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Providers

Blockfrost Provider

Connect to Cardano blockchain data through Blockfrost's high-performance API infrastructure.

Overview

Blockfrost provides instant access to Cardano blockchain data through a reliable REST API. Use the Blockfrost provider to fetch UTXOs, submit transactions, query account information, and more—without running your own node.

When to use Blockfrost:

  • Building production dApps that need reliable blockchain access
  • Rapid prototyping without infrastructure setup
  • Applications requiring high availability and low latency

Quick Start

import { BlockfrostProvider } from "@meshsdk/core";

// Initialize with your API key from https://blockfrost.io
const provider = new BlockfrostProvider("<YOUR_API_KEY>");

// Fetch UTXOs for an address
const utxos = await provider.fetchAddressUTxOs(
  "addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9"
);

Get your free API key at blockfrost.io.

Configuration Options

OptionTypeDescription
apiKeystringYour Blockfrost API key (required for hosted service)
urlstringCustom Blockfrost URL for self-hosted instances

Self-hosted Blockfrost:

const provider = new BlockfrostProvider("https://your-blockfrost-instance.com");

API Reference

fetchAccountInfo

Retrieve staking information for a stake address, including rewards, delegation status, and pool ID.

const accountInfo = await provider.fetchAccountInfo(
  "stake_test1uzw5mnt7g4xjgdqkfa80hrk7kdvds6sa4k0vvgjvlj7w8eskffj2n"
);

Returns:

{
  active: true,
  poolId: "pool1...",
  balance: "1000000",
  rewards: "50000",
  withdrawals: "0"
}

fetchAddressAssets

Retrieve all native assets held at an address.

const assets = await provider.fetchAddressAssets(
  "addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9"
);

Returns:

[
  { unit: "lovelace", quantity: "5000000" },
  { unit: "d9312da562da182b02322fd8acb536f37eb9d29fba7c49dc172555274d657368546f6b656e", quantity: "1" }
]

fetchAddressUTxOs

Retrieve all UTXOs controlled by an address. Optionally filter by a specific asset.

// All UTXOs
const utxos = await provider.fetchAddressUTxOs(
  "addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9"
);

// UTXOs containing a specific asset
const filteredUtxos = await provider.fetchAddressUTxOs(
  "addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9",
  "d9312da562da182b02322fd8acb536f37eb9d29fba7c49dc172555274d657368546f6b656e"
);
ParameterTypeRequiredDescription
addressstringYesBech32 address to query
assetstringNoAsset unit (policy ID + asset name hex) to filter by

fetchAssetAddresses

Find all addresses holding a specific asset.

const addresses = await provider.fetchAssetAddresses(
  "d9312da562da182b02322fd8acb536f37eb9d29fba7c49dc172555274d657368546f6b656e"
);

fetchAssetMetadata

Retrieve on-chain metadata for a specific asset.

const metadata = await provider.fetchAssetMetadata(
  "d9312da562da182b02322fd8acb536f37eb9d29fba7c49dc172555274d657368546f6b656e"
);

fetchBlockInfo

Retrieve information about a specific block by its hash.

const blockInfo = await provider.fetchBlockInfo(
  "79f60880b097ec7dabb81f75f0b52fedf5e922d4f779a11c0c432dcf22c56089"
);

fetchCollectionAssets

Retrieve all assets minted under a policy ID with pagination support.

// First page
const { assets, next } = await provider.fetchCollectionAssets(
  "d9312da562da182b02322fd8acb536f37eb9d29fba7c49dc17255527"
);

// Next page (if next is not null)
const page2 = await provider.fetchCollectionAssets(
  "d9312da562da182b02322fd8acb536f37eb9d29fba7c49dc17255527",
  next
);
ParameterTypeRequiredDescription
policyIdstringYesPolicy ID of the collection
cursornumberNoPagination cursor (default: 1)

fetchHandleAddress

Resolve an ADA Handle to its associated address.

const address = await provider.fetchHandleAddress("meshsdk");
// Returns: "addr_test1qz..."

fetchHandle

Retrieve full metadata for a CIP-68 ADA Handle.

const handleData = await provider.fetchHandle("meshsdk");

fetchProtocolParameters

Retrieve current protocol parameters. Optionally specify an epoch.

// Current epoch
const params = await provider.fetchProtocolParameters();

// Specific epoch
const historicalParams = await provider.fetchProtocolParameters(400);

fetchTxInfo

Retrieve details of a confirmed transaction.

const txInfo = await provider.fetchTxInfo(
  "f4ec9833a3bf95403d395f699bc564938f3419537e7fb5084425d3838a4b6159"
);

fetchUTxOs

Retrieve UTXOs for a transaction hash, optionally filtering by output index.

