Welcome to microraiden’s documentation!¶

Contents¶

Proxy tutorial¶

Introduction¶

In this tutorial we will create a simple paywalled server that will echo a requested path paramter, payable with a custom token. You can find example code for this tutorial in microraiden/examples/echo_server.py.

Requirements¶

Please refer to README.md to install all required dependencies. You will also need a Chrome browser with the MetaMask plugin.

Setting up the proxy¶

Initialization¶

For initialization you will have to supply the following parameters:

The private key of the account receiving the payments (to extract it from a keystore file you can use MyEtherWallet’s “View Wallet Info” functionality).
A file in which the proxy stores off-chain balance proofs. Set this to a path writable by the user that starts the server.

from microraiden.make_helpers import make_paywalled_proxy
app = make_paywalled_proxy(private_key, state_file_name)

make_paywalled_proxy() is a helper that handles the setup of the channel manager and returns a PaywalledProxy instance. Microraiden also includes other helpers that parse common commandline options. We are not using them in this example - for a quick overview how to use them, refer to i.e. __main__()

The channel manager will start syncing with the blockchain immediately.

Resource types¶

Now we will create a custom resource class that simply echoes a path-parameter of the user’s request for a fixed price. The workflow is the same as with the Flask-restful: Subclass microraiden.proxy.resources.Expensive and implement the HTTP methods you want to expose.

from microraiden.proxy.resources import Expensive

class StaticPriceResource(Expensive):
    def get(self, url: str, param: str):
            log.info('Resource requested: {} with param "{}"'.format(request.url, param))
            return param

We add one static resource to our PaywalledProxy instance. The url argument will comply with standard flask routing rules.

app.add_paywalled_resource(
    cls=StaticPriceResource,
    url="/echofix/<string:param>",
    price=5
)

The resource will then be available for example at the URI /echofix/foo. Only after a payment of 5 tokens, the proxy will send the foo parameter back to the user and will set the Content-Type header appropriately. Without payment, the server responds with 402 Payment Required.

A probably more useful paywalled resource is a URL. This is useful to fetch content from a remote CDN:

from microraiden.proxy.content import PaywalledProxyUrl

app.add_paywalled_resource(
    cls=PaywalledProxyUrl,
    url="cdn\/.*",
    resource_class_kwargs={"domain": 'http://cdn.myhost.com:8000/resource42'}
)

Note, that the kwargs for the constructor of the resource-class (here our PaywalledProxyUrl) have to be passed as a dict with the resource_class_kwargs argument. In this case, the domain kwarg is the remote URL specifying where to fetch the content from.

Setting a price for the resource dynamically¶

We can also construct the Resource in a way that the price will be dynamically calculated, e.g. based on the requests parameters.

class DynamicPriceResource(Expensive):
    def get(self, url: str, param: str):
            log.info('Resource requested: {} with param "{}"'.format(request.url, param))
            return param

    def price(self):
            return len(request.view_args['param'])


app.add_paywalled_resource(
    cls=DynamicPriceResource,
    url="/echodyn/<string:param>",
)

Here, the price to be paid is the length of the requested string. A request of the /echodyn/foo resource, would therefore require a payment of 3 tokens.

Starting/stopping the proxy¶

You start proxy by calling run() method. This call is non-blocking – the proxy is started as a WSGI greenlet. Use join() to sync with the task. This will block until proxy has stopped. To terminate the server, call stop() from another greenlet.

app.run(debug=True)
app.join()

Accessing the content¶

Browser¶

To access the content with your browser, navigate to the URL of the resource you’d like to get. You’ll be faced with a paywall – a site requesting you to pay for the resource. To do so, you first have to open a new channel. If you have the MetaMask extension installed, you can set the amount to be deposited to the channel. After confirming the deposit, you can navigate and payments will be done automatically.

Side notes¶

Proxy state file¶

Off-chain transactions are stored in a sqlite database. You should do regular backups of this file – it contains balance signatures of the client, and if you lose them, you will have no way of proving that the client is settling the channel using less funds than he has actually paid to the proxy.

