fat-py

Python library for the Factom Asset Token standard. Currently supports FAT-0 and FAT-1 token standards.

Installation

The easiest way to install is with pip or pipenv from PyPi:

pipenv install fat

You can also clone the repo and build it from source. The recommended way to do this is with pipenv:

git clone git@github.com:samuelvanderwaal/fat-py.git

cd fat-py

Install requirements from the Pipfile:

pipenv install

Activate the virtual environment:

pipenv shell

See pipenv's documentation for more usage details.

Quick Start

Issue a new token:

from fat.fat0 import Issuance
from factom import Factomd

factomd = Factomd()

issuance = Issuance(
    token_id="mytoken",
    issuer_id="8888...",
    supply=-1,
    symbol="tkn1",
    ec_address="EC3...",
    ec_priv_key="ES3...",
    server_priv_key="sk1..."
)

issuance.issue_token(factomd)

Build and submit a token transaction:

from fat.fat0 import Transaction
from fat import FATd

fatd = FATd()

address1 = "FA2gCmih3PaSYRVMt1jLkdG4Xpo2koebUpQ6FpRRnqw5FfTSN2vW"
private_fct_key1 = "Fs..."
address2 = "FA3j68XNwKwvHXV2TKndxPpyCK3KrWTDyyfxzi8LwuM5XRuEmhy6"
chain_id = "a9d7791caffd852f8e3710e3c38f1ad1b056d4ecb2d4d54216581dfd0dac8edd"

tx1 = Transaction()
tx1.add_input(address1, 100)
tx1.add_output(address2, 100)
tx1.add_signer(private_fct_key1)
tx1.set_chain_id(chain_id)
tx1.sign()

fatd.submit_transaction(tx1)

Usage

The two main ways to use this library are the Issuance and Transaction classes. In addition, the library exposes all the fatd RPC methods which can be accessed through the FATd class.

Issuance

The Issuance class supports object initialization through multiple methods:

Individual property assignment:

issuance = Issuance()
issuance.token_id = "mytoken"
issuance.issuer_id = "888888a37cbf303c0bfc8d0cc7e77885c42000b757bd4d9e659de994477a0904"
issuance.supply = -1
issuance.symbol = "tkn1"
issuance.ec_address = "EC3cQ1QnsE5rKWR1B5mzVHdTkAReK5kJwaQn5meXzU9wANyk7Aej"
issuance.ec_priv_key = "ES..."
issuance.server_priv_key = "sk1..."

Passing all values as part of the constructor:

issuance = Issuance(
	token_id="mytoken",
    issuer_id="8888...",
    supply=-1,
    symbol="tkn1",
    ec_address="EC3...",
    ec_priv_key="ES3...",
    server_priv_key="sk1..."
)

Once the issuance object has all the required values, the issue_token() method can be used to perform all the necessary factomd calls to issue and initialize a new token.

from fat.fat0 import Issuance
from factom import Factomd

factomd = Factomd()

issuance = Issuance(
	token_id="mytoken",
    issuer_id="8888...",
    supply=-1,
    symbol="tkn1",
    ec_address="EC3...",
    ec_priv_key="ES3...",
    server_priv_key="sk1..."
)

issuance.issue_token(factomd)

Issuance supports both the Python native str type and key objects from the factom_keys library for EC and server ID keys. When strings are passed to it, internally it uses the factom_keys library to validate the key and address values.

...
from factom_keys.ec import ECAddress

ec_address1 = ECAddress(key_string="EC3cQ1QnsE5rKWR1B5mzVHdTkAReK5kJwaQn5meXzU9wANyk7Aej")
ec_address2 = "EC3cQ1QnsE5rKWR1B5mzVHdTkAReK5kJwaQn5meXzU9wANyk7Aej"
issuance = Issuance()
...
issuance.ec_address = ec_address1
# or
issuance.ec_address = ec_address2

FAT-0 and FAT-1 issuance has the same usage, just import the specific Issuance class needed. Use import aliases if both are required simultaneously:

from fat.fat0 import Issuance as FAT0Issuance
from fat.fat1 import Issuance as FAT1Issuance

