fix: preserve refund payouts through recovery failures

docs/api/endpoints.md

@@ -510,7 +510,7 @@ Content-Type: application/json
 
 | Parameter | Type | Required | Default | Description |
 |-----------|------|----------|---------|-------------|
-| `lightning_address` | string | No | Key's stored refund address | Lightning address or LNURL to pay. Overrides the stored address for this request. Resolved only for a request that can open a new claim, before any balance is debited. |
+| `lightning_address` | string | No | Key's stored refund address | Lightning address or LNURL to pay. Overrides the stored address for this request. The effective address (request or stored) is resolved only for a request that can open a new claim, before any balance is debited. |
 
 **Response (Lightning):**
 
@@ -540,7 +540,7 @@ The amount field is `sats` or `msats` depending on the key's refund currency. It
 
 - The balance is debited and a refund claim is recorded before the payout is attempted. A key has at most one open claim at a time.
 - If the payout fails cleanly, the claim is closed and the balance is restored. Retry the request.
-- Once a melt quote has been recorded the mint may already have paid it, so any later failure returns `502` and withholds the balance rather than restoring it.
+- Once a melt quote has been recorded or a Cashu token has been issued, the payout may already have happened, so any later failure returns `502` and withholds the balance rather than restoring it. The exception is the mint answering the melt itself with `unpaid`: that is proof nothing was sent, so the balance is restored at once and the request returns `503`.
 - If the Lightning payment is dispatched but the mint cannot confirm the outcome, the request returns `502`, the balance stays withheld, and a background reconciler asks the mint until it answers. The balance is restored if the mint reports the payment unpaid.
 - An unresolved claim is reported before any replay: a request on a key with an open claim returns `409` with that claim's `refund_id` and `status`.
 - Calling again on a zero-balance key with no open claim returns the last paid Lightning refund, or the Cashu token issued by the last paid claim while it remains uncollected.
@@ -556,8 +556,9 @@ The amount field is `sats` or `msats` depending on the key's refund currency. It
 | `409` | `refund_in_progress`: another refund claim for this key is still open. The body carries its `refund_id` and `status` |
 | `409` | `refund_unresolved`: a claim for this key is `stuck` and needs operator reconciliation |
 | `410` | Previously issued Cashu refund token has been swept |
+| `500` | Payout failed before anything was dispatched. Balance restored. Retry. |
 | `502` | Payment dispatched, outcome unconfirmed. Balance withheld pending reconciliation. Do not retry. |
-| `503` | Mint unavailable. Balance restored. Retry later. |
+| `503` | Mint unavailable, or the mint reported the Lightning payment unpaid. Balance restored. Retry later. |
 
 **X-Cashu refunds:**
 

routstr/balance.py

@@ -406,9 +406,10 @@ async def refund_wallet_endpoint(
         raise HTTPException(status_code=400, detail="No balance to refund")
 
     requested = refund_request.lightning_address if refund_request else None
-    if requested:
-        await refund.validate_lightning_destination(requested)
     destination = requested or key.refund_address
+    if destination:
+        # Stored addresses can rot too; reject before any balance is debited.
+        await refund.validate_lightning_destination(destination)
 
     claim = await refund.open_claim(
         session,

routstr/payment/lnurl.py

@@ -50,6 +50,14 @@ class MeltOutcomeAmbiguousError(LNURLError):
     """
 
 
+class MeltUnpaidError(LNURLError):
+    """The mint answered the melt request itself with ``unpaid``.
+
+    Unlike :class:`MeltOutcomeAmbiguousError` this is proof that no Lightning
+    payment was made, so callers may restore what they debited.
+    """
+
+
 _MAX_LNURL_REDIRECTS = 3
 _MAX_LNURL_RESPONSE_BYTES = 64 * 1024
 _NON_PUBLIC_HOST_SUFFIXES = (".localhost", ".local", ".internal")
@@ -97,9 +105,7 @@ async def _require_public_https_destination(url: httpx.URL) -> None:
         try:
             resolved = ipaddress.ip_address(info[4][0])
         except ValueError as e:
-            raise LNURLError(
+            raise LNURLError("LNURL destination resolved to an invalid address") from e
-                "LNURL destination resolved to an invalid address"
-            ) from e
         if not resolved.is_global:
             raise LNURLError("LNURL destination is not a public host")
 