REST API¶

Introduction¶

µRaiden exposes a Restful API to provide insight into a channel state, balances, and it allows proxy operator to close and settle the channels.

Proxy endpoints¶

Getting the status of the proxy¶

/api/1/stats

Return proxy status: balances, open channels, contract ABI etc.

deposit_sum - sum of all open channel deposits
open_channels - count of all open channels
pending_channels - count of all closed, but not yet settled channels
balance_sum - sum of all spent, but not yet settled funds
unique_senders - count of all unique addresses that have channels open
liquid_balance - amount of tokens that are settled and available to the receiver
token_address - token contract address
contract_address - channel manager contract address
receiver_address - server’s ethereum address
manager_abi - ABI of the channel manager contract
token_abi - ABI of the token contract

Example Request¶

GET /api/1/stats

Example Response¶

200 OK and

{
  "deposit_sum": "268",
  "open_channels": "33",
  "pending_channels": "15",
  "balance_sum": "12",
  "unique_senders": "6",
  "liquid_balance": "334",
  "token_address" : "0x8227a53130c90d32e0294cdde576411379138ba8",
  "contract_address": "0x69f8b894d89fb7c4f6f082f4eb84b2b2c3311605",
  "receiver_address": "0xe67104491127e419064335ea5bf714622a209660",
  "manager_abi": "{ ... }",
  "token_abi": "{ ... }",
}

Channel endpoints¶

Getting all open channels¶

/api/1/channels/

Return a list of all open channels.

Example Request¶

GET /api/1/channels

Example Response¶

200 OK and

[
{
    "sender_address" : "0x5601ea8445a5d96eeebf89a67c4199fbb7a43fbb",
    "open_block"  : "3241462",
    "balance"     : "0",
    "deposit"     : "10",
},
{
    "sender_address" : "0x5176305093fff279697d3fc9b6bc09574303edb4",
    "open_block"  : "32654234",
    "balance"     : "0",
    "deposit"     : "25",
},
]

Getting all open channels for a given sender¶

/api/1/channels/<sender_address>

Return a list of all open channels for the sender specified in the second argument of the URL.

Example Request¶

GET /api/1/channels/0x5601ea8445a5d96eeebf89a67c4199fbb7a43fbb

Example Response¶

200 OK and

[
{
    "sender_address" : "0x5601ea8445a5d96eeebf89a67c4199fbb7a43fbb",
    "open_block"  : "3241462",
    "balance"     : "0",
    "deposit"     : "10",
    "state"       : "open",
},
]

Getting a single channel info¶

/api/1/channels/<sender_address>/<open_block>

Return an info about the channel, identified by sender and open block id.

Example Request¶

GET /api/1/channels/0x5601ea8445a5d96eeebf89a67c4199fbb7a43fbb/3241462

Example Response¶

200 OK and

{
    "sender_address" : "0x5601ea8445a5d96eeebf89a67c4199fbb7a43fbb",
    "open_block"  : "3241462",
    "balance"     : "0",
    "deposit"     : "10",
    "state"       : "open",
}

Cooperatively closing a channel¶

/api/1/channels/<sender_address>/<open_block>

Return a receiver’s signature that can be used to settle the channel immediately (by calling contract’s cooperativeClose() function).

Example Request¶

DELETE /api/1/channels/0x5601ea8445a5d96eeebf89a67c4199fbb7a43fbb/3241642

with payload balance - last balance of the channel

{
    "balance": 13000,
}

Example Response¶

200 OK and

{
    "close_signature" : "0xb30809f9a32e4f5012a3e7a7275e4f0f96eaff49f7a34747507abc3147a0975c31cf9f9aa318d1f9675d6e39f062a565213bcef4baa820f0332616f0c38324fe01",
}

Possible Responses¶

HTTP Code	Condition
200 OK	For a successful coop-close
500 Server Error	Internal Raiden node error
400 Bad request	Invalid address, signature, or channel doesn’t exist.

