-u]
              [-b BITCOIND_URL] [-o path-to-output-file]
              argument [argument ...]
    tx: error: can't find Tx with id 49d2adb6e476fa46d8357babf78b1b501fd39e177ac7833124b3f67b17c40c2a

Oops! We don't have web services set up. Let's do that now.

    $ PYCOIN_CACHE_DIR=~/.pycoin_cache
    $ PYCOIN_SERVICE_PROVIDERS=BLOCKR_IO:BLOCKCHAIN_INFO:BITEASY:BLOCKEXPLORER
    $ export PYCOIN_CACHE_DIR PYCOIN_SERVICE_PROVIDERS

It's not done automatically so a command-line tool won't leak potentially private information about what transactions you're interested in to a third party web site. If you don't care, you could put these lines into your .profile.

Let's try again:

    $ tx 49d2adb6e476fa46d8357babf78b1b501fd39e177ac7833124b3f67b17c40c2a
    Version:  1  tx hash 49d2adb6e476fa46d8357babf78b1b501fd39e177ac7833124b3f67b17c40c2a  159 bytes   
    TxIn count: 1; TxOut count: 1
    Lock time: 0 (valid anytime)
    Input:
      0:                          (unknown) from 1e133f7de73ac7d074e2746a3d6717dfc99ecaa8e9f9fade2cb8b0b20a5e0441:0
    Output:
      0: 1CZDM6oTttND6WPdt3D6bydo7DYKzd9Qik receives 10000000.00000 mBTC
    Total output 10000000.00000 mBTC
    including unspents in hex dump since transaction not fully signed
    010000000141045e0ab2b0b82cdefaf9e9a8ca9ec9df17673d6a74e274d0c73ae77d3f131e000000004a493046022100a7f26eda874931999c90f87f01ff1ffc76bcd058fe16137e0e63fdb6a35c2d78022100a61e9199238eb73f07c8f209504c84b80f03e30ed8169edd44f80ed17ddf451901ffffffff010010a5d4e80000001976a9147ec1003336542cae8bded8909cdd6b5e48ba0ab688ac00000000

    ** can't validate transaction as source transactions missing

The final line appears because to validate the transactions' signatures, you technically need to the source transactions. So let's add ```-a``` to augment the transactions with source information.

    $ tx -a 49d2adb6e476fa46d8357babf78b1b501fd39e177ac7833124b3f67b17c40c2a
    warning: transaction fees recommendations casually calculated and estimates may be incorrect
    warning: transaction fee lower than (casually calculated) expected value of 0.1 mBTC, transaction might not propogate
    Version:  1  tx hash 49d2adb6e476fa46d8357babf78b1b501fd39e177ac7833124b3f67b17c40c2a  159 bytes   
    TxIn count: 1; TxOut count: 1
    Lock time: 0 (valid anytime)
    Input:
      0: 17WFx2GQZUmh6Up2NDNCEDk3deYomdNCfk from 1e133f7de73ac7d074e2746a3d6717dfc99ecaa8e9f9fade2cb8b0b20a5e0441:0 10000000.00000 mBTC  sig ok
    Output:
      0: 1CZDM6oTttND6WPdt3D6bydo7DYKzd9Qik receives 10000000.00000 mBTC
    Total input  10000000.00000 mBTC
    Total output 10000000.00000 mBTC
    Total fees        0.00000 mBTC
    010000000141045e0ab2b0b82cdefaf9e9a8ca9ec9df17673d6a74e274d0c73ae77d3f131e000000004a493046022100a7f26eda874931999c90f87f01ff1ffc76bcd058fe16137e0e63fdb6a35c2d78022100a61e9199238eb73f07c8f209504c84b80f03e30ed8169edd44f80ed17ddf451901ffffffff010010a5d4e80000001976a9147ec1003336542cae8bded8909cdd6b5e48ba0ab688ac00000000
    all incoming transaction values validated

We can see the transactions have been cached.

    $ ls ~/.pycoin_cache/txs/
    1e133f7de73ac7d074e2746a3d6717dfc99ecaa8e9f9fade2cb8b0b20a5e0441_tx.bin
    49d2adb6e476fa46d8357babf78b1b501fd39e177ac7833124b3f67b17c40c2a_tx.bin

Now, let's create a new transaction with some Satoshi coinbase coins. In block #1, we see a coinbase transaction to 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX. Let's use fetch_unspent to find all coins in this address.

