diff --git a/example.py b/example.py
index d62d959d..4732859d 100644
--- a/example.py
+++ b/example.py
@@ -13,7 +13,7 @@ client = openai.OpenAI(
 history: list = []
 
 
-def chat():
+def chat() -> None:
     while True:
         user_msg = {"role": "user", "content": input("\nYou: ")}
         history.append(user_msg)
@@ -25,8 +25,10 @@ def chat():
             stream=True,
         ):
             if len(chunk.choices) > 0:
-                ai_msg["content"] += chunk.choices[0].delta.content
-                print(chunk.choices[0].delta.content, end="", flush=True)
+                content = chunk.choices[0].delta.content
+                if content is not None:
+                    ai_msg["content"] += content
+                    print(content, end="", flush=True)
         print()
         history.append(ai_msg)
 
diff --git a/router/account.py b/router/account.py
index f9fe9fa9..a0d11db5 100644
--- a/router/account.py
+++ b/router/account.py
@@ -1,4 +1,4 @@
-from typing import Annotated
+from typing import Annotated, NoReturn
 
 from fastapi import APIRouter, Depends, Header, HTTPException
 
@@ -49,8 +49,9 @@ async def topup_wallet_endpoint(
     cashu_token: str,
     key: ApiKey = Depends(get_key_from_header),
     session: AsyncSession = Depends(get_session),
-):
-    return await credit_balance(cashu_token, key, session)
+) -> dict[str, int]:
+    amount_msats = await credit_balance(cashu_token, key, session)
+    return {"msats": amount_msats}
 
 
 @wallet_router.post("/refund")
@@ -88,9 +89,12 @@ async def refund_wallet_endpoint(
 
 
 @wallet_router.api_route(
-    "/{path:path}", methods=["GET", "POST", "PUT", "DELETE"], include_in_schema=False
+    "/{path:path}",
+    methods=["GET", "POST", "PUT", "DELETE"],
+    include_in_schema=False,
+    response_model=None,
 )
-async def wallet_catch_all(path: str):
+async def wallet_catch_all(path: str) -> NoReturn:
     raise HTTPException(
         status_code=404, detail="Not found check /docs for available endpoints"
     )
diff --git a/router/admin.py b/router/admin.py
index c46158dd..d44dba8a 100644
--- a/router/admin.py
+++ b/router/admin.py
@@ -155,7 +155,7 @@ async def dashboard(request: Request) -> str:
 
 
 @admin_router.get("/", response_class=HTMLResponse)
-async def admin(request: Request):
+async def admin(request: Request) -> str:
     admin_cookie = request.cookies.get("admin_password")
     if admin_cookie and admin_cookie == os.getenv("ADMIN_PASSWORD"):
         return await dashboard(request)
diff --git a/router/cashu.py b/router/cashu.py
index f30fea12..35ab6be3 100644
--- a/router/cashu.py
+++ b/router/cashu.py
@@ -25,12 +25,12 @@ async def delete_key_if_zero_balance(key: ApiKey, session: AsyncSession) -> None
         await session.commit()
 
 
-async def init_wallet():
+async def init_wallet() -> None:
     global WALLET
     WALLET = await Wallet.create(nsec=NSEC, mint_urls=[MINT])
 
 
-async def close_wallet():
+async def close_wallet() -> None:
     global WALLET
     await WALLET.aclose()
 
diff --git a/router/discovery.py b/router/discovery.py
index 2d849b88..2a301540 100644
--- a/router/discovery.py
+++ b/router/discovery.py
@@ -139,7 +139,7 @@ async def fetch_onion(provider: str) -> dict:
 
 
 @providers_router.get("/")
-async def get_providers(include_json: bool = False):
+async def get_providers(include_json: bool = False) -> dict[str, list[dict | str]]:
     npub = "npub130mznv74rxs032peqym6g3wqavh472623mt3z5w73xq9r6qqdufs7ql29s"
 
     # Relays that support NIP-50 text search
diff --git a/router/main.py b/router/main.py
index bd0ce175..f96f6624 100644
--- a/router/main.py
+++ b/router/main.py
@@ -1,6 +1,7 @@
 import asyncio
 import os
 from contextlib import asynccontextmanager
+from typing import AsyncGenerator
 
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
@@ -17,7 +18,7 @@ __version__ = "0.0.1"
 
