Coco Cashu Docs

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Melting Tokens ​

Melting converts Cashu proofs back into sats by paying a Lightning invoice through the mint. Coco wraps this as a melt operation (saga) so fees are known up front and operations can be recovered if your app restarts.

Pay a BOLT11 invoice ​

ts
await coco.mint.addMint(mintUrl, { trusted: true });

const prepared = await coco.ops.melt.prepare({
  mintUrl,
  method: 'bolt11',
  methodData: { invoice },
});

console.log('Quote:', prepared.quoteId);
console.log('Amount:', prepared.amount);
console.log('Fee reserve:', prepared.fee_reserve);
console.log('Needs swap:', prepared.needsSwap);

const result = await coco.ops.melt.execute(prepared.id);

if (result.state === 'finalized') {
  console.log('Change returned:', result.changeAmount);
  console.log('Effective fee:', result.effectiveFee);
}

if (result.state === 'pending') {
  const refreshed = await coco.ops.melt.refresh(result.id);
  console.log('Updated state:', refreshed.state);
}

coco.ops.melt.prepare() creates the melt quote, reserves proofs, and calculates any swap fees. coco.ops.melt.execute() pays the invoice immediately when possible or returns a pending operation that you can refresh later.

For newly finalized melts, changeAmount and effectiveFee show the actual settlement result. Older finalized melt records may not include those fields.

Resume by quote ​

ts
const operation = await coco.ops.melt.getByQuote(mintUrl, quoteId);

if (operation) {
  const result = await coco.ops.melt.execute(operation.id);
}

Use this when you only persisted the quote id (for example after a restart). The older coco.quotes melt workflow helpers are deprecated aliases.

For the full saga walkthrough, see Melt Operations.