Fetch Bitcoin chain data and submit transactions via the public Blockstream Esplora API — no API key required.

Overview

Blockstream operates a public Esplora REST API for Bitcoin mainnet and testnet. BlockstreamBitcoinProvider wraps this API and implements IBitcoinProvider from @meshsdk/provider, making it a drop-in data source for BitcoinHeadlessWallet.

When to use Blockstream:

Development and prototyping — no account or API key required
Low-to-medium volume production applications
Testnet development before deploying to mainnet

Quick Start

npm install @meshsdk/provider @meshsdk/wallet

import { BlockstreamBitcoinProvider } from "@meshsdk/provider";
import { BitcoinHeadlessWallet } from "@meshsdk/wallet";

const provider = new BlockstreamBitcoinProvider("testnet"); // "mainnet" | "testnet"

const wallet = await BitcoinHeadlessWallet.fromMnemonic({
  network: "Testnet4",
  mnemonic: ["word1", "word2", "..."],
  provider,
});

const balance = await wallet.getBalance();
// { confirmed: "100000", unconfirmed: "0", total: "100000" }

Configuration Options

Parameter	Type	Required	Description
`network`	`"mainnet" \| "testnet"`	Yes	Bitcoin network to connect to

The base URLs used internally:

Network	Base URL
`"mainnet"`	`https://blockstream.info/api`
`"testnet"`	`https://blockstream.info/testnet/api`

API Reference

fetchAddressInfo

Retrieve chain and mempool statistics for a Bitcoin address.

await provider.fetchAddressInfo(address: string): Promise<BitcoinAddressInfo>

Parameter	Type	Required	Description
`address`	`string`	Yes	Bitcoin address (bech32, P2PKH, P2SH, etc.)

Returns: BitcoinAddressInfo — confirmed and mempool funding/spending counts and sums.

Example:

import { BlockstreamBitcoinProvider } from "@meshsdk/provider";

const provider = new BlockstreamBitcoinProvider("mainnet");

const info = await provider.fetchAddressInfo("bc1q...");

console.log(info.chain_stats.funded_txo_sum);   // total confirmed received (sats)
console.log(info.mempool_stats.funded_txo_sum); // unconfirmed incoming (sats)

Return shape:

{
  address: "bc1q...",
  chain_stats: {
    funded_txo_count: 5,
    funded_txo_sum: 500000,
    spent_txo_count: 3,
    spent_txo_sum: 300000,
    tx_count: 8
  },
  mempool_stats: {
    funded_txo_count: 1,
    funded_txo_sum: 50000,
    spent_txo_count: 0,
    spent_txo_sum: 0,
    tx_count: 1
  }
}

fetchAddressUTxOs

Retrieve all unspent outputs for a Bitcoin address.

await provider.fetchAddressUTxOs(address: string): Promise<BitcoinUTxO[]>

Parameter	Type	Required	Description
`address`	`string`	Yes	Bitcoin address to query

Returns: Array of BitcoinUTxO objects.

Example:

const utxos = await provider.fetchAddressUTxOs("bc1q...");

utxos.forEach((utxo) => {
  console.log(`${utxo.txid}:${utxo.vout} — ${utxo.value} sats`);
});

Return shape:

[
  {
    txid: "abc123...",
    vout: 0,
    value: 50000,
    status: {
      confirmed: true,
      block_height: 840000,
      block_hash: "00000000...",
      block_time: 1710000000
    }
  }
]

fetchUTxO

Retrieve specific unspent output(s) from a transaction. Filters out already-spent outputs by cross-referencing the outspends endpoint.

await provider.fetchUTxO(txid: string, vout?: number): Promise<BitcoinUTxO[]>

Parameter	Type	Required	Description
`txid`	`string`	Yes	Transaction ID (64-char hex)
`vout`	`number`	No	Output index to filter to; omit to return all unspent outputs

Example:

// All unspent outputs from a transaction
const utxos = await provider.fetchUTxO("abc123...");

// A specific output (only returned if unspent)
const utxo = await provider.fetchUTxO("abc123...", 0);

fetchAddressTxs

Retrieve transaction history for a Bitcoin address, sorted newest-first. Supports cursor-based pagination.

await provider.fetchAddressTxs(
  address: string,
  lastSeenTxid?: string,
): Promise<BitcoinTxInfo[]>

Parameter	Type	Required	Description
`address`	`string`	Yes	Bitcoin address to query
`lastSeenTxid`	`string`	No	Txid of the last transaction seen; fetches the next page of results