 
 @asynccontextmanager
-async def lifespan(_: FastAPI):
+async def lifespan(_: FastAPI) -> AsyncGenerator[None, None]:
     await init_db()
     await init_wallet()
     pricing_task = asyncio.create_task(update_sats_pricing())
@@ -51,7 +52,7 @@ app.add_middleware(
 
 
 @app.get("/")
-async def info():
+async def info() -> dict:
     return {
         "name": app.title,
         "description": app.description,
diff --git a/router/proxy.py b/router/proxy.py
index f388a340..4ce77d55 100644
--- a/router/proxy.py
+++ b/router/proxy.py
@@ -1,6 +1,7 @@
 import json
 import os
 import re
+from typing import AsyncGenerator
 
 import httpx
 from fastapi import APIRouter, BackgroundTasks, Depends, Request
@@ -16,12 +17,10 @@ UPSTREAM_API_KEY = os.environ.get("UPSTREAM_API_KEY", "")
 proxy_router = APIRouter()
 
 
-@proxy_router.api_route(
-    "/{path:path}", methods=["GET", "POST"]
-)
+@proxy_router.api_route("/{path:path}", methods=["GET", "POST"], response_model=None)
 async def proxy(
     request: Request, path: str, session: AsyncSession = Depends(get_session)
-):
+) -> Response | StreamingResponse:
     auth = request.headers.get("Authorization", "")
     bearer_key = auth.replace("Bearer ", "") if auth.startswith("Bearer ") else ""
     refund_address = request.headers.get("Refund-LNURL", None)
@@ -146,7 +145,7 @@ async def proxy(
 
             if is_streaming and response.status_code == 200:
                 # Process streaming response and extract cost from the last chunk
-                async def stream_with_cost():
+                async def stream_with_cost() -> AsyncGenerator[bytes, None]:
                     # Store all chunks to analyze
                     stored_chunks = []
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 0790e18b..cd661420 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -7,7 +7,7 @@ import pytest
 import pytest_asyncio
 from fastapi.testclient import TestClient
 from httpx import ASGITransport, AsyncClient
-from sqlalchemy.ext.asyncio import create_async_engine
+from sqlalchemy.ext.asyncio import AsyncEngine, create_async_engine
 from sqlmodel import SQLModel
 from sqlmodel.ext.asyncio.session import AsyncSession
 
@@ -61,7 +61,7 @@ with patch("sixty_nuts.Wallet") as mock_wallet_class:
 
 
 @pytest.fixture(scope="session")
-def event_loop():
+def event_loop() -> Generator[asyncio.AbstractEventLoop, None, None]:
     """Create an instance of the default event loop for the test session."""
     loop = asyncio.get_event_loop_policy().new_event_loop()
     yield loop
@@ -69,7 +69,7 @@ def event_loop():
 
 
 @pytest_asyncio.fixture(scope="function")
-async def test_engine():
+async def test_engine() -> AsyncGenerator[AsyncEngine, None]:
     """Create a test database engine - new for each test."""
     engine = create_async_engine(
         "sqlite+aiosqlite:///:memory:",
@@ -86,7 +86,7 @@ async def test_engine():
 
 
 @pytest_asyncio.fixture
-async def test_session(test_engine) -> AsyncGenerator[AsyncSession, None]:
+async def test_session(test_engine: AsyncEngine) -> AsyncGenerator[AsyncSession, None]:
     """Create a test database session."""
     from sqlmodel.ext.asyncio.session import AsyncSession as SqlModelAsyncSession
 
@@ -123,10 +123,10 @@ def test_client() -> Generator[TestClient, None, None]:
 
 
 @pytest_asyncio.fixture
-async def async_client(test_session) -> AsyncGenerator[AsyncClient, None]:
+async def async_client(test_session: AsyncSession) -> AsyncGenerator[AsyncClient, None]:
     """Create an async test client with dependency overrides."""
 
