Accessing and processing information stored on the blockchain

Blockfrost provides restful APIs which allows your app to access information stored on the blockchain. Get started:

const blockfrostProvider = new BlockfrostProvider('<BLOCKFROST_API_KEY>');

If you are using a privately hosted Blockfrost instance, you can set the URL in the parameter:

const blockfrostProvider = new BlockfrostProvider('<BLOCKFROST_URL>');

Choose network for this demo:


Fetch account infomation

await blockfrostProvider.fetchAccountInfo(


Fetch UTXOs in the provided address. Optionally, you can filter UTXOs containing a particular asset by providing asset, where it is the concatenation of policy ID and asset.

await blockfrostProvider.fetchAddressUTxOs(


Fetch a list of a addresses containing a specific asset where it is the concatenation of policy ID and asset.

await blockfrostProvider.fetchAssetAddresses(


Fetch the asset metadata by providing asset's unit, which is the concatenation of policy ID and asset name in hex.

await blockfrostProvider.fetchAssetMetadata(


Fetch block infomation. You can get the hash from fetchTxInfo().

await blockfrostProvider.fetchBlockInfo(


Fetch a list of assets belonging to a collection by providing its Policy ID.

await blockfrostProvider.fetchCollectionAssets(
  'd9312da562da182b02322fd8acb536f37eb9d29fba7c49dc17255527', 1,

The API will return a list of assets and a cursor next. If the cursor is not null, you can use it to fetch the next page of results. Here is an example of the response.

  "assets": [
      "unit": "d9312da562da182b02322fd8acb536f37eb9d29fba7c49dc172555274d657368546f6b656e",
      "quantity": "1"
  "next": null


ADA Handle allows users to use a human-readable "Handle" to associate an address.

Each Handle is a unique NFT, minted and issued on the Cardano blockchain. These NFTs act as unique identifiers for the UTXO that they reside in.

Working together with blockfrostProvider, we can resolve the handle's address with this API.

await blockfrostProvider.fetchHandleAddress(

Note: if you get an error here, you could be on the wrong network. Change the provider's network at the top of the page.


Fetch the latest protocol parameters. Optionally, you can provide an epoch number to fetch the protocol parameters of that epoch.

await blockfrostProvider.fetchProtocolParameters(10)


Fetch transaction infomation. Only confirmed transaction can be retrieved.

await blockfrostProvider.fetchTxInfo(


Submit a serialized transaction to the network.

await blockfrostProvider.submitTx(signedTx)


Allow you to listen to a transaction confirmation. Upon confirmation, the callback will be called.

const tx = new Transaction({ initiator: wallet });
tx.sendLovelace('addr_test1vpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0c7e4cxr', '5000000');

const unsignedTx = await;
const signedTx = await wallet.signTx(unsignedTx);
const txHash = await wallet.submitTx(signedTx);

blockfrostProvider.onTxConfirmed(txHash, () => {
  console.log('Transaction confirmed');