[Mint] Add support for BTC and EUR in StrikeWallet backend, add EUR to FakeWallet (#561)

* strike for btc and eur

* strike works with eur

* backend check

.env.example

@@ -50,13 +50,14 @@ MINT_DERIVATION_PATH="m/0'/0'/0'"
 # m/0'/0'/0' is "sat" (default)
 # m/0'/1'/0' is "msat"
 # m/0'/2'/0' is "usd"
+# m/0'/3'/0' is "eur"
 # In this example, we have 2 keysets for sat, 1 for msat and 1 for usd
 # MINT_DERIVATION_PATH_LIST=["m/0'/0'/0'", "m/0'/0'/1'", "m/0'/1'/0'", "m/0'/2'/0'"]
 
 MINT_DATABASE=data/mint
 
 # Funding source backends
-# Supported: FakeWallet, LndRestWallet, CoreLightningRestWallet, BlinkWallet, LNbitsWallet, StrikeUSDWallet
+# Supported: FakeWallet, LndRestWallet, CoreLightningRestWallet, BlinkWallet, LNbitsWallet, StrikeWallet
 MINT_BACKEND_BOLT11_SAT=FakeWallet
 # Only works if a usd derivation path is set
 # MINT_BACKEND_BOLT11_SAT=FakeWallet
@@ -78,7 +79,7 @@ MINT_CORELIGHTNING_REST_CERT="./clightning-2-rest/certificate.pem"
 # Use with BlinkWallet
 MINT_BLINK_KEY=blink_abcdefgh
 
-# Use with StrikeUSDWallet (usd only, does not currently support sats/msats)
+# Use with StrikeWallet for BTC, USD, and EUR
 MINT_STRIKE_KEY=ABC123
 
 # fee to reserve in percent of the amount

cashu/core/base.py

@@ -436,6 +436,8 @@ class Unit(Enum):
     sat = 0
     msat = 1
     usd = 2
+    eur = 3
+    btc = 4
 
     def str(self, amount: int) -> str:
         if self == Unit.sat:
@@ -444,6 +446,10 @@ class Unit(Enum):
             return f"{amount} msat"
         elif self == Unit.usd:
             return f"${amount/100:.2f} USD"
+        elif self == Unit.eur:
+            return f"{amount/100:.2f} EUR"
+        elif self == Unit.btc:
+            return f"{amount/1e8:.8f} BTC"
         else:
             raise Exception("Invalid unit")
 
@@ -478,6 +484,33 @@ class Amount:
         else:
             return self
 
+    def to_float_string(self) -> str:
+        if self.unit == Unit.usd or self.unit == Unit.eur:
+            return self.cents_to_usd()
+        elif self.unit == Unit.sat:
+            return self.sat_to_btc()
+        else:
+            raise Exception("Amount must be in satoshis or cents")
+
+    @classmethod
+    def from_float(cls, amount: float, unit: Unit) -> "Amount":
+        if unit == Unit.usd or unit == Unit.eur:
+            return cls(unit, int(amount * 100))
+        elif unit == Unit.sat:
+            return cls(unit, int(amount * 1e8))
+        else:
+            raise Exception("Amount must be in satoshis or cents")
+
+    def sat_to_btc(self) -> str:
+        if self.unit != Unit.sat:
+            raise Exception("Amount must be in satoshis")
+        return f"{self.amount/1e8:.8f}"
+
+    def cents_to_usd(self) -> str:
+        if self.unit != Unit.usd and self.unit != Unit.eur:
+            raise Exception("Amount must be in cents")
+        return f"{self.amount/100:.2f}"
+
     def str(self) -> str:
         return self.unit.str(self.amount)
 

cashu/core/settings.py

@@ -67,6 +67,7 @@ class MintBackends(MintSettings):
     mint_lightning_backend: str = Field(default="")  # deprecated
     mint_backend_bolt11_sat: str = Field(default="")
     mint_backend_bolt11_usd: str = Field(default="")
+    mint_backend_bolt11_eur: str = Field(default="")
 
     mint_lnbits_endpoint: str = Field(default=None)
     mint_lnbits_key: str = Field(default=None)

cashu/lightning/__init__.py

@@ -5,7 +5,14 @@ from .corelightningrest import CoreLightningRestWallet  # noqa: F401
 from .fake import FakeWallet  # noqa: F401
 from .lnbits import LNbitsWallet  # noqa: F401
 from .lndrest import LndRestWallet  # noqa: F401
-from .strike import StrikeUSDWallet  # noqa: F401
+from .strike import StrikeWallet  # noqa: F401
 