-    async def override_get_session():
+    async def override_get_session() -> AsyncGenerator[AsyncSession, None]:
         yield test_session
 
     app.dependency_overrides[get_session] = override_get_session
@@ -164,7 +164,7 @@ async def async_client(test_session) -> AsyncGenerator[AsyncClient, None]:
 
 
 @pytest.fixture
-def mock_models():
+def mock_models() -> list[dict]:
     """Mock models data for testing."""
     return [
         {
@@ -199,7 +199,7 @@ def mock_models():
 
 # Cleanup after all tests
 @pytest.fixture(scope="session", autouse=True)
-def cleanup():
+def cleanup() -> Generator[None, None, None]:
     yield
     # Restore original environment carefully
     current_keys = set(os.environ.keys())
diff --git a/tests/test_account.py b/tests/test_account.py
index 28ac6efa..32f4eaeb 100644
--- a/tests/test_account.py
+++ b/tests/test_account.py
@@ -39,10 +39,11 @@ async def test_api_key(test_session: AsyncSession) -> ApiKey:
 @pytest.mark.asyncio
 async def test_account_info_with_valid_key(
     async_client: AsyncClient, test_api_key: ApiKey
-):
+) -> None:
     """Test getting account info with a valid API key."""
     response = await async_client.get(
-        "/v1/wallet/info", headers={"Authorization": f"Bearer sk-{test_api_key.hashed_key}"}
+        "/v1/wallet/info",
+        headers={"Authorization": f"Bearer sk-{test_api_key.hashed_key}"},
     )
 
     assert response.status_code == 200
@@ -53,7 +54,7 @@ async def test_account_info_with_valid_key(
 
 
 @pytest.mark.asyncio
-async def test_account_info_without_auth(async_client: AsyncClient):
+async def test_account_info_without_auth(async_client: AsyncClient) -> None:
     """Test that account info requires authentication."""
     response = await async_client.get("/v1/wallet/")
 
@@ -61,7 +62,7 @@ async def test_account_info_without_auth(async_client: AsyncClient):
 
 
 @pytest.mark.asyncio
-async def test_account_info_with_invalid_key(async_client: AsyncClient):
+async def test_account_info_with_invalid_key(async_client: AsyncClient) -> None:
     """Test account info with an invalid API key."""
     response = await async_client.get(
         "/v1/wallet/info", headers={"Authorization": "Bearer invalid-key"}
@@ -73,7 +74,7 @@ async def test_account_info_with_invalid_key(async_client: AsyncClient):
 @pytest.mark.asyncio
 async def test_refund_balance_with_address(
     async_client: AsyncClient, test_api_key: ApiKey, test_session: AsyncSession
-):
+) -> None:
     """Test refunding balance when refund address is set."""
     # Need to patch the refund_balance at the module level to intercept the call
     with patch("router.account.refund_balance", new_callable=AsyncMock) as mock_refund:
@@ -101,7 +102,7 @@ async def test_refund_balance_with_address(
 @pytest.mark.asyncio
 async def test_refund_balance_without_address(
     async_client: AsyncClient, test_session: AsyncSession
-):
+) -> None:
     """Test refunding balance when no refund address is set."""
     # Create key without refund address - with unique ID
     unique_id = str(uuid.uuid4())[:8]
@@ -144,11 +145,11 @@ async def test_refund_balance_without_address(
 @pytest.mark.asyncio
 async def test_topup_balance_endpoint(
     async_client: AsyncClient, test_api_key: ApiKey, test_session: AsyncSession
-):
+) -> None:
     """Test topping up balance with a cashu token."""
     # Mock at the router.account module level to intercept the import
     with patch("router.account.credit_balance", new_callable=AsyncMock) as mock_credit:
-        mock_credit.return_value = {"msats": 500000}
+        mock_credit.return_value = 500000  # Return integer msats value
 
         response = await async_client.post(
             "/v1/wallet/topup?cashu_token=cashuBqQSEQ...",
@@ -166,7 +167,7 @@ async def test_topup_balance_endpoint(
 @pytest.mark.asyncio
 async def test_topup_balance_requires_cashu_token(
     async_client: AsyncClient, test_api_key: ApiKey
-):
+) -> None:
     """Test that topup endpoint requires a cashu token."""
     response = await async_client.post(
         "/v1/wallet/topup",
@@ -180,7 +181,7 @@ async def test_topup_balance_requires_cashu_token(
 @pytest.mark.asyncio
 async def test_account_with_cashu_token(
     async_client: AsyncClient, test_session: AsyncSession
-):
+) -> None:
     """Test authentication with a cashu token creates a new account."""
     cashu_token = "cashuBqQSEQ123456"
 
@@ -212,7 +213,7 @@ async def test_account_with_cashu_token(
 
 
 @pytest.mark.asyncio
-async def test_account_with_invalid_cashu_token(async_client: AsyncClient):
+async def test_account_with_invalid_cashu_token(async_client: AsyncClient) -> None:
     """Test authentication with an invalid cashu token returns 401."""
 
