[Agent: cross-repo-impact] Handle sweep_tx event in GetTransactionsStream + add sweptVtxos to TxNotification

[arkanaai]

Context

arkd PR #988 (merged 2026-03-23) added two API changes that ts-sdk needs to implement:

1. New sweep_tx field in GetTransactionsStreamResponse (service.proto field 4)

message GetTransactionsStreamResponse {
  oneof data {
    TxNotification commitment_tx = 1;
    TxNotification ark_tx = 2;
    Heartbeat heartbeat = 3;
    TxNotification sweep_tx = 4;  // NEW
  }
}

2. New swept_vtxos field in TxNotification (types.proto field 6)

message TxNotification {
  // ... existing fields ...
  repeated Outpoint swept_vtxos = 6;  // NEW
}

Current state (verified 2026-05-22)

sweptVtxos is already handled in the subscription stream (getSubscription) in both:

• providers/indexer.ts lines 508–510
• providers/expoIndexer.ts lines 106–108

These cover the subscription stream, NOT the transactions stream.

Remaining work in src/providers/ark.ts

1. TxNotification interface (line 175) — add sweptVtxos?: Outpoint[]
2. getTransactionsStream return type (line 247–250) — add sweepTx?: TxNotification
3. parseTransactionNotification() (lines 855–890) — add handler for data.sweepTx before the console.warn fallthrough

Required changes in src/providers/ark.ts

TxNotification interface

Add: sweptVtxos?: Outpoint[]

getTransactionsStream return type

getTransactionsStream(signal: AbortSignal): AsyncIterableIterator<{
    commitmentTx?: TxNotification;
    arkTx?: TxNotification;
    sweepTx?: TxNotification;  // ADD
}>;

parseTransactionNotification()

if (data.sweepTx) {
    return {
        sweepTx: {
            txid: data.sweepTx.txid,
            tx: data.sweepTx.tx,
            spentVtxos: data.sweepTx.spentVtxos.map(mapVtxo),
            spendableVtxos: data.sweepTx.spendableVtxos.map(mapVtxo),
            checkpointTxs: data.sweepTx.checkpointTxs,
            sweptVtxos: data.sweepTx.sweptVtxos || [],
        },
    };
}

Why it matters

Clients using getTransactionsStream will silently miss sweep events (dropped at console.warn). Swept VTXO outpoints are needed for wallet sync to mark outputs as swept.

Reference

• arkd PR: Transaction stream: add sweep tx event arkd#988
• Closes [API sync] Handle sweep_tx event and swept_vtxos from GetTransactionsStream (arkd#988) #374 (duplicate)