-if settings.mint_backend_bolt11_sat is None or settings.mint_backend_bolt11_usd is None:
+backend_settings = [
-    raise Exception("MINT_BACKEND_BOLT11_SAT or MINT_BACKEND_BOLT11_USD not set")
+    settings.mint_backend_bolt11_sat,
+    settings.mint_backend_bolt11_usd,
+    settings.mint_backend_bolt11_eur,
+]
+if all([s is None for s in backend_settings]):
+    raise Exception(
+        "MINT_BACKEND_BOLT11_SAT or MINT_BACKEND_BOLT11_USD or MINT_BACKEND_BOLT11_EUR not set"
+    )

cashu/lightning/fake.py

@@ -45,7 +45,7 @@ class FakeWallet(LightningBackend):
         32,
     ).hex()
 
-    supported_units = set([Unit.sat, Unit.msat, Unit.usd])
+    supported_units = set([Unit.sat, Unit.msat, Unit.usd, Unit.eur])
     unit = Unit.sat
 
     supports_incoming_payment_stream: bool = True
@@ -113,7 +113,7 @@ class FakeWallet(LightningBackend):
         amount_msat = 0
         if self.unit == Unit.sat:
             amount_msat = MilliSatoshi(amount.to(Unit.msat, round="up").amount)
-        elif self.unit == Unit.usd:
+        elif self.unit == Unit.usd or self.unit == Unit.eur:
             amount_msat = MilliSatoshi(
                 math.ceil(amount.amount / self.fake_btc_price * 1e9)
             )
@@ -194,10 +194,10 @@ class FakeWallet(LightningBackend):
             fees_msat = fee_reserve(amount_msat)
             fees = Amount(unit=Unit.msat, amount=fees_msat)
             amount = Amount(unit=Unit.msat, amount=amount_msat)
-        elif self.unit == Unit.usd:
+        elif self.unit == Unit.usd or self.unit == Unit.eur:
             amount_usd = math.ceil(invoice_obj.amount_msat / 1e9 * self.fake_btc_price)
-            amount = Amount(unit=Unit.usd, amount=amount_usd)
+            amount = Amount(unit=self.unit, amount=amount_usd)
-            fees = Amount(unit=Unit.usd, amount=2)
+            fees = Amount(unit=self.unit, amount=2)
         else:
             raise NotImplementedError()
 

cashu/lightning/strike.py

@@ -17,15 +17,17 @@ from .base import (
 )
 
 
-class StrikeUSDWallet(LightningBackend):
+class StrikeWallet(LightningBackend):
-    """https://github.com/lnbits/lnbits"""
+    """https://docs.strike.me/api/"""
 
-    supported_units = [Unit.usd]
+    supported_units = [Unit.sat, Unit.usd, Unit.eur]
+    currency_map = {Unit.sat: "BTC", Unit.usd: "USD", Unit.eur: "EUR"}
 
-    def __init__(self, unit: Unit = Unit.usd, **kwargs):
+    def __init__(self, unit: Unit, **kwargs):
         self.assert_unit_supported(unit)
         self.unit = unit
         self.endpoint = "https://api.strike.me"
+        self.currency = self.currency_map[self.unit]
 