     with patch("router.auth.credit_balance", new_callable=AsyncMock) as mock_credit:
@@ -225,4 +226,3 @@ async def test_account_with_invalid_cashu_token(async_client: AsyncClient):
         assert response.status_code == 401
         error = response.json()
         assert error["detail"]["error"]["code"] == "invalid_api_key"
-
diff --git a/tests/test_main.py b/tests/test_main.py
index fc5b59d7..245e7303 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -1,11 +1,12 @@
 from unittest.mock import patch
 
 import pytest
+from fastapi.testclient import TestClient
 from httpx import AsyncClient
 
 
 @pytest.mark.asyncio
-async def test_root_endpoint(async_client: AsyncClient):
+async def test_root_endpoint(async_client: AsyncClient) -> None:
     """Test the root endpoint returns expected information."""
     # Mock the environment variables for this specific test
     env_vars = {
@@ -16,13 +17,13 @@ async def test_root_endpoint(async_client: AsyncClient):
         "HTTP_URL": "http://test.example.com",
         "ONION_URL": "http://test.onion",
     }
-    
+
     with patch.dict("os.environ", env_vars, clear=False):
         response = await async_client.get("/")
-        
+
         assert response.status_code == 200
         data = response.json()
-        
+
         # The app reads from env vars during import, so check what we actually get
         assert "name" in data
         assert "description" in data
@@ -35,16 +36,16 @@ async def test_root_endpoint(async_client: AsyncClient):
 
 
 @pytest.mark.asyncio
-async def test_cors_headers(async_client: AsyncClient):
+async def test_cors_headers(async_client: AsyncClient) -> None:
     """Test that CORS headers are properly set."""
     response = await async_client.options(
         "/",
         headers={
             "Origin": "http://localhost:3000",
             "Access-Control-Request-Method": "GET",
-        }
+        },
     )
-    
+
     assert response.status_code == 200
     # Check that CORS is working (might be * or specific origin)
     assert "access-control-allow-origin" in response.headers
@@ -52,7 +53,7 @@ async def test_cors_headers(async_client: AsyncClient):
 
 
 @pytest.mark.asyncio
-async def test_startup_event_initializes_properly(test_client):
+async def test_startup_event_initializes_properly(test_client: TestClient) -> None:
     """Test that the startup event runs without errors."""
     # The test_client fixture already triggers the startup event
     # This test ensures no exceptions are raised during startup
diff --git a/tests/test_models.py b/tests/test_models.py
index 6476c6a9..99e14276 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -1,6 +1,6 @@
 import asyncio
+from typing import Any
 from unittest.mock import AsyncMock, patch
-
 import pytest
 
 from router.models import (
@@ -27,7 +27,7 @@ def sample_model() -> Model:
             input_modalities=["text"],
             output_modalities=["text"],
             tokenizer="test_tokenizer",
-            instruct_type="chat"
+            instruct_type="chat",
         ),
         pricing=Pricing(
             prompt=0.01,
@@ -35,63 +35,71 @@ def sample_model() -> Model:
             request=0.001,
             image=0.0,
             web_search=0.0,
-            internal_reasoning=0.0
+            internal_reasoning=0.0,
         ),
         top_provider=TopProvider(
-            context_length=4096,
-            max_completion_tokens=2048,
-            is_moderated=False
-        )
+            context_length=4096, max_completion_tokens=2048, is_moderated=False
+        ),
     )
 