@@ -446,7 +452,7 @@ async def raw_send_to_lnurl(
         return final_amount
     if melt_state == MeltQuoteState.unpaid:
         await wallet.set_reserved_for_send(proofs, reserved=False)
-        raise LNURLError("Cashu mint confirmed that the melt was unpaid")
+        raise MeltUnpaidError("Cashu mint confirmed that the melt was unpaid")
 
     try:
         quote = await run_mint_operation(

routstr/refund.py

@@ -11,6 +11,7 @@ from sqlmodel import col, func, select, update
 
 from .core.db import (
     REFUND_OPEN_STATUSES,
+    REFUND_UNRESOLVED_STATUSES,
     ApiKey,
     AsyncSession,
     Refund,
@@ -21,7 +22,12 @@ from .core.db import (
 )
 from .core.logging import get_logger
 from .core.settings import settings
-from .payment.lnurl import LNURLError, MeltOutcomeAmbiguousError, get_lnurl_data
+from .payment.lnurl import (
+    LNURLError,
+    MeltOutcomeAmbiguousError,
+    MeltUnpaidError,
+    get_lnurl_data,
+)
 from .wallet import (
     check_bolt11_payment_status,
     is_mint_connection_error,
@@ -118,22 +124,38 @@ async def _close(
     refund: Refund,
     *,
     require_no_quote: bool = False,
+    require_no_token: bool = False,
+    from_statuses: tuple[str, ...] = REFUND_OPEN_STATUSES,
     **values: object,
 ) -> bool:
     stmt = (
         update(Refund)
         .where(col(Refund.id) == refund.id)
-        .where(col(Refund.status).in_(REFUND_OPEN_STATUSES))
+        .where(col(Refund.status).in_(from_statuses))
     )
     if require_no_quote:
         # A quote recorded since the row was read means a melt may be in flight.
         stmt = stmt.where(col(Refund.quote_id).is_(None))
+    if require_no_token:
+        stmt = stmt.where(col(Refund.token).is_(None))
     result = await session.exec(  # type: ignore[call-overload]
         stmt.values(claimed_at=None, updated_at=int(time.time()), **values)
     )
     return bool(result.rowcount)
 
 
+async def renew_lease(refund: Refund) -> None:
+    """Push the reconciler lease forward before a slow mint step."""
+    async with create_session() as session:
+        await session.exec(  # type: ignore[call-overload]
+            update(Refund)
+            .where(col(Refund.id) == refund.id)
+            .where(col(Refund.status).in_(REFUND_OPEN_STATUSES))
+            .values(claimed_at=int(time.time()))
+        )
+        await session.commit()
+
+
 async def record_quote(refund: Refund, quote_id: str, mint_url: str) -> None:
     """Store the quote and its mint before the melt is sent; raises if the claim closed.
 
@@ -174,7 +196,11 @@ async def settle(
         values["token"] = token
     if mint_url is not None:
         values["mint_url"] = mint_url
-    settled = await _close(session, refund, **values)
+    # The payout side knows the money moved, so a claim the reconciler gave up
+    # on (stuck) is closed as paid too.
+    settled = await _close(
+        session, refund, from_statuses=REFUND_UNRESOLVED_STATUSES, **values
+    )
     await session.commit()
     if not settled:
         logger.warning(
@@ -211,8 +237,19 @@ async def release(
     return True
 
 
-async def hold(session: AsyncSession, refund: Refund, quote_id: str | None) -> None:
+async def hold(
-    await _close(session, refund, status="ambiguous", quote_id=quote_id)
+    session: AsyncSession,
+    refund: Refund,
+    quote_id: str | None,
+    *,
+    token: str | None = None,
+) -> None:
+    """Withhold the balance; the quote or token names what the mint may have paid."""
+    values: dict[str, Any] = {"status": "ambiguous", "quote_id": quote_id}
+    if token is not None:
+        values["token"] = token
+        values["mint_url"] = refund.mint_url
+    await _close(session, refund, **values)
     await session.commit()
 
 
@@ -283,7 +320,7 @@ def describe(refund: Refund) -> dict[str, str]:
     return body
 
 
-async def _pay_lightning(session: AsyncSession, refund: Refund) -> None:
+async def _pay_lightning(session: AsyncSession, refund: Refund) -> bool:
     async def capture_quote(quote: str, mint_url: str) -> None:
         await record_quote(refund, quote, mint_url)
 
@@ -307,16 +344,18 @@ async def _pay_lightning(session: AsyncSession, refund: Refund) -> None:
             },
         )
         raise
-    await settle(session, refund, quote_id=refund.quote_id)
+    return await settle(session, refund, quote_id=refund.quote_id)
 
