wallet.ops.receive(...) accepts an encoded token string, a decoded Token, or raw Proof[].
const proofs = await wallet.ops.receive(token).run();
// Or use prepare() instead of run() to do a dry run preview first
const preview = await wallet.ops.receive(token).prepare();
const { keep } = await wallet.completeSwap(preview);
You can also receive an array of raw proofs directly:
const oldProofs: Proof[] = [proof1, proof2, proof3, ...];
const freshProofs = await wallet.ops.receive(oldProofs).run();
const proofs = await wallet.ops
.receive(token)
.asDeterministic() // counter=0 => auto-reserve
.requireDleq(true) // reject incoming proofs without DLEQ for the selected keyset
.keyset('0123456')
.onCountersReserved((c) => console.log('RX counters', c))
.run();
const proofs = await wallet.ops
.receive(token)
.asP2PK({ pubkey, locktime }) // NUT-11 options for new proofs
.privkey(['k1', 'k2', 'k3']) // sign incoming P2PK proofs
.proofsWeHave(myExistingProofs) // helps denomination selection
.run();
const proofsA = await wallet.ops
.receive(tokenA)
.asFactory(makeOutputData, [8, 4, 16]) // split must include these denoms
.run();
const proofsB = await wallet.ops
.receive(tokenB)
.asCustom(prebuiltRxOutputs) // amounts must sum to final received amount after fees
.run();
A one-shot run() that dies between the mint's reply and your storage write has spent the
inputs without you ever seeing the new proofs. Persisting the preview closes that window:
completeSwap builds its request purely from the preview, so replaying a persisted preview
posts a byte-identical /v1/swap body, and a mint that caches the endpoint (NUT-19) returns
the original signatures.
import { deserializeSwapPreview, serializeSwapPreview } from '@cashu/cashu-ts';
const preview = await wallet.ops.receive(token).prepare();
// Persist before completing. Previews contain Amount, bigint and Uint8Array values,
// so use the helper rather than calling JSON.stringify(preview) directly.
const stored = JSON.stringify(serializeSwapPreview(preview));
const { keep } = await wallet.completeSwap(preview);
// ... after a restart: load the mint again, then replay the same preview ...
const { keep: recovered } = await wallet.completeSwap(deserializeSwapPreview(JSON.parse(stored)));
The serialized preview contains
inputsin the clear, so it is spendable bearer material. Store it with the same protection as the proof database, and delete it once the swap settles.
The replay window has bounds:
/v1/swap in its NUT-19 cached_endpoints, and the replay must
happen inside the advertised TTL. See NUT-19 Cached Responses.