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Fees

These methods help you figure out how much to pay in transaction fees. Set the fee too low and your transaction may sit unconfirmed for a long time. Set it too high and you waste money.

Use them when you want to:

  • Know the current network fee rate before sending
  • Estimate what fee will get your transaction confirmed in N blocks
  • Build fee-selection logic into a wallet or payment tool
flowchart LR
    A[App] -->|estimateSmartFee\nnblocks = 6| B[Node]
    B -->|feerate in FIRO/kB| A
    A -->|use feerate to\nbuild transaction| C[Transaction]

Methods​

getFeeRate()​

Returns the current fee rate in satoshis per kilobyte. This is a simple, static snapshot of what the node considers a normal fee right now.

const { rate } = await client.getFeeRate();
console.log(`Current rate: ${rate} sat/kB`);

estimateFee(nblocks)​

Estimates the fee rate (in FIRO per kilobyte) needed to get a transaction confirmed within nblocks blocks.

Returns -1 if there's not enough data to estimate.

const rate = await client.estimateFee(6);
if (rate === -1) {
  console.log('Not enough data to estimate');
} else {
  console.log(`Fee for ~6 block confirmation: ${rate} FIRO/kB`);
}

estimateSmartFee(nblocks)​

A smarter fee estimator that also returns how many blocks it actually expects confirmation to take. Prefers this over estimateFee when available.

const estimate = await client.estimateSmartFee(6);
console.log(`Fee rate: ${estimate.feerate} FIRO/kB`);
console.log(`Expected within: ${estimate.blocks} blocks`);

estimatePriority(nblocks)​

Estimates the transaction priority needed to get confirmed within nblocks blocks without paying a fee (zero-fee transactions). Returns -1 if there's insufficient data.

const priority = await client.estimatePriority(6);

estimateSmartPriority(nblocks)​

Like estimatePriority but returns a smarter estimate along with how many blocks are actually expected.

const estimate = await client.estimateSmartPriority(6);
console.log(`Priority: ${estimate.priority}`);
console.log(`Expected within: ${estimate.blocks} blocks`);

Example: Picking a Fee​

// Aim for confirmation within 3 blocks
const { feerate, blocks } = await client.estimateSmartFee(3);

console.log(`To confirm within ~${blocks} blocks, use ${feerate} FIRO/kB`);