[WIP] LN Gateway

cashu/core/base.py

@@ -279,6 +279,7 @@ def from_row(cls, row: Row):
             quote=row["quote"],
             method=row["method"],
             request=row["request"],
+            expiry=row["expiry"],
             checking_id=row["checking_id"],
             unit=row["unit"],
             amount=row["amount"],

cashu/core/settings.py

@@ -63,6 +63,19 @@ class MintSettings(CashuSettings):
     mint_input_fee_ppk: int = Field(default=0)
 
 
+class GatewaySettings(CashuSettings):
+    gateway_private_key: str = Field(default=None)
+    gateway_listen_host: str = Field(default="127.0.0.1")
+    gateway_listen_port: int = Field(default=3838)
+    gateway_database: str = Field(default="data/gateway")
+
+    gateway_backend_bolt11_sat: str = Field(default="")
+    gateway_bolt11_sat_fee_ppm: int = Field(default=1000)
+    gateway_bolt11_sat_base_fee: int = Field(default=2)
+
+    gateway_mint_urls: List[str] = Field(default=[])
+
+
 class MintBackends(MintSettings):
     mint_lightning_backend: str = Field(default="")  # deprecated
     mint_backend_bolt11_sat: str = Field(default="")
@@ -172,6 +185,7 @@ class WalletSettings(CashuSettings):
 
     locktime_delta_seconds: int = Field(default=86400)  # 1 day
     proofs_batch_size: int = Field(default=1000)
+    wallet_gateways: List[str] = Field(default=[])
 
     wallet_target_amount_count: int = Field(default=3)
 
@@ -201,6 +215,7 @@ class Settings(
     MintSettings,
     MintInformation,
     WalletSettings,
+    GatewaySettings,
     CashuSettings,
 ):
     version: str = Field(default=VERSION)

cashu/gateway/__main__.py

@@ -0,0 +1,3 @@
+from .main import main
+
+main()

cashu/gateway/app.py

@@ -0,0 +1,91 @@
+import sys
+from traceback import print_exception
+
+from fastapi import FastAPI, status
+from fastapi.responses import JSONResponse
+from loguru import logger
+from starlette.requests import Request
+
+from ..core.errors import CashuError
+from ..core.logging import configure_logger
+from ..core.settings import settings
+from .router import router
+from .startup import start_gateway_init
+
+if settings.debug_profiling:
+    pass
+
+if settings.mint_rate_limit:
+    pass
+
+# this errors with the tests but is the appropriate way to handle startup and shutdown
+# until then, we use @app.on_event("startup")
+# @asynccontextmanager
+# async def lifespan(app: FastAPI):
+#     # startup routines here
+#     await start_mint_init()
+#     yield
+#     # shutdown routines here
+
+
+def create_app(config_object="core.settings") -> FastAPI:
+    configure_logger()
+
+    app = FastAPI(
+        title="Nutshell Cashu Mint",
+        description="Ecash wallet and mint based on the Cashu protocol.",
+        version=settings.version,
+        license_info={
+            "name": "MIT License",
+            "url": "https://raw.githubusercontent.com/cashubtc/cashu/main/LICENSE",
+        },
+    )
+
+    return app
+
+
+app = create_app()
+
+
+@app.middleware("http")
+async def catch_exceptions(request: Request, call_next):
+    CORS_HEADERS = {
+        "Access-Control-Allow-Origin": "*",
+        "Access-Control-Allow-Methods": "*",
+        "Access-Control-Allow-Headers": "*",
+        "Access-Control-Allow-Credentials": "true",
+    }
+    try:
+        return await call_next(request)
+    except Exception as e:
+        try:
+            err_message = str(e)
+        except Exception:
+            err_message = e.args[0] if e.args else "Unknown error"
+
+        if isinstance(e, CashuError) or isinstance(e.args[0], CashuError):
+            logger.error(f"CashuError: {err_message}")
+            code = e.code if isinstance(e, CashuError) else e.args[0].code
+            # return with cors headers
+            return JSONResponse(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                content={"detail": err_message, "code": code},
+                headers=CORS_HEADERS,
+            )
+        logger.error(f"Exception: {err_message}")
+        if settings.debug:
+            print_exception(*sys.exc_info())
+        return JSONResponse(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            content={"detail": err_message, "code": 0},
+            headers=CORS_HEADERS,
+        )
+
+
+# Add exception handlers
+app.include_router(router=router, tags=["Gateway"])
+
+
+@app.on_event("startup")
+async def startup_gateway():
+    await start_gateway_init()