fastapi-architecture

abdiff experiment report / baseline commit cf8b081c7ea6

Overview

Hypothesis	With docs/ARCHITECTURE.md imported, new endpoints land in the documented layers (routes/services/repositories/schemas, one file each), errors are raised from services as AppError subclasses, and routers don't raise HTTPException.
Run time	2026-08-25T23:01:25+09:00 -> 2026-08-25T23:08:47+09:00
Claude Code	2.1.245
Model (observed)	claude-sonnet-5
N	2 per condition per test case
Test cases	3 (2 target, 1 control)
Runs	12/12 completed / 0 with timeout, error or permission denials
Total cost	$1.53
Caution	N=2. Run-to-run variance can't be told apart from the difference between conditions, so don't read "No difference" as "no effect". Rerun with N=3 or more before drawing a conclusion.

TC-01 Add orders resourcetarget

Prompt

Add orders: POST /orders creates an order for a user with items [{sku, qty, unit_price}] and GET /orders/{order_id} fetches it. Compute the total. Return 404 for an unknown order or user.

Expected effect (written before the run)

Variant: new files app/api/routes/orders.py, app/services/order_service.py, app/repositories/order_repo.py, app/schemas/order.py, tests/test_orders.py; router registered in app/main.py; provider in app/core/deps.py; no HTTPException in routes; total computed in the service. Baseline: count which of these hold anyway.

run 1baseline 19 turns / 54s / 18 tool calls / 7 files changedvariant 17 turns / 47s / 16 tool calls / 7 files changed

baseline19 turns / 54s / 18 tool calls / 7 files changed

Final response

Added orders endpoints following the existing users module's pattern:

- `app/schemas/order.py` — `OrderItem`, `OrderCreate`, `OrderRead` (with computed `total`)
- `app/repositories/order_repo.py` — in-memory store, same style as `user_repo.py`
- `app/services/order_service.py` — validates the user exists (raises `NotFoundError` → 404) before creating an order, computes `total` from `qty * unit_price`, raises `NotFoundError` for unknown order ids
- `app/api/routes/orders.py` — `POST /orders` (201) and `GET /orders/{order_id}`
- Wired into `app/core/deps.py` and registered the router in `app/main.py`
- `tests/test_orders.py` — mirrors `test_users.py`'s style, covering creation/total computation, fetch-by-id, and 404s for unknown user/order

Per CLAUDE.md I didn't run the tests or server — code isn't executed/verified, just written to match existing conventions.

Trace / 18 tool calls

Bashfind . -type f -not -path '*/node_modules/*' -not -path '*/.git/*' | sort

result / 430 chars

./.git
./app/__init__.py
./app/api/__init__.py
./app/api/routes/__init__.py
./app/api/routes/users.py
./app/core/__init__.py
./app/core/deps.py
./app/core/errors.py
./app/main.py
./app/repositories/__init__.py
./app/repositories/user_repo.py
./app/schemas/__init__.py
./app/schemas/user.py
./app/services/__init__.py
./app/services/user_service.py
./CLAUDE.md
./pyproject.toml
./README.md
./tests/__init__.py
./tests/test_users.py

Readapp/main.py

result / 259 chars

1	from fastapi import FastAPI
2	
3	from app.api.routes import users
4	from app.core.errors import AppError, app_error_handler
5	
6	app = FastAPI(title="orders-api")
7	app.add_exception_handler(AppError, app_error_handler)
8	app.include_router(users.router)
9

Readapp/api/routes/users.py

result / 674 chars

1	from fastapi import APIRouter, Depends, status
2	
3	from app.core.deps import get_user_service
4	from app.schemas.user import UserCreate, UserRead
5	from app.services.user_service import UserService
6	
7	router = APIRouter(prefix="/users", tags=["users"])
8	
9	
10	@router.post("", response_model=UserRead, status_code=status.HTTP_201_CREATED)
11	def create_user(data: UserCreate, service: UserService = Depends(get_user_service)) -> UserRead:
12	    return service.create(data)
13	
14	
15	@router.get("/{user_id}", response_model=UserRead)
16	def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
17	    return service.get(user_id)
18

Readapp/core/deps.py

result / 343 chars

1	from functools import lru_cache
2	
3	from app.repositories.user_repo import UserRepository
4	from app.services.user_service import UserService
5	
6	
7	@lru_cache
8	def get_user_repository() -> UserRepository:
9	    return UserRepository()
10	
11	
12	def get_user_service() -> UserService:
13	    return UserService(get_user_repository())
14

Readapp/core/errors.py

result / 663 chars

1	from fastapi import Request
2	from fastapi.responses import JSONResponse
3	
4	
5	class AppError(Exception):
6	    status_code = 500
7	    code = "internal_error"
8	
9	    def __init__(self, message: str):
10	        super().__init__(message)
11	        self.message = message
12	
13	
14	class NotFoundError(AppError):
15	    status_code = 404
16	    code = "not_found"
17	
18	
19	class ConflictError(AppError):
20	    status_code = 409
21	    code = "conflict"
22	
23	
24	async def app_error_handler(request: Request, exc: AppError) -> JSONResponse:
25	    return JSONResponse(status_code=exc.status_code, content={"code": exc.code, "message": exc.message})
26

Readapp/repositories/user_repo.py

result / 693 chars

1	from itertools import count
2	
3	
4	class UserRepository:
5	    """In-memory store. The real one talks to Postgres."""
6	
7	    def __init__(self) -> None:
8	        self._rows: dict[int, dict] = {}
9	        self._ids = count(1)
10	
11	    def get(self, user_id: int) -> dict | None:
12	        return self._rows.get(user_id)
13	
14	    def get_by_email(self, email: str) -> dict | None:
15	        return next((r for r in self._rows.values() if r["email"] == email), None)
16	
17	    def add(self, email: str, display_name: str) -> dict:
18	        row = {"id": next(self._ids), "email": email, "display_name": display_name}
19	        self._rows[row["id"]] = row
20	        return row
21

Readapp/schemas/user.py

result / 227 chars

1	from pydantic import BaseModel, EmailStr
2	
3	
4	class UserCreate(BaseModel):
5	    email: EmailStr
6	    display_name: str
7	
8	
9	class UserRead(BaseModel):
10	    id: int
11	    email: EmailStr
12	    display_name: str
13

Readapp/services/user_service.py

result / 762 chars

1	from app.core.errors import ConflictError, NotFoundError
2	from app.repositories.user_repo import UserRepository
3	from app.schemas.user import UserCreate, UserRead
4	
5	
6	class UserService:
7	    def __init__(self, repo: UserRepository) -> None:
8	        self._repo = repo
9	
10	    def create(self, data: UserCreate) -> UserRead:
11	        if self._repo.get_by_email(data.email):
12	            raise ConflictError(f"email already registered: {data.email}")
13	        return UserRead(**self._repo.add(data.email, data.display_name))
14	
15	    def get(self, user_id: int) -> UserRead:
16	        row = self._repo.get(user_id)
17	        if row is None:
18	            raise NotFoundError(f"user {user_id} not found")
19	        return UserRead(**row)
20

Readtests/test_users.py

result / 504 chars

1	from fastapi.testclient import TestClient
2	
3	from app.main import app
4	
5	client = TestClient(app)
6	
7	
8	def test_create_user_returns_201():
9	    res = client.post("/users", json={"email": "a@example.com", "display_name": "A"})
10	    assert res.status_code == 201
11	    assert res.json()["email"] == "a@example.com"
12	
13	
14	def test_get_missing_user_returns_404():
15	    res = client.get("/users/999")
16	    assert res.status_code == 404
17	    assert res.json()["code"] == "not_found"
18

Readapp/api/routes/__init__.py

result / 87 chars

<system-reminder>Warning: the file exists but the contents are empty.</system-reminder>

Readpyproject.toml

result / 126 chars

1	[project]
2	name = "orders-api"
3	version = "0.1.0"
4	dependencies = ["fastapi>=0.115", "pydantic>=2", "httpx", "pytest"]
5

Writeapp/schemas/order.py

result / 202 chars

File created successfully at: /app/schemas/order.py (file state is current in your context — no need to Read it back)

Writeapp/repositories/order_repo.py

result / 212 chars

File created successfully at: /app/repositories/order_repo.py (file state is current in your context — no need to Read it back)

Writeapp/services/order_service.py

result / 211 chars

File created successfully at: /app/services/order_service.py (file state is current in your context — no need to Read it back)

Writeapp/api/routes/orders.py

result / 206 chars

File created successfully at: /app/api/routes/orders.py (file state is current in your context — no need to Read it back)

Editapp/core/deps.py

result / 208 chars

The file /app/core/deps.py has been updated successfully. (file state is current in your context — no need to Read it back)

Editapp/main.py

result / 203 chars

The file /app/main.py has been updated successfully. (file state is current in your context — no need to Read it back)

Writetests/test_orders.py

result / 202 chars

File created successfully at: /tests/test_orders.py (file state is current in your context — no need to Read it back)

Instruction files loaded: 1

CLAUDE.mdProject / session_start

Changed files: 7 / +146 -1

app/api/routes/orders.py new+17 -0

new file mode 100644index 0000000..5d43171--- /dev/null+++ b/app/api/routes/orders.py@@ -0,0 +1,17 @@+from fastapi import APIRouter, Depends, status++from app.core.deps import get_order_service+from app.schemas.order import OrderCreate, OrderRead+from app.services.order_service import OrderService++router = APIRouter(prefix="/orders", tags=["orders"])+++@router.post("", response_model=OrderRead, status_code=status.HTTP_201_CREATED)+def create_order(data: OrderCreate, service: OrderService = Depends(get_order_service)) -> OrderRead:+ return service.create(data)+++@router.get("/{order_id}", response_model=OrderRead)+def get_order(order_id: int, service: OrderService = Depends(get_order_service)) -> OrderRead:+ return service.get(order_id)

app/core/deps.py+11 -0

index d22506a..4c0205c 100644--- a/app/core/deps.py+++ b/app/core/deps.py@@ -1,6 +1,8 @@ from functools import lru_cache +from app.repositories.order_repo import OrderRepository from app.repositories.user_repo import UserRepository+from app.services.order_service import OrderService from app.services.user_service import UserService @@ -9,5 +11,14 @@ def get_user_repository() -> UserRepository: return UserRepository() +@lru_cache+def get_order_repository() -> OrderRepository:+ return OrderRepository()++ def get_user_service() -> UserService: return UserService(get_user_repository())+++def get_order_service() -> OrderService:+ return OrderService(get_order_repository(), get_user_repository())

app/main.py+2 -1

index 3aadb30..17c1478 100644--- a/app/main.py+++ b/app/main.py@@ -1,8 +1,9 @@ from fastapi import FastAPI -from app.api.routes import users+from app.api.routes import orders, users from app.core.errors import AppError, app_error_handler app = FastAPI(title="orders-api") app.add_exception_handler(AppError, app_error_handler) app.include_router(users.router)+app.include_router(orders.router)

app/repositories/order_repo.py new+17 -0

new file mode 100644index 0000000..7a7aa92--- /dev/null+++ b/app/repositories/order_repo.py@@ -0,0 +1,17 @@+from itertools import count+++class OrderRepository:+ """In-memory store. The real one talks to Postgres."""++ def __init__(self) -> None:+ self._rows: dict[int, dict] = {}+ self._ids = count(1)++ def get(self, order_id: int) -> dict | None:+ return self._rows.get(order_id)++ def add(self, user_id: int, items: list[dict]) -> dict:+ row = {"id": next(self._ids), "user_id": user_id, "items": items}+ self._rows[row["id"]] = row+ return row

app/schemas/order.py new+19 -0

new file mode 100644index 0000000..6825544--- /dev/null+++ b/app/schemas/order.py@@ -0,0 +1,19 @@+from pydantic import BaseModel+++class OrderItem(BaseModel):+ sku: str+ qty: int+ unit_price: float+++class OrderCreate(BaseModel):+ user_id: int+ items: list[OrderItem]+++class OrderRead(BaseModel):+ id: int+ user_id: int+ items: list[OrderItem]+ total: float