 
 @pytest.mark.asyncio
-async def test_update_sats_pricing_calculation(sample_model: Model):
+async def test_update_sats_pricing_calculation(sample_model: Model) -> None:
     """Test that sats pricing is calculated correctly."""
     # Mock the sats_usd_ask_price function
-    with patch("router.models.sats_usd_ask_price", new_callable=AsyncMock) as mock_price:
+    with patch(
+        "router.models.sats_usd_ask_price", new_callable=AsyncMock
+    ) as mock_price:
         mock_price.return_value = 0.0001  # 1 sat = 0.0001 USD
-        
+
         # Temporarily replace MODELS
         original_models = MODELS[:]
         MODELS.clear()
         MODELS.append(sample_model)
-        
+
         # Run one iteration of the pricing update
         sleep_called = asyncio.Event()
-        
-        async def mock_sleep(duration):
+
+        async def mock_sleep(duration: float) -> None:
             sleep_called.set()
             raise asyncio.CancelledError()
-        
+
         with patch("asyncio.sleep", side_effect=mock_sleep):
             try:
                 # Create and run the task
                 task = asyncio.create_task(update_sats_pricing())
-                
+
                 # Wait for the first iteration to complete
                 await sleep_called.wait()
-                
+
                 # Check that sats pricing was calculated
                 assert sample_model.sats_pricing is not None
-                
+
                 # Verify calculations (prices in USD / sats_to_usd)
-                assert sample_model.sats_pricing.prompt == pytest.approx(0.01 / 0.0001)  # 100 sats
-                assert sample_model.sats_pricing.completion == pytest.approx(0.02 / 0.0001)  # 200 sats
-                assert sample_model.sats_pricing.request == pytest.approx(0.001 / 0.0001)  # 10 sats
-                
+                assert sample_model.sats_pricing.prompt == pytest.approx(
+                    0.01 / 0.0001
+                )  # 100 sats
+                assert sample_model.sats_pricing.completion == pytest.approx(
+                    0.02 / 0.0001
+                )  # 200 sats
+                assert sample_model.sats_pricing.request == pytest.approx(
+                    0.001 / 0.0001
+                )  # 10 sats
+
                 # Verify max_cost calculation for model with top_provider
                 expected_max_context = 4096 * sample_model.sats_pricing.prompt
                 expected_max_completion = 2048 * sample_model.sats_pricing.completion
-                assert sample_model.sats_pricing.max_cost == pytest.approx(expected_max_context + expected_max_completion)
-                
+                assert sample_model.sats_pricing.max_cost == pytest.approx(
+                    expected_max_context + expected_max_completion
+                )
+
                 # Cancel and await the task
                 task.cancel()
                 try:
                     await task
                 except asyncio.CancelledError:
                     pass
-                
+
             except asyncio.CancelledError:
                 pass
             finally:
@@ -101,7 +109,7 @@ async def test_update_sats_pricing_calculation(sample_model: Model):
 
 
 @pytest.mark.asyncio
-async def test_update_sats_pricing_without_top_provider():
+async def test_update_sats_pricing_without_top_provider() -> None:
     """Test sats pricing calculation for models without top_provider."""
     model_without_top = Model(
         id="test-model-no-top",
@@ -114,7 +122,7 @@ async def test_update_sats_pricing_without_top_provider():
             input_modalities=["text"],
             output_modalities=["text"],
             tokenizer="test_tokenizer",
-            instruct_type=None
+            instruct_type=None,
         ),
         pricing=Pricing(
             prompt=0.01,
@@ -122,31 +130,33 @@ async def test_update_sats_pricing_without_top_provider():
             request=0.001,
             image=0.01,
             web_search=0.005,
-            internal_reasoning=0.015
+            internal_reasoning=0.015,
         ),
-        top_provider=None
+        top_provider=None,
     )
-    
-    with patch("router.models.sats_usd_ask_price", new_callable=AsyncMock) as mock_price:
+
+    with patch(
+        "router.models.sats_usd_ask_price", new_callable=AsyncMock
+    ) as mock_price:
         mock_price.return_value = 0.0001  # 1 sat = 0.0001 USD
-        
+
         original_models = MODELS[:]
         MODELS.clear()
         MODELS.append(model_without_top)
-        
+
         sleep_called = asyncio.Event()
-        
-        async def mock_sleep(duration):
+
+        async def mock_sleep(duration: float) -> None:
             sleep_called.set()
             raise asyncio.CancelledError()
-        
+
         with patch("asyncio.sleep", side_effect=mock_sleep):
             try:
                 task = asyncio.create_task(update_sats_pricing())
                 await sleep_called.wait()
-                
+
                 assert model_without_top.sats_pricing is not None
-                
+
                 # Verify the fallback max_cost calculation
                 p = model_without_top.sats_pricing.prompt * 1_000_000
                 c = model_without_top.sats_pricing.completion * 32_000
@@ -155,16 +165,18 @@ async def test_update_sats_pricing_without_top_provider():
                 w = model_without_top.sats_pricing.web_search * 1000
                 ir = model_without_top.sats_pricing.internal_reasoning * 100
                 expected_max = p + c + r + i + w + ir
-                
-                assert model_without_top.sats_pricing.max_cost == pytest.approx(expected_max)
-                
+
+                assert model_without_top.sats_pricing.max_cost == pytest.approx(
+                    expected_max
+                )
+
                 # Cancel and await the task
                 task.cancel()
                 try:
                     await task
                 except asyncio.CancelledError:
                     pass
-                
+
             except asyncio.CancelledError:
                 pass
             finally:
@@ -173,59 +185,61 @@ async def test_update_sats_pricing_without_top_provider():
 