 
-async def _pay_cashu(session: AsyncSession, refund: Refund) -> None:
+async def _pay_cashu(session: AsyncSession, refund: Refund) -> bool:
     amount = amount_in_unit(refund.amount_msats, refund.unit)
+    await renew_lease(refund)
     token = await send_token(amount, refund.unit, refund.mint_url)
-    mint_url = token_mint_url(token, refund.mint_url)
+    # From here the token is bearer money: keep it on the claim so a failed
-    await settle(session, refund, token=token, mint_url=mint_url)
+    # settle withholds the balance instead of restoring it.
     refund.token = token
-    refund.mint_url = mint_url
+    refund.mint_url = token_mint_url(token, refund.mint_url)
+    return await settle(session, refund, token=token, mint_url=refund.mint_url)
 
 
 async def _record_cashu_payout(refund: Refund) -> None:
@@ -356,22 +395,23 @@ def unresolved_refund_error() -> HTTPException:
 
 
 async def _abort(session: AsyncSession, refund: Refund) -> None:
-    """Fail the claim, or withhold it once a melt quote exists.
+    """Fail the claim, or withhold it once a melt quote or token exists.
 
-    A recorded quote means the mint may already have paid, so the balance
+    A recorded quote means the mint may already have paid; an issued token is
-    must not be restored.
+    already bearer money. In both cases the balance must not be restored.
     """
-    if refund.quote_id is None:
+    if refund.quote_id is None and refund.token is None:
         await release(session, refund)
         return
-    await hold(session, refund, refund.quote_id)
+    await hold(session, refund, refund.quote_id, token=refund.token)
     logger.error(
-        "refund failed after its melt quote was recorded; balance withheld "
+        "refund failed after its payout was dispatched; balance withheld "
         "pending reconciliation",
         extra={
             "refund_id": refund.id,
             "key_hash": refund.api_key_hashed_key[:8],
             "quote_id": refund.quote_id,
+            "has_token": refund.token is not None,
             "mint_url": refund.mint_url,
         },
     )
@@ -379,18 +419,41 @@ async def _abort(session: AsyncSession, refund: Refund) -> None:
 
 
 async def execute(session: AsyncSession, refund: Refund) -> dict[str, str]:
+    attached_refund = refund
+    # Keep payout evidence outside the identity map: a failed flush/commit can
+    # expire attached attributes, including the only copy of an issued token.
+    refund = Refund(**refund.model_dump())
     try:
         if refund.method == "lightning":
-            await _pay_lightning(session, refund)
+            settled = await _pay_lightning(session, refund)
         else:
-            await _pay_cashu(session, refund)
+            settled = await _pay_cashu(session, refund)
     except MeltOutcomeAmbiguousError:
         # Already held by _pay_lightning; releasing here would pay out twice.
         raise unresolved_refund_error()
+    except MeltUnpaidError as e:
+        # The mint answered the melt itself with unpaid: proof that nothing was
+        # sent, so the balance goes back now rather than after reconciliation.
+        await release(session, refund)
+        logger.warning(
+            "refund melt unpaid at the mint; balance restored",
+            extra={
+                "refund_id": refund.id,
+                "error": str(e),
+                "key_hash": refund.api_key_hashed_key[:8],
+                "quote_id": refund.quote_id,
+            },
+        )
+        raise HTTPException(
+            status_code=503,
+            detail="Lightning payment failed at the mint; balance restored. Retry later.",
+        )
     except HTTPException:
+        await session.rollback()
         await _abort(session, refund)
         raise
     except Exception as e:
+        await session.rollback()
         await _abort(session, refund)
         logger.error(
             "refund payout failed",
@@ -410,8 +473,13 @@ async def execute(session: AsyncSession, refund: Refund) -> dict[str, str]:
     if refund.method == "cashu":
         await _record_cashu_payout(refund)
 