    $ fetch_unspent 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX
    a3a6f902a51a2cbebede144e48a88c05e608c2cce28024041a5b9874013a1e2a/0/76a914119b098e2e980a229e139a9ed01a469e518e6f2688ac/333000
    cea36d008badf5c7866894b191d3239de9582d89b6b452b596f1f1b76347f8cb/31/76a914119b098e2e980a229e139a9ed01a469e518e6f2688ac/10000
    065ef6b1463f552f675622a5d1fd2c08d6324b4402049f68e767a719e2049e8d/86/76a914119b098e2e980a229e139a9ed01a469e518e6f2688ac/10000
    a66dddd42f9f2491d3c336ce5527d45cc5c2163aaed3158f81dc054447f447a2/0/76a914119b098e2e980a229e139a9ed01a469e518e6f2688ac/10000
    ffd901679de65d4398de90cefe68d2c3ef073c41f7e8dbec2fb5cd75fe71dfe7/0/76a914119b098e2e980a229e139a9ed01a469e518e6f2688ac/100
    d658ab87cc053b8dbcfd4aa2717fd23cc3edfe90ec75351fadd6a0f7993b461d/5/76a914119b098e2e980a229e139a9ed01a469e518e6f2688ac/911
    36ebe0ca3237002acb12e1474a3859bde0ac84b419ec4ae373e63363ebef731c/1/76a914119b098e2e980a229e139a9ed01a469e518e6f2688ac/100000
    fd87f9adebb17f4ebb1673da76ff48ad29e64b7afa02fda0f2c14e43d220fe24/0/76a914119b098e2e980a229e139a9ed01a469e518e6f2688ac/1
    dfdf0b375a987f17056e5e919ee6eadd87dad36c09c4016d4a03cea15e5c05e3/1/76a914119b098e2e980a229e139a9ed01a469e518e6f2688ac/1337
    cb2679bfd0a557b2dc0d8a6116822f3fcbe281ca3f3e18d3855aa7ea378fa373/0/76a914119b098e2e980a229e139a9ed01a469e518e6f2688ac/1337
    d6be34ccf6edddc3cf69842dce99fe503bf632ba2c2adb0f95c63f6706ae0c52/1/76a914119b098e2e980a229e139a9ed01a469e518e6f2688ac/2000000
    0e3e2357e806b6cdb1f70b54c3a3a17b6714ee1f0e68bebb44a74b1efd512098/0/410496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52da7589379515d4e0a604f8141781e62294721166bf621e73a82cbf2342c858eeac/5000000000

Wow, that yields a lot of options. The last one is the coinbase source from block #1. Let's write a transaction that sends these coins to my donation address.

    $ tx 0e3e2357e806b6cdb1f70b54c3a3a17b6714ee1f0e68bebb44a74b1efd512098/0/410496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52da7589379515d4e0a604f8141781e62294721166bf621e73a82cbf2342c858eeac/5000000000 1KissFDVu2wAYWPRm4UGh5ZCDU9sE9an8T -o tx.bin
    all incoming transaction values validated
    $ ls -l tx.bin 
    -rw-r--r--  1 kiss  staff  161 Apr 27 18:23 tx.bin

Now, let's dump it.

    $ tx tx.bin
    warning: transaction fees recommendations casually calculated and estimates may be incorrect
    Version:  1  tx hash 3d36aed60ecb311a55a6329f5c2af785f06e147fc35b7678eb798eca7f603c83  85 bytes   
    TxIn count: 1; TxOut count: 1
    Lock time: 0 (valid anytime)
    Input:
      0: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from 0e3e2357e806b6cdb1f70b54c3a3a17b6714ee1f0e68bebb44a74b1efd512098:0  50000.00000 mBTC  BAD SIG
    Output:
      0: 1KissFDVu2wAYWPRm4UGh5ZCDU9sE9an8T receives  49999.90000 mBTC
    Total input   50000.00000 mBTC
    Total output  49999.90000 mBTC
    Total fees        0.10000 mBTC
    including unspents in hex dump since transaction not fully signed
    0100000001982051fd1e4ba744bbbe680e1fee14677ba1a3c3540bf7b1cdb606e857233e0e0000000000ffffffff01f0ca052a010000001976a914cd5dc792f0abb0aa8ba4ca36c9fe5eda8e495ff988ac0000000000f2052a0100000043410496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52da7589379515d4e0a604f8141781e62294721166bf621e73a82cbf2342c858eeac
    all incoming transaction values validated