Example:

// First page (most recent 25 transactions)
const txs = await provider.fetchAddressTxs("bc1q...");

// Next page
const moreTxs = await provider.fetchAddressTxs("bc1q...", txs[txs.length - 1].txid);

Blockstream paginates using path-based cursors: /address/{address}/txs/chain/{lastSeenTxid}.

fetchTxInfo

Retrieve the confirmation status of a transaction.

await provider.fetchTxInfo(txid: string): Promise<BitcoinTxStatus>

Parameter	Type	Required	Description
`txid`	`string`	Yes	Transaction ID (64-char hex)

Returns: BitcoinTxStatus — confirmation status and block details.

Example:

const status = await provider.fetchTxInfo("abc123...");

if (status.confirmed) {
  console.log(`Confirmed at block ${status.block_height}`);
} else {
  console.log("Pending in mempool");
}

Return shape:

{
  confirmed: true,
  block_height: 840000,
  block_hash: "00000000...",
  block_time: 1710000000
}

fetchFeeEstimates

Retrieve the recommended fee rate (sat/vB) for a target confirmation within blocks blocks. Falls back to the next-closest target if an exact match is unavailable; defaults to 2 sat/vB if the fee API is unreachable.

await provider.fetchFeeEstimates(blocks: number): Promise<number>

Parameter	Type	Required	Description
`blocks`	`number`	Yes	Target confirmation speed in blocks (e.g. `1`, `6`, `144`)

Example:

const feeRate = await provider.fetchFeeEstimates(6); // next ~1 hour
console.log(`Recommended: ${feeRate} sat/vB`);

fetchScriptInfo

Retrieve chain and mempool statistics for a script hash (P2SH / P2WSH).

await provider.fetchScriptInfo(hash: string): Promise<BitcoinScriptInfo>

Parameter	Type	Required	Description
`hash`	`string`	Yes	Script hash (hex, SHA256 of the script)

fetchScriptUTxOs

Retrieve unspent outputs locked by a script hash.

await provider.fetchScriptUTxOs(hash: string): Promise<BitcoinUTxO[]>

fetchScriptTxs

Retrieve transaction history for a script hash, with optional pagination.

await provider.fetchScriptTxs(
  hash: string,
  lastSeenTxid?: string,
): Promise<BitcoinTxInfo[]>

submitTx

Broadcast a signed raw transaction to the Bitcoin network.

await provider.submitTx(txHex: string): Promise<string>

Parameter	Type	Required	Description
`txHex`	`string`	Yes	Signed raw transaction in hex format

Returns: The broadcast transaction ID (64-char hex).

Example:

const txid = await provider.submitTx(signedRawTxHex);
console.log(`Broadcast: ${txid}`);

Blockstream's /tx endpoint accepts text/plain and returns the txid as plain text on success.

Complete Example

import { BlockstreamBitcoinProvider } from "@meshsdk/provider";
import { BitcoinHeadlessWallet, AddressPurpose } from "@meshsdk/wallet";

async function sendBitcoin() {
  const provider = new BlockstreamBitcoinProvider("testnet");

  const wallet = await BitcoinHeadlessWallet.fromMnemonic({
    network: "Testnet4",
    mnemonic: ["your", "twelve", "word", "mnemonic", "phrase", "here", "..."],
    provider,
  });

  // Check balance
  const balance = await wallet.getBalance();
  console.log(`Balance: ${balance.total} sats`);

  // Get receive address
  const [address] = await wallet.getAddresses([AddressPurpose.Payment]);
  console.log(`Address: ${address.address}`);

  // Send to a recipient
  const txid = await wallet.signTransfer([
    { address: "tb1q...", amount: 10_000 }, // satoshis
  ]);
  console.log(`Sent: ${txid}`);
}

References

Blockstream Esplora API Reference - Full endpoint documentation
Blockstream Explorer - Block explorer powered by the same API

Maestro Bitcoin Provider - Enterprise-grade alternative with an API key
Bitcoin Headless Wallet - Use this provider with a self-custodial HD wallet
All Providers - Compare with Cardano providers

Blockstream Bitcoin Provider

Overview

Quick Start

Configuration Options

API Reference

fetchAddressInfo

fetchAddressUTxOs

fetchUTxO

fetchAddressTxs

fetchTxInfo

fetchFeeEstimates

fetchScriptInfo

fetchScriptUTxOs

fetchScriptTxs

submitTx

Complete Example

References

On this page