-    refund.status = "paid"
+    if settled:
-    refund.claimed_at = None
+        refund.status = "paid"
+        refund.claimed_at = None
+    else:
+        # Report the row as it stands rather than a status that was not written.
+        await session.refresh(attached_refund)
+        refund = attached_refund
     logger.info(
         "refund paid",
         extra={
@@ -442,9 +510,14 @@ async def _lease(refund_id: str, now: int, lease_cutoff: int) -> bool:
 
 async def _reconcile(refund: Refund, now: int) -> None:
     if refund.method != "lightning":
+        if refund.token is not None:
+            # The token was issued and kept on the claim; the payout is done.
+            async with create_session() as session:
+                await settle(session, refund)
+            return
         # No quote to query for cashu; withhold the balance and alert once.
         async with create_session() as session:
-            if await _close(session, refund, status="stuck"):
+            if await _close(session, refund, require_no_token=True, status="stuck"):
                 await session.commit()
                 logger.critical(
                     "cashu refund stuck; balance withheld, manual reconciliation required",
@@ -454,6 +527,11 @@ async def _reconcile(refund: Refund, now: int) -> None:
                         "amount_msats": refund.amount_msats,
                     },
                 )
+            else:
+                await session.commit()
+                current = await session.get(Refund, refund.id)
+                if current is not None and current.token is not None:
+                    await settle(session, current)
         return
 
     if refund.quote_id is None:

tests/integration/test_refund_claims.py

@@ -599,7 +599,10 @@ async def test_endpoint_replays_paid_lightning_refund_on_empty_balance(
     integration_session: AsyncSession, patched_db_engine: None
 ) -> None:
     await _seed_key(integration_session, address=ADDRESS)
-    with patch("routstr.refund.send_to_lnurl", _lnurl_stub()):
+    with (
+        patch("routstr.refund.get_lnurl_data", AsyncMock()),
+        patch("routstr.refund.send_to_lnurl", _lnurl_stub()),
+    ):
         first = await refund_wallet_endpoint(
             authorization=f"Bearer sk-{KEY_HASH}",
             x_cashu=None,
@@ -785,7 +788,10 @@ async def test_open_claim_is_reported_over_an_older_paid_claim(
     """A paid claim from a previous cycle must not be replayed as the outcome
     of the claim that is still settling."""
     await _seed_key(integration_session, address=ADDRESS)
-    with patch("routstr.refund.send_to_lnurl", _lnurl_stub()):
+    with (
+        patch("routstr.refund.get_lnurl_data", AsyncMock()),
+        patch("routstr.refund.send_to_lnurl", _lnurl_stub()),
+    ):
         paid = await refund_wallet_endpoint(
             authorization=f"Bearer sk-{KEY_HASH}",
             x_cashu=None,

