Query Balances

This guide will cover the following query methods:

• mnovad & Tendermint RPC

• JSON-RPC

• gRPC

mnovad & Tendermint RPC

Upon installation and configuration of the Metanovaverse Daemon, developers can query account balances using mnovad with the following CLI command:

$ blockxd query bank balances $MNOVAADDRESS --count-total=$COUNTTOTAL --height=$HEIGHT --output=$OUTPUT --node=$NODE
balances:
- amount: "1000000000000000000"
  denom: amnv
- amount: "100000"
  denom: ibc/ED07A3391A112B175915CD8FAF43A2DA8E4790EDE12566649D0C2F97716B8518
pagination:
  next_key: null
  total: "0"

where:

• $MNOVAADDRESS is the Metanovaverse address with balances of interest (eg. mnova...).

• (optional) $COUNTTOTAL counts the total number of records in all balances to query for.

• (optional) $HEIGHT is the specific height to query state at (can error if node is pruning state).

• (optional) $OUTPUT is the output format (eg. text).

• (optional if running local node) $NODE is the Tendermint RPC node information is requested from

Details of non-native currencies can be queried with the following CLI command:

$ mnovad query erc20 token-pair $DENOM --node=$NODE --height=$HEIGHT --output=$OUTPUT
token_pair:
  contract_owner: OWNER_MODULE
  denom: ibc/ED07A3391A112B175915CD8FAF43A2DA8E4790EDE12566649D0C2F97716B8518
  enabled: true
  erc20_address: 0xFA3C22C069B9556A4B2f7EcE1Ee3B467909f4864

where $DENOM is the denomination of the coin (eg. ibc/ED07A3391A1...).

JSON-RPC

Developers can query account balances of amnv using the eth_getBalance JSON-RPC method in conjunction with curl:

# Request
curl -X POST --data '{"jsonrpc":"2.0","method":"eth_getBalance","params":[`$ETHADDRESS`, `$BLOCK`],"id":1}' -H "Content-Type: application/json" $NODE

# Result
{"jsonrpc":"2.0","id":1,"result":"0x36354d5575577c8000"}

where:

• $ETHADDRESS is the Etherum hex-address the balance is to be queried from. Note that MNOVA addresses

• $BLOCK is the block number or block hash (eg. "0x0"). The reasoning for this parameter is due to EIP-1898.

• (optional if running local node) $NODE is the JSON-RPC node information is requested from

Developers can also query account balances of x/erc20-module registered coins using the eth_call JSON-RPC method in conjunction with curl:

# Request
curl -X POST --data '{"jsonrpc":"2.0","method":"eth_call","params":[{"from":`SENDERCONTRACTADDRESS`, "to":`ERCCONTRACTADDRESS`, "data":`$DATA`}, `$BLOCK`],"id":1}'  -H "Content-Type: application/json" $NODE

# Result
{"jsonrpc":"2.0","id":1,"result":"0x"}

where:

• $SENDERCONTRACTADDRESS is the Ethereum hex-address this smart contract call is sent from.

• $ERCCONTRACTADDRESS is the Ethereum hex-address of the ERC-20 contract corresponding to the coin denomination being queried.

• $DATA is the hash of the balanceof method signature and encoded parameters. balanceOf is a required method in every ERC-20 contract, and the encoded parameter is the address which is having its balance queried. For additional information, see the Ethereum Contract ABI.

• $BLOCK is the block number or block hash (eg. "0x0"). The reasoning for this parameter is due to EIP-1898.

• (optional if running local node) $NODE is the JSON-RPC node information is requested from

gRPC

Developers can use grpcurl with the AllBalances endpoint to query account balance by address for all denominations:

# Request
grpcurl $OUTPUT -d '{"address":`$MNOVAADDRESS`}' $NODE cosmos.bank.v1beta1.Query/AllBalances

# Result
{
  "balances": [
    {
      "denom": "stake",
      "amount": "1000000000"
    }
  ],
  "pagination": {
    "total": "1"
  }
}

where:

• $MNVADDRESS is the Metanovaverse address with balances of interest (eg. "mnova...").

• $NODE is the Cosmos gRPC node information is requested

• (optional) $OUTPUT is the output format (eg. plaintext).

State can also be queried using gRPC within a Go program. The idea is to create a gRPC connection, then use the Protobuf-generated client code to query the gRPC server.

import (
    "context"
    "fmt"

  "google.golang.org/grpc"

    sdk "github.com/cosmos/cosmos-sdk/types"
  "github.com/cosmos/cosmos-sdk/types/tx"
)

func queryState() error {
    myAddress, err := GetMNovaAddressFromBech32("mnova...") // blockx address with balances of interest.
    if err != nil {
        return err
    }

    // Create a connection to the gRPC server.
    grpcConn := grpc.Dial(
        "https://grpc.bd.metanovaverse.com:9090", // your gRPC server address.
        grpc.WithInsecure(), // the SDK doesn't support any transport security mechanism.
    )
    defer grpcConn.Close()

    // This creates a gRPC client to query the x/bank service.
    bankClient := banktypes.NewQueryClient(grpcConn)
    bankRes, err := bankClient.AllBalances(
        context.Background(),
        &banktypes.QueryAllBalancesRequest{Address: myAddress},
    )
    if err != nil {
        return err
    }

    fmt.Println(bankRes.GetBalances()) // prints the account balances.

    return nil
}