Marmopy-sdk

Description

Marmopy-sdk helps python developers to consume Marmo Relayer.

Simple Summary

Allowing users to sign messages to show intent of execution, but allowing a third party relayer to execute them is an emerging pattern being used in many projects. This pattern simplifies the integration with any Ethereum based platform. Marmo relayer: (https://github.com/ripio/marmo-relayer).

Abstract

User pain points:

• Users don't want to think about ether
• Users want to be able to pay for transactions using whatever they have
• Users don’t want to download apps/extensions (at least on the desktop) to connect to their apps

Ecosystem Graph

General WIKI ecosystem.

• Work in progress.

API layer

• Marmo relayer doc: (https://github.com/ripio/marmo-relayer/blob/master/README.md)

CORE layer

• Marmo contracts doc: (https://github.com/ripio/marmo-contracts/blob/master/README.md)

Features

• Complete implementation of Intent functionality for Marmo relay.
• Ethereum wallet support.
• Comprehensive integration tests demonstrating a number of the above scenarios.

Runtime dependencies:

• web3py (https://pypi.org/project/web3/).

Getting started

Prerequisites

• Python2 or Python3

Pip install from git url:

pip install git+https://github.com/ripio/marmopy-sdk

Intent Flowchart

Dependencies

• T0 -> -
• T1 -> -
• T2 -> T1
• T3 -> T1
• T4 -> T1
• T5 -> T1, T4
• T6 -> T2
• T7 -> T2
• T8 -> T2
• T9 -> T3
• T10 -> T4
• T11 -> T5
• T12 -> T6
• T13 -> T7
• T14 -> T8
• T15 -> T9
• T16 -> T10
• T17 -> T10
• T18 -> T11
• T19 -> T13
• T20 -> T14
• T21 -> T15
• T22 -> T18
• T23 -> T19
• T24 -> T21
• T25 -> T22
• T26 -> T12, T23, T20, T15
• T27 -> T24
• T28 -> T25
• T29 -> T27

Configure SDK

from marmopy import DefaultConf

DefaultConf.ROPSTEN.as_default()

Create a Marmo wallet

from marmopy import Wallet

wallet = Wallet("Your private key here")
print(wallet.address) # This is your Marmo wallet address!

Build a intent

from marmopy import Intent, IntentAction, DefaultConf

class Contract:
    def __init__(self,contractAddress):
        self.contractAddress = contractAddress
        
    @IntentAction
    def transfer(self, to='address', value='uint256') : return 'bool'
    

erc20 = Contract("0x2f45b6fb2f28a73f110400386da31044b2e953d4")  #example of ERC20 contract with IntentActions injections. 
intentAction = erc20.transfer("0x7F5EB5bB5cF88cfcEe9613368636f458800e62CB", 0)

intent = Intent(intent_action = intentAction)

Build a intent generic

from marmopy import Intent, IntentGeneric	
from examples.generic_contract import Contract	

// can load the full abi, in var abi, of any contract for the demonstration mode, 	
// only the necessary part for the example is loaded	
	
abi = """	
[	
	{	
		"constant":false,	
		"inputs":[	
			{	
				"name":"_to",	
				"type":"address"	
			},	
			{	
				"name":"_value",	
				"type":"uint256"	
			}	
		],	
		"name":"transfer",	
		"outputs":[	
			{	
				"name":"success",	
				"type":"bool"	
			}	
		],	
		"payable":false,	
		"type":"function"	
	}	
]	
"""	
    	
token_contract_address = "0x2f45b6fb2f28a73f110400386da31044b2e953d4" #RCN TOKEN	
to = "0xA6693e041aAfE9b9D722338Ca9f8A6e7746d7148"	
data = Contract(abi).transfer({"_to":to, "_value":0})	

intent = IntentGeneric(data, token_contract_address, 0)

Sign and relay intent

signedIntent = wallet.sign(intent)
signedIntent.relay("<Relayer URL>")

Structure of builder

Name	Type/Format	Mandatory	Default	Description
id	hexstring	yes	Autogenerated	A unique identifier for the intent.
dependencies	hexstring[]	no	Empty	Define a correlation id for intent.
signer	hexstring	yes	-	The address of the signer that sign the intent.
wallet	hexstring	no	Autogenerated	Contract address or Marmo instance.
salt	hexstring	no	0x0	Use to send the same intent many times if needed.
minGasLimit	Int	no	0	Minimum gas price.
maxGasPrice	Int	no	99999999	Maximum gas price.
intentAction	IntentAction	yes	0x0	IntentAction Example -> marmopy-sdk.examples.ERC20.
expiration	Int	no	15	Contract Expiration Date in Days.

Run Tests

First install nose -> pip install nose Then run:

 nosetests tests/*