tests/integration/test_refund_payout_recovery.py

@@ -0,0 +1,368 @@
+"""Refund payouts that finish after the claim row stopped cooperating.
+
+Each test pins one guarantee of the claim table that the happy path cannot
+exercise: the payout side has authoritative knowledge of what the mint did,
+and the claim row must end up agreeing with it.
+"""
+
+import time
+from typing import Any
+from unittest.mock import AsyncMock, patch
+
+import pytest
+from fastapi import HTTPException
+from sqlalchemy import event
+from sqlalchemy.exc import OperationalError
+
+from routstr import refund
+from routstr.balance import RefundRequest, refund_wallet_endpoint
+from routstr.core.db import ApiKey, AsyncSession, Refund, total_user_liability
+from routstr.payment.lnurl import MeltUnpaidError
+
+KEY_HASH = "refundrecoverykey"
+ADDRESS = "user@ln.example.com"
+BALANCE_MSATS = 5_000_000
+
+
+async def _seed_key(session: AsyncSession, *, address: str | None = None) -> ApiKey:
+    key = ApiKey(hashed_key=KEY_HASH)
+    key.balance = BALANCE_MSATS
+    key.reserved_balance = 0
+    key.refund_currency = "sat"
+    key.refund_address = address
+    key.total_spent = 0
+    key.total_requests = 0
+    session.add(key)
+    await session.commit()
+    await session.refresh(key)
+    return key
+
+
+async def _load_key(session: AsyncSession) -> ApiKey:
+    key = await session.get(ApiKey, KEY_HASH)
+    assert key is not None
+    await session.refresh(key)
+    return key
+
+
+async def _load_refund(session: AsyncSession, refund_id: str) -> Refund:
+    row = await session.get(Refund, refund_id)
+    assert row is not None
+    await session.refresh(row)
+    return row
+
+
+def _cashu_payout(token: str, send: Any | None = None) -> Any:
+    return (
+        patch("routstr.refund.send_token", send or AsyncMock(return_value=token)),
+        patch("routstr.refund.token_mint_url", lambda t, mint: mint),
+        patch("routstr.refund.store_cashu_transaction", AsyncMock()),
+    )
+
+
+# --- cashu token issued after the reconciler gave up -----------------------
+
+
+@pytest.mark.asyncio
+async def test_cashu_token_issued_after_reconciler_marked_claim_stuck_settles_it(
+    integration_session: AsyncSession, patched_db_engine: None
+) -> None:
+    """A token in the customer's hands must leave its claim ``paid``: a row
+    left ``stuck`` keeps the amount in liability forever and tells the operator
+    to reconcile a payout that already happened."""
+    key = await _seed_key(integration_session)
+    claim = await refund.open_claim(
+        integration_session, key, method="cashu", destination=None
+    )
+
+    async def slow_send_token(amount: int, unit: str, mint_url: str) -> str:
+        # The lease lapses while the mint is still working.
+        row = await _load_refund(integration_session, claim.id)
+        row.claimed_at = (row.claimed_at or 0) - 10_000
+        integration_session.add(row)
+        await integration_session.commit()
+        await refund.reconcile_once()
+        assert (await _load_refund(integration_session, claim.id)).status == "stuck"
+        return "cashuAlate"
+
+    send, mint, store = _cashu_payout("cashuAlate", slow_send_token)
+    with send, mint, store:
+        body = await refund.execute(integration_session, claim)
+
+    assert (body["token"], body["status"]) == ("cashuAlate", "paid")
+    row = await _load_refund(integration_session, claim.id)
+    assert (row.status, row.token, row.claimed_at) == ("paid", "cashuAlate", None)
+    assert await total_user_liability(integration_session) == 0
+
+
+@pytest.mark.asyncio
+async def test_cashu_payout_renews_lease_before_asking_the_mint(
+    integration_session: AsyncSession, patched_db_engine: None
+) -> None:
+    """The reconciler leaves a claim alone while its lease is fresh, so the
+    payout renews it right before the slow step."""
+    key = await _seed_key(integration_session)
+    claim = await refund.open_claim(
+        integration_session, key, method="cashu", destination=None
+    )
+    row = await _load_refund(integration_session, claim.id)
+    row.claimed_at = (row.claimed_at or 0) - 10_000
+    integration_session.add(row)
+    await integration_session.commit()
+
+    async def send_token(amount: int, unit: str, mint_url: str) -> str:
+        await refund.reconcile_once()
+        return "cashuAfresh"
+
+    send, mint, store = _cashu_payout("cashuAfresh", send_token)
+    with send, mint, store, patch("routstr.refund.logger") as log:
+        await refund.execute(integration_session, claim)
+
+    log.critical.assert_not_called()
+    assert (await _load_refund(integration_session, claim.id)).status == "paid"
+
+
+# --- cashu token issued, claim write failed --------------------------------
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("failure_point", ["execute", "autoflush", "commit"])
+async def test_cashu_claim_write_failure_after_token_creation_withholds_balance(
+    integration_session: AsyncSession,
+    patched_db_engine: None,
+    integration_engine: Any,
+    failure_point: str,
+) -> None:
+    key = await _seed_key(integration_session)
+    claim = await refund.open_claim(
+        integration_session, key, method="cashu", destination=None
+    )
+    claim_id = claim.id
+    fired = False
+    armed = False
+
+    def fail_once(*args: Any) -> None:
+        nonlocal fired
+        statement = args[2] if failure_point != "commit" else "COMMIT"
+        if (
+            armed
+            and not fired
+            and (statement.startswith("UPDATE refunds") or statement == "COMMIT")
+        ):
+            fired = True
+            raise OperationalError(statement, {}, Exception("database is locked"))
+
+    async def send_token(amount: int, unit: str, mint_url: str) -> str:
+        nonlocal armed
+        if failure_point == "autoflush":
+            # A pending ORM write makes SQLAlchemy invalidate the transaction
+            # and expire attached objects when the actual SQL execution fails.
+            claim.updated_at -= 1
+        armed = True
+        return "cashuAstranded"
+
+    event_name = "commit" if failure_point == "commit" else "before_cursor_execute"
+    event.listen(integration_engine.sync_engine, event_name, fail_once)
+    send, _, store = _cashu_payout("cashuAstranded", send_token)
+    try:
+        with (
+            send,
+            store,
+            patch(
+                "routstr.refund.token_mint_url", return_value="https://fallback.mint"
+            ),
+        ):
+            with pytest.raises(HTTPException) as exc_info:
+                await refund.execute(integration_session, claim)
+    finally:
+        event.remove(integration_engine.sync_engine, event_name, fail_once)
+
+    assert fired
+    assert exc_info.value.status_code == 502
+    row = await _load_refund(integration_session, claim_id)
+    assert (row.status, row.token, row.mint_url) == (
+        "ambiguous",
+        "cashuAstranded",
+        "https://fallback.mint",
+    )
+    assert (await _load_key(integration_session)).balance == 0
+    assert await total_user_liability(integration_session) == BALANCE_MSATS
+
+    await refund.reconcile_once()
+    row = await _load_refund(integration_session, claim_id)
