diff --git a/cashu/core/base.py b/cashu/core/base.py
index ac5b1ada..e7cb961c 100644
--- a/cashu/core/base.py
+++ b/cashu/core/base.py
@@ -249,12 +249,6 @@ class KeysetsResponse_deprecated(BaseModel):
 # ------- API: MINT -------
 
 
-class GetMintRequest(BaseModel):
-    amount: int
-    method: str
-    symbol: str
-
-
 class GetMintResponse(BaseModel):
     request: str  # payment request
     method: str  # payment method
diff --git a/cashu/mint/crud.py b/cashu/mint/crud.py
index 35b90c18..a6e7c2f9 100644
--- a/cashu/mint/crud.py
+++ b/cashu/mint/crud.py
@@ -34,7 +34,7 @@ async def get_secrets_used(
         self,
         db: Database,
         conn: Optional[Connection] = None,
-    ) -> List[str]:
+    ) -> Optional[List[str]]:
         ...
 
     async def invalidate_proof(
@@ -169,11 +169,11 @@ async def get_secrets_used(
         *,
         db: Database,
         conn: Optional[Connection] = None,
-    ) -> List[str]:
+    ) -> Optional[List[str]]:
         rows = await (conn or db).fetchall(f"""
             SELECT secret from {table_with_schema(db, 'proofs_used')}
             """)
-        return [row[0] for row in rows]
+        return [row[0] for row in rows] if rows else None
 
     async def invalidate_proof(
         self,
diff --git a/cashu/mint/ledger.py b/cashu/mint/ledger.py
index ef72bfe1..3b7e8ea1 100644
--- a/cashu/mint/ledger.py
+++ b/cashu/mint/ledger.py
@@ -599,8 +599,9 @@ async def load_used_proofs(self) -> None:
         """Load all used proofs from database."""
         logger.trace("crud: loading used proofs")
         secrets_used = await self.crud.get_secrets_used(db=self.db)
-        logger.trace(f"crud: loaded {len(secrets_used)} used proofs")
-        self.secrets_used = set(secrets_used)
+        if secrets_used:
+            logger.trace(f"crud: loaded {len(secrets_used)} used proofs")
+            self.secrets_used = set(secrets_used)
 
     def _check_spendable(self, proof: Proof) -> bool:
         """Checks whether the proof was already spent."""
diff --git a/cashu/mint/router.py b/cashu/mint/router.py
index 01047d91..60082d6f 100644
--- a/cashu/mint/router.py
+++ b/cashu/mint/router.py
@@ -10,7 +10,6 @@
     CheckSpendableRequest,
     CheckSpendableResponse,
     GetInfoResponse,
-    GetMintRequest,
     GetMintResponse,
     KeysetsResponse,
     KeysetsResponseKeyset,
@@ -141,26 +140,26 @@ async def keysets() -> KeysetsResponse:
         " after payment."
     ),
 )
-async def request_mint(payload: GetMintRequest) -> GetMintResponse:
+async def request_mint(amount: int) -> GetMintResponse:
     """
     Request minting of new tokens. The mint responds with a Lightning invoice.
     This endpoint can be used for a Lightning invoice UX flow.
 
     Call `POST /mint` after paying the invoice.
     """
-    logger.trace(f"> GET /mint: amount={payload.amount}")
-    if payload.amount > 21_000_000 * 100_000_000 or payload.amount <= 0:
+    logger.trace(f"> GET /mint: amount={amount}")
+    if amount > 21_000_000 * 100_000_000 or amount <= 0:
         raise CashuError(code=0, detail="Amount must be a valid amount of sat.")
     if settings.mint_peg_out_only:
         raise CashuError(code=0, detail="Mint does not allow minting new tokens.")
 
-    payment_request, id = await ledger.request_mint(payload.amount)
+    payment_request, id = await ledger.request_mint(amount)
     resp = GetMintResponse(
         request=payment_request,
         id=id,
         method="bolt11",
         symbol="sat",
-        amount=payload.amount,
+        amount=amount,
     )
     logger.trace(f"< GET /mint: {resp}")
     return resp
diff --git a/cashu/mint/startup.py b/cashu/mint/startup.py
index 162c853f..d9a39f81 100644
--- a/cashu/mint/startup.py
+++ b/cashu/mint/startup.py
@@ -10,7 +10,7 @@
 from ..core.migrations import migrate_databases
 from ..core.settings import settings
 from ..mint import migrations
-from ..mint.crud import LedgerCrud
+from ..mint.crud import LedgerCrudSqlite
 from ..mint.ledger import Ledger
 
 logger.debug("Enviroment Settings:")
@@ -27,7 +27,7 @@
     seed=settings.mint_private_key,
     derivation_path=settings.mint_derivation_path,
     lightning=lightning_backend,
-    crud=LedgerCrud(),
+    crud=LedgerCrudSqlite(),
 )
 
 
diff --git a/cashu/wallet/deprecated.py b/cashu/wallet/deprecated.py
index c6e84cac..8830a542 100644
--- a/cashu/wallet/deprecated.py
+++ b/cashu/wallet/deprecated.py
@@ -190,7 +190,7 @@ async def request_mint_deprecated(self, amount) -> Invoice:
         self.raise_on_error(resp)
         return_dict = resp.json()
         mint_response = GetMintResponse_deprecated.parse_obj(return_dict)
-        return Invoice(amount=amount, pr=mint_response.pr, hash=mint_response.hash)
+        return Invoice(amount=amount, bolt11=mint_response.pr, id=mint_response.hash)
 
     @async_set_requests
     async def mint_deprecated(
diff --git a/tests/conftest.py b/tests/conftest.py
index 02751323..9eecb01e 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -14,7 +14,7 @@
 from cashu.core.settings import settings
 from cashu.lightning.fake import FakeWallet
 from cashu.mint import migrations as migrations_mint
-from cashu.mint.crud import LedgerCrud
+from cashu.mint.crud import LedgerCrudSqlite
 from cashu.mint.ledger import Ledger
 
 SERVER_PORT = 3337
@@ -65,7 +65,7 @@ async def start_mint_init(ledger: Ledger):
         seed=settings.mint_private_key,
         derivation_path=settings.mint_derivation_path,
         lightning=FakeWallet(),
-        crud=LedgerCrud(),
+        crud=LedgerCrudSqlite(),
     )
     await start_mint_init(ledger)
     yield ledger