We see a transaction that sends most of the 50 BTC to a new address. The signature is not correct though. If we had the private key, we could sign it like this:

    $ tx tx.bin -f wifs.gpg -o signed_tx.bin

    You need a passphrase to unlock the secret key for
    user: "Richard Kiss <him@richardkiss.com>"
    2048-bit ELG-E key, ID 681E71C8, created 1999-11-08 (main key ID DBD8AB6A)

    gpg: encrypted with 2048-bit ELG-E key, ID 681E71C8, created 1999-11-08
          "Richard Kiss <him@richardkiss.com>"
    signing...
    warning: 1 TxIn items still unsigned
    all incoming transaction values validated

Yep, if the file passed to -f ends with ```.gpg```, then ```gpg -d``` is automatically invoked, and you can type your GPG passphrase. So ```tx``` plus ```gpg``` is actually a pretty reasonably secure solution! And if you keep your WIF.gpg file on an airgapped machine, this solves the problem of cold storage!

    $ shasum tx.bin signed_tx.bin
    3ba7db8417e0fe1aeb7b4a1cbf13880bf84f38bc  tx.bin
    3ba7db8417e0fe1aeb7b4a1cbf13880bf84f38bc  signed_tx.bin

Unfortunately for me, this file didn't include the WIF to the outgoing transaction, so the transaction remains unsigned.

You can also use ```-i``` to fetch all unspents (via the web) for a given bitcoin address and split it up.

    $ tx -F 85000 -i 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX 1KissFDVu2wAYWPRm4UGh5ZCDU9sE9an8T 1KissEskteXTAXbh17qJYLtMes1B6kJxZj 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX/50
    warning: transaction fees recommendations casually calculated and estimates may be incorrect
    warning: transaction fee of 0.85 exceeds expected value of 0.1 mBTC
    Version:  1  tx hash fb3551086baa047f4e8b55a28c275502b48c637c003b89dbececb3cab8897089  604 bytes   
    TxIn count: 12; TxOut count: 3
    Lock time: 0 (valid anytime)
    Inputs:
      0: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from a3a6f902a51a2cbebede144e48a88c05e608c2cce28024041a5b9874013a1e2a:0      3.33000 mBTC  BAD SIG
      1: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from cea36d008badf5c7866894b191d3239de9582d89b6b452b596f1f1b76347f8cb:31      0.10000 mBTC  BAD SIG
      2: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from 065ef6b1463f552f675622a5d1fd2c08d6324b4402049f68e767a719e2049e8d:86      0.10000 mBTC  BAD SIG
      3: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from a66dddd42f9f2491d3c336ce5527d45cc5c2163aaed3158f81dc054447f447a2:0      0.10000 mBTC  BAD SIG
      4: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from ffd901679de65d4398de90cefe68d2c3ef073c41f7e8dbec2fb5cd75fe71dfe7:0      0.00100 mBTC  BAD SIG
      5: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from d658ab87cc053b8dbcfd4aa2717fd23cc3edfe90ec75351fadd6a0f7993b461d:5      0.00911 mBTC  BAD SIG
      6: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from 36ebe0ca3237002acb12e1474a3859bde0ac84b419ec4ae373e63363ebef731c:1      1.00000 mBTC  BAD SIG
      7: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from fd87f9adebb17f4ebb1673da76ff48ad29e64b7afa02fda0f2c14e43d220fe24:0      0.00001 mBTC  BAD SIG
      8: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from dfdf0b375a987f17056e5e919ee6eadd87dad36c09c4016d4a03cea15e5c05e3:1      0.01337 mBTC  BAD SIG
      9: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from cb2679bfd0a557b2dc0d8a6116822f3fcbe281ca3f3e18d3855aa7ea378fa373:0      0.01337 mBTC  BAD SIG
     10: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from d6be34ccf6edddc3cf69842dce99fe503bf632ba2c2adb0f95c63f6706ae0c52:1     20.00000 mBTC  BAD SIG
     11: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX from 0e3e2357e806b6cdb1f70b54c3a3a17b6714ee1f0e68bebb44a74b1efd512098:0  50000.00000 mBTC  BAD SIG
    Outputs:
      0: 1KissFDVu2wAYWPRm4UGh5ZCDU9sE9an8T receives  25011.90818 mBTC
      1: 1KissEskteXTAXbh17qJYLtMes1B6kJxZj receives  25011.90818 mBTC
      2: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX receives      0.00050 mBTC
    Total input   50024.66686 mBTC
    Total output  50023.81686 mBTC
    Total fees        0.85000 mBTC
    including unspents in hex dump since transaction not fully signed
     