Components overview¶

HTTP Headers¶

Response Headers¶

200 OK¶

Headers	Type	Description
RDN-Gateway-Path	bytes	Path root of the channel management app
RDN-Receiver-Address	address	Address of the Merchant
RDN-Contract-Address	address	Address of RaidenMicroTransferChannels contract
RDN-Token-Address	address	Address of the Token contract
RDN-Price	uint	Resource price
RDN-Sender-Address	address	Address of the Client
RDN-Sender-Balance	uint	Balance of the Channel

402 Payment Required¶

Headers	Type	Description
RDN-Gateway-Path	bytes	Path root of the channel management app
RDN-Receiver-Address	address	Address of the Merchant
RDN-Contract-Address	address	Address of RaidenMicroTransferChannels contract
RDN-Token-Address	address	Address of the Token contract
RDN-Price	uint	Resource price
RDN-Sender-Address	address	Address of the Client
RDN-Sender-Balance	uint	Balance of the Channel
RDN-Balance-Signature	bytes	Optional. Last saved balance proof from the sender.
		+ one of the following:
RDN-Insufficient-Conf irmations	uint	Failure - not enough confirmations after the channel creation. Client should wait and retry.
RDN-Nonexisting-Channel	string	Failure - channel does not exist or was closed.
RDN-Invalid-Balance- Proof	uint	Failure - Balance must not be greater than deposit or The balance must not decrease.
RDN-Invalid-Amount	uint	Failure - wrong payment value

409¶

ValueError

502¶

Ethereum node is not responding
Channel manager ETH balance is below limit

Request Headers¶

Headers	Type	Description
RDN-Contract-Address	address	Address of MicroTransferChannels contract
RDN-Receiver-Address	address	Address of the Merchant
RDN-Sender-Address	address	Address of the Client
RDN-Payment	uint	Amount of the payment
RDN-Sender-Balance	uint	Balance of the Channel
RDN-Balance-Signature	bytes	Signature from the Sender, signing the balance (post payment)
RDN-Open-Block	uint	Opening block number of the channel required for unique identification

Off-Chain Micropayment Sequence¶

(not-so-standard sequence diagram) For a better overview, also check out how the smart contract does a balance-proof validation.

µRaiden Server¶

Non-detailed components overview. For function arguments and types, please check source code and docstrings.

Channel manager¶

Proxy¶

Python Client¶

Web Client¶

For an overview of the web client, please refer to the JavaScript client library documentation.

Smart Contract¶

For an overview of the RaidenMicroTransferChannels smart contract, please refer to the Smart Contract API documentation.

JavaScript client library¶

Introduction¶

For a quick overview on how to use the Javascript client library please refer to the README

API documentation¶

The autodocumented API reference currently also resides in our GitHub.

Smart Contract¶

Smart Contracts, Unittests and Infrastructure for RaidenPaymentChannel

Installation¶

The Smart Contracts can be installed separately from the other components.

Prerequisites¶

Python 3.6
pip

Setup¶

pip install -r requirements.txt

Usage¶

from root/contracts:

# compilation
populus compile

# tests
pytest
pytest -p no:warnings -s
pytest tests/test_uraiden.py -p no:warnings -s

# Recommended for speed:
# you have to comment lines in tests/conftest.py to use this
pip install pytest-xdist==1.17.1
pytest -p no:warnings -s -n NUM_OF_CPUs

Deployment¶

Chain setup for testing¶

Note - you can change RPC/IPC chain connection, timeout parameters etc. in project.json

privtest¶

Start the geth-node from the commandline:

geth --ipcpath="~/Library/Ethereum/privtest/geth.ipc" \
     --datadir="~/Library/Ethereum/privtest" \
     --dev \
     ---rpc --rpccorsdomain '\*' --rpcport 8545 \
     --rpcapi eth,net,web3,personal \
     --unlock 0xf590ee24CbFB67d1ca212e21294f967130909A5a \
     --password ~/password.txt