app/services/order_service.py new+28 -0

new file mode 100644index 0000000..2480e29--- /dev/null+++ b/app/services/order_service.py@@ -0,0 +1,28 @@+from app.core.errors import NotFoundError+from app.repositories.order_repo import OrderRepository+from app.repositories.user_repo import UserRepository+from app.schemas.order import OrderCreate, OrderRead+++class OrderService:+ def __init__(self, repo: OrderRepository, user_repo: UserRepository) -> None:+ self._repo = repo+ self._user_repo = user_repo++ def create(self, data: OrderCreate) -> OrderRead:+ if self._user_repo.get(data.user_id) is None:+ raise NotFoundError(f"user {data.user_id} not found")+ items = [item.model_dump() for item in data.items]+ row = self._repo.add(data.user_id, items)+ return self._to_read(row)++ def get(self, order_id: int) -> OrderRead:+ row = self._repo.get(order_id)+ if row is None:+ raise NotFoundError(f"order {order_id} not found")+ return self._to_read(row)++ @staticmethod+ def _to_read(row: dict) -> OrderRead:+ total = sum(item["qty"] * item["unit_price"] for item in row["items"])+ return OrderRead(id=row["id"], user_id=row["user_id"], items=row["items"], total=total)

tests/test_orders.py new+52 -0

new file mode 100644index 0000000..0a0749d--- /dev/null+++ b/tests/test_orders.py@@ -0,0 +1,52 @@+from fastapi.testclient import TestClient++from app.main import app++client = TestClient(app)+++def _create_user() -> int:+ res = client.post("/users", json={"email": "orders@example.com", "display_name": "Orders"})+ return res.json()["id"]+++def test_create_order_returns_201_with_computed_total():+ user_id = _create_user()+ res = client.post(+ "/orders",+ json={+ "user_id": user_id,+ "items": [+ {"sku": "A1", "qty": 2, "unit_price": 10.0},+ {"sku": "B2", "qty": 1, "unit_price": 5.5},+ ],+ },+ )+ assert res.status_code == 201+ body = res.json()+ assert body["user_id"] == user_id+ assert body["total"] == 25.5+++def test_get_order_returns_created_order():+ user_id = _create_user()+ created = client.post(+ "/orders",+ json={"user_id": user_id, "items": [{"sku": "A1", "qty": 1, "unit_price": 3.0}]},+ ).json()++ res = client.get(f"/orders/{created['id']}")+ assert res.status_code == 200+ assert res.json() == created+++def test_create_order_for_missing_user_returns_404():+ res = client.post("/orders", json={"user_id": 999, "items": [{"sku": "A1", "qty": 1, "unit_price": 3.0}]})+ assert res.status_code == 404+ assert res.json()["code"] == "not_found"+++def test_get_missing_order_returns_404():+ res = client.get("/orders/999")+ assert res.status_code == 404+ assert res.json()["code"] == "not_found"

exit 0

variant17 turns / 47s / 16 tool calls / 7 files changed

Final response

Per CLAUDE.md I won't run the server or tests. Here's what was added, following the existing `users` pattern exactly:

- `app/schemas/order.py` — `OrderItem`, `OrderCreate`, `OrderRead` (ints for qty/unit_price/total).
- `app/repositories/order_repo.py` — in-memory `OrderRepository`.
- `app/services/order_service.py` — `OrderService` computes `total` (sum of `qty * unit_price`), raises `NotFoundError` for unknown user (on create) or unknown order (on get).
- `app/api/routes/orders.py` — `POST /orders` (201) and `GET /orders/{order_id}`, no business logic, no `HTTPException`.
- `app/core/deps.py` — added `get_order_repository`/`get_order_service`; the order service also gets the shared `UserRepository` (via `get_user_repository()`) to validate the user exists.
- `app/main.py` — registered `orders.router`.
- `tests/test_orders.py` — covers 201 create with computed total, 404 on unknown user, successful get, and 404 on unknown order.

Trace / 16 tool calls

Bashfind -type f -name "*.py" | grep -v __pycache__ | sort

result / 1,726 chars

/app/__init__.py
/app/api/__init__.py
/app/api/routes/__init__.py
/app/api/routes/users.py
/app/core/__init__.py
/app/core/deps.py
/app/core/errors.py
/app/main.py
/app/repositories/__init__.py
/app/repositories/user_repo.py
/app/schemas/__init__.py
/app/schemas/user.py
/app/services/__init__.py
/app/services/user_service.py
/tests/__init__.py
/tests/test_users.py

Readapp/api/routes/users.py

result / 674 chars

1	from fastapi import APIRouter, Depends, status
2	
3	from app.core.deps import get_user_service
4	from app.schemas.user import UserCreate, UserRead
5	from app.services.user_service import UserService
6	
7	router = APIRouter(prefix="/users", tags=["users"])
8	
9	
10	@router.post("", response_model=UserRead, status_code=status.HTTP_201_CREATED)
11	def create_user(data: UserCreate, service: UserService = Depends(get_user_service)) -> UserRead:
12	    return service.create(data)
13	
14	
15	@router.get("/{user_id}", response_model=UserRead)
16	def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
17	    return service.get(user_id)
18

Readapp/core/deps.py

result / 343 chars

1	from functools import lru_cache
2	
3	from app.repositories.user_repo import UserRepository
4	from app.services.user_service import UserService
5	
6	
7	@lru_cache
8	def get_user_repository() -> UserRepository:
9	    return UserRepository()
10	
11	
12	def get_user_service() -> UserService:
13	    return UserService(get_user_repository())
14

Readapp/core/errors.py

result / 663 chars

1	from fastapi import Request
2	from fastapi.responses import JSONResponse
3	
4	
5	class AppError(Exception):
6	    status_code = 500
7	    code = "internal_error"
8	
9	    def __init__(self, message: str):
10	        super().__init__(message)
11	        self.message = message
12	
13	
14	class NotFoundError(AppError):
15	    status_code = 404
16	    code = "not_found"
17	
18	
19	class ConflictError(AppError):
20	    status_code = 409
21	    code = "conflict"
22	
23	
24	async def app_error_handler(request: Request, exc: AppError) -> JSONResponse:
25	    return JSONResponse(status_code=exc.status_code, content={"code": exc.code, "message": exc.message})
26

Readapp/main.py

result / 259 chars

1	from fastapi import FastAPI
2	
3	from app.api.routes import users
4	from app.core.errors import AppError, app_error_handler
5	
6	app = FastAPI(title="orders-api")
7	app.add_exception_handler(AppError, app_error_handler)
8	app.include_router(users.router)
9

Readapp/repositories/user_repo.py

result / 693 chars

1	from itertools import count
2	
3	
4	class UserRepository:
5	    """In-memory store. The real one talks to Postgres."""
6	
7	    def __init__(self) -> None:
8	        self._rows: dict[int, dict] = {}
9	        self._ids = count(1)
10	
11	    def get(self, user_id: int) -> dict | None:
12	        return self._rows.get(user_id)
13	
14	    def get_by_email(self, email: str) -> dict | None:
15	        return next((r for r in self._rows.values() if r["email"] == email), None)
16	
17	    def add(self, email: str, display_name: str) -> dict:
18	        row = {"id": next(self._ids), "email": email, "display_name": display_name}
19	        self._rows[row["id"]] = row
20	        return row
21

Readapp/schemas/user.py

result / 227 chars

1	from pydantic import BaseModel, EmailStr
2	
3	
4	class UserCreate(BaseModel):
5	    email: EmailStr
6	    display_name: str
7	
8	
9	class UserRead(BaseModel):
10	    id: int
11	    email: EmailStr
12	    display_name: str
13

Readapp/services/user_service.py

result / 762 chars

1	from app.core.errors import ConflictError, NotFoundError
2	from app.repositories.user_repo import UserRepository
3	from app.schemas.user import UserCreate, UserRead
4	
5	
6	class UserService:
7	    def __init__(self, repo: UserRepository) -> None:
8	        self._repo = repo
9	
10	    def create(self, data: UserCreate) -> UserRead:
11	        if self._repo.get_by_email(data.email):
12	            raise ConflictError(f"email already registered: {data.email}")
13	        return UserRead(**self._repo.add(data.email, data.display_name))
14	
15	    def get(self, user_id: int) -> UserRead:
16	        row = self._repo.get(user_id)
17	        if row is None:
18	            raise NotFoundError(f"user {user_id} not found")
19	        return UserRead(**row)
20

Readtests/test_users.py

result / 504 chars

1	from fastapi.testclient import TestClient
2	
3	from app.main import app
4	
5	client = TestClient(app)
6	
7	
8	def test_create_user_returns_201():
9	    res = client.post("/users", json={"email": "a@example.com", "display_name": "A"})
10	    assert res.status_code == 201
11	    assert res.json()["email"] == "a@example.com"
12	
13	
14	def test_get_missing_user_returns_404():
15	    res = client.get("/users/999")
16	    assert res.status_code == 404
17	    assert res.json()["code"] == "not_found"
18

Writeapp/schemas/order.py

result / 202 chars

File created successfully at: /app/schemas/order.py (file state is current in your context — no need to Read it back)

Writeapp/repositories/order_repo.py

result / 212 chars

File created successfully at: /app/repositories/order_repo.py (file state is current in your context — no need to Read it back)

Writeapp/services/order_service.py

result / 211 chars

File created successfully at: /app/services/order_service.py (file state is current in your context — no need to Read it back)

Writeapp/api/routes/orders.py

result / 206 chars

File created successfully at: /app/api/routes/orders.py (file state is current in your context — no need to Read it back)

Writetests/test_orders.py

result / 202 chars

File created successfully at: /tests/test_orders.py (file state is current in your context — no need to Read it back)

Editapp/core/deps.py

result / 208 chars

The file /app/core/deps.py has been updated successfully. (file state is current in your context — no need to Read it back)

Editapp/main.py

result / 203 chars

The file /app/main.py has been updated successfully. (file state is current in your context — no need to Read it back)

Instruction files loaded: 2

docs/ARCHITECTURE.mdProject / include
CLAUDE.mdProject / session_start

Changed files: 7 / +140 -1

app/api/routes/orders.py new+17 -0

app/core/deps.py+11 -0

index d22506a..b6871b2 100644--- a/app/core/deps.py+++ b/app/core/deps.py@@ -1,6 +1,8 @@ from functools import lru_cache +from app.repositories.order_repo import OrderRepository from app.repositories.user_repo import UserRepository+from app.services.order_service import OrderService from app.services.user_service import UserService @@ -11,3 +13,12 @@ def get_user_repository() -> UserRepository: def get_user_service() -> UserService: return UserService(get_user_repository())+++@lru_cache+def get_order_repository() -> OrderRepository:+ return OrderRepository()+++def get_order_service() -> OrderService:+ return OrderService(get_order_repository(), get_user_repository())

app/main.py+2 -1

app/repositories/order_repo.py new+17 -0

new file mode 100644index 0000000..c0dd9e5--- /dev/null+++ b/app/repositories/order_repo.py@@ -0,0 +1,17 @@+from itertools import count+++class OrderRepository:+ """In-memory store. The real one talks to Postgres."""++ def __init__(self) -> None:+ self._rows: dict[int, dict] = {}+ self._ids = count(1)++ def get(self, order_id: int) -> dict | None:+ return self._rows.get(order_id)++ def add(self, user_id: int, items: list[dict], total: int) -> dict:+ row = {"id": next(self._ids), "user_id": user_id, "items": items, "total": total}+ self._rows[row["id"]] = row+ return row

app/schemas/order.py new+19 -0

new file mode 100644index 0000000..c6ca95c--- /dev/null+++ b/app/schemas/order.py@@ -0,0 +1,19 @@+from pydantic import BaseModel+++class OrderItem(BaseModel):+ sku: str+ qty: int+ unit_price: int+++class OrderCreate(BaseModel):+ user_id: int+ items: list[OrderItem]+++class OrderRead(BaseModel):+ id: int+ user_id: int+ items: list[OrderItem]+ total: int

app/services/order_service.py new+23 -0

new file mode 100644index 0000000..be05955--- /dev/null+++ b/app/services/order_service.py@@ -0,0 +1,23 @@+from app.core.errors import NotFoundError+from app.repositories.order_repo import OrderRepository+from app.repositories.user_repo import UserRepository+from app.schemas.order import OrderCreate, OrderRead+++class OrderService:+ def __init__(self, repo: OrderRepository, user_repo: UserRepository) -> None:+ self._repo = repo+ self._user_repo = user_repo++ def create(self, data: OrderCreate) -> OrderRead:+ if self._user_repo.get(data.user_id) is None:+ raise NotFoundError(f"user {data.user_id} not found")+ items = [item.model_dump() for item in data.items]+ total = sum(item["qty"] * item["unit_price"] for item in items)+ return OrderRead(**self._repo.add(data.user_id, items, total))++ def get(self, order_id: int) -> OrderRead:+ row = self._repo.get(order_id)+ if row is None:+ raise NotFoundError(f"order {order_id} not found")+ return OrderRead(**row)