 
 @pytest.mark.asyncio
-async def test_update_sats_pricing_handles_errors():
+async def test_update_sats_pricing_handles_errors() -> None:
     """Test that update_sats_pricing handles errors gracefully."""
-    with patch("router.models.sats_usd_ask_price", new_callable=AsyncMock) as mock_price:
+    with patch(
+        "router.models.sats_usd_ask_price", new_callable=AsyncMock
+    ) as mock_price:
         mock_price.side_effect = Exception("API Error")
-        
+
         error_printed = False
         original_print = print
-        
-        def mock_print(*args, **kwargs):
+
+        def mock_print(*args: Any, **kwargs: Any) -> None:
             nonlocal error_printed
             message = " ".join(str(a) for a in args)
             if "API Error" in message and "Error updating sats pricing" in message:
                 error_printed = True
             original_print(*args, **kwargs)
-        
+
         with patch("builtins.print", side_effect=mock_print):
             sleep_called = asyncio.Event()
-            
-            async def mock_sleep(duration):
+
+            async def mock_sleep(duration: float) -> None:
                 sleep_called.set()
                 raise asyncio.CancelledError()
-            
+
             with patch("asyncio.sleep", side_effect=mock_sleep):
                 try:
                     task = asyncio.create_task(update_sats_pricing())
                     await sleep_called.wait()
-                    
+
                     # Verify error was printed
                     assert error_printed
-                    
+
                     # Cancel and await the task
                     task.cancel()
                     try:
                         await task
                     except asyncio.CancelledError:
                         pass
-                    
+
                 except asyncio.CancelledError:
                     pass
 
 
-def test_model_serialization(sample_model: Model):
+def test_model_serialization(sample_model: Model) -> None:
     """Test that models can be serialized and deserialized correctly."""
     model_dict = sample_model.dict()
-    
+
     # Verify all fields are present
     assert model_dict["id"] == "test-model"
     assert model_dict["name"] == "Test Model"
     assert model_dict["pricing"]["prompt"] == 0.01
     assert model_dict["architecture"]["modality"] == "text"
     assert model_dict["top_provider"]["context_length"] == 4096
-    
+
     # Test deserialization
     new_model = Model(**model_dict)
     assert new_model.id == sample_model.id
-    assert new_model.pricing.prompt == pytest.approx(sample_model.pricing.prompt) 
+    assert new_model.pricing.prompt == pytest.approx(sample_model.pricing.prompt)
diff --git a/tests/test_proxy.py b/tests/test_proxy.py
index f7970302..a07b18e1 100644
--- a/tests/test_proxy.py
+++ b/tests/test_proxy.py
@@ -1,6 +1,7 @@
 import json
 import os
 import uuid
+from typing import AsyncGenerator
 from unittest.mock import AsyncMock, patch
 
 import pytest
@@ -28,7 +29,7 @@ async def api_key_with_balance(test_session: AsyncSession) -> ApiKey:
 
 
 @pytest.mark.asyncio
-async def test_proxy_requires_authentication(async_client: AsyncClient):
+async def test_proxy_requires_authentication(async_client: AsyncClient) -> None:
     """Test that proxy endpoints require authentication."""
     response = await async_client.post("/v1/chat/completions")
 
@@ -42,7 +43,7 @@ async def test_proxy_requires_authentication(async_client: AsyncClient):
 @pytest.mark.asyncio
 async def test_proxy_with_insufficient_balance(
     async_client: AsyncClient, test_session: AsyncSession
-):
+) -> None:
     """Test proxy request with insufficient balance."""
     # Create key with minimal balance
     unique_id = str(uuid.uuid4())[:8]
@@ -71,7 +72,7 @@ async def test_proxy_with_insufficient_balance(
 @pytest.mark.asyncio
 async def test_proxy_invalid_json_body(
     async_client: AsyncClient, api_key_with_balance: ApiKey
-):
+) -> None:
     """Test proxy request with invalid JSON body."""
     response = await async_client.post(
         "/v1/chat/completions",
@@ -91,7 +92,7 @@ async def test_proxy_invalid_json_body(
 @pytest.mark.asyncio
 async def test_proxy_successful_request_mock(
     async_client: AsyncClient, api_key_with_balance: ApiKey, test_session: AsyncSession
-):
+) -> None:
     """Test successful proxy request with mocked upstream."""
     mock_response_data = {
         "id": "chatcmpl-123",
@@ -162,7 +163,7 @@ async def test_proxy_successful_request_mock(
 @pytest.mark.asyncio
 async def test_proxy_streaming_response(
     async_client: AsyncClient, api_key_with_balance: ApiKey
-):
+) -> None:
     """Test proxy request with streaming response."""
     # Mock SSE stream chunks
     stream_chunks = [
@@ -172,7 +173,7 @@ async def test_proxy_streaming_response(
         b"data: [DONE]\n\n",
     ]
 
