Most wallets — Minibits, Nutstash, cdk-cli — default to reading cashuB
(V4) now, so that is what we send. cashuA stays as the fallback rather
than the default: it is still valid everywhere, so a token this wallet
cannot express in V4 (a multi-mint one) is worth sending in V3 rather
than failing the send outright. That path warns, because by the time
`send_token_at` serializes, the proofs are already marked spent.
The V4 encoder is the reference implementation's, not ours. The envelope
puts the keyset id and signature on the wire as raw CBOR bytes under
single-letter keys, and a token subtly wrong there is money the receiver
cannot redeem — so upstream owns the encoding, the way it already owns
keyset-id resolution. Our own hand-written decoder reads what upstream
writes in the new test, which is agreement between two independent
implementations rather than a round trip through one codec.
Two refusals are deliberate and tested: a multi-mint token has no V4
form, and a truncated v2 keyset id must never be baked into a token we
emit (the framework-pt case) — it is only resolvable against the mint's
keyset list.
Also folds SendBitcoinModal onto the shared PaymentSuccessPane it had a
private copy of, so on-chain, Lightning and ecash all show the same
screen and the copyable-identifier row is defined once.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Two independent fixes, both found while exercising the routes headlessly.
**Mint fees (NUT-02).** A mint may charge a per-input fee and rejects any
swap whose outputs don't equal inputs minus that fee — `11005 Transaction
inputs should equal outputs less fee`, which is what sending hit against
testnut.cashu.space. We ignored the fee entirely, so the wallet could not
spend at ANY fee-charging mint; Minibits charges zero, which is why
production never saw it. `MintKeyset`/`KeysetInfo` now carry
`input_fee_ppk`, `swap_fee_for` computes the NUT-02 sum (rounded up), and
`MintClient::swap` reduces its outputs to cover it — applied there rather
than at each call site so send, receive and cross-mint swaps are all
covered at once. Inputs from a keyset the mint doesn't list contribute no
fee: the mint is the authority, and guessing high would burn the sender's
coins.
**Damaged-wallet erasure.** `load_wallet` used `unwrap_or_default()`, so a
truncated `ecash.json` read as an EMPTY wallet — and because the next
operation saves the wallet back, that empty state was then written over the
only copy of the proofs. A corrupt file became permanent loss. Now a file
that exists but doesn't parse fails with a message naming the file and
stating the coins are still in it, and the bytes are left untouched for
recovery; an empty file is still treated as a fresh wallet, since a create
that never got its first write is not damage. The accepted-mints list gets
the same treatment, where corruption would have silently reset the operator
to trusting only the default mint.
Writes are now atomic (temp + fsync + rename) for both files. The previous
plain write truncated the real file first, which is exactly how a wallet
ends up unparseable after a crash or power cut.
Tests cover: a damaged file errors and survives on disk, an empty file is
fresh, saving leaves no temp behind and round-trips, and — guarding the
on-disk contract against exactly this update — a verbatim pre-update wallet
file still loads with its balance, proofs and history intact.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Executes steps 1-3 of docs/cashu-cdk-migration-plan.md, plus the test-coin
switch needed to exercise these routes without spending real sats.
Protocol layer: depend on `cashu` 0.17.5 (MIT, the crate CDK is built on,
default-features off, `wallet` only). Keyset ids now go through upstream's
`Id::from_short_keyset_id` / `ShortKeysetId` instead of the prefix match
hand-rolled in 2277fc46 — same repair, but implemented by the reference
code that defines the rule, so the next spec turn is a version bump rather
than another incident. `MintClient` feeds it the mint's `/v1/keysets` in
upstream's own `KeySetInfo` shape, parsing entries individually so one
keyset in an unmodelled unit can't block resolving the id we need.
Adding the crate required relaxing `bip39 = "=2.1.0"` to `"2.1"` (resolves
2.2.2): the exact pin held `unicode-normalization` at 0.1.22 and no
resolution existed otherwise. The pin carried no recorded rationale; seed
tests cover the bump.
Network switch: `wallet.ecash-network` / `wallet.ecash-set-network`, with a
Test mode toggle in Wallet Settings → Cashu. Cashu has no testnet, so this
points the wallet at the public `testnut` mint — but crucially each network
gets its OWN wallet and accepted-mints file, because test and real proofs
in one purse would be spendable interchangeably and the balance would be a
lie. Mainnet keeps the original filenames, so existing funds files are
untouched and switching is reversible: tests assert a real balance survives
a round trip through test mode.
Headless coverage: scripts/test-ecash-routes.sh drives every ecash RPC over
the real HTTP path (network get/set, balance, history, mint quote + claim,
send, receive, double-redeem refusal, garbage input, melt quote), restores
the node's original network on exit, and exits non-zero with the failure
count.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