# geth console
# you have to mine yourself: miner.start()
geth attach ipc:/Users/loredana/Library/Ethereum/privtest/geth.ipc

kovan¶

Get some testnet-Ether at the kovan-faucet
Modify the project.json to change the default account
Start the Parity node from the commandline:

parity --geth \
       --chain kovan \
       --force-ui --reseal-min-period 0 \
       --jsonrpc-cors http://localhost \
       --jsonrpc-apis web3,eth,net,parity,traces,rpc,personal \
       --unlock 0x5601Ea8445A5d96EEeBF89A67C4199FbB7a43Fbb \
       --password ~/password.txt \
       --author 0x5601Ea8445A5d96EEeBF89A67C4199FbB7a43Fbb

ropsten¶

Get some testnet-Ether at the ropsten-faucet
Modify the project.json to change the default account
Start the geth node from the commandline:

geth --testnet \
     --rpc --rpcport 8545 \
     --unlock 0xbB5AEb01acF5b75bc36eC01f5137Dd2728FbE983 \
     --password ~/password.txt

rinkeby¶

Get some testnet-Ether at the rinkeby-faucet
Modify the /contracts/project.json to change the default account

Fast deployment¶

There are some scripts to provide you with convenient ways to setup a quick deployment.

# Fast deploy on kovan | ropsten | rinkeby | tester | privtest

# Following two calls are equivalent
python -m deploy.deploy_testnet  # --owner is web.eth.accounts[0]
python -m deploy.deploy_testnet \
  --chain kovan \
  --owner 0x5601Ea8445A5d96EEeBF89A67C4199FbB7a43Fbb \
  --challenge-period 500 \
  --token-name CustomToken --token-symbol TKN \
  --supply 10000000 --token-decimals 18

# Provide a custom deployed token
python -m deploy.deploy_testnet --token-address TOKEN_ADDRESS

API¶

Generated docs¶

There is an Auto-Generated-API, that is compiled with soldocs.

Prerequisites

pip install soldocs
populus compile
soldocs --input build/contracts.json --output docs/contract/RaidenMicroTransferChannels.md --contracts RaidenMicroTransferChannels

Opening a transfer channel¶

ERC223 compatible (recommended)¶

Sender sends tokens to the Contract, with a payload for calling createChannelPrivate.

Token.transfer(_to, _value, _data)

Gas cost (testing): 88976

_to = Contract.address
_value = deposit value (number of tokens)
_data contains the Sender and Receiver addresses encoded in 20 bytes
in python _data = bytes.fromhex(sender_address[2:] + receiver_address[2:])

ERC20 compatible¶

# approve token transfers to the contract from the Sender's behalf
Token.approve(contract, deposit)

Contract.createChannel(receiver_address, deposit)

Gas cost (testing): 120090

Topping up a channel¶

Adding tokens to an already opened channel.

ERC223 compatible (recommended)¶

Sender sends tokens to the Contract, with a payload for calling topUp.

Token.transfer(_to, _value, _data)

Gas cost (testing): 54885

_to = Contract.address
_value = deposit value (number of tokens)
_data contains the Sender and Receiver addresses encoded in 20 bytes + the open_block_number in 4 bytes
in python

_data = sender_address[2:] + receiver_address[2:] + hex(open_block_number)[2:].zfill(8)
_data = bytes.fromhex(_data)

ERC20 compatible¶

#approve token transfers to the contract from the Sender's behalf
Token.approve(contract, added_deposit)

# open_block_number = block number at which the channel was opened
Contract.topUp(receiver_address, open_block_number, added_deposit)

Gas cost (testing): 85414

Generating and validating a balance proof¶

(to be updated post EIP712)

# Sender has to provide a balance proof to the Receiver when making a micropayment
# The contract implements some helper functions for that

# Balance message
bytes32 balance_message_hash = keccak256(
    keccak256(
        'string message_id',
        'address receiver',
        'uint32 block_created',
        'uint192 balance',
        'address contract'
    ),
    keccak256(
        'Sender balance proof signature',
        _receiver_address,
        _open_block_number,
        _balance,
        address(this)
    )
);