-    async def mock_aiter_bytes():
+    async def mock_aiter_bytes() -> AsyncGenerator[bytes, None]:
         for chunk in stream_chunks:
             yield chunk
 
@@ -213,7 +214,7 @@ async def test_proxy_streaming_response(
 @pytest.mark.asyncio
 async def test_proxy_handles_upstream_errors(
     async_client: AsyncClient, api_key_with_balance: ApiKey
-):
+) -> None:
     """Test proxy handles upstream connection errors gracefully."""
     with patch("httpx.AsyncClient") as mock_client_class:
         mock_client = AsyncMock()
@@ -245,7 +246,7 @@ async def test_proxy_handles_upstream_errors(
 @pytest.mark.asyncio
 async def test_proxy_with_model_based_pricing(
     async_client: AsyncClient, test_session: AsyncSession
-):
+) -> None:
     """Test proxy with model-based pricing enabled."""
     # Create API key with sufficient balance
     unique_id = str(uuid.uuid4())[:8]
diff --git a/tests/test_shutdown.py b/tests/test_shutdown.py
index 09eabb58..059c2454 100644
--- a/tests/test_shutdown.py
+++ b/tests/test_shutdown.py
@@ -8,11 +8,11 @@ from tests.conftest import TEST_ENV
 
 
 @pytest.mark.asyncio
-async def test_background_tasks_cancel_on_shutdown():
+async def test_background_tasks_cancel_on_shutdown() -> None:
     pricing_started = asyncio.Event()
     pricing_cancelled = asyncio.Event()
 
-    async def fake_update():
+    async def fake_update() -> None:
         pricing_started.set()
         try:
             await asyncio.Event().wait()
@@ -23,7 +23,7 @@ async def test_background_tasks_cancel_on_shutdown():
     refund_started = asyncio.Event()
     refund_cancelled = asyncio.Event()
 
-    async def fake_refund():
+    async def fake_refund() -> None:
         refund_started.set()
         try:
             await asyncio.Event().wait()
@@ -31,7 +31,7 @@ async def test_background_tasks_cancel_on_shutdown():
             refund_cancelled.set()
             raise
 
-    with patch.dict('os.environ', TEST_ENV, clear=True):
+    with patch.dict("os.environ", TEST_ENV, clear=True):
         mock_wallet = AsyncMock()
         mock_wallet.__aenter__ = AsyncMock(return_value=mock_wallet)
         mock_wallet.__aexit__ = AsyncMock(return_value=None)
@@ -40,13 +40,16 @@ async def test_background_tasks_cancel_on_shutdown():
         mock_wallet.fetch_wallet_state = AsyncMock(return_value=mock_state)
         mock_wallet.send_to_lnurl = AsyncMock(return_value=100)
         mock_wallet.redeem = AsyncMock(return_value=1)
-        mock_wallet.send = AsyncMock(return_value='cashu:token123')
+        mock_wallet.send = AsyncMock(return_value="cashu:token123")
 
-        with patch('router.cashu.Wallet.create', AsyncMock(return_value=mock_wallet)), \
-             patch('router.cashu.WALLET', mock_wallet):
-
-            with patch('router.main.update_sats_pricing', new=fake_update), \
-                 patch('router.main.check_for_refunds', new=fake_refund):
+        with (
+            patch("router.cashu.Wallet.create", AsyncMock(return_value=mock_wallet)),
+            patch("router.cashu.WALLET", mock_wallet),
+        ):
+            with (
+                patch("router.main.update_sats_pricing", new=fake_update),
+                patch("router.main.check_for_refunds", new=fake_refund),
+            ):
                 async with lifespan(app):
                     await pricing_started.wait()
                     await refund_started.wait()