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Overview

A Provider is an interface that abstracts the interaction with the Tendermint2 chain, making it easier for users to communicate with it. Rather than requiring users to understand which endpoints are exposed, what their return types are, and how they are parsed, the Provider abstraction handles all of this behind the scenes. It exposes useful API methods that users can use and expects concrete types in return.

Currently, the tm2-js-client package provides support for two Provider implementations:

  • JSON-RPC Provider: executes each call as a separate HTTP RPC call.
  • WS Provider: executes each call through an active WebSocket connection, which requires closing when not needed anymore.

Account Methods​

getBalance​

Fetches the denomination balance of the account

Parameters​

  • address string the bech32 address of the account
  • denomination string the balance denomination (optional, default ugnot)
  • height number the height for querying. If omitted, the latest height is used (optional, default 0)

Returns Promise<number>

Usage​

await provider.getBalance('g1u7y667z64x2h7vc6fmpcprgey4ck233jaww9zq', 'atom');
// 100

getAccountSequence​

Fetches the account sequence

Parameters​

  • address string the bech32 address of the account
  • height number the height for querying. If omitted, the latest height is used. (optional, default 0)

Returns Promise<number>

Usage​

await provider.getAccountSequence('g1u7y667z64x2h7vc6fmpcprgey4ck233jaww9zq');
// 42

getAccountNumber​

Fetches the account number. Errors out if the account is not initialized

Parameters​

  • address string the bech32 address of the account
  • height number the height for querying. If omitted, the latest height is used (optional, default 0)

Returns Promise<number>

Usage​

await provider.getAccountNumber('g1u7y667z64x2h7vc6fmpcprgey4ck233jaww9zq');
// 100

Block methods​

getBlock​

Fetches the block at the specific height, if any

Parameters​

  • height number the height for querying

Returns Promise<BlockInfo>

Usage​

await provider.getBlock(1);
/*
{
  block_meta: {
    block_id: {
      hash: "TxHKEGxFm/4+D7gxOJdVUaR+xTDZzlPrCVXuVm7SqHw=",
      parts: {
        total: "1",
        hash: "+dqI9oyngnnlKyno7y+RxCLEPA9FxWA/MmXyJ4uoJAY="
      }
    },
    header: {
      version: "v1.0.0-rc.0",
      chain_id: "dev",
      height: "1",
      time: "2023-05-01T10:32:20.807541Z",
      num_txs: "0",
      total_txs: "0",
      app_version: "",
      last_block_id: {
        hash: null,
        parts: {
          total: "0",
          hash: null
        }
      },
      last_commit_hash: null,
      data_hash: null,
      validators_hash: "FnuBaDvDLg4FotGRcZAFvhLkEjkb+kNLaAZrAVhL5Aw=",
      next_validators_hash: "FnuBaDvDLg4FotGRcZAFvhLkEjkb+kNLaAZrAVhL5Aw=",
      consensus_hash: "uKhnXFmGUkxgQSJf17ogbYLNXDo3UEPwQvzddo4Vkuw=",
      app_hash: null,
      last_results_hash: null,
      proposer_address: "g1vsqzyy9a4h9ah8cxzkaw09rpzy369mkl70lfdk"
    }
  },
  block: {
    header: {
      version: "v1.0.0-rc.0",
      chain_id: "dev",
      height: "1",
      time: "2023-05-01T10:32:20.807541Z",
      num_txs: "0",
      total_txs: "0",
      app_version: "",
      last_block_id: {
        hash: null,
        parts: {
          total: "0",
          hash: null
        }
      },
      last_commit_hash: null,
      data_hash: null,
      validators_hash: "FnuBaDvDLg4FotGRcZAFvhLkEjkb+kNLaAZrAVhL5Aw=",
      next_validators_hash: "FnuBaDvDLg4FotGRcZAFvhLkEjkb+kNLaAZrAVhL5Aw=",
      consensus_hash: "uKhnXFmGUkxgQSJf17ogbYLNXDo3UEPwQvzddo4Vkuw=",
      app_hash: null,
      last_results_hash: null,
      proposer_address: "g1vsqzyy9a4h9ah8cxzkaw09rpzy369mkl70lfdk"
    },
    data: {
      txs: null
    },
    last_commit: {
      block_id: {
        hash: null,
        parts: {
          total: "0",
          hash: null
        }
      },
      precommits: null
    }
  }
}
*/

getBlockResult​

Fetches the block at the specific height, if any

Parameters​

  • height number the height for querying

Returns Promise<BlockResult>

Usage​

await provider.getBlockResult(1);
/*
{
  height: "1",
  results: {
    deliver_tx: null,
    end_block: {
      ResponseBase: {
        Error: null,
        Data: null,
        Events: null,
        Log: "",
        Info: ""
      },
      ValidatorUpdates: null,
      ConsensusParams: null,
      Events: null
    },
    begin_block: {
      ResponseBase: {
        Error: null,
        Data: null,
        Events: null,
        Log: "",
        Info: ""
      }
    }
  }
}
*/