    all incoming transaction values validated

Note that 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX was explicitly budgeted 50 satoshis. A custom fee of 85000 satoshis was paid, and the remainder was split between the other two addresses.

OK, let's try actually signing a transaction. Let's use the WIF for secret exponent 1.

    $ ku -a -u 1
    1EHNa6Q4Jz2uvNExL497mE43ikXhwF6kZm

Investigation on blockchain.info show a transaction payable to this bitcoin address with id d61aa2a5f5bce59d2a57447134f7ce9ce9d29b5c471f4bf747c43bf82aa26c2a.

    $ tx -u d61aa2a5f5bce59d2a57447134f7ce9ce9d29b5c471f4bf747c43bf82aa26c2a
    d61aa2a5f5bce59d2a57447134f7ce9ce9d29b5c471f4bf747c43bf82aa26c2a/0/76a9149b92770a85b1252448ec69900e77f1371d6a620188ac/70594320
    d61aa2a5f5bce59d2a57447134f7ce9ce9d29b5c471f4bf747c43bf82aa26c2a/1/76a91491b24bf9f5288532960ac687abb035127b1d28a588ac/12345678

    ** can't validate transaction as source transactions missing

The ```-u``` shows the unspents, which can be passed as inputs to tx.

    $ tx d61aa2a5f5bce59d2a57447134f7ce9ce9d29b5c471f4bf747c43bf82aa26c2a/1/76a91491b24bf9f5288532960ac687abb035127b1d28a588ac/12345678 1KissFDVu2wAYWPRm4UGh5ZCDU9sE9an8T -o tx.bin
    all incoming transaction values validated

    $ tx tx.bin 
    warning: transaction fees recommendations casually calculated and estimates may be incorrect
    Version:  1  tx hash ab963a39df0e095bbd76840de90fe208e903d5d43e891ef245b217dbcd29a8a7  85 bytes   
    TxIn count: 1; TxOut count: 1
    Lock time: 0 (valid anytime)
    Input:
      0: 1EHNa6Q4Jz2uvNExL497mE43ikXhwF6kZm from d61aa2a5f5bce59d2a57447134f7ce9ce9d29b5c471f4bf747c43bf82aa26c2a:1    123.45678 mBTC  BAD SIG
    Output:
      0: 1KissFDVu2wAYWPRm4UGh5ZCDU9sE9an8T receives    123.35678 mBTC
    Total input     123.45678 mBTC
    Total output    123.35678 mBTC
    Total fees        0.10000 mBTC
    including unspents in hex dump since transaction not fully signed
    01000000012a6ca22af83bc447f74b1f475c9bd2e99ccef7347144572a9de5bcf5a5a21ad60100000000ffffffff013e3abc00000000001976a914cd5dc792f0abb0aa8ba4ca36c9fe5eda8e495ff988ac000000004e61bc00000000001976a91491b24bf9f5288532960ac687abb035127b1d28a588ac
    all incoming transaction values validated

Now, let's sign it.

