Go SDK - Fetch Data

You can use the Aptos client to get on-chain data using a variety of helper functions. Specifically, many of the functions listed in the reference docs will retrieve data from on-chain e.g. Account, AccountResources, Transactions.

Here’s an example showing how to fetch common data you may need in your application:

client, err := aptos.NewClient(aptos.DevnetConfig)
if err != nil {
  panic("Failed to create client:" + err.Error())
}

address := aptos.AccountAddress{}
err := address.ParseStringRelaxed("0x123")
if err != nil {
  panic("Failed to parse address:" + err.Error())
}

accountInfo, err := client.Account(address)
resources, err := client.AccountResources(address)
transactions, err := client.Transactions()

The Aptos client can out of the box query both network data from fullnodes and the Indexer API which contains aggregated and enriched data. If you want to use a custom query for Indexer API data, you can use client.QueryIndexer() like so:

  var out []CoinBalance
  var q struct {
    Current_coin_balances []struct {
      CoinType     string `graphql:"coin_type"`
      Amount       uint64
      OwnerAddress string `graphql:"owner_address"`
    } `graphql:"current_coin_balances(where: {owner_address: {_eq: $address}})"`
  }

  variables := map[string]any{
    "address": address.StringLong(),
  }
  err := ic.Query(&q, variables)

  if err != nil {
    return nil, err
  }

  for _, coin := range q.Current_coin_balances {
    out = append(out, CoinBalance{
      CoinType: coin.CoinType,
      Amount:   coin.Amount,
    })
  }

Using Move View Functions

You can call view functions which return custom data from on-chain by using client.View.

For example, you can look up the network you are using with the chain_id view function:

viewResponse, err := client.View(&aptos.ViewPayload {
  Module: aptos.ModuleId{Address: aptos.AccountAddress{}, Name: "chain_id"},
  Function: "get",
  ArgTypes: []aptos.TypeTag{},
  Args: [][]byte{},
)

chainId := viewResponse[0]

Ensuring Fresh Indexer Data

Behind the scenes, some requests use the Indexer API to access data which has been processed or aggregated. That extra parsing can take a bit of time, so the data may lag slightly behind the latest ledger.

If you want to ensure that the data is fresh, you can wait on a specific version from the indexer.

// Wait on processorName to reach version 12345
err := client.WaitOnIndexer("processorName", 12345)