+    assert (row.status, row.token) == ("paid", "cashuAstranded")
+    assert await total_user_liability(integration_session) == 0
+    with patch("routstr.refund.send_token", AsyncMock()) as send_again:
+        replay = await refund_wallet_endpoint(
+            refund_request=RefundRequest(),
+            authorization=f"Bearer sk-{KEY_HASH}",
+            x_cashu=None,
+            session=integration_session,
+        )
+    assert isinstance(replay, dict)
+    assert replay["token"] == "cashuAstranded"
+    send_again.assert_not_awaited()
+    assert (await _load_key(integration_session)).balance == 0
+
+
+@pytest.mark.asyncio
+async def test_reconciler_settles_held_cashu_claim_that_carries_a_token(
+    integration_session: AsyncSession, patched_db_engine: None
+) -> None:
+    """A held cashu claim whose row carries the token is a completed payout;
+    the reconciler closes it as paid instead of escalating it to stuck."""
+    key = await _seed_key(integration_session)
+    claim = await refund.open_claim(
+        integration_session, key, method="cashu", destination=None
+    )
+    await refund.hold(integration_session, claim, None, token="cashuAheld")
+    row = await _load_refund(integration_session, claim.id)
+    row.claimed_at = None
+    row.updated_at -= 10_000
+    integration_session.add(row)
+    await integration_session.commit()
+
+    with patch("routstr.refund.logger") as log:
+        await refund.reconcile_once()
+
+    log.critical.assert_not_called()
+    row = await _load_refund(integration_session, claim.id)
+    assert (row.status, row.token) == ("paid", "cashuAheld")
+    assert await total_user_liability(integration_session) == 0
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("hold_before_lease", [True, False])
+async def test_stale_cashu_reconciliation_preserves_newly_held_token(
+    integration_session: AsyncSession,
+    patched_db_engine: None,
+    integration_engine: Any,
+    hold_before_lease: bool,
+) -> None:
+    key = await _seed_key(integration_session)
+    claim = await refund.open_claim(
+        integration_session, key, method="cashu", destination=None
+    )
+    claim_id = claim.id
+    now = int(time.time())
+    cutoff = now - refund.settings.refund_claim_timeout_seconds
+    claim.claimed_at = cutoff - 1
+    await integration_session.commit()
+    async with AsyncSession(integration_engine, expire_on_commit=False) as session:
+        stale = await session.get(Refund, claim_id)
+    assert stale is not None and stale.token is None
+
+    if hold_before_lease:
+        await refund.hold(integration_session, claim, None, token="cashuAheld")
+    assert await refund._lease(claim_id, now, cutoff)
+    real_close = refund._close
+
+    async def hold_before_close(session: AsyncSession, row: Refund, **kw: Any) -> bool:
+        if not hold_before_lease and kw.get("status") == "stuck":
+            # Token arrives at the last moment, even after a potential reload.
+            await real_close(
+                integration_session, claim, status="ambiguous", token="cashuAheld"
+            )
+            await integration_session.commit()
+        return await real_close(session, row, **kw)
+
+    with patch.object(refund, "_close", hold_before_close):
+        await refund._reconcile(stale, now)
+
+    row = await _load_refund(integration_session, claim_id)
+    assert (row.status, row.token) == ("paid", "cashuAheld")
+    assert (await _load_key(integration_session)).balance == 0
+    assert await total_user_liability(integration_session) == 0
+    with patch("routstr.refund.send_token", AsyncMock()) as send_again:
+        replay = await refund_wallet_endpoint(
+            refund_request=RefundRequest(),
+            authorization=f"Bearer sk-{KEY_HASH}",
+            x_cashu=None,
+            session=integration_session,
+        )
+    assert isinstance(replay, dict)
+    assert replay["token"] == "cashuAheld"
+    send_again.assert_not_awaited()
+
+
+# --- mint proved the melt unpaid -------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_mint_confirmed_unpaid_melt_restores_balance_immediately(
+    integration_session: AsyncSession, patched_db_engine: None
+) -> None:
+    """The mint answering ``unpaid`` to the melt itself is proof no payment
+    happened, so the customer gets the balance back now, not after the
+    reconciler timeout."""
+    key = await _seed_key(integration_session)
+    claim = await refund.open_claim(
+        integration_session, key, method="lightning", destination=ADDRESS
+    )
+
+    async def send(*args: Any, on_melt_quote: Any = None, **kwargs: Any) -> int:
+        await on_melt_quote("quote-unpaid", claim.mint_url)
+        raise MeltUnpaidError("Cashu mint confirmed that the melt was unpaid")
+
+    with patch("routstr.refund.send_to_lnurl", send):
+        with pytest.raises(HTTPException) as exc_info:
+            await refund.execute(integration_session, claim)
+
+    assert exc_info.value.status_code == 503
+    row = await _load_refund(integration_session, claim.id)
+    assert (row.status, row.quote_id) == ("failed", "quote-unpaid")
+    assert (await _load_key(integration_session)).balance == BALANCE_MSATS
+
+
+# --- response reflects the persisted claim ---------------------------------
+
+
+@pytest.mark.asyncio
+async def test_response_status_reflects_persisted_claim(
+    integration_session: AsyncSession, patched_db_engine: None
+) -> None:
+    """When ``settle`` closes nothing the response must not invent ``paid``."""
+    key = await _seed_key(integration_session)
+    claim = await refund.open_claim(
+        integration_session, key, method="cashu", destination=None
+    )
+
+    async def send_token(amount: int, unit: str, mint_url: str) -> str:
+        # Somebody closed the row as failed while the mint was working.
+        await refund._close(integration_session, claim, status="failed")
+        await integration_session.commit()
+        return "cashuAorphan"
+
+    send, mint, store = _cashu_payout("cashuAorphan", send_token)
+    with send, mint, store:
+        body = await refund.execute(integration_session, claim)
+
+    assert body["status"] == "failed"
+    assert (await _load_refund(integration_session, claim.id)).status == "failed"
+
+
+@pytest.mark.asyncio
+async def test_stored_refund_address_is_validated_before_debit(
+    integration_session: AsyncSession, patched_db_engine: None
+) -> None:
+    """A bad address stored on the key is a client error, not a payout failure."""
+    await _seed_key(integration_session, address="nobody@invalid.example")
+    send = AsyncMock()
+    with (
+        patch(
+            "routstr.refund.get_lnurl_data",
+            AsyncMock(side_effect=refund.LNURLError("no such user")),
+        ),
+        patch("routstr.refund.send_to_lnurl", send),
+    ):
+        with pytest.raises(HTTPException) as exc_info:
+            await refund_wallet_endpoint(
+                refund_request=RefundRequest(),
+                authorization=f"Bearer sk-{KEY_HASH}",
+                x_cashu=None,
+                session=integration_session,
+            )
+
+    assert exc_info.value.status_code == 400
+    send.assert_not_awaited()
+    assert (await _load_key(integration_session)).balance == BALANCE_MSATS