    $ tx tx.bin KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU73sVHnoWn -o signed_tx.hex 
    signing...
    all incoming transaction values validated
    $ cat signed_tx.hex 
    01000000012a6ca22af83bc447f74b1f475c9bd2e99ccef7347144572a9de5bcf5a5a21ad6010000008b48304502210084fd73b302520381dea1885efda58bc446653998864db7a2cd04906fc6d5536302206325303c8e50f84d25c95eff2849441382d4aafb2f678f636a6d164b721bf0f101410479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8ffffffff013e3abc00000000001976a914cd5dc792f0abb0aa8ba4ca36c9fe5eda8e495ff988ac00000000
    $ tx -a signed_tx.hex 
    warning: transaction fees recommendations casually calculated and estimates may be incorrect
    Version:  1  tx hash 0995cf6f55e1cf22f7c31f5ad52d111e897b0b9b7e37a1bb755a470324b4a2c4  224 bytes   
    TxIn count: 1; TxOut count: 1
    Lock time: 0 (valid anytime)
    Input:
      0: 1EHNa6Q4Jz2uvNExL497mE43ikXhwF6kZm from d61aa2a5f5bce59d2a57447134f7ce9ce9d29b5c471f4bf747c43bf82aa26c2a:1    123.45678 mBTC  sig ok
    Output:
      0: 1KissFDVu2wAYWPRm4UGh5ZCDU9sE9an8T receives    123.35678 mBTC
    Total input     123.45678 mBTC
    Total output    123.35678 mBTC
    Total fees        0.10000 mBTC
    01000000012a6ca22af83bc447f74b1f475c9bd2e99ccef7347144572a9de5bcf5a5a21ad6010000008b48304502210084fd73b302520381dea1885efda58bc446653998864db7a2cd04906fc6d5536302206325303c8e50f84d25c95eff2849441382d4aafb2f678f636a6d164b721bf0f101410479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8ffffffff013e3abc00000000001976a914cd5dc792f0abb0aa8ba4ca36c9fe5eda8e495ff988ac00000000
    all incoming transaction values validated

Wow! It worked! (It wrote the output as hex because of the ".hex" suffix.)

So why not just broadcast this transaction and collect our winnings? Well, the coins have already been spent. Oh well.

Note that pycoin uses a deterministic algorithm to create the signatures, so if you try this at home, you will get the exact same transaction with the exact same 0995cf6f55e1cf22f7c31f5ad52d111e897b0b9b7e37a1bb755a470324b4a2c4 hash.


[PIZZA]: https://bitcointalk.org/index.php?topic=137.0

--------------

You can also use pycoin to create and validate keys programmatically.


    >>> from pycoin.key import Key
    >>> k = Key.from_text("1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH")
    >>> print(k.address())
    1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH
    >>> print(k.hash160())
    b'u\x1ev\xe8\x19\x91\x96\xd4T\x94\x1cE\xd1\xb3\xa3#\xf1C;\xd6'
    >>> from pycoin.serialize import b2h
    >>> print(b2h(k.hash160()))
    751e76e8199196d454941c45d1b3a323f1433bd6

Compare to using ku:

    $ ku 1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH

    input                   : 1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH
    network                 : Bitcoin mainnet
    netcode                 : BTC
    hash160                 : 751e76e8199196d454941c45d1b3a323f1433bd6
    Bitcoin mainnet address : 1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH

    >>> from pycoin.key.validate import is_address_valid
    >>> v = is_address_valid("1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH")
    >>> print(v)
    'BTC'
    # you can also specify certain networks, like Litecoin
    >>> v = is_address_valid("1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH", allowable_netcodes=["LTC"])
    >>> print(v)
    None
    # not a valid LTC address
    >>> v = is_address_valid("1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH", allowable_types=["pay_to_script"])
    >>> print(v)
    None
    # not a valid pay-to-script address (they start with a "3")
    >>> v = is_address_valid("1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH", allowable_types=["address"])
    >>> print(v)
    BTC

    >>> from pycoin.key import Key
    >>> k = Key(secret_exponent=1)
    >>> print(k.address())
    1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH
    >>> print(k.wif())
    KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU73sVHnoWn
    >>> print(k.as_text())
    KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU73sVHnoWn

    $ ku KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU73sVHnoWn

    input                        : KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU73sVHnoWn
    network                      : Bitcoin mainnet
    netcode                      : BTC
    secret exponent              : 1
     hex                         : 1
    wif                          : KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU73sVHnoWn
     uncompressed                : 5HpHagT65TZzG1PH3CSu63k8DbpvD8s5ip4nEB3kEsreAnchuDf
    public pair x                : 55066263022277343669578718895168534326250603453777594175500187360389116729240
    public pair y                : 32670510020758816978083085130507043184471273380659243275938904335757337482424
     x as hex                    : 79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
     y as hex                    : 483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8
    y parity                     : even
    key pair as sec              : 0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
     uncompressed                : 0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798
                                     483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8
    hash160                      : 751e76e8199196d454941c45d1b3a323f1433bd6
     uncompressed                : 91b24bf9f5288532960ac687abb035127b1d28a5
    Bitcoin mainnet address      : 1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH
    Bitcoin mainnet uncompressed : 1EHNa6Q4Jz2uvNExL497mE43ikXhwF6kZm

Different networks have different representations of the same WIF.

