End of support notice: Amazon Managed Blockchain (AMB) will stop accepting new customers on October 29, 2026. Existing customers can continue using Amazon Managed Blockchain (AMB) until September 29, 2027. After September 29, 2027 you will no longer be able to access Amazon Managed Blockchain (AMB). For more information, see [Amazon Managed Blockchain (AMB) end of support](https://docs.aws.amazon.com/managed-blockchain/latest/hyperledger-fabric-dev/managed-blockchain-end-of-support.html).
# Use cases with Amazon Managed Blockchain (AMB) Query
This topic provides a list AMB Query use cases.
**Topics**
+ [Query current and historical token balances](#query-token-balances)
+ [Retrieve historical transaction data](#query-transactions)
+ [Get all token balances for a given address](#query-token-balances)
+ [List events emitted for a transaction](#query-tokens-minted)
+ [Get all tokens minted by a contract](#query-transaction-events)
+ [List contracts and get contract information](#query-contract-info)
## Query current and historical token balances
The [`GetTokenBalance`](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/API_GetTokenBalance.html) API gets the balance of supported tokens (ERC20, ERC721, ERC1155) and native coins (ETH, BTC) to get the current or a historical balance by using a universal timestamp (Unix timestamp, in seconds) of externally owned accounts (EOAs). For example, you can use the `GetTokenBalance` API operation to get an address balance of the ERC20 token, USDC, on the Ethereum Mainnet. You can also batch-retrieve balances of tokens and native coins by using the `BatchGetTokenBalance` API operation.
For more information, see the [Amazon Managed Blockchain (AMB) Query Reference Guide](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/Welcome.html).
## Retrieve historical transaction data
With Amazon Managed Blockchain (AMB) Query, you can retrieve historical data from public blockchains such as Ethereum and Bitcoin. This features enables several use cases, such as retrieving a transaction history on a blockchain wallet or providing contextual information about a transaction based on its transaction hash. You can use the [`ListTransactions`](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/API_ListTransactions.html) API operation to get a list of transactions for a given externally owned address (EOA) on the Ethereum Mainnet, and then you can use the [`GetTransaction`](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/API_GetTransaction.html) API operation to retrieve the transaction details for a single transaction from the list.
For more information, see the [Amazon Managed Blockchain (AMB) Query Reference Guide](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/Welcome.html).
## Get all token balances for a given address
You can use the [`ListTokenBalances`](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/API_ListTokenBalances.html) API operation to get balances on wallets, user interfaces, web3 utilities, and more. This API operation returns a list of all balances for an address across tokens (ERC20, ERC721, ERC1155) and native coins (ETH, BTC) on a given public blockchain by using a single API operation. For example, you can provide an externally owned address (EOA) and a network (the Ethereum Mainnet), and you can receive a list of tokens and native coin balances in the response.
For more information, see the [Amazon Managed Blockchain (AMB) Query Reference Guide](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/Welcome.html).
## List events emitted for a transaction
You can use the [`ListTransactionEvents`](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/API_ListTransactionEvents.html) API operation to retrieve a list of contract events that are emitted as a result of a given transaction, identified by its hash (transaction identifier). For example, you can use [`ListTransactionEvents`](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/API_ListTransactionEvents.html) to retrieve the resulting events of a transaction that calls a function of an ERC20 token contract on the Ethereum Blockchain, such as a *Transfer* event or a *Withdrawal* event from the ERC20 contract.
For more information, see the [Amazon Managed Blockchain (AMB) Query Reference Guide](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/Welcome.html).
## Get all tokens minted by a contract
You can use the [`ListTokenBalances`](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/API_ListTokenBalances.html) API operation to return a list of all supported tokens (ERC20, ERC721, ERC1155) minted by a contract when passed the contract address as input. For example, you can retrieve information related to non-fungible tokens (NFTs) minted by the ERC721 contract standard on the Ethereum blockchain by using the [`ListTokenBalances`](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/API_ListTokenBalances.html) API operation.
For more information, see the [Amazon Managed Blockchain (AMB) Query Reference Guide](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/Welcome.html).
## List contracts and get contract information
You can use the [`ListAssetContracts`](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/ListAssetContracts.html) API operation to list ERC-721, ERC-1155, or ERC-20 contracts deployed by a given address. Additionally, if you have the contract address, you can use the [`GetAssetContract`](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/ListAssetContracts.html) API operation to retrieve the contract's properties, such as the contract type deployer address, and relevant token metadata.
For more information, see the [Amazon Managed Blockchain (AMB) Query Reference Guide](https://docs.aws.amazon.com/managed-blockchain/latest/AMBQ-APIReference/Welcome.html).