// All outputs
const utxos = await provider.fetchUTxOs(
  "dfd2a2616e6154a092807b1ceebb9ddcadc0f22cf5c8e0e6b0757815083ccb70"
);

// Specific output
const singleUtxo = await provider.fetchUTxOs(
  "dfd2a2616e6154a092807b1ceebb9ddcadc0f22cf5c8e0e6b0757815083ccb70",
  0
);

fetchGovernanceProposal

Retrieve information about a governance proposal.

const proposal = await provider.fetchGovernanceProposal(
  "372d688faa77e146798b581b322c0f2981a9023764736ade5d12e0e4e796af8c",
  0
);

evaluateTx

Evaluate execution units for a transaction containing Plutus scripts. Use this to optimize redeemer budgets.

import { MeshTxBuilder, BlockfrostProvider } from "@meshsdk/core";

const provider = new BlockfrostProvider("<YOUR_API_KEY>");
const txBuilder = new MeshTxBuilder({ fetcher: provider });

// Build your transaction
const unsignedTx = await txBuilder
  .spendingPlutusScriptV2()
  // ... your transaction details
  .complete();

// Evaluate execution units
const evaluation = await provider.evaluateTx(unsignedTx);

Returns:

[
  {
    index: 0,
    tag: "SPEND",
    budget: {
      mem: 1700,
      steps: 368100
    }
  }
]

Use these values to set precise budgets in your redeemer:

const redeemer = {
  data: { alternative: 0, fields: [] },
  budget: {
    mem: 1700,
    steps: 368100
  }
};

submitTx

Submit a signed transaction to the network.

const txHash = await provider.submitTx(signedTx);

onTxConfirmed

Subscribe to transaction confirmation events.

import { MeshTxBuilder, BlockfrostProvider } from "@meshsdk/core";

const provider = new BlockfrostProvider("<YOUR_API_KEY>");

// After submitting a transaction
const txHash = await wallet.submitTx(signedTx);

// Listen for confirmation
provider.onTxConfirmed(txHash, () => {
  console.log("Transaction confirmed!");
  // Update UI, trigger next action, etc.
});

get

Make custom requests to any Blockfrost endpoint.

const transactions = await provider.get(
  "/addresses/addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9/transactions"
);

Complete Example

import { BlockfrostProvider, MeshTxBuilder } from "@meshsdk/core";
import { MeshCardanoHeadlessWallet, AddressType } from "@meshsdk/wallet";

// Initialize provider
const provider = new BlockfrostProvider("<YOUR_API_KEY>");

// Create wallet instance
const wallet = await MeshCardanoHeadlessWallet.fromMnemonic({
  networkId: 0, // 0 = testnet, 1 = mainnet
  walletAddressType: AddressType.Base,
  fetcher: provider,
  submitter: provider,
  mnemonic: ["your", "mnemonic", "phrase", "..."],
});

// Build transaction
const txBuilder = new MeshTxBuilder({
  fetcher: provider,
  verbose: true,
});

const utxos = await wallet.getUtxosMesh();
const changeAddress = await wallet.getChangeAddressBech32();

const unsignedTx = await txBuilder
  .txOut("addr_test1qz...", [{ unit: "lovelace", quantity: "5000000" }])
  .changeAddress(changeAddress)
  .selectUtxosFrom(utxos)
  .complete();

// Sign and submit
const signedTx = await wallet.signTx(unsignedTx, false);
const txHash = await wallet.submitTx(signedTx);

// Wait for confirmation
provider.onTxConfirmed(txHash, () => {
  console.log(`Transaction ${txHash} confirmed!`);
});

Troubleshooting

"Project not found" or 403 error

Your API key is invalid or doesn't have access to the requested network. Verify:

  • The key is correct and active at blockfrost.io/dashboard
  • You're using a key for the correct network (mainnet vs testnet)

"Rate limit exceeded" (429 error)

You've exceeded the request limit for your plan. Solutions:

  • Implement request caching
  • Upgrade your Blockfrost plan
  • Add request throttling to your application

"Transaction submit error"

Common causes:

  • Insufficient funds (check UTXOs cover amount + fees)
  • Invalid transaction structure (missing inputs, outputs, or signatures)
  • UTXOs already spent (refresh UTXOs before building)

Slow response times

  • Use fetchAddressUTxOs with asset filter when you only need specific assets
  • Cache frequently-accessed data like protocol parameters
  • Consider self-hosting Blockfrost for high-volume applications

Providers

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Hydra Provider (beta)

Build high-throughput applications on Cardano's Layer 2 scaling solution

On this page

OverviewQuick StartConfiguration OptionsAPI ReferencefetchAccountInfofetchAddressAssetsfetchAddressUTxOsfetchAssetAddressesfetchAssetMetadatafetchBlockInfofetchCollectionAssetsfetchHandleAddressfetchHandlefetchProtocolParametersfetchTxInfofetchUTxOsfetchGovernanceProposalevaluateTxsubmitTxonTxConfirmedgetComplete ExampleTroubleshooting"Project not found" or 403 error"Rate limit exceeded" (429 error)"Transaction submit error"Slow response timesRelated