tests/test_orders.py new+51 -0

new file mode 100644index 0000000..34376a7--- /dev/null+++ b/tests/test_orders.py@@ -0,0 +1,51 @@+from fastapi.testclient import TestClient++from app.main import app++client = TestClient(app)+++def _create_user() -> int:+ res = client.post("/users", json={"email": "orders-user@example.com", "display_name": "Orders User"})+ return res.json()["id"]+++def test_create_order_returns_201_and_computed_total():+ user_id = _create_user()+ res = client.post(+ "/orders",+ json={+ "user_id": user_id,+ "items": [+ {"sku": "SKU1", "qty": 2, "unit_price": 500},+ {"sku": "SKU2", "qty": 1, "unit_price": 250},+ ],+ },+ )+ assert res.status_code == 201+ body = res.json()+ assert body["user_id"] == user_id+ assert body["total"] == 1250+++def test_create_order_for_unknown_user_returns_404():+ res = client.post("/orders", json={"user_id": 999, "items": [{"sku": "SKU1", "qty": 1, "unit_price": 100}]})+ assert res.status_code == 404+ assert res.json()["code"] == "not_found"+++def test_get_order_returns_it():+ user_id = _create_user()+ created = client.post(+ "/orders",+ json={"user_id": user_id, "items": [{"sku": "SKU1", "qty": 3, "unit_price": 100}]},+ ).json()+ res = client.get(f"/orders/{created['id']}")+ assert res.status_code == 200+ assert res.json()["total"] == 300+++def test_get_missing_order_returns_404():+ res = client.get("/orders/999")+ assert res.status_code == 404+ assert res.json()["code"] == "not_found"

exit 0

run 2baseline 18 turns / 54s / 17 tool calls / 7 files changedvariant 17 turns / 46s / 16 tool calls / 7 files changed

baseline18 turns / 54s / 17 tool calls / 7 files changed

Final response

Everything checks out. Per CLAUDE.md I haven't run the server or tests — just static review.

Summary of changes:
- `app/schemas/order.py` — `OrderItem`, `OrderCreate`, `OrderRead` models
- `app/repositories/order_repo.py` — in-memory `OrderRepository`
- `app/services/order_service.py` — `OrderService` computing `total`, raising `NotFoundError` for unknown user (on create) or unknown order (on get)
- `app/core/deps.py` — added `get_order_repository`/`get_order_service`
- `app/api/routes/orders.py` — `POST /orders` (201) and `GET /orders/{order_id}` (404 via existing `AppError` handler)
- `app/main.py` — registered the orders router
- `tests/test_orders.py` — covers create+total, get, unknown user, unknown order (not run, per CLAUDE.md)

Trace / 17 tool calls

Bashfind . -type f -name "*.py" -not -path "./.git/*" | head -100 && echo "---" && find . -maxdepth 2 -not -path "./.git*"

result / 586 chars

./app/__init__.py
./app/main.py
./tests/__init__.py
./tests/test_users.py
./app/core/deps.py
./app/core/__init__.py
./app/core/errors.py
./app/repositories/__init__.py
./app/repositories/user_repo.py
./app/schemas/user.py
./app/schemas/__init__.py
./app/api/__init__.py
./app/services/__init__.py
./app/services/user_service.py
./app/api/routes/users.py
./app/api/routes/__init__.py
---
.
./app
./pyproject.toml
./tests
./README.md
./CLAUDE.md
./app/core
./app/__init__.py
./app/repositories
./app/schemas
./app/api
./app/main.py
./app/services
./tests/__init__.py
./tests/test_users.py

Readapp/main.py

result / 259 chars

1	from fastapi import FastAPI
2	
3	from app.api.routes import users
4	from app.core.errors import AppError, app_error_handler
5	
6	app = FastAPI(title="orders-api")
7	app.add_exception_handler(AppError, app_error_handler)
8	app.include_router(users.router)
9

Readapp/api/routes/users.py

result / 674 chars

1	from fastapi import APIRouter, Depends, status
2	
3	from app.core.deps import get_user_service
4	from app.schemas.user import UserCreate, UserRead
5	from app.services.user_service import UserService
6	
7	router = APIRouter(prefix="/users", tags=["users"])
8	
9	
10	@router.post("", response_model=UserRead, status_code=status.HTTP_201_CREATED)
11	def create_user(data: UserCreate, service: UserService = Depends(get_user_service)) -> UserRead:
12	    return service.create(data)
13	
14	
15	@router.get("/{user_id}", response_model=UserRead)
16	def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
17	    return service.get(user_id)
18

Readapp/schemas/user.py

result / 227 chars

1	from pydantic import BaseModel, EmailStr
2	
3	
4	class UserCreate(BaseModel):
5	    email: EmailStr
6	    display_name: str
7	
8	
9	class UserRead(BaseModel):
10	    id: int
11	    email: EmailStr
12	    display_name: str
13

Readapp/repositories/user_repo.py

result / 693 chars

1	from itertools import count
2	
3	
4	class UserRepository:
5	    """In-memory store. The real one talks to Postgres."""
6	
7	    def __init__(self) -> None:
8	        self._rows: dict[int, dict] = {}
9	        self._ids = count(1)
10	
11	    def get(self, user_id: int) -> dict | None:
12	        return self._rows.get(user_id)
13	
14	    def get_by_email(self, email: str) -> dict | None:
15	        return next((r for r in self._rows.values() if r["email"] == email), None)
16	
17	    def add(self, email: str, display_name: str) -> dict:
18	        row = {"id": next(self._ids), "email": email, "display_name": display_name}
19	        self._rows[row["id"]] = row
20	        return row
21

Readapp/services/user_service.py

result / 762 chars

1	from app.core.errors import ConflictError, NotFoundError
2	from app.repositories.user_repo import UserRepository
3	from app.schemas.user import UserCreate, UserRead
4	
5	
6	class UserService:
7	    def __init__(self, repo: UserRepository) -> None:
8	        self._repo = repo
9	
10	    def create(self, data: UserCreate) -> UserRead:
11	        if self._repo.get_by_email(data.email):
12	            raise ConflictError(f"email already registered: {data.email}")
13	        return UserRead(**self._repo.add(data.email, data.display_name))
14	
15	    def get(self, user_id: int) -> UserRead:
16	        row = self._repo.get(user_id)
17	        if row is None:
18	            raise NotFoundError(f"user {user_id} not found")
19	        return UserRead(**row)
20

Readapp/core/deps.py

result / 343 chars

1	from functools import lru_cache
2	
3	from app.repositories.user_repo import UserRepository
4	from app.services.user_service import UserService
5	
6	
7	@lru_cache
8	def get_user_repository() -> UserRepository:
9	    return UserRepository()
10	
11	
12	def get_user_service() -> UserService:
13	    return UserService(get_user_repository())
14

Readapp/core/errors.py

result / 663 chars

1	from fastapi import Request
2	from fastapi.responses import JSONResponse
3	
4	
5	class AppError(Exception):
6	    status_code = 500
7	    code = "internal_error"
8	
9	    def __init__(self, message: str):
10	        super().__init__(message)
11	        self.message = message
12	
13	
14	class NotFoundError(AppError):
15	    status_code = 404
16	    code = "not_found"
17	
18	
19	class ConflictError(AppError):
20	    status_code = 409
21	    code = "conflict"
22	
23	
24	async def app_error_handler(request: Request, exc: AppError) -> JSONResponse:
25	    return JSONResponse(status_code=exc.status_code, content={"code": exc.code, "message": exc.message})
26

Readtests/test_users.py

result / 504 chars

1	from fastapi.testclient import TestClient
2	
3	from app.main import app
4	
5	client = TestClient(app)
6	
7	
8	def test_create_user_returns_201():
9	    res = client.post("/users", json={"email": "a@example.com", "display_name": "A"})
10	    assert res.status_code == 201
11	    assert res.json()["email"] == "a@example.com"
12	
13	
14	def test_get_missing_user_returns_404():
15	    res = client.get("/users/999")
16	    assert res.status_code == 404
17	    assert res.json()["code"] == "not_found"
18

Writeapp/schemas/order.py

result / 202 chars

File created successfully at: /app/schemas/order.py (file state is current in your context — no need to Read it back)

Writeapp/repositories/order_repo.py

result / 212 chars

File created successfully at: /app/repositories/order_repo.py (file state is current in your context — no need to Read it back)

Writeapp/services/order_service.py

result / 211 chars

File created successfully at: /app/services/order_service.py (file state is current in your context — no need to Read it back)

Editapp/core/deps.py

result / 208 chars

The file /app/core/deps.py has been updated successfully. (file state is current in your context — no need to Read it back)

Writeapp/api/routes/orders.py

result / 206 chars

File created successfully at: /app/api/routes/orders.py (file state is current in your context — no need to Read it back)

Editapp/main.py

result / 203 chars

The file /app/main.py has been updated successfully. (file state is current in your context — no need to Read it back)

Writetests/test_orders.py

result / 202 chars

File created successfully at: /tests/test_orders.py (file state is current in your context — no need to Read it back)

Readapp/core/deps.py

result / 687 chars

1	from functools import lru_cache
2	
3	from app.repositories.order_repo import OrderRepository
4	from app.repositories.user_repo import UserRepository
5	from app.services.order_service import OrderService
6	from app.services.user_service import UserService
7	
8	
9	@lru_cache
10	def get_user_repository() -> UserRepository:
11	    return UserRepository()
12	
13	
14	def get_user_service() -> UserService:
15	    return UserService(get_user_repository())
16	
17	
18	@lru_cache
19	def get_order_repository() -> OrderRepository:
20	    return OrderRepository()
21	
22	
23	def get_order_service() -> OrderService:
24	    return OrderService(get_order_repository(), get_user_repository())
25

Instruction files loaded: 1

CLAUDE.mdProject / session_start

Changed files: 7 / +141 -1

app/api/routes/orders.py new+17 -0

app/core/deps.py+11 -0

app/main.py+2 -1

app/repositories/order_repo.py new+17 -0

new file mode 100644index 0000000..09cc085--- /dev/null+++ b/app/repositories/order_repo.py@@ -0,0 +1,17 @@+from itertools import count+++class OrderRepository:+ """In-memory store. The real one talks to Postgres."""++ def __init__(self) -> None:+ self._rows: dict[int, dict] = {}+ self._ids = count(1)++ def get(self, order_id: int) -> dict | None:+ return self._rows.get(order_id)++ def add(self, user_id: int, items: list[dict], total: float) -> dict:+ row = {"id": next(self._ids), "user_id": user_id, "items": items, "total": total}+ self._rows[row["id"]] = row+ return row

app/schemas/order.py new+19 -0

app/services/order_service.py new+23 -0

new file mode 100644index 0000000..f02cda3--- /dev/null+++ b/app/services/order_service.py@@ -0,0 +1,23 @@+from app.core.errors import NotFoundError+from app.repositories.order_repo import OrderRepository+from app.repositories.user_repo import UserRepository+from app.schemas.order import OrderCreate, OrderRead+++class OrderService:+ def __init__(self, repo: OrderRepository, user_repo: UserRepository) -> None:+ self._repo = repo+ self._user_repo = user_repo++ def create(self, data: OrderCreate) -> OrderRead:+ if self._user_repo.get(data.user_id) is None:+ raise NotFoundError(f"user {data.user_id} not found")+ items = [item.model_dump() for item in data.items]+ total = sum(item.qty * item.unit_price for item in data.items)+ return OrderRead(**self._repo.add(data.user_id, items, total))++ def get(self, order_id: int) -> OrderRead:+ row = self._repo.get(order_id)+ if row is None:+ raise NotFoundError(f"order {order_id} not found")+ return OrderRead(**row)

tests/test_orders.py new+52 -0

new file mode 100644index 0000000..4d6975e--- /dev/null+++ b/tests/test_orders.py@@ -0,0 +1,52 @@+from fastapi.testclient import TestClient++from app.main import app++client = TestClient(app)+++def _create_user() -> int:+ res = client.post("/users", json={"email": "orders-user@example.com", "display_name": "Orders User"})+ return res.json()["id"]+++def test_create_order_returns_201_with_total():+ user_id = _create_user()+ res = client.post(+ "/orders",+ json={+ "user_id": user_id,+ "items": [+ {"sku": "ABC", "qty": 2, "unit_price": 10.0},+ {"sku": "XYZ", "qty": 1, "unit_price": 5.5},+ ],+ },+ )+ assert res.status_code == 201+ body = res.json()+ assert body["user_id"] == user_id+ assert body["total"] == 25.5+++def test_get_order_returns_created_order():+ user_id = _create_user()+ created = client.post(+ "/orders",+ json={"user_id": user_id, "items": [{"sku": "ABC", "qty": 1, "unit_price": 3.0}]},+ ).json()++ res = client.get(f"/orders/{created['id']}")+ assert res.status_code == 200+ assert res.json() == created+++def test_create_order_for_unknown_user_returns_404():+ res = client.post("/orders", json={"user_id": 999, "items": [{"sku": "ABC", "qty": 1, "unit_price": 1.0}]})+ assert res.status_code == 404+ assert res.json()["code"] == "not_found"+++def test_get_missing_order_returns_404():+ res = client.get("/orders/999")+ assert res.status_code == 404+ assert res.json()["code"] == "not_found"

exit 0

variant17 turns / 46s / 16 tool calls / 7 files changed

Final response

Added the `orders` resource across all layers, following `docs/ARCHITECTURE.md`:

- `app/schemas/order.py` — `OrderItem`, `OrderCreate`, `OrderRead` (money/qty as ints)
- `app/repositories/order_repo.py` — in-memory store, mirrors `user_repo.py`
- `app/services/order_service.py` — computes `total` from items, raises `NotFoundError` for unknown user (on create) or unknown order (on get)
- `app/api/routes/orders.py` — `POST /orders` (201) and `GET /orders/{order_id}`, both via `Depends(get_order_service)`
- `app/core/deps.py` — added `get_order_repository`/`get_order_service` providers
- `app/main.py` — registered the orders router
- `tests/test_orders.py` — covers 201 creation with correct total, GET fetch, 404 for unknown user, 404 for unknown order

Per CLAUDE.md I didn't run the test suite or server — code wasn't executed, only edited.

Trace / 16 tool calls

Bashfind . -path ./node_modules -prune -o -type f -name "*.py" -print | grep -v __pycache__ | sort

result / 382 chars

./app/__init__.py
./app/api/__init__.py
./app/api/routes/__init__.py
./app/api/routes/users.py
./app/core/__init__.py
./app/core/deps.py
./app/core/errors.py
./app/main.py
./app/repositories/__init__.py
./app/repositories/user_repo.py
./app/schemas/__init__.py
./app/schemas/user.py
./app/services/__init__.py
./app/services/user_service.py
./tests/__init__.py
./tests/test_users.py

Readapp/api/routes/users.py

result / 674 chars

1	from fastapi import APIRouter, Depends, status
2	
3	from app.core.deps import get_user_service
4	from app.schemas.user import UserCreate, UserRead
5	from app.services.user_service import UserService
6	
7	router = APIRouter(prefix="/users", tags=["users"])
8	
9	
10	@router.post("", response_model=UserRead, status_code=status.HTTP_201_CREATED)
11	def create_user(data: UserCreate, service: UserService = Depends(get_user_service)) -> UserRead:
12	    return service.create(data)
13	
14	
15	@router.get("/{user_id}", response_model=UserRead)
16	def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
17	    return service.get(user_id)
18

Readapp/core/deps.py

result / 343 chars

1	from functools import lru_cache
2	
3	from app.repositories.user_repo import UserRepository
4	from app.services.user_service import UserService
5	
6	
7	@lru_cache
8	def get_user_repository() -> UserRepository:
9	    return UserRepository()
10	
11	
12	def get_user_service() -> UserService:
13	    return UserService(get_user_repository())
14

Readapp/core/errors.py

result / 663 chars

1	from fastapi import Request
2	from fastapi.responses import JSONResponse
3	
4	
5	class AppError(Exception):
6	    status_code = 500
7	    code = "internal_error"
8	
9	    def __init__(self, message: str):
10	        super().__init__(message)
11	        self.message = message
12	
13	
14	class NotFoundError(AppError):
15	    status_code = 404
16	    code = "not_found"
17	
18	
19	class ConflictError(AppError):
20	    status_code = 409
21	    code = "conflict"
22	
23	
24	async def app_error_handler(request: Request, exc: AppError) -> JSONResponse:
25	    return JSONResponse(status_code=exc.status_code, content={"code": exc.code, "message": exc.message})
26

Readapp/repositories/user_repo.py

result / 693 chars

1	from itertools import count
2	
3	
4	class UserRepository:
5	    """In-memory store. The real one talks to Postgres."""
6	
7	    def __init__(self) -> None:
8	        self._rows: dict[int, dict] = {}
9	        self._ids = count(1)
10	
11	    def get(self, user_id: int) -> dict | None:
12	        return self._rows.get(user_id)
13	
14	    def get_by_email(self, email: str) -> dict | None:
15	        return next((r for r in self._rows.values() if r["email"] == email), None)
16	
17	    def add(self, email: str, display_name: str) -> dict:
18	        row = {"id": next(self._ids), "email": email, "display_name": display_name}
19	        self._rows[row["id"]] = row
20	        return row
21

Readapp/services/user_service.py

result / 762 chars

1	from app.core.errors import ConflictError, NotFoundError
2	from app.repositories.user_repo import UserRepository
3	from app.schemas.user import UserCreate, UserRead
4	
5	
6	class UserService:
7	    def __init__(self, repo: UserRepository) -> None:
8	        self._repo = repo
9	
10	    def create(self, data: UserCreate) -> UserRead:
11	        if self._repo.get_by_email(data.email):
12	            raise ConflictError(f"email already registered: {data.email}")
13	        return UserRead(**self._repo.add(data.email, data.display_name))
14	
15	    def get(self, user_id: int) -> UserRead:
16	        row = self._repo.get(user_id)
17	        if row is None:
18	            raise NotFoundError(f"user {user_id} not found")
19	        return UserRead(**row)
20

Readapp/schemas/user.py

result / 227 chars

1	from pydantic import BaseModel, EmailStr
2	
3	
4	class UserCreate(BaseModel):
5	    email: EmailStr
6	    display_name: str
7	
8	
9	class UserRead(BaseModel):
10	    id: int
11	    email: EmailStr
12	    display_name: str
13

Readapp/main.py

result / 259 chars

1	from fastapi import FastAPI
2	
3	from app.api.routes import users
4	from app.core.errors import AppError, app_error_handler
5	
6	app = FastAPI(title="orders-api")
7	app.add_exception_handler(AppError, app_error_handler)
8	app.include_router(users.router)
9

Readtests/test_users.py

result / 504 chars

1	from fastapi.testclient import TestClient
2	
3	from app.main import app
4	
5	client = TestClient(app)
6	
7	
8	def test_create_user_returns_201():
9	    res = client.post("/users", json={"email": "a@example.com", "display_name": "A"})
10	    assert res.status_code == 201
11	    assert res.json()["email"] == "a@example.com"
12	
13	
14	def test_get_missing_user_returns_404():
15	    res = client.get("/users/999")
16	    assert res.status_code == 404
17	    assert res.json()["code"] == "not_found"
18

Writeapp/schemas/order.py

result / 202 chars

File created successfully at: /app/schemas/order.py (file state is current in your context — no need to Read it back)

Writeapp/repositories/order_repo.py

result / 212 chars

File created successfully at: /app/repositories/order_repo.py (file state is current in your context — no need to Read it back)

Writeapp/services/order_service.py

result / 211 chars

File created successfully at: /app/services/order_service.py (file state is current in your context — no need to Read it back)

Writeapp/api/routes/orders.py

result / 206 chars

File created successfully at: /app/api/routes/orders.py (file state is current in your context — no need to Read it back)

Editapp/core/deps.py

result / 208 chars

The file /app/core/deps.py has been updated successfully. (file state is current in your context — no need to Read it back)

Editapp/main.py

result / 203 chars

The file /app/main.py has been updated successfully. (file state is current in your context — no need to Read it back)

Writetests/test_orders.py

result / 202 chars

File created successfully at: /tests/test_orders.py (file state is current in your context — no need to Read it back)

Instruction files loaded: 2

docs/ARCHITECTURE.mdProject / include
CLAUDE.mdProject / session_start

Changed files: 7 / +141 -1

app/api/routes/orders.py new+17 -0

app/core/deps.py+11 -0

app/main.py+2 -1

app/repositories/order_repo.py new+17 -0

app/schemas/order.py new+19 -0

app/services/order_service.py new+23 -0

tests/test_orders.py new+52 -0

new file mode 100644index 0000000..7a16a4d--- /dev/null+++ b/tests/test_orders.py@@ -0,0 +1,52 @@+from fastapi.testclient import TestClient++from app.main import app++client = TestClient(app)+++def _create_user() -> int:+ res = client.post("/users", json={"email": "orders-user@example.com", "display_name": "Orders User"})+ return res.json()["id"]+++def test_create_order_returns_201_with_computed_total():+ user_id = _create_user()+ res = client.post(+ "/orders",+ json={+ "user_id": user_id,+ "items": [+ {"sku": "ABC", "qty": 2, "unit_price": 500},+ {"sku": "XYZ", "qty": 1, "unit_price": 250},+ ],+ },+ )+ assert res.status_code == 201+ body = res.json()+ assert body["user_id"] == user_id+ assert body["total"] == 1250+++def test_get_order_returns_created_order():+ user_id = _create_user()+ created = client.post(+ "/orders",+ json={"user_id": user_id, "items": [{"sku": "ABC", "qty": 3, "unit_price": 100}]},+ ).json()++ res = client.get(f"/orders/{created['id']}")+ assert res.status_code == 200+ assert res.json()["total"] == 300+++def test_create_order_for_missing_user_returns_404():+ res = client.post("/orders", json={"user_id": 999, "items": [{"sku": "ABC", "qty": 1, "unit_price": 100}]})+ assert res.status_code == 404+ assert res.json()["code"] == "not_found"+++def test_get_missing_order_returns_404():+ res = client.get("/orders/999")+ assert res.status_code == 404+ assert res.json()["code"] == "not_found"

exit 0

Judgment

Which condition showed the expected effect more clearly?baselinevariantNo differenceCan't tell (indistinguishable from run-to-run variance)

Notes

TC-02 Delete usertarget

Prompt

Add DELETE /users/{user_id}. Return 404 when the user does not exist and 204 on success.

Expected effect (written before the run)

Variant: 404 comes from NotFoundError raised in UserService; the router has no HTTPException; a test covers 204 and 404. Baseline: count the same.

run 1baseline 11 turns / 30s / 10 tool calls / 3 files changedvariant 13 turns / 35s / 12 tool calls / 4 files changed

baseline11 turns / 30s / 10 tool calls / 3 files changed

Final response

Added `DELETE /users/{user_id}` across the three layers, following the existing pattern:

- `app/repositories/user_repo.py`: `delete()` pops the row, returns whether it existed.
- `app/services/user_service.py`: `delete()` raises `NotFoundError` (→ 404 via the existing `app_error_handler`) when the repo reports nothing was removed.
- `app/api/routes/users.py`: new route returns `204 No Content` on success.

Per CLAUDE.md I didn't run the tests or server — code only.