tests/integration/test_wallet_refund.py

@@ -7,7 +7,7 @@ import asyncio
 import base64
 import json
 from typing import Any
-from unittest.mock import patch
+from unittest.mock import AsyncMock, patch
 
 import pytest
 from httpx import AsyncClient
@@ -622,7 +622,10 @@ async def test_refund_with_expired_key(
     integration_client.headers["Authorization"] = f"Bearer {api_key}"
 
     # Mock the refund to LN address
-    with patch("routstr.refund.send_to_lnurl") as mock_send_to_lnurl:
+    with (
+        patch("routstr.refund.get_lnurl_data", AsyncMock()),
+        patch("routstr.refund.send_to_lnurl") as mock_send_to_lnurl,
+    ):
         mock_send_to_lnurl.return_value = 500
 
         response = await integration_client.post("/v1/wallet/refund")

tests/unit/test_balance.py

@@ -349,7 +349,10 @@ async def test_apikey_refund_stores_cashu_transaction_with_apikey_source() -> No
     session.rollback = AsyncMock()
 
     with (
-        patch("routstr.refund.send_token", AsyncMock(return_value=refund_token)),
+        patch("routstr.refund.renew_lease", AsyncMock()),
+        patch(
+            "routstr.refund.send_token", AsyncMock(return_value=refund_token)
+        ) as mock_send_token,
         patch("routstr.refund.store_cashu_transaction", AsyncMock()) as mock_store,
     ):
         result = await refund_wallet_endpoint(
@@ -358,6 +361,7 @@ async def test_apikey_refund_stores_cashu_transaction_with_apikey_source() -> No
             session=session,
         )
 