         # bearer auth with settings.mint_strike_key
         bearer_auth = {
@@ -57,8 +59,13 @@ class StrikeUSDWallet(LightningBackend):
             )
 
         for balance in data:
-            if balance["currency"] == "USD":
+            if balance["currency"] == self.currency:
-                return StatusResponse(error_message=None, balance=balance["total"])
+                return StatusResponse(
+                    error_message=None,
+                    balance=Amount.from_float(
+                        float(balance["total"]), self.unit
+                    ).amount,
+                )
 
     async def create_invoice(
         self,
@@ -79,7 +86,7 @@ class StrikeUSDWallet(LightningBackend):
         payload = {
             "correlationId": secrets.token_hex(16),
             "description": "Invoice for order 123",
-            "amount": {"amount": str(amount.amount / 100), "currency": "USD"},
+            "amount": {"amount": amount.to_float_string(), "currency": self.currency},
         }
         try:
             r = await self.client.post(url=f"{self.endpoint}/v1/invoices", json=payload)
@@ -126,7 +133,7 @@ class StrikeUSDWallet(LightningBackend):
         try:
             r = await self.client.post(
                 url=f"{self.endpoint}/v1/payment-quotes/lightning",
-                json={"sourceCurrency": "USD", "lnInvoice": bolt11},
+                json={"sourceCurrency": self.currency, "lnInvoice": bolt11},
                 timeout=None,
             )
             r.raise_for_status()
@@ -135,11 +142,11 @@ class StrikeUSDWallet(LightningBackend):
             raise Exception(error_message)
         data = r.json()
 
-        amount_cent = int(float(data.get("amount").get("amount")) * 100)
+        amount = Amount.from_float(float(data.get("amount").get("amount")), self.unit)
         quote = PaymentQuoteResponse(
-            amount=Amount(Unit.usd, amount=amount_cent),
+            amount=amount,
             checking_id=data.get("paymentQuoteId"),
-            fee=Amount(Unit.usd, 0),
+            fee=Amount(self.unit, 0),
         )
         return quote
 

cashu/mint/startup.py

@@ -55,6 +55,11 @@ if settings.mint_backend_bolt11_usd:
         unit=Unit.usd
     )
     backends.setdefault(Method.bolt11, {})[Unit.usd] = backend_bolt11_usd
+if settings.mint_backend_bolt11_eur:
+    backend_bolt11_eur = getattr(wallets_module, settings.mint_backend_bolt11_eur)(
+        unit=Unit.eur
+    )
+    backends.setdefault(Method.bolt11, {})[Unit.eur] = backend_bolt11_eur
 if not backends:
     raise Exception("No backends are set.")
 

cashu/mint/tasks.py

@@ -26,8 +26,15 @@ class LedgerTasks(SupportsDb, SupportsBackends, SupportsEvents):
                 asyncio.create_task(self.invoice_listener(backend))
 
     async def invoice_listener(self, backend: LightningBackend) -> None:
-        async for checking_id in backend.paid_invoices_stream():
+        if backend.supports_incoming_payment_stream:
-            await self.invoice_callback_dispatcher(checking_id)
+            while True:
+                try:
+                    async for checking_id in backend.paid_invoices_stream():
+                        await self.invoice_callback_dispatcher(checking_id)
+                except Exception as e:
+                    logger.error(f"Error in invoice listener: {e}")
+                    logger.info("Restarting invoice listener...")
+                    await asyncio.sleep(1)
 
     async def invoice_callback_dispatcher(self, checking_id: str) -> None:
         logger.debug(f"Invoice callback dispatcher: {checking_id}")

cashu/wallet/cli/cli.py

@@ -262,7 +262,7 @@ async def invoice(ctx: Context, amount: float, id: str, split: int, no_check: bo
     wallet: Wallet = ctx.obj["WALLET"]
     await wallet.load_mint()
     await print_balance(ctx)
-    amount = int(amount * 100) if wallet.unit == Unit.usd else int(amount)
+    amount = int(amount * 100) if wallet.unit in [Unit.usd, Unit.eur] else int(amount)
     print(f"Requesting invoice for {wallet.unit.str(amount)}.")
     # in case the user wants a specific split, we create a list of amounts
     optional_split = None
@@ -546,7 +546,7 @@ async def send_command(
     include_fees: bool,
 ):
     wallet: Wallet = ctx.obj["WALLET"]
-    amount = int(amount * 100) if wallet.unit == Unit.usd else int(amount)
+    amount = int(amount * 100) if wallet.unit in [Unit.usd, Unit.eur] else int(amount)
     if not nostr and not nopt:
         await send(
             wallet,