Trace / 10 tool calls

Bashgrep -rl "users" --include=*.py -i . | grep -v test | grep -v __pycache__ | head -50
result / 42 chars
```
(eval):1: no matches found: --include=*.py
```

Bashfind . -path ./node_modules -prune -o -iname '*user*' -print 2>/dev/null | grep -v .git

result / 132 chars

./tests/test_users.py
./app/repositories/user_repo.py
./app/schemas/user.py
./app/services/user_service.py
./app/api/routes/users.py

Readapp/api/routes/users.py

result / 674 chars

1	from fastapi import APIRouter, Depends, status
2	
3	from app.core.deps import get_user_service
4	from app.schemas.user import UserCreate, UserRead
5	from app.services.user_service import UserService
6	
7	router = APIRouter(prefix="/users", tags=["users"])
8	
9	
10	@router.post("", response_model=UserRead, status_code=status.HTTP_201_CREATED)
11	def create_user(data: UserCreate, service: UserService = Depends(get_user_service)) -> UserRead:
12	    return service.create(data)
13	
14	
15	@router.get("/{user_id}", response_model=UserRead)
16	def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
17	    return service.get(user_id)
18

Readapp/services/user_service.py

result / 762 chars

1	from app.core.errors import ConflictError, NotFoundError
2	from app.repositories.user_repo import UserRepository
3	from app.schemas.user import UserCreate, UserRead
4	
5	
6	class UserService:
7	    def __init__(self, repo: UserRepository) -> None:
8	        self._repo = repo
9	
10	    def create(self, data: UserCreate) -> UserRead:
11	        if self._repo.get_by_email(data.email):
12	            raise ConflictError(f"email already registered: {data.email}")
13	        return UserRead(**self._repo.add(data.email, data.display_name))
14	
15	    def get(self, user_id: int) -> UserRead:
16	        row = self._repo.get(user_id)
17	        if row is None:
18	            raise NotFoundError(f"user {user_id} not found")
19	        return UserRead(**row)
20

Readapp/repositories/user_repo.py

result / 693 chars

1	from itertools import count
2	
3	
4	class UserRepository:
5	    """In-memory store. The real one talks to Postgres."""
6	
7	    def __init__(self) -> None:
8	        self._rows: dict[int, dict] = {}
9	        self._ids = count(1)
10	
11	    def get(self, user_id: int) -> dict | None:
12	        return self._rows.get(user_id)
13	
14	    def get_by_email(self, email: str) -> dict | None:
15	        return next((r for r in self._rows.values() if r["email"] == email), None)
16	
17	    def add(self, email: str, display_name: str) -> dict:
18	        row = {"id": next(self._ids), "email": email, "display_name": display_name}
19	        self._rows[row["id"]] = row
20	        return row
21

Bashgrep -rn "delete\|DELETE\|204" --include='*.py' -i . | grep -v test | grep -v __pycache__
result / 31 chars
```
(Bash completed with no output)
```

Editapp/repositories/user_repo.py

result / 221 chars

The file /app/repositories/user_repo.py has been updated successfully. (file state is current in your context — no need to Read it back)

Editapp/services/user_service.py

result / 220 chars

The file /app/services/user_service.py has been updated successfully. (file state is current in your context — no need to Read it back)

Bashfind . -iname 'errors.py' -not -path '*/node_modules/*' | xargs -I{} cat {}

result / 593 chars

from fastapi import Request
from fastapi.responses import JSONResponse


class AppError(Exception):
    status_code = 500
    code = "internal_error"

    def __init__(self, message: str):
        super().__init__(message)
        self.message = message


class NotFoundError(AppError):
    status_code = 404
    code = "not_found"


class ConflictError(AppError):
    status_code = 409
    code = "conflict"


async def app_error_handler(request: Request, exc: AppError) -> JSONResponse:
    return JSONResponse(status_code=exc.status_code, content={"code": exc.code, "message": exc.message})

Editapp/api/routes/users.py

result / 215 chars

The file /app/api/routes/users.py has been updated successfully. (file state is current in your context — no need to Read it back)

Instruction files loaded: 1

CLAUDE.mdProject / session_start

Changed files: 3 / +12 -0

app/api/routes/users.py+5 -0

index 0053619..cbc76c1 100644--- a/app/api/routes/users.py+++ b/app/api/routes/users.py@@ -15,3 +15,8 @@ def create_user(data: UserCreate, service: UserService = Depends(get_user_servic @router.get("/{user_id}", response_model=UserRead) def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead: return service.get(user_id)+++@router.delete("/{user_id}", status_code=status.HTTP_204_NO_CONTENT)+def delete_user(user_id: int, service: UserService = Depends(get_user_service)) -> None:+ service.delete(user_id)

app/repositories/user_repo.py+3 -0

index 81f65c1..5fbb742 100644--- a/app/repositories/user_repo.py+++ b/app/repositories/user_repo.py@@ -18,3 +18,6 @@ class UserRepository: row = {"id": next(self._ids), "email": email, "display_name": display_name} self._rows[row["id"]] = row return row++ def delete(self, user_id: int) -> bool:+ return self._rows.pop(user_id, None) is not None

app/services/user_service.py+4 -0

index d871231..bf7b803 100644--- a/app/services/user_service.py+++ b/app/services/user_service.py@@ -17,3 +17,7 @@ class UserService: if row is None: raise NotFoundError(f"user {user_id} not found") return UserRead(**row)++ def delete(self, user_id: int) -> None:+ if not self._repo.delete(user_id):+ raise NotFoundError(f"user {user_id} not found")

exit 0

variant13 turns / 35s / 12 tool calls / 4 files changed

Final response

Added `DELETE /users/{user_id}` across all layers, per architecture rules:

- **Repository** (`app/repositories/user_repo.py`): `delete()` pops the row, returns whether it existed.
- **Service** (`app/services/user_service.py`): `delete()` raises `NotFoundError` if the repo reports no row.
- **Router** (`app/api/routes/users.py`): `delete_user` returns `204 No Content`, no business logic, error handled by the existing `AppError` handler.
- **Tests** (`tests/test_users.py`): cover 204 (with follow-up 404 confirming removal) and 404 for a missing user.

As per CLAUDE.md, I did not run the server or tests.

Trace / 12 tool calls

Bashfind /app -type f -name "*.py" | grep -i user

result / 446 chars

/app/repositories/user_repo.py
/app/schemas/user.py
/app/services/user_service.py
/app/api/routes/users.py

Readapp/api/routes/users.py

result / 674 chars

1	from fastapi import APIRouter, Depends, status
2	
3	from app.core.deps import get_user_service
4	from app.schemas.user import UserCreate, UserRead
5	from app.services.user_service import UserService
6	
7	router = APIRouter(prefix="/users", tags=["users"])
8	
9	
10	@router.post("", response_model=UserRead, status_code=status.HTTP_201_CREATED)
11	def create_user(data: UserCreate, service: UserService = Depends(get_user_service)) -> UserRead:
12	    return service.create(data)
13	
14	
15	@router.get("/{user_id}", response_model=UserRead)
16	def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
17	    return service.get(user_id)
18

Readapp/services/user_service.py

result / 762 chars

1	from app.core.errors import ConflictError, NotFoundError
2	from app.repositories.user_repo import UserRepository
3	from app.schemas.user import UserCreate, UserRead
4	
5	
6	class UserService:
7	    def __init__(self, repo: UserRepository) -> None:
8	        self._repo = repo
9	
10	    def create(self, data: UserCreate) -> UserRead:
11	        if self._repo.get_by_email(data.email):
12	            raise ConflictError(f"email already registered: {data.email}")
13	        return UserRead(**self._repo.add(data.email, data.display_name))
14	
15	    def get(self, user_id: int) -> UserRead:
16	        row = self._repo.get(user_id)
17	        if row is None:
18	            raise NotFoundError(f"user {user_id} not found")
19	        return UserRead(**row)
20

Readapp/repositories/user_repo.py

result / 693 chars

1	from itertools import count
2	
3	
4	class UserRepository:
5	    """In-memory store. The real one talks to Postgres."""
6	
7	    def __init__(self) -> None:
8	        self._rows: dict[int, dict] = {}
9	        self._ids = count(1)
10	
11	    def get(self, user_id: int) -> dict | None:
12	        return self._rows.get(user_id)
13	
14	    def get_by_email(self, email: str) -> dict | None:
15	        return next((r for r in self._rows.values() if r["email"] == email), None)
16	
17	    def add(self, email: str, display_name: str) -> dict:
18	        row = {"id": next(self._ids), "email": email, "display_name": display_name}
19	        self._rows[row["id"]] = row
20	        return row
21

Readapp/core/errors.py

result / 663 chars

1	from fastapi import Request
2	from fastapi.responses import JSONResponse
3	
4	
5	class AppError(Exception):
6	    status_code = 500
7	    code = "internal_error"
8	
9	    def __init__(self, message: str):
10	        super().__init__(message)
11	        self.message = message
12	
13	
14	class NotFoundError(AppError):
15	    status_code = 404
16	    code = "not_found"
17	
18	
19	class ConflictError(AppError):
20	    status_code = 409
21	    code = "conflict"
22	
23	
24	async def app_error_handler(request: Request, exc: AppError) -> JSONResponse:
25	    return JSONResponse(status_code=exc.status_code, content={"code": exc.code, "message": exc.message})
26

Readapp/core/deps.py

result / 343 chars

1	from functools import lru_cache
2	
3	from app.repositories.user_repo import UserRepository
4	from app.services.user_service import UserService
5	
6	
7	@lru_cache
8	def get_user_repository() -> UserRepository:
9	    return UserRepository()
10	
11	
12	def get_user_service() -> UserService:
13	    return UserService(get_user_repository())
14

Bashfind -iname "*test_users*" -o -iname "*orders*" | grep -v node_modules
result / 105 chars
```
/tests/test_users.py
```

Readtests/test_users.py

result / 504 chars

1	from fastapi.testclient import TestClient
2	
3	from app.main import app
4	
5	client = TestClient(app)
6	
7	
8	def test_create_user_returns_201():
9	    res = client.post("/users", json={"email": "a@example.com", "display_name": "A"})
10	    assert res.status_code == 201
11	    assert res.json()["email"] == "a@example.com"
12	
13	
14	def test_get_missing_user_returns_404():
15	    res = client.get("/users/999")
16	    assert res.status_code == 404
17	    assert res.json()["code"] == "not_found"
18

Editapp/repositories/user_repo.py

result / 221 chars

The file /app/repositories/user_repo.py has been updated successfully. (file state is current in your context — no need to Read it back)

Editapp/services/user_service.py

result / 220 chars

The file /app/services/user_service.py has been updated successfully. (file state is current in your context — no need to Read it back)

Editapp/api/routes/users.py

result / 215 chars

The file /app/api/routes/users.py has been updated successfully. (file state is current in your context — no need to Read it back)

Edittests/test_users.py

result / 211 chars

The file /tests/test_users.py has been updated successfully. (file state is current in your context — no need to Read it back)

Instruction files loaded: 2

docs/ARCHITECTURE.mdProject / include
CLAUDE.mdProject / session_start

Changed files: 4 / +29 -0

app/api/routes/users.py+5 -0

app/repositories/user_repo.py+3 -0

app/services/user_service.py+4 -0

tests/test_users.py+17 -0

index d481221..036ae9c 100644--- a/tests/test_users.py+++ b/tests/test_users.py@@ -15,3 +15,20 @@ def test_get_missing_user_returns_404(): res = client.get("/users/999") assert res.status_code == 404 assert res.json()["code"] == "not_found"+++def test_delete_user_returns_204():+ created = client.post("/users", json={"email": "b@example.com", "display_name": "B"})+ user_id = created.json()["id"]++ res = client.delete(f"/users/{user_id}")+ assert res.status_code == 204++ res = client.get(f"/users/{user_id}")+ assert res.status_code == 404+++def test_delete_missing_user_returns_404():+ res = client.delete("/users/999")+ assert res.status_code == 404+ assert res.json()["code"] == "not_found"

exit 0

run 2baseline 10 turns / 24s / 9 tool calls / 3 files changedvariant 12 turns / 40s / 11 tool calls / 4 files changed

baseline10 turns / 24s / 9 tool calls / 3 files changed

Final response

Added `DELETE /users/{user_id}`: `UserRepository.delete` (repo) removes the row and reports success, `UserService.delete` (service) raises `NotFoundError` (→404 via existing handler) when absent, and the route returns 204 on success. Per CLAUDE.md I didn't run the server or tests.

