> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sequence.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Fetch balance updates from specific contracts

> This content provides instructions on fetching balance updates from specific contracts.

# Balance Updates API

## `GetBalanceUpdates`

* Request: POST /rpc/IndexerGateway/GetBalanceUpdates
* Content-Type: application/json
* ボディ（JSON形式）：
  * `chainIds` (\[]int - optional) -- return results only for the chains that match the given ID.
  * `networks` (\[]string - optional) -- return results only for the chains that match the given names.
  * `contractAddress` (string)
  * `lastBlockNumber` (int - optional)
  * `lastBlockHash` (string - optional)

### Get the summary of balances of verified tokens on specific networks

Example: query balance updates of the USDT contract on Ethereum network.

<CodeGroup>
  ```shell [Curl] theme={null}
  curl -X POST \
    -H "Content-Type: application/json" \
    -H "X-Access-Key: AQAAAAAAAF_JvPALhBthL7VGn6jV0YDqaFY" \
    https://indexer.sequence.app/rpc/IndexerGateway/GetBalanceUpdates \
    -d '{
      "chainIds": [
          1
      ],
      "contractAddress": "0xdac17f958d2ee523a2206206994597c13d831ec7"
    }'
  ```

  ```ts [Typescript] theme={null}
  import { SequenceIndexerGateway } from '@0xsequence/indexer'

  const INDEXER_TOKEN = 'AQAAAAAAAF_JvPALhBthL7VGn6jV0YDqaFY';
  const CONTRACT_ADDRESS = '0xdac17f958d2ee523a2206206994597c13d831ec7';

  const indexerGateway = new SequenceIndexerGateway(
    'https://indexer.sequence.app',
    INDEXER_TOKEN
  )

  const res = await indexerGateway.getBalanceUpdates({
    chainIds: [1],
    contractAddress: CONTRACT_ADDRESS
  })

  res.balances.forEach(({ chainId, error, results }) => {
    if (error) {
      console.error(`Error fetching balance updates for chainId ${chainId}: ${error}`);
      return;
    }
    console.log(`chainId: ${chainId}`);
    results.forEach(({ accountAddress, balance }) => {
      if (balance === '0') {
        return;
      }
      console.log(`\taccountAddress: ${accountAddress}, balance: ${balance}`);
    });
  });
  ```

  ```go [Go] theme={null}
  package main

  import (
  	"context"
  	"fmt"
  	"log"
  	"net/http"

  	"github.com/0xsequence/go-sequence/indexer"
  )

  const indexerToken = "AQAAAAAAAF_JvPALhBthL7VGn6jV0YDqaFY"

  func main() {
  	ctx := context.TODO()

  	seqIndexerGW := indexer.NewIndexerGatewayClient(
  		"https://indexer.sequence.app",
  		http.DefaultClient,
  	)

  	authCtx, err := indexer.WithHTTPRequestHeaders(ctx, http.Header{
  		"X-Access-Key": []string{indexerToken},
  	})
  	if err != nil {
  		log.Fatal(err)
  	}

  	contractAddress := "0xdac17f958d2ee523a2206206994597c13d831ec7"
  	chainIDs := []uint64{1} // Ethereum Mainnet

  	_, balanceUpdates, err := seqIndexerGW.GetBalanceUpdates(
  		authCtx,
  		chainIDs,
  		nil, // No network names
  		contractAddress,
  		0,   // No lastBlockNumber filter
  		nil, // No lastBlockHash filter
  		nil, // Default page
  	)
  	if err != nil {
  		log.Fatal(err)
  	}

  	for _, update := range balanceUpdates {
  		fmt.Printf("chainId: %d\n", update.ChainID)
  		for _, result := range update.Results {
  			if result.Balance.Int64() == 0 {
  				continue
  			}
  			fmt.Printf("\taccountAddress: %s, balance: %s\n",
  				result.AccountAddress, result.Balance)
  		}
  	}
  }
  ```
</CodeGroup>