Blockchain

These methods let you read the state of the Firo blockchain — the chain of blocks, individual transactions, and the unspent coin set. They're read-only and work without a wallet.

Use them when you want to:

• Check how far along the chain your node is
• Look up a block or transaction by its ID
• Verify that a transaction output hasn't been spent
• Get an overview of the entire chain's statistics

sequenceDiagram
    participant App
    participant Client
    participant Node

    App->>Client: getBlock(hash)
    Client->>Node: JSON-RPC getblock
    Node-->>Client: Block data
    Client-->>App: Block object

Chain Overview

getBlockchainInfo()

Returns a summary of the chain your node is on — the network name, block height, sync progress, and active protocol upgrades (soft forks).

const info = await client.getBlockchainInfo();

console.log(info.chain);               // "main", "test", or "regtest"
console.log(info.blocks);              // current block height
console.log(info.verificationprogress); // 0.0–1.0 sync progress

getBlockCount()

Returns the current block height — how many blocks are in the chain.

const height = await client.getBlockCount();
console.log(`Node is at block ${height}`);

getBestBlockHash()

Returns the hash of the most recent block at the tip of the chain.

const hash = await client.getBestBlockHash();

getTxOutSetInfo()

Returns statistics about all unspent transaction outputs (UTXOs) currently in the chain. Useful for auditing the total coin supply.

const stats = await client.getTxOutSetInfo();

console.log(`Total FIRO in circulation: ${stats.total_amount}`);
console.log(`Unspent outputs: ${stats.txouts}`);
console.log(`At block: ${stats.height}`);

Blocks

getBlockHash(height)

Converts a block height (a number) into its hash (a hex string). You need the hash to fetch the full block.

const hash = await client.getBlockHash(100000);

getBlock(hash)

Fetches a full block including all its transactions.

const block = await client.getBlock(hash);

console.log(`Block #${block.height}`);
console.log(`Transactions: ${block.tx.length}`);
console.log(`Mined at: ${new Date(block.time * 1000).toISOString()}`);

getBlockHeader(hash)

Fetches the block header only — no transactions. Much lighter than getBlock when you only need metadata like timestamp or difficulty.

const header = await client.getBlockHeader(hash);
// Pass false as second argument to get the raw hex instead
const hex = await client.getBlockHeader(hash, false);

Transactions

getRawTransaction(txid)

Fetches a transaction by its ID. Returns a fully decoded transaction object by default.

Requires txindex=1 in firo.conf for transactions outside your wallet or the mempool.

const tx = await client.getRawTransaction(txid);

console.log(`Inputs:  ${tx.vin.length}`);
console.log(`Outputs: ${tx.vout.length}`);
console.log(`Confirmations: ${tx.confirmations}`);

// Pass false to get raw hex instead
const hex = await client.getRawTransaction(txid, false);

getTxOut(txid, outputIndex)

Checks whether a specific output of a transaction is still unspent. Returns null if the output has already been spent.

const output = await client.getTxOut(txid, 0);

if (output === null) {
  console.log('Output already spent');
} else {
  console.log(`Value: ${output.value} FIRO`);
}

Mempool

The mempool is a waiting area for transactions that have been broadcast but not yet included in a block.

getMempoolInfo()

Returns a summary of the mempool: how many transactions are waiting, how much memory they use, and the minimum fee rate required for acceptance.

const info = await client.getMempoolInfo();

console.log(`Waiting transactions: ${info.size}`);
console.log(`Memory used: ${info.bytes} bytes`);
console.log(`Min fee rate: ${info.mempoolminfee}`);

getRawMempool()

Returns all transactions currently in the mempool with their details.

const mempool = await client.getRawMempool();

for (const [txid, entry] of Object.entries(mempool)) {
  console.log(`${txid}: fee ${entry.fee}, size ${entry.size}`);
}

// Pass false to get just a list of txids
const txids = await client.getRawMempool(false);

getMempoolEntry(txid)

Fetches details for a single transaction in the mempool by its ID.

const entry = await client.getMempoolEntry(txid);

console.log(`Fee: ${entry.fee}`);
console.log(`Time in mempool: ${entry.time}`);