+    mock_send_token.assert_awaited_once()
     assert isinstance(result, dict)
     assert result["token"] == refund_token
 
@@ -382,7 +386,10 @@ async def test_apikey_refund_logs_token() -> None:
     session.rollback = AsyncMock()
 
     with (
-        patch("routstr.refund.send_token", AsyncMock(return_value=refund_token)),
+        patch("routstr.refund.renew_lease", AsyncMock()),
+        patch(
+            "routstr.refund.send_token", AsyncMock(return_value=refund_token)
+        ) as mock_send_token,
         patch("routstr.refund.store_cashu_transaction", AsyncMock()),
         patch("routstr.refund.logger") as mock_logger,
     ):
@@ -392,6 +399,7 @@ async def test_apikey_refund_logs_token() -> None:
             session=session,
         )
 
+    mock_send_token.assert_awaited_once()
     calls = [str(c) for c in mock_logger.info.call_args_list]
     assert any("refund paid" in c for c in calls)
 
@@ -409,7 +417,10 @@ async def test_apikey_refund_log_identifies_the_claim() -> None:
     session.rollback = AsyncMock()
 
     with (
-        patch("routstr.refund.send_token", AsyncMock(return_value=refund_token)),
+        patch("routstr.refund.renew_lease", AsyncMock()),
+        patch(
+            "routstr.refund.send_token", AsyncMock(return_value=refund_token)
+        ) as mock_send_token,
         patch("routstr.refund.store_cashu_transaction", AsyncMock()),
         patch("routstr.refund.logger") as mock_logger,
     ):
@@ -419,6 +430,7 @@ async def test_apikey_refund_log_identifies_the_claim() -> None:
             session=session,
         )
 
+    mock_send_token.assert_awaited_once()
     paid_calls = [
         c
         for c in mock_logger.info.call_args_list
@@ -508,10 +520,11 @@ async def test_apikey_refund_restores_balance_on_mint_failure() -> None:
     session.rollback = AsyncMock()
 
     with (
+        patch("routstr.refund.renew_lease", AsyncMock()),
         patch(
             "routstr.refund.send_token",
             AsyncMock(side_effect=MintConnectionError("raw mint outage detail")),
-        ),
+        ) as mock_send_token,
         patch("routstr.refund.store_cashu_transaction", AsyncMock()),
         patch("routstr.refund.logger"),
     ):
@@ -522,6 +535,7 @@ async def test_apikey_refund_restores_balance_on_mint_failure() -> None:
                 session=session,
             )
 
+    mock_send_token.assert_awaited_once()
     assert exc_info.value.status_code == 503
     assert exc_info.value.detail == "Mint service unavailable"
     assert "raw mint outage detail" not in exc_info.value.detail
@@ -545,9 +559,10 @@ async def test_apikey_refund_generic_failure_is_sanitized_500() -> None:
     session.rollback = AsyncMock()
 
     with (
+        patch("routstr.refund.renew_lease", AsyncMock()),
         patch(
             "routstr.refund.send_token", AsyncMock(side_effect=RuntimeError(raw_error))
-        ),
+        ) as mock_send_token,
         patch("routstr.refund.store_cashu_transaction", AsyncMock()),
         patch("routstr.refund.logger"),
     ):
@@ -558,6 +573,7 @@ async def test_apikey_refund_generic_failure_is_sanitized_500() -> None:
                 session=session,
             )
 
+    mock_send_token.assert_awaited_once()
     assert exc_info.value.status_code == 500
     assert exc_info.value.detail == "Refund failed"
     assert raw_error not in exc_info.value.detail
@@ -892,6 +908,7 @@ async def test_apikey_refund_ambiguous_melt_does_not_restore_balance() -> None:
             AsyncMock(side_effect=MeltOutcomeAmbiguousError("outcome is ambiguous")),
         ),
         patch("routstr.refund.release", AsyncMock()) as mock_restore,
+        patch("routstr.refund.get_lnurl_data", AsyncMock()),
     ):
         with pytest.raises(HTTPException) as exc_info:
             await refund_wallet_endpoint(
@@ -923,6 +940,7 @@ async def test_apikey_refund_clean_failure_still_restores_balance() -> None:
             AsyncMock(side_effect=RuntimeError("mint rejected melt")),
         ),
         patch("routstr.refund.release", AsyncMock()) as mock_restore,
+        patch("routstr.refund.get_lnurl_data", AsyncMock()),
     ):
         with pytest.raises(HTTPException):
             await refund_wallet_endpoint(