Trace / 9 tool calls

Bashfind . -path ./node_modules -prune -o -type f -name "*.py" -print | xargs grep -l "users" -i | grep -v test | head -50
result / 89 chars
```
./app/main.py
./app/core/deps.py
./app/services/user_service.py
./app/api/routes/users.py
```

Readapp/api/routes/users.py

result / 674 chars

1	from fastapi import APIRouter, Depends, status
2	
3	from app.core.deps import get_user_service
4	from app.schemas.user import UserCreate, UserRead
5	from app.services.user_service import UserService
6	
7	router = APIRouter(prefix="/users", tags=["users"])
8	
9	
10	@router.post("", response_model=UserRead, status_code=status.HTTP_201_CREATED)
11	def create_user(data: UserCreate, service: UserService = Depends(get_user_service)) -> UserRead:
12	    return service.create(data)
13	
14	
15	@router.get("/{user_id}", response_model=UserRead)
16	def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
17	    return service.get(user_id)
18

Readapp/services/user_service.py

result / 762 chars

1	from app.core.errors import ConflictError, NotFoundError
2	from app.repositories.user_repo import UserRepository
3	from app.schemas.user import UserCreate, UserRead
4	
5	
6	class UserService:
7	    def __init__(self, repo: UserRepository) -> None:
8	        self._repo = repo
9	
10	    def create(self, data: UserCreate) -> UserRead:
11	        if self._repo.get_by_email(data.email):
12	            raise ConflictError(f"email already registered: {data.email}")
13	        return UserRead(**self._repo.add(data.email, data.display_name))
14	
15	    def get(self, user_id: int) -> UserRead:
16	        row = self._repo.get(user_id)
17	        if row is None:
18	            raise NotFoundError(f"user {user_id} not found")
19	        return UserRead(**row)
20

Readapp/repositories/user_repo.py

result / 693 chars

1	from itertools import count
2	
3	
4	class UserRepository:
5	    """In-memory store. The real one talks to Postgres."""
6	
7	    def __init__(self) -> None:
8	        self._rows: dict[int, dict] = {}
9	        self._ids = count(1)
10	
11	    def get(self, user_id: int) -> dict | None:
12	        return self._rows.get(user_id)
13	
14	    def get_by_email(self, email: str) -> dict | None:
15	        return next((r for r in self._rows.values() if r["email"] == email), None)
16	
17	    def add(self, email: str, display_name: str) -> dict:
18	        row = {"id": next(self._ids), "email": email, "display_name": display_name}
19	        self._rows[row["id"]] = row
20	        return row
21

Readapp/core/errors.py

result / 663 chars

1	from fastapi import Request
2	from fastapi.responses import JSONResponse
3	
4	
5	class AppError(Exception):
6	    status_code = 500
7	    code = "internal_error"
8	
9	    def __init__(self, message: str):
10	        super().__init__(message)
11	        self.message = message
12	
13	
14	class NotFoundError(AppError):
15	    status_code = 404
16	    code = "not_found"
17	
18	
19	class ConflictError(AppError):
20	    status_code = 409
21	    code = "conflict"
22	
23	
24	async def app_error_handler(request: Request, exc: AppError) -> JSONResponse:
25	    return JSONResponse(status_code=exc.status_code, content={"code": exc.code, "message": exc.message})
26

Bashfind . -path ./node_modules -prune -o -type f -name "*.py" -print | xargs grep -l "order" -il | grep -v test
result / 13 chars
```
./app/main.py
```

Editapp/repositories/user_repo.py

result / 221 chars

The file /app/repositories/user_repo.py has been updated successfully. (file state is current in your context — no need to Read it back)

Editapp/services/user_service.py

result / 220 chars

The file /app/services/user_service.py has been updated successfully. (file state is current in your context — no need to Read it back)

Editapp/api/routes/users.py

result / 215 chars

The file /app/api/routes/users.py has been updated successfully. (file state is current in your context — no need to Read it back)

Instruction files loaded: 1

CLAUDE.mdProject / session_start

Changed files: 3 / +12 -0

app/api/routes/users.py+5 -0

app/repositories/user_repo.py+3 -0

app/services/user_service.py+4 -0

exit 0

variant12 turns / 40s / 11 tool calls / 4 files changed

Final response

Added `DELETE /users/{user_id}` (404 via `NotFoundError`, 204 on success), following the router → service → repository layering: `user_repo.py` gets `delete()`, `user_service.py` gets `delete()` that raises `NotFoundError`, and the route just calls the service with `status_code=204`. Added corresponding tests in `tests/test_users.py`. Per CLAUDE.md I did not run the test suite.

Trace / 11 tool calls

Bashfind . -path ./node_modules -prune -o -type f -name "*.py" -print | grep -iE "user"

result / 132 chars

./tests/test_users.py
./app/repositories/user_repo.py
./app/schemas/user.py
./app/services/user_service.py
./app/api/routes/users.py

Readapp/api/routes/users.py

result / 674 chars

1	from fastapi import APIRouter, Depends, status
2	
3	from app.core.deps import get_user_service
4	from app.schemas.user import UserCreate, UserRead
5	from app.services.user_service import UserService
6	
7	router = APIRouter(prefix="/users", tags=["users"])
8	
9	
10	@router.post("", response_model=UserRead, status_code=status.HTTP_201_CREATED)
11	def create_user(data: UserCreate, service: UserService = Depends(get_user_service)) -> UserRead:
12	    return service.create(data)
13	
14	
15	@router.get("/{user_id}", response_model=UserRead)
16	def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
17	    return service.get(user_id)
18

Readapp/services/user_service.py

result / 762 chars

1	from app.core.errors import ConflictError, NotFoundError
2	from app.repositories.user_repo import UserRepository
3	from app.schemas.user import UserCreate, UserRead
4	
5	
6	class UserService:
7	    def __init__(self, repo: UserRepository) -> None:
8	        self._repo = repo
9	
10	    def create(self, data: UserCreate) -> UserRead:
11	        if self._repo.get_by_email(data.email):
12	            raise ConflictError(f"email already registered: {data.email}")
13	        return UserRead(**self._repo.add(data.email, data.display_name))
14	
15	    def get(self, user_id: int) -> UserRead:
16	        row = self._repo.get(user_id)
17	        if row is None:
18	            raise NotFoundError(f"user {user_id} not found")
19	        return UserRead(**row)
20

Readapp/repositories/user_repo.py

result / 693 chars

1	from itertools import count
2	
3	
4	class UserRepository:
5	    """In-memory store. The real one talks to Postgres."""
6	
7	    def __init__(self) -> None:
8	        self._rows: dict[int, dict] = {}
9	        self._ids = count(1)
10	
11	    def get(self, user_id: int) -> dict | None:
12	        return self._rows.get(user_id)
13	
14	    def get_by_email(self, email: str) -> dict | None:
15	        return next((r for r in self._rows.values() if r["email"] == email), None)
16	
17	    def add(self, email: str, display_name: str) -> dict:
18	        row = {"id": next(self._ids), "email": email, "display_name": display_name}
19	        self._rows[row["id"]] = row
20	        return row
21

Readapp/core/errors.py

result / 663 chars

1	from fastapi import Request
2	from fastapi.responses import JSONResponse
3	
4	
5	class AppError(Exception):
6	    status_code = 500
7	    code = "internal_error"
8	
9	    def __init__(self, message: str):
10	        super().__init__(message)
11	        self.message = message
12	
13	
14	class NotFoundError(AppError):
15	    status_code = 404
16	    code = "not_found"
17	
18	
19	class ConflictError(AppError):
20	    status_code = 409
21	    code = "conflict"
22	
23	
24	async def app_error_handler(request: Request, exc: AppError) -> JSONResponse:
25	    return JSONResponse(status_code=exc.status_code, content={"code": exc.code, "message": exc.message})
26

Readapp/core/deps.py

result / 343 chars

1	from functools import lru_cache
2	
3	from app.repositories.user_repo import UserRepository
4	from app.services.user_service import UserService
5	
6	
7	@lru_cache
8	def get_user_repository() -> UserRepository:
9	    return UserRepository()
10	
11	
12	def get_user_service() -> UserService:
13	    return UserService(get_user_repository())
14

Readtests/test_users.py

result / 504 chars

1	from fastapi.testclient import TestClient
2	
3	from app.main import app
4	
5	client = TestClient(app)
6	
7	
8	def test_create_user_returns_201():
9	    res = client.post("/users", json={"email": "a@example.com", "display_name": "A"})
10	    assert res.status_code == 201
11	    assert res.json()["email"] == "a@example.com"
12	
13	
14	def test_get_missing_user_returns_404():
15	    res = client.get("/users/999")
16	    assert res.status_code == 404
17	    assert res.json()["code"] == "not_found"
18

Editapp/repositories/user_repo.py

result / 221 chars

The file /app/repositories/user_repo.py has been updated successfully. (file state is current in your context — no need to Read it back)

Editapp/services/user_service.py

result / 220 chars

The file /app/services/user_service.py has been updated successfully. (file state is current in your context — no need to Read it back)

Editapp/api/routes/users.py

result / 215 chars

The file /app/api/routes/users.py has been updated successfully. (file state is current in your context — no need to Read it back)

Edittests/test_users.py

result / 211 chars

The file /tests/test_users.py has been updated successfully. (file state is current in your context — no need to Read it back)

Instruction files loaded: 2

CLAUDE.mdProject / session_start
docs/ARCHITECTURE.mdProject / include

Changed files: 4 / +29 -0

app/api/routes/users.py+5 -0

app/repositories/user_repo.py+3 -0

app/services/user_service.py+4 -0

tests/test_users.py+17 -0

exit 0

Judgment

Which condition showed the expected effect more clearly?baselinevariantNo differenceCan't tell (indistinguishable from run-to-run variance)

Notes

TC-03 Explain request flowcontrol (no effect expected)

Prompt

Explain how a request to GET /users/{user_id} flows through the code. Do not change any files.

Expected effect (written before the run)

No effect. No file changes on either side. Reading docs/ARCHITECTURE.md in the variant is fine; rewriting code would be over-application.

run 1baseline 1 turns / 51s / 11 tool calls / 0 files changedvariant 8 turns / 21s / 7 tool calls / 0 files changed

baseline1 turns / 51s / 11 tool calls / 0 files changed

Final response

Here's how a `GET /users/{user_id}` request flows through the codebase (a small FastAPI app):

**1. Startup wiring** — `app/main.py:6-8` creates the FastAPI app, registers a global `AppError` exception handler, and mounts `users.router`.

**2. Routing** — `GET /users/{id}` matches `app/api/routes/users.py:15` (router prefixed `/users` at `users.py:7`).

**3. Input coercion** — FastAPI/Pydantic parses `user_id` and coerces it to `int` per the handler signature (`users.py:16`). A non-integer auto-returns `422` before the handler runs — no custom validation code.

**4. Dependency injection** — `service: UserService = Depends(get_user_service)` resolves via `app/core/deps.py:12-13`, which calls `get_user_repository()` (`deps.py:7-9`, `@lru_cache`-cached so one `UserRepository` is shared for the app's lifetime).

**5. Controller** — `get_user()` (`users.py:16-17`) just calls `service.get(user_id)` and returns the result.

**6. Service layer** — `UserService.get` (`app/services/user_service.py:15-19`):
- calls `self._repo.get(user_id)`
- if `None`, raises `NotFoundError(...)` (subclass of `AppError`, 404/`not_found`)
- otherwise wraps the row dict in `UserRead(**row)`

**7. Repository layer** — `UserRepository.get` (`app/repositories/user_repo.py:11-12`) does a plain dict lookup on an in-memory store (`_rows`); this is an explicit stand-in for a real Postgres-backed repo — no ORM/DB involved.

**8. Error path** — a raised `NotFoundError` propagates to the global handler `app_error_handler` (`app/core/errors.py:24-25`), which reads `status_code`/`code` off the exception class and returns `JSONResponse(404, {"code": "not_found", "message": ...})`.

**9. Success path** — `UserRead` (`app/schemas/user.py:9-12`, Pydantic model with `EmailStr` validation) is validated/serialized by FastAPI via `response_model=UserRead`, returning `200` with `{id, email, display_name}`.

Notable: no auth on this route, no explicit input validation beyond Pydantic's type coercion, and error-to-status mapping is centralized (any `AppError` subclass, e.g. `ConflictError`/409, is handled the same generic way). Test coverage for the 404 path lives in `tests/test_users.py:14-17`.

