Blockchain Command-Line Interface

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Since Greenfield Command Line interface is derived from Cosmos, The majority of the content in this page is copied from the Cosmos SDK.

There is no set way to create a CLI, but Greenfield typically use the Cobra Library. Building a CLI with Cobra entails defining commands, arguments, and flags. Commands understand the actions users wish to take, such as tx for creating a transaction and query for querying the application. Each command can also have nested subcommands, necessary for naming the specific transaction type. Users also supply Arguments, such as account numbers to send coins to, and flags to modify various aspects of the commands, such as gas prices or which node to broadcast to.

Transaction Command

Here is an example of a command a user might enter to interact with gnfd in order to send some tokens:

gnfd tx bank send $MY_ADDRESS $RECIPIENT 1000BNB --gas auto

The first four strings specify the command:

The subcommand tx, which contains all commands that let users create transactions.
The subcommand bank to indicate which module to route the command to x/bank module in this case.
The type of transaction send.

The next two strings are arguments: the from_address the user wishes to send from, the to_address of the recipient, and the amount they want to send. Finally, the last few strings of the command are optional flags to indicate how much the user is willing to pay in fees.

Transaction Data

Greenfield utilizes the EIP712 transaction format. To view the transaction data, you can use the print-eip712-msg-type flag. Below is an example of how to display the transaction data of sending tokens.

gnfd tx bank send $MY_ADDRESS $RECIPIENT 1000BNB --print-eip712-msg-type

From the output, we can obtain the following three fields:

EIP712MessageType: This field represents the EIP712 messages format of the transaction.

{
  "Coin": [
    {
      "name": "amount",
      "type": "uint256"
    },
    {
      "name": "denom",
      "type": "string"
    }
  ],
  "EIP712Domain": [
    {
      "name": "chainId",
      "type": "uint256"
    },
    {
      "name": "name",
      "type": "string"
    },
    {
      "name": "salt",
      "type": "string"
    },
    {
      "name": "verifyingContract",
      "type": "string"
    },
    {
      "name": "version",
      "type": "string"
    }
  ],
  "Fee": [
    {
      "name": "amount",
      "type": "Coin[]"
    },
    {
      "name": "gas_limit",
      "type": "uint256"
    },
    {
      "name": "granter",
      "type": "string"
    },
    {
      "name": "payer",
      "type": "string"
    }
  ],
  "Msg1": [
    {
      "name": "amount",
      "type": "TypeMsg1Amount[]"
    },
    {
      "name": "from_address",
      "type": "string"
    },
    {
      "name": "to_address",
      "type": "string"
    },
    {
      "name": "type",
      "type": "string"
    }
  ],
  "Tx": [
    {
      "name": "account_number",
      "type": "uint256"
    },
    {
      "name": "chain_id",
      "type": "uint256"
    },
    {
      "name": "fee",
      "type": "Fee"
    },
    {
      "name": "memo",
      "type": "string"
    },
    {
      "name": "msg1",
      "type": "Msg1"
    },
    {
      "name": "sequence",
      "type": "uint256"
    },
    {
      "name": "timeout_height",
      "type": "uint256"
    }
  ],
  "TypeMsg1Amount": [
    {
      "name": "amount",
      "type": "string"
    },
    {
      "name": "denom",
      "type": "string"
    }
  ]
}

MessageData: This field represents the messages data of the transaction, displayed in a readable format.

{
  "msg1": {
    "amount": [
      {
        "amount": "1000",
        "denom": "BNB"
      }
    ],
    "from_address": "0x0aA5170C854AA093e1c32F15285dE4Bf7f6802Ce",
    "to_address": "0x2123B607e1b9E8Ae65FbE12585C1bE6838Bb32C7",
    "type": "/cosmos.bank.v1beta1.MsgSend"
  }
}

TxRawBytes: This field represents the encoded byte array of the transaction.

0a88010a85010a1c2f636f736d6f732e62616e6b2e763162657461312e4d736753656e6412650a2a307830614135313730433835344141303933653163333246313532383564453442663766363830324365122a3078323132334236303765316239453841653635466245313235383543316245363833384262333243371a0b0a03424e4212043130303012021200

Once you have obtained these three fields of the transaction, you can use gnfd-tx-sender to send the transaction instead of using a command. Here are the steps:

Visit the gnfd-tx-sender website.
Connect your wallet and switch to the correct network.
Navigate to the Custom Tx page and fill in the aforementioned three fields accordingly.
Click the Submit button and sign in the wallet when prompted.
Wait for confirmation.

Query Commands

Queries are objects that allow users to retrieve information about the application's state.

This queryCommand function adds all the queries available to end-users for the application. This typically includes:

QueryTx and/or other transaction query commands from the auth module which allow the user to search for a transaction by inputting its hash, a list of tags, or a block height. These queries allow users to see if transactions have been included in a block.
Account command from the auth module, which displays the state (e.g. account balance) of an account given an address.
Validator command from the Cosmos SDK rpc client tools, which displays the validator set of a given height.
Block command from the Cosmos SDK rpc client tools, which displays the block data for a given height.
**All module query commands the application is dependent on,

Here is an example of a queryCommand:

## query the metadata of BNB
gnfd q bank denom-metadata --node https://greenfield-chain.bnbchain.org:443

Environment variables

Each flag is bound to its respective named environment variable. Then name of the environment variable consist of two parts

capital case basename followed by flag name of the flag. - must be substituted with _.
For example flag --home for application with basename GNFD is bound to GNFD_HOME. It allows reducing the amount of flags typed for routine operations. For example instead of:

gnfd --home=./ --node=<node address> --chain-id="greenfield_1017-1" tx ... --from=<key name>

this will be more convenient:

# define env variables in .env, .envrc etc
GNFD_HOME=<path to home>
GNFD_NODE=<node address>
GNFD_CHAIN_ID="greenfield_1017-1"
GNFD_KEYRING_BACKEND="file"

# and later just use
gnfd tx ... --from=<key name>

Blockchain Command-Line Interface

Transaction Command​

Transaction Data​

Query Commands​

Environment variables​

Transaction Command

Transaction Data

Query Commands

Environment variables