    $ ku -W 1
    KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU73sVHnoWn
    $ ku -W -n XTN 1
    cMahea7zqjxrtgAbB7LSGbcQUr1uX1ojuat9jZodMN87JcbXMTcA
    $ ku -W 1 -n DOGE
    QNcdLVw8fHkixm6NNyN6nVwxKek4u7qrioRbQmjxac5TVoTtZuot
    $ ku -W 1 -n LTC
    T33ydQRKp4FCW5LCLLUB7deioUMoveiwekdwUwyfRDeGZm76aUjV

--------------

Fetch, parse a tx, stream a tx

$ tx 0e3e2357e806b6cdb1f70b54c3a3a17b6714ee1f0e68bebb44a74b1efd512098 -o tx.out
all incoming transaction values validated

>>> from pycoin.tx import Tx
>>> tx = Tx.parse(open("tx.out", "rb"))
>>> print(tx)
Tx [0e3e2357e806b6cdb1f70b54c3a3a17b6714ee1f0e68bebb44a74b1efd512098]
>>> print(tx.txs_in[0])
TxIn<COINBASE: 04ffff001d0104>
>>> print(tx.txs_out[0])
TxOut<5E+4 mbtc "0496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52da7589379515d4e0a604f8141781e62294721166bf621e73a82cbf2342c858ee OP_CHECKSIG">
>>> f1 = open("tx1.out", "wb")
>>> tx.stream(f1)
$ ls -l tx1.out 
-rw-r--r--  1 kiss  staff  134 Jun 11 17:02 tx1.out
$ tx tx1.out 
warning: transaction fees recommendations casually calculated and estimates may be incorrect
warning: transaction fee lower than (casually calculated) expected value of 0.1 mBTC, transaction might not propogate
Version:  1  tx hash 0e3e2357e806b6cdb1f70b54c3a3a17b6714ee1f0e68bebb44a74b1efd512098  134 bytes   
TxIn count: 1; TxOut count: 1
Lock time: 0 (valid anytime)
Input:
  0: COINBASE   50000.00000 mBTC
Output:
  0: 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX receives  50000.00000 mBTC
Total input   50000.00000 mBTC
Total output  50000.00000 mBTC
Total fees        0.00000 mBTC
01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff0704ffff001d0104ffffffff0100f2052a0100000043410496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52da7589379515d4e0a604f8141781e62294721166bf621e73a82cbf2342c858eeac00000000
all incoming transaction values validated



-----------

A simple script to grab and spend coins.

    #!/usr/bin/env python

    from pycoin.key import Key

    from pycoin.key.validate import is_address_valid, is_wif_valid
    from pycoin.services import spendables_for_address
    from pycoin.tx.tx_utils import create_signed_tx

    def get_address(which):
        while 1:
            print("enter the %s address=> " % which, end='')
            address = input()
            is_valid = is_address_valid(address)
            if is_valid:
                return address
            print("invalid address, please try again")

    src_address = get_address("source")
    spendables = spendables_for_address(src_address)
    print(spendables)

    while 1:
        print("enter the WIF for %s=> " % src_address, end='')
        wif = input()
        is_valid = is_wif_valid(wif)
        if is_valid:
            break
        print("invalid wif, please try again")

    key = Key.from_text(wif)
    if src_address not in (key.address(use_uncompressed=False), key.address(use_uncompressed=True)):
        print("** WIF doesn't correspond to %s" % src_address)
    print("The secret exponent is %d" % key.secret_exponent())

    dst_address = get_address("destination")

    tx = create_signed_tx(spendables, payables=[dst_address], wifs=[wif])

    print("here is the signed output transaction")
    print(tx.as_hex())