getBlockNumber​

Fetches the latest block number from the chain

Returns Promise<number>

Usage​

await provider.getBlockNumber();
// 1300

Network methods​

getNetwork​

Fetches the network information

Returns Promise<NetworkInfo>

Usage​

await provider.getNetwork();
/*
{
  listening: true,
  listeners: [
    "Listener(@)"
  ],
  n_peers: "0",
  peers: []
}
*/

getConsensusParams​

Fetches the consensus params for the specific block height

Parameters​

  • height number the height for querying

Returns Promise<ConsensusParams>

Usage​

await provider.getConsensusParams(1);
/*
{
  block_height: "1",
  consensus_params: {
    Block: {
      MaxTxBytes: "1000000",
      MaxDataBytes: "2000000",
      MaxBlockBytes: "0",
      MaxGas: "10000000",
      TimeIotaMS: "100"
    },
    Validator: {
      PubKeyTypeURLs: [
        "/tm.PubKeyEd25519"
      ]
    }
  }
}
*/

getStatus​

Fetches the current node status

Returns Promise<Status>

Usage​

await provider.getStatus();
/*
{
  node_info: {
    version_set: [
      {
        Name: "abci",
        Version: "v1.0.0-rc.0",
        Optional: false
      },
      {
        Name: "app",
        Version: "",
        Optional: false
      },
      {
        Name: "bft",
        Version: "v1.0.0-rc.0",
        Optional: false
      },
      {
        Name: "blockchain",
        Version: "v1.0.0-rc.0",
        Optional: false
      },
      {
        Name: "p2p",
        Version: "v1.0.0-rc.0",
        Optional: false
      }
    ],
    net_address: "g1z0wa6rspsshkm2k7jlqvnjs8jdt4kvg4e9j640@0.0.0.0:26656",
    network: "dev",
    software: "",
    version: "v1.0.0-rc.0",
    channels: "QCAhIiMw",
    moniker: "voyager.lan",
    other: {
      tx_index: "off",
      rpc_address: "tcp://127.0.0.1:26657"
    }
  },
  sync_info: {
    latest_block_hash: "x5ewEBhf9+MGXbEFkUdOm3RsE40D+plUia2u0PuVfHs=",
    latest_app_hash: "7dB/+EmqLqEX2RkH2Zx+GcFo8c2vTs2ttW8urYyyFT4=",
    latest_block_height: "55",
    latest_block_time: "2023-05-06T11:28:35.643575Z",
    catching_up: false
  },
  validator_info: {
    address: "g1vsqzyy9a4h9ah8cxzkaw09rpzy369mkl70lfdk",
    pub_key: {
      "@type": "/tm.PubKeyEd25519",
      value: "X8ZS1DYu1eJ3HYnZ0OWk+0GgCdI7zA++kgWiprWMs3w="
    },
    voting_power: "0"
  }
}
*/

getGasPrice​

NOTE: Not supported yet

Fetches the current (recommended) average gas price

Returns Promise<number>

estimateGas​

NOTE: Not supported yet

Estimates the gas limit for the transaction

Parameters​

  • tx Tx the transaction that needs estimating

Returns Promise<number>

Transaction methods​

sendTransaction​

Sends the transaction to the node for committing and returns the transaction hash. The transaction needs to be signed beforehand.

Parameters​

  • tx string the base64-encoded signed transaction

Returns Promise<string>

Usage​

await provider.sendTransaction('ZXhhbXBsZSBzaWduZWQgdHJhbnNhY3Rpb24');
// "dHggaGFzaA=="

waitForTransaction​

Waits for the transaction to be committed on the chain. NOTE: This method will not take in the fromHeight parameter once proper transaction indexing is added - the implementation should simply try to fetch the transaction first to see if it's included in a block before starting to wait for it; Until then, this method should be used in the sequence: get latest block -> send transaction -> waitForTransaction(block before send)

Parameters​

  • hash string The transaction hash
  • fromHeight number The block height used to begin the search (optional, default latest)
  • timeout number Optional wait timeout in MS (optional, default 15000)

Returns Promise<Tx>

Usage​

await provider.waitForTransaction('ZXhhbXBsZSBzaWduZWQgdHJhbnNhY3Rpb24');
/*
{
   messages:[], // should be filled with the appropriate message type
   fee:{
      gasWanted: "100",
      gasFee: "1ugnot"
   },
   signatures:[
      {
         pubKey:[
            {
                type: "/tm.PubKeySecp256k1"
                value: "X8ZS1DYu1eJ3HYnZ0OWk+0GgCdI7zA++kgWiprWMs3w="
            }
         ],
         signature: "X8ZS1DYu1eJ3HYnZ0OWk+0GgCdI7zA++kgWiprWMs3w="
      }
   ],
   memo: "check out gno.land!"
}
*/