Fetch Data via the Go SDK

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:

fetch_data.go

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()

Many have optional inputs such as ledgerVersion to specify which ledger version to query state.

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:

fetch_data.go

	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,
		})
	}

Note that all values in the GraphQL must be capitalized and CamelCased. To convert to direct database field names, use the graphql tag.

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:

fetch_data.go

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.

fetch_data.go

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

Accounts Transactions