# balance_message_hash is signed by the Sender with MetaMask
balance_msg_sig

# Data is sent to the Receiver (receiver, open_block_number, balance, balance_msg_sig)

Generating and validating a closing agreement¶

from eth_utils import encode_hex

# Sender has to provide a balance proof to the Contract and
# a closing agreement proof from Receiver (closing_sig)
# closing_sig is created in the same way as balance_msg_sig, but it is signed by the Receiver

# Closing signature message
bytes32 balance_message_hash = keccak256(
    keccak256(
        'string message_id',
        'address sender',
        'uint32 block_created',
        'uint192 balance',
        'address contract'
    ),
    keccak256(
        'Receiver closing signature',
        _sender_address,
        _open_block_number,
        _balance,
        address(this)
    )
);

# balance_message_hash is signed by the Sender with MetaMask
balance_msg_sig

# balance_msg_sig is signed by the Receiver inside the microraiden code
closing_sig

# Send to the Contract (example of collaborative closing, transaction sent by Sender)
Contract.transact({ "from": Sender }).cooperativeClose(
    _receiver_address,
    _open_block_number,
    _balance,
    _balance_msg_sig,
    _closing_sig
)

Balance proof / closing agreement signature verification:¶

sender_address = Contract.call().extractBalanceProofSignature(receiver_address, open_block_number, balance, balance_msg_sig)

receiver_address = Contract.call().extractClosingSignature(sender_address, open_block_number, balance, closing_sig)

Closing a channel¶

# 1. Receiver calls Contract with the sender's signed balance message = instant close & settle
# 2. Client calls Contract with receiver's closing signature = instant close & settle
# Gas cost (testing): 71182
Contract.cooperativeClose(receiver_address, open_block_number, balance, balance_msg_sig, closing_sig)

# 3. Client calls Contract without receiver's closing signature = challenge period starts, channel is not settled yet
# Gas cost (testing): 53876
Contract.uncooperativeClose(receiver_address, open_block_number, balance)

# 3.a. During the challenge period, 1. can happen.

# 3.b. Client calls Contract after settlement period ends
# Gas cost (testing): 40896
Contract.settle(receiver_address, open_block_number)

Welcome to microraiden’s documentation!¶

Contents¶

Proxy tutorial¶

Introduction¶

Requirements¶

Setting up the proxy¶

Initialization¶

Resource types¶

Setting a price for the resource dynamically¶

Starting/stopping the proxy¶

Accessing the content¶

Browser¶

Side notes¶

Proxy state file¶

REST API¶

Introduction¶

Proxy endpoints¶

Getting the status of the proxy¶

Example Request¶

Example Response¶

Channel endpoints¶

Getting all open channels¶

Example Request¶

Example Response¶

Getting all open channels for a given sender¶

Example Request¶

Example Response¶

Getting a single channel info¶

Example Request¶

Example Response¶

Cooperatively closing a channel¶

Example Request¶

Example Response¶

Possible Responses¶

Components overview¶

HTTP Headers¶

Response Headers¶

200 OK¶

402 Payment Required¶

409¶

502¶

Request Headers¶

Off-Chain Micropayment Sequence¶

µRaiden Server¶

Channel manager¶

Proxy¶

Python Client¶

Web Client¶

Smart Contract¶

JavaScript client library¶

Introduction¶

API documentation¶

Smart Contract¶

Installation¶

Prerequisites¶

Setup¶

Usage¶

Deployment¶

Chain setup for testing¶

privtest¶

kovan¶

ropsten¶

rinkeby¶

Fast deployment¶

API¶

Generated docs¶

Opening a transfer channel¶

ERC223 compatible (recommended)¶

ERC20 compatible¶

Topping up a channel¶

ERC223 compatible (recommended)¶

ERC20 compatible¶

Generating and validating a balance proof¶

Generating and validating a closing agreement¶

Balance proof / closing agreement signature verification:¶

Closing a channel¶

Indices and tables¶