Transaction

The Transaction class also supports multiple methods of initialization:

Passing all values through the constructor:

tx1 = Transaction(
	inputs={"FA...": 100, "FA3...": 50},
    outputs={"FA3Z...": 150},
    chain_id="a9d7791caffd852f8e3710e3c38f1ad1b056d4ecb2d4d54216581dfd0dac8edd",
    signers=["FS...", "Fs..."]
)
tx1.sign()

Adding values individually:

tx1 = Transaction()
tx1.add_input(coinbase_address, 100)
tx1.add_output(address1, 50)
tx1.add_output(address2, 50)
tx1.add_signer(issuer_signer)
tx1.set_chain_id(chain_id)
tx1.sign()

Builder method:

tx1 = Transaction()
(
 tx1.add_input(coinbase_address, 100)
    .add_output(address1, 50)
    .add_output(address2, 50)
    .add_signer(issuer_signer)
    .set_chain_id(chain_id)
    .sign()
)

Transaction supports both the native Python str type and key objects from the factom_keys library for Factoid private keys, Factoid addresses and for server ID private keys.

...
from factom_keys.ec import FactoidAddress, FactoidPrivateKey
from factom_keys.serverid import ServerIDPrivateKey

address1 = FactoidAddress(address_string="FA2gCmih3PaSYRVMt1jLkdG4Xpo2koebUpQ6FpRRnqw5FfTSN2vW")
address2 = "FA2gCmih3PaSYRVMt1jLkdG4Xpo2koebUpQ6FpRRnqw5FfTSN2vW"
fct_priv_key1 = FactoidPrivateKey(key_string="Fs...")
fct_priv_key2 = "Fs..."

tx = Transaction()
tx.add_input(address1, 50)
tx.add_signer(fct_priv_key1)
# or
tx.add_input(address2, 50)
tx.add_signer(fct_priv_key2)

Once a transaction has been built and signed, it can be passed to the submit_transaction() method on FATd for submission to the blockchain.

FAT-0:

from fat.fat0 import Transaction
from fat import FATd

fatd = FATd()

address1 = "FA2gCmih3PaSYRVMt1jLkdG4Xpo2koebUpQ6FpRRnqw5FfTSN2vW"
private_fct_key1 = "Fs..."
address2 = "FA3j68XNwKwvHXV2TKndxPpyCK3KrWTDyyfxzi8LwuM5XRuEmhy6"
chain_id = "a9d7791caffd852f8e3710e3c38f1ad1b056d4ecb2d4d54216581dfd0dac8edd"

tx1 = Transaction()
tx1.add_input(address1, 100)
tx1.add_output(address2, 100)
tx1.add_signer(private_fct_key1)
tx1.set_chain_id(chain_id)
tx1.sign()

fatd.submit_transaction(tx1)

FAT-1:

from fat.fat1 import Transaction
from fat import FATd

fatd = FATd()

address1 = "FA2gCmih3PaSYRVMt1jLkdG4Xpo2koebUpQ6FpRRnqw5FfTSN2vW"
private_fct_key1 = "Fs..."
address2 = "FA3j68XNwKwvHXV2TKndxPpyCK3KrWTDyyfxzi8LwuM5XRuEmhy6"
chain_id = "a9d7791caffd852f8e3710e3c38f1ad1b056d4ecb2d4d54216581dfd0dac8edd"

tx1 = Transaction()
tx1.add_input(address1, [1,3])
tx1.add_output(address2, [1,3])
tx1.add_signer(private_fct_key1)
tx1.set_chain_id(chain_id)
tx1.sign()

fatd.submit_transaction(tx1)

FATd RPC Methods

All FATd RPC and Daemon methods are exposed via the FATd class:

from fat import FATd

fatd= FATd()

chain_id = "a9d7791caffd852f8e3710e3c38f1ad1b056d4ecb2d4d54216581dfd0dac8edd"
address = "FA2gCmih3PaSYRVMt1jLkdG4Xpo2koebUpQ6FpRRnqw5FfTSN2vW"

fatd.get_issuance(chain_id=chain_id)
fad.get_balance(address, chain_id=chain_id)
fatd.get_daemon_properties()