Nethereum.GSN

NuGet: Nethereum.GSN | Source: src/Nethereum.GSN/

Nethereum.GSN

Gas Station Network is the ultimate solution for Ethereum decentralized applications. It removes the barrier between users and dApps but increases the complexity of dApps.

Pre-requirements

1. Contract should be GSN-capable
2. Contract should have positive balance in RelayHub. It can be done via CLI or RelayHubHelper in the project

   RelayHubHelper.DepositRelayHub(
       "ED3...",                                           // Private key of sender
       "https://rinkeby.infura.io/v3/...",                 // RPC Endpoint
       "0xD216153c06E857cD7f72665E0aF1d7D82172F494",       // RelayHub address (https://gsn.openzeppelin.com/relays)
       "0x...",                                            // Contract address
       Nethereum.Web3.Web3.Convert.ToWei(1)                // Amount
   );

Getting started

In order to add GSN support to Nethereum Web3 instance, follow the next steps:

1. Initialize Web3 with RpcClient paramenter only

   var client = new RpcClient(new Uri("https://rinkeby.infura.io/v3/..."));
   web3 = new Web3(client);

2. Initialize GSNTransactionManager

   var options = new GSNOptions { UseGSN = true };
   var relayClient = new RelayClient(options.HttpTimeout);
   
   // Discovers relays registered on the RelayHub via its events
   var relayQuery = new RelayQuery(options.RelayLookupLimitBlocks, web3.Eth, relayClient);
   var relayHubManager = new RelayHubManager(web3.Eth, relayQuery);
   
   // The Relayer selects a ready relay by policy and validates the recipient balance
   var balanceValidator = new RecipientBalanceValidator(web3.Eth);
   var relayer = new Relayer(relayHubManager, balanceValidator, new DefaultRelayPolicy());
   
   var transactionManager = new GSNTransactionManager(
       options,
       relayer,
       web3.Eth,
       web3.Client,
       relayClient,
       "ED3..."                                            // Private key of sender
   );

3. Set Interceptor of Web3 instance

   web3.Client.OverridingRequestInterceptor = new GSNTransactionInterceptor(transactionManager);

References

0. EIP-1613
1. Getting started with the Gas Station Network
2. Available Relays
3. To discuss