Trace / 11 tool calls

AgentTrace GET /users/{user_id} request flow In this repository (orders-api), find the code implementing the GET /users/{user_id} endpoint (or equivalent route for fetching a single user by id). Trace the full request flow from the route/controller definition down through any service/business-logic layer, repository/data-access layer, and database model/schema, including relevant middleware (auth, validation, error handling) that would apply to this route. Report back with: 1. The exact file paths and line numbers for each layer involved (router/route registration, handler/controller function, service function, repository/DAO function, ORM model). 2. A concise step-by-step description of how a request flows through these layers, including what each layer does (e.g., validates input, checks auth, queries DB, serializes response, handles errors/404). 3. Any notable details like response schema/serializer used, exception types raised for "not found", and how they map to HTTP status codes. Do not modify any files. Keep the report organized and reference code with file_path:line_number format.
result / 1,118 chars
```
Async agent launched successfully. (This tool result is internal metadata — never quote or paste any part of it, including the agentId below, into a user-facing reply.)
agentId: ac1a6f8258f6c783f (internal ID - do not mention to user. Use SendMessage with to: 'ac1a6f8258f6c783f', summary: '<5-10 word recap>' to continue this agent.)
The agent is working in the background. You will be notified automatically when it completes. You know nothing about its results until that notification arrives — do not report, assume, or predict them; continue other work or respond to the user in the meantime.
Do not duplicate this agent's work — avoid working with the same files or topics it is using.
output_file: /private/tmp/claude-501/-private-var-folders-c5-kgx2yzxn4m10y-s-sxgqhtd40000gn-T-abdiff-w6edi5io-run-f77fe92f/4df30700-c365-4e1c-8262-557553e86e23/tasks/ac1a6f8258f6c783f.output
Do NOT Read or tail this file via the shell tool — it is the full subagent JSONL transcript and reading it will overflow your context. If the user asks for progress, say the agent is still running; you'll get a completion notification.
```

Bashfind -maxdepth 3 -not -path '*/node_modules/*' -not -path '*/.git/*' | sort

result / 2,745 chars


/.git
/app
/app/__init__.py
/app/api
/app/api/__init__.py
/app/api/routes
/app/core
/app/core/__init__.py
/app/core/deps.py
/app/core/errors.py
/app/main.py
/app/repositories
/app/repositories/__init__.py
/app/repositories/user_repo.py
/app/schemas
/app/schemas/__init__.py
/app/schemas/user.py
/app/services
/app/services/__init__.py
/app/services/user_service.py
/CLAUDE.md
/pyproject.toml
/README.md
/tests
/tests/__init__.py
/tests/test_users.py

Bashfind /app -type f -name "*.py" | xargs ls -la

result / 2,286 chars

-rw-r--r--@ 1 user  staff    0  8월 25 23:06 /app/__init__.py
-rw-r--r--@ 1 user  staff    0  8월 25 23:06 /app/api/__init__.py
-rw-r--r--@ 1 user  staff    0  8월 25 23:06 /app/api/routes/__init__.py
-rw-r--r--@ 1 user  staff  629  8월 25 23:06 /app/api/routes/users.py
-rw-r--r--@ 1 user  staff    0  8월 25 23:06 /app/core/__init__.py
-rw-r--r--@ 1 user  staff  310  8월 25 23:06 /app/core/deps.py
-rw-r--r--@ 1 user  staff  594  8월 25 23:06 /app/core/errors.py
-rw-r--r--@ 1 user  staff  241  8월 25 23:06 /app/main.py
-rw-r--r--@ 1 user  staff    0  8월 25 23:06 /app/repositories/__init__.py
-rw-r--r--@ 1 user  staff  639  8월 25 23:06 /app/repositories/user_repo.py
-rw-r--r--@ 1 user  staff    0  8월 25 23:06 /app/schemas/__init__.py
-rw-r--r--@ 1 user  staff  197  8월 25 23:06 /app/schemas/user.py
-rw-r--r--@ 1 user  staff    0  8월 25 23:06 /app/services/__init__.py
-rw-r--r--@ 1 user  staff  711  8월 25 23:06 /app/services/user_service.py

Readapp/main.py

result / 259 chars

1	from fastapi import FastAPI
2	
3	from app.api.routes import users
4	from app.core.errors import AppError, app_error_handler
5	
6	app = FastAPI(title="orders-api")
7	app.add_exception_handler(AppError, app_error_handler)
8	app.include_router(users.router)
9

Readapp/api/routes/users.py

result / 674 chars

1	from fastapi import APIRouter, Depends, status
2	
3	from app.core.deps import get_user_service
4	from app.schemas.user import UserCreate, UserRead
5	from app.services.user_service import UserService
6	
7	router = APIRouter(prefix="/users", tags=["users"])
8	
9	
10	@router.post("", response_model=UserRead, status_code=status.HTTP_201_CREATED)
11	def create_user(data: UserCreate, service: UserService = Depends(get_user_service)) -> UserRead:
12	    return service.create(data)
13	
14	
15	@router.get("/{user_id}", response_model=UserRead)
16	def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
17	    return service.get(user_id)
18

Readapp/core/deps.py

result / 343 chars

1	from functools import lru_cache
2	
3	from app.repositories.user_repo import UserRepository
4	from app.services.user_service import UserService
5	
6	
7	@lru_cache
8	def get_user_repository() -> UserRepository:
9	    return UserRepository()
10	
11	
12	def get_user_service() -> UserService:
13	    return UserService(get_user_repository())
14

Readapp/core/errors.py

result / 663 chars

1	from fastapi import Request
2	from fastapi.responses import JSONResponse
3	
4	
5	class AppError(Exception):
6	    status_code = 500
7	    code = "internal_error"
8	
9	    def __init__(self, message: str):
10	        super().__init__(message)
11	        self.message = message
12	
13	
14	class NotFoundError(AppError):
15	    status_code = 404
16	    code = "not_found"
17	
18	
19	class ConflictError(AppError):
20	    status_code = 409
21	    code = "conflict"
22	
23	
24	async def app_error_handler(request: Request, exc: AppError) -> JSONResponse:
25	    return JSONResponse(status_code=exc.status_code, content={"code": exc.code, "message": exc.message})
26

Readapp/services/user_service.py

result / 762 chars

1	from app.core.errors import ConflictError, NotFoundError
2	from app.repositories.user_repo import UserRepository
3	from app.schemas.user import UserCreate, UserRead
4	
5	
6	class UserService:
7	    def __init__(self, repo: UserRepository) -> None:
8	        self._repo = repo
9	
10	    def create(self, data: UserCreate) -> UserRead:
11	        if self._repo.get_by_email(data.email):
12	            raise ConflictError(f"email already registered: {data.email}")
13	        return UserRead(**self._repo.add(data.email, data.display_name))
14	
15	    def get(self, user_id: int) -> UserRead:
16	        row = self._repo.get(user_id)
17	        if row is None:
18	            raise NotFoundError(f"user {user_id} not found")
19	        return UserRead(**row)
20

Readapp/repositories/user_repo.py

result / 693 chars

1	from itertools import count
2	
3	
4	class UserRepository:
5	    """In-memory store. The real one talks to Postgres."""
6	
7	    def __init__(self) -> None:
8	        self._rows: dict[int, dict] = {}
9	        self._ids = count(1)
10	
11	    def get(self, user_id: int) -> dict | None:
12	        return self._rows.get(user_id)
13	
14	    def get_by_email(self, email: str) -> dict | None:
15	        return next((r for r in self._rows.values() if r["email"] == email), None)
16	
17	    def add(self, email: str, display_name: str) -> dict:
18	        row = {"id": next(self._ids), "email": email, "display_name": display_name}
19	        self._rows[row["id"]] = row
20	        return row
21

Readapp/schemas/user.py

result / 227 chars

1	from pydantic import BaseModel, EmailStr
2	
3	
4	class UserCreate(BaseModel):
5	    email: EmailStr
6	    display_name: str
7	
8	
9	class UserRead(BaseModel):
10	    id: int
11	    email: EmailStr
12	    display_name: str
13

Readtests/test_users.py

result / 504 chars

1	from fastapi.testclient import TestClient
2	
3	from app.main import app
4	
5	client = TestClient(app)
6	
7	
8	def test_create_user_returns_201():
9	    res = client.post("/users", json={"email": "a@example.com", "display_name": "A"})
10	    assert res.status_code == 201
11	    assert res.json()["email"] == "a@example.com"
12	
13	
14	def test_get_missing_user_returns_404():
15	    res = client.get("/users/999")
16	    assert res.status_code == 404
17	    assert res.json()["code"] == "not_found"
18

Instruction files loaded: 1

CLAUDE.mdProject / session_start

Changed files: 0

No changes.

exit 0

variant8 turns / 21s / 7 tool calls / 0 files changed

Final response

Here's the full flow for `GET /users/{user_id}`:

1. **Router** — `app/api/routes/users.py:15-17`
   FastAPI matches `GET /users/{user_id}`, parses `user_id` as `int` from the path. `Depends(get_user_service)` resolves a `UserService` instance. The route just calls `service.get(user_id)` and returns the result; `response_model=UserRead` tells FastAPI how to serialize it (default status 200).

2. **Dependency wiring** — `app/core/deps.py`
   `get_user_service()` builds a `UserService` from `get_user_repository()`, which is `@lru_cache`d so the same `UserRepository` (and its in-memory dict) is reused across requests.

3. **Service** — `app/services/user_service.py:15-19`
   `UserService.get(user_id)` calls `self._repo.get(user_id)`. If the repo returns `None`, it raises `NotFoundError(f"user {user_id} not found")`. Otherwise it wraps the raw row dict in a `UserRead` pydantic model and returns it.

4. **Repository** — `app/repositories/user_repo.py:11-12`
   `UserRepository.get(user_id)` does a plain dict lookup: `self._rows.get(user_id)`, returning the row dict or `None`. This is the in-memory storage layer (would be Postgres in production).

5. **Error path** — if `NotFoundError` is raised, it propagates up through the service and router (the router never catches it), and `app_error_handler` in `app/core/errors.py:24-25` (registered as an exception handler in `main.py`) turns it into a `404` JSON response: `{"code": "not_found", "message": "user <id> not found"}`.

6. **Success path** — the row dict is validated into `UserRead` (`app/schemas/user.py:9-12`, with `id`, `email`, `display_name`), and FastAPI serializes it as the `200` JSON response.

This matches the layered architecture in `docs/ARCHITECTURE.md`: router → service → repository, with errors as `AppError` subclasses converted to JSON by the central handler rather than `HTTPException` in the router.

Trace / 7 tool calls

Bashfind . -path ./node_modules -prune -o -type f -name "*.py" -print | grep -i user

result / 132 chars

./tests/test_users.py
./app/repositories/user_repo.py
./app/schemas/user.py
./app/services/user_service.py
./app/api/routes/users.py

Readapp/api/routes/users.py

result / 674 chars

1	from fastapi import APIRouter, Depends, status
2	
3	from app.core.deps import get_user_service
4	from app.schemas.user import UserCreate, UserRead
5	from app.services.user_service import UserService
6	
7	router = APIRouter(prefix="/users", tags=["users"])
8	
9	
10	@router.post("", response_model=UserRead, status_code=status.HTTP_201_CREATED)
11	def create_user(data: UserCreate, service: UserService = Depends(get_user_service)) -> UserRead:
12	    return service.create(data)
13	
14	
15	@router.get("/{user_id}", response_model=UserRead)
16	def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
17	    return service.get(user_id)
18

Readapp/services/user_service.py

result / 762 chars

1	from app.core.errors import ConflictError, NotFoundError
2	from app.repositories.user_repo import UserRepository
3	from app.schemas.user import UserCreate, UserRead
4	
5	
6	class UserService:
7	    def __init__(self, repo: UserRepository) -> None:
8	        self._repo = repo
9	
10	    def create(self, data: UserCreate) -> UserRead:
11	        if self._repo.get_by_email(data.email):
12	            raise ConflictError(f"email already registered: {data.email}")
13	        return UserRead(**self._repo.add(data.email, data.display_name))
14	
15	    def get(self, user_id: int) -> UserRead:
16	        row = self._repo.get(user_id)
17	        if row is None:
18	            raise NotFoundError(f"user {user_id} not found")
19	        return UserRead(**row)
20

Readapp/repositories/user_repo.py

result / 693 chars

1	from itertools import count
2	
3	
4	class UserRepository:
5	    """In-memory store. The real one talks to Postgres."""
6	
7	    def __init__(self) -> None:
8	        self._rows: dict[int, dict] = {}
9	        self._ids = count(1)
10	
11	    def get(self, user_id: int) -> dict | None:
12	        return self._rows.get(user_id)
13	
14	    def get_by_email(self, email: str) -> dict | None:
15	        return next((r for r in self._rows.values() if r["email"] == email), None)
16	
17	    def add(self, email: str, display_name: str) -> dict:
18	        row = {"id": next(self._ids), "email": email, "display_name": display_name}
19	        self._rows[row["id"]] = row
20	        return row
21

Readapp/schemas/user.py

result / 227 chars

1	from pydantic import BaseModel, EmailStr
2	
3	
4	class UserCreate(BaseModel):
5	    email: EmailStr
6	    display_name: str
7	
8	
9	class UserRead(BaseModel):
10	    id: int
11	    email: EmailStr
12	    display_name: str
13

Readapp/core/deps.py

result / 343 chars

1	from functools import lru_cache
2	
3	from app.repositories.user_repo import UserRepository
4	from app.services.user_service import UserService
5	
6	
7	@lru_cache
8	def get_user_repository() -> UserRepository:
9	    return UserRepository()
10	
11	
12	def get_user_service() -> UserService:
13	    return UserService(get_user_repository())
14

Readapp/core/errors.py

result / 663 chars

1	from fastapi import Request
2	from fastapi.responses import JSONResponse
3	
4	
5	class AppError(Exception):
6	    status_code = 500
7	    code = "internal_error"
8	
9	    def __init__(self, message: str):
10	        super().__init__(message)
11	        self.message = message
12	
13	
14	class NotFoundError(AppError):
15	    status_code = 404
16	    code = "not_found"
17	
18	
19	class ConflictError(AppError):
20	    status_code = 409
21	    code = "conflict"
22	
23	
24	async def app_error_handler(request: Request, exc: AppError) -> JSONResponse:
25	    return JSONResponse(status_code=exc.status_code, content={"code": exc.code, "message": exc.message})
26

Instruction files loaded: 2

CLAUDE.mdProject / session_start
docs/ARCHITECTURE.mdProject / include

Changed files: 0

No changes.

exit 0

run 2baseline 10 turns / 19s / 9 tool calls / 0 files changedvariant 8 turns / 21s / 7 tool calls / 0 files changed

baseline10 turns / 19s / 9 tool calls / 0 files changed

Final response

Here's the full flow for `GET /users/{user_id}`:

**1. App wiring** (`app/main.py`)
FastAPI app registers `users.router` and a global exception handler for `AppError`.

**2. Route** (`app/api/routes/users.py:15-17`)
```python
@router.get("/{user_id}", response_model=UserRead)
def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
    return service.get(user_id)
```
- FastAPI parses `user_id` from the path and validates/coerces it to `int` (a non-numeric value auto-fails with a 422 before your code ever runs).
- `Depends(get_user_service)` resolves a `UserService` instance via `app/core/deps.py`, which itself builds it from an `@lru_cache`d singleton `UserRepository` (so the in-memory store persists across requests within the process).

