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SKALE

Important! This feature is currently in development and is currently in a work in progress state

Overview​

The SKALE minds system is a custodial wallet system that acts as a replacement to the "offchain" Minds system. Tokens are transacted between wallets internally, simplifying UX significantly. This guide focuses on development on this system.

Setting up Metamask​

To set up on testnet, add a new network to Metamask with the below details:

  • Name: SKALE Testnet (rapping-zuben-elakrab)
  • RPC URL: https://staging-v2.skalenodes.com/v1/rapping-zuben-elakrab
  • Chain ID: 0x4a393bf89c676
  • Currency Symbol: sFuel

Then import a new token, with the address 0x86f5Fd15235C58fb4d250b3674e6ad252e5bB796 for whatever wallet you are using.

It can be helpful to import wallets from the sandbox into your Metamask - when you do this you may need to re-add the token. More on how to do this below under Printing Wallet Info.

Configuration​

The following keys can be lifted from the settings.example.php, located in the blockchain section of the config. Explanations for different values:

  • rpc_endpoints

Array of RPC endpoints - only the first entry is currently used. Other entries in future will work as backups.

  • development_mode

Whether to run in development mode - will allow output of private keys.

  • minds_token_address

Token address of MINDS token on SKALE network.

  • gas_price_wei

Gas price in Wei - the value of this is fixed for a chain and doesn't vary like gas price in the Ethereum network, but varies from SKALE chain to chain. At the time of writing, 100000 Wei is correct for whispering-turais.

  • default_sfuel_distributor_guid

The GUID of the user delegated as the sFuel distributor. The purpose of this user is to have a linked wallet that holds reserves of sFuel - sFuel can be requested from wallets and distributed from this users balance when a wallet does not hold enough sFuel to make a transaction. If using the Tools class in PHP (called by the CLI), distribution will happen automatically when a custodial wallet attempts to make a token transfer without enough sFuel, prior to attempting the transaction.

  • default_sfuel_distribution_amount_wei

The amount of sFuel that should be distributed when a request for sFuel distribution is made (unless manually overrode, such as by the CLI).

  • sfuel_low_threshold

The value in Wei that constitutes a low sFuel balance - when a wallet crosses below this threshold, if they attempt to make a token transfer, sFuel will be distributed to their address prior to the transfer being attempted.

  • confirmation_timeout_seconds

When a transaction is made, confirmation of the transaction onchain is awaited. This value controls the maximum time that the server will wait for a transaction before it stops listening.

  • confirmation_polling_gap_seconds

The gap in between polling attempts to check for transaction completion.

  • balance_cache_ttl_seconds

How long in seconds the TTL should be for storage of sFuel and MINDS (SKALE) balances in cache.

Useful Tools​

CLI​

Minds CLI tool can be used to interact with the SKALE chain in various ways.

Generate Wallet for User​

To generate a wallet for a user, you need to run in the CLI below - if development mode is enabled, the private key will be printed.

php cli.php Skale generateKeys --username=userA

Printing Wallet Info​

Prints keys for a given user:

php cli.php Skale printKeys --username=userA

Get Token Balance​

You can request the token balance of the custodial wallet linked to a user, or any Ethereum address using one of the below commands:

php cli.php Skale getTokenBalance --username=userA
php cli.php Skale getTokenBalance --address=0x00....

Get sFuel Balance​

Similarly, you can request the sFuel balance of the custodial wallet linked to a user, or any Ethereum address:

php cli.php Skale getSFuelBalance --username=userA
php cli.php Skale getSFuelBalance --address=0x00000...

Send Tokens​

Tokens can be sent via the below commands.

# Between two custodial wallets
php cli.php Skale sendTokens --senderUsername=userA --receiverUsername=userB --amountWei=10000000000000000

# From a custodial wallet to an Ethereum address
php cli.php Skale sendTokens --senderUsername=userA --receiverAddress=0x00000... --amountWei=10000000000000000

Note that if the sender user does not have enough sFuel, an transaction will be sent to the wallet prior to dispatching the token transfer to give the wallet sFuel- confirmation of this will be awaited, so the command may take slightly longer.

Send sFuel​

sFuel can be sent manually using one of the below commands:

# Between two custodial wallets - will use default distribution amount
php cli.php Skale sendSFuel --senderUsername=userA --receiverUsername=userB

# From a custodial wallet to an Ethereum address - will use default distribution amount
php cli.php Skale sendSFuel --senderUsername=userA --receiverAddress=0x00000...

# Between two custodial wallets - custom distribution amount.
php cli.php Skale sendSFuel --senderUsername=userA --receiverUsername=userB --amountWei=100000000000