**3. Service** (`app/services/user_service.py:15-19`)
```python
def get(self, user_id: int) -> UserRead:
    row = self._repo.get(user_id)
    if row is None:
        raise NotFoundError(f"user {user_id} not found")
    return UserRead(**row)
```
- Delegates the lookup to the repository.
- If nothing is found, raises `NotFoundError` (a subclass of `AppError`, `status_code=404`).
- Otherwise wraps the raw dict in the `UserRead` pydantic model.

**4. Repository** (`app/repositories/user_repo.py:11-12`)
```python
def get(self, user_id: int) -> dict | None:
    return self._rows.get(user_id)
```
- Simple in-memory dict lookup (`{id: {"id", "email", "display_name"}}`); no real DB call yet (comment notes the real implementation would talk to Postgres).

**5. Response / error path**
- Success: `UserRead` is returned, FastAPI serializes it per `response_model` → `200` with `{id, email, display_name}`.
- Not found: `NotFoundError` propagates up and is caught by the `AppError` handler registered in `main.py` (`app_error_handler`), which returns `JSONResponse(status_code=404, content={"code": "not_found", "message": "user {id} not found"})`.

No files were changed.

Trace / 9 tool calls

Bashfind . -type f -name "*.py" -not -path "*/node_modules/*" -not -path "*/.git/*" | xargs grep -l "user_id" 2>/dev/null | head -50
result / 88 chars
```
./app/repositories/user_repo.py
./app/services/user_service.py
./app/api/routes/users.py
```

Read./app/api/routes/users.py

result / 674 chars

1	from fastapi import APIRouter, Depends, status
2	
3	from app.core.deps import get_user_service
4	from app.schemas.user import UserCreate, UserRead
5	from app.services.user_service import UserService
6	
7	router = APIRouter(prefix="/users", tags=["users"])
8	
9	
10	@router.post("", response_model=UserRead, status_code=status.HTTP_201_CREATED)
11	def create_user(data: UserCreate, service: UserService = Depends(get_user_service)) -> UserRead:
12	    return service.create(data)
13	
14	
15	@router.get("/{user_id}", response_model=UserRead)
16	def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
17	    return service.get(user_id)
18

Read./app/services/user_service.py

result / 762 chars

1	from app.core.errors import ConflictError, NotFoundError
2	from app.repositories.user_repo import UserRepository
3	from app.schemas.user import UserCreate, UserRead
4	
5	
6	class UserService:
7	    def __init__(self, repo: UserRepository) -> None:
8	        self._repo = repo
9	
10	    def create(self, data: UserCreate) -> UserRead:
11	        if self._repo.get_by_email(data.email):
12	            raise ConflictError(f"email already registered: {data.email}")
13	        return UserRead(**self._repo.add(data.email, data.display_name))
14	
15	    def get(self, user_id: int) -> UserRead:
16	        row = self._repo.get(user_id)
17	        if row is None:
18	            raise NotFoundError(f"user {user_id} not found")
19	        return UserRead(**row)
20

Read./app/repositories/user_repo.py

result / 693 chars

1	from itertools import count
2	
3	
4	class UserRepository:
5	    """In-memory store. The real one talks to Postgres."""
6	
7	    def __init__(self) -> None:
8	        self._rows: dict[int, dict] = {}
9	        self._ids = count(1)
10	
11	    def get(self, user_id: int) -> dict | None:
12	        return self._rows.get(user_id)
13	
14	    def get_by_email(self, email: str) -> dict | None:
15	        return next((r for r in self._rows.values() if r["email"] == email), None)
16	
17	    def add(self, email: str, display_name: str) -> dict:
18	        row = {"id": next(self._ids), "email": email, "display_name": display_name}
19	        self._rows[row["id"]] = row
20	        return row
21

Bashfind . -path ./node_modules -prune -o -type f -name "*.py" -print | xargs grep -lE "get_user_service|NotFoundError|include_router|exception_handler" 2>/dev/null
result / 110 chars
```
./app/main.py
./app/core/deps.py
./app/core/errors.py
./app/services/user_service.py
./app/api/routes/users.py
```

Read./app/main.py

result / 259 chars

1	from fastapi import FastAPI
2	
3	from app.api.routes import users
4	from app.core.errors import AppError, app_error_handler
5	
6	app = FastAPI(title="orders-api")
7	app.add_exception_handler(AppError, app_error_handler)
8	app.include_router(users.router)
9

Read./app/core/deps.py

result / 343 chars

1	from functools import lru_cache
2	
3	from app.repositories.user_repo import UserRepository
4	from app.services.user_service import UserService
5	
6	
7	@lru_cache
8	def get_user_repository() -> UserRepository:
9	    return UserRepository()
10	
11	
12	def get_user_service() -> UserService:
13	    return UserService(get_user_repository())
14

Read./app/core/errors.py

result / 663 chars

1	from fastapi import Request
2	from fastapi.responses import JSONResponse
3	
4	
5	class AppError(Exception):
6	    status_code = 500
7	    code = "internal_error"
8	
9	    def __init__(self, message: str):
10	        super().__init__(message)
11	        self.message = message
12	
13	
14	class NotFoundError(AppError):
15	    status_code = 404
16	    code = "not_found"
17	
18	
19	class ConflictError(AppError):
20	    status_code = 409
21	    code = "conflict"
22	
23	
24	async def app_error_handler(request: Request, exc: AppError) -> JSONResponse:
25	    return JSONResponse(status_code=exc.status_code, content={"code": exc.code, "message": exc.message})
26

Read./app/schemas/user.py

result / 227 chars

1	from pydantic import BaseModel, EmailStr
2	
3	
4	class UserCreate(BaseModel):
5	    email: EmailStr
6	    display_name: str
7	
8	
9	class UserRead(BaseModel):
10	    id: int
11	    email: EmailStr
12	    display_name: str
13

Instruction files loaded: 1

CLAUDE.mdProject / session_start

Changed files: 0

No changes.

exit 0

variant8 turns / 21s / 7 tool calls / 0 files changed

Final response

Here's the flow for `GET /users/{user_id}`:

**1. Router — `app/api/routes/users.py:16-17`**
FastAPI matches the path, parses `user_id` as `int`, and injects a `UserService` via `Depends(get_user_service)`. It calls `service.get(user_id)` and declares `response_model=UserRead` (default 200 status).

**2. Dependency wiring — `app/core/deps.py:12-13`**
`get_user_service()` builds a `UserService`, injecting a `UserRepository` from `get_user_repository()`, which is `@lru_cache`d so the same in-memory repo instance is reused across requests.

**3. Service — `app/services/user_service.py:15-19`**
`UserService.get()` calls `self._repo.get(user_id)`. If the repo returns `None`, it raises `NotFoundError(f"user {user_id} not found")` (no HTTP knowledge here — just the `AppError` subclass). Otherwise it wraps the row dict into a `UserRead` and returns it.

**4. Repository — `app/repositories/user_repo.py:11-12`**
`UserRepository.get()` does a plain dict lookup (`self._rows.get(user_id)`) against the in-memory store and returns the row dict or `None`.

**5. Back up through the layers**
- If found: the row dict flows back up, gets validated/serialized as `UserRead` (`app/schemas/user.py:9-12`), and FastAPI returns it as JSON with status 200.
- If not found: the `NotFoundError` propagates up through the service and router (routers never catch/raise `HTTPException` per the architecture rules) to the global handler `app_error_handler` in `app/core/errors.py:24-25`, registered presumably via `app.add_exception_handler` in `main.py`. It converts the error into a `404` JSON response: `{"code": "not_found", "message": "user <id> not found"}`.

So the path strictly follows router → service → repository, with error translation happening centrally rather than in the router, matching the architecture rules in `docs/ARCHITECTURE.md`.

Trace / 7 tool calls

Bashfind . -path ./node_modules -prune -o -iname "*user*" -print 2>/dev/null | grep -v "\.git"

result / 132 chars

./tests/test_users.py
./app/repositories/user_repo.py
./app/schemas/user.py
./app/services/user_service.py
./app/api/routes/users.py

Readapp/api/routes/users.py

result / 674 chars

1	from fastapi import APIRouter, Depends, status
2	
3	from app.core.deps import get_user_service
4	from app.schemas.user import UserCreate, UserRead
5	from app.services.user_service import UserService
6	
7	router = APIRouter(prefix="/users", tags=["users"])
8	
9	
10	@router.post("", response_model=UserRead, status_code=status.HTTP_201_CREATED)
11	def create_user(data: UserCreate, service: UserService = Depends(get_user_service)) -> UserRead:
12	    return service.create(data)
13	
14	
15	@router.get("/{user_id}", response_model=UserRead)
16	def get_user(user_id: int, service: UserService = Depends(get_user_service)) -> UserRead:
17	    return service.get(user_id)
18

Readapp/services/user_service.py

result / 762 chars

1	from app.core.errors import ConflictError, NotFoundError
2	from app.repositories.user_repo import UserRepository
3	from app.schemas.user import UserCreate, UserRead
4	
5	
6	class UserService:
7	    def __init__(self, repo: UserRepository) -> None:
8	        self._repo = repo
9	
10	    def create(self, data: UserCreate) -> UserRead:
11	        if self._repo.get_by_email(data.email):
12	            raise ConflictError(f"email already registered: {data.email}")
13	        return UserRead(**self._repo.add(data.email, data.display_name))
14	
15	    def get(self, user_id: int) -> UserRead:
16	        row = self._repo.get(user_id)
17	        if row is None:
18	            raise NotFoundError(f"user {user_id} not found")
19	        return UserRead(**row)
20

Readapp/repositories/user_repo.py

result / 693 chars

1	from itertools import count
2	
3	
4	class UserRepository:
5	    """In-memory store. The real one talks to Postgres."""
6	
7	    def __init__(self) -> None:
8	        self._rows: dict[int, dict] = {}
9	        self._ids = count(1)
10	
11	    def get(self, user_id: int) -> dict | None:
12	        return self._rows.get(user_id)
13	
14	    def get_by_email(self, email: str) -> dict | None:
15	        return next((r for r in self._rows.values() if r["email"] == email), None)
16	
17	    def add(self, email: str, display_name: str) -> dict:
18	        row = {"id": next(self._ids), "email": email, "display_name": display_name}
19	        self._rows[row["id"]] = row
20	        return row
21

Readapp/schemas/user.py

result / 227 chars

1	from pydantic import BaseModel, EmailStr
2	
3	
4	class UserCreate(BaseModel):
5	    email: EmailStr
6	    display_name: str
7	
8	
9	class UserRead(BaseModel):
10	    id: int
11	    email: EmailStr
12	    display_name: str
13

Readapp/core/deps.py

result / 343 chars

1	from functools import lru_cache
2	
3	from app.repositories.user_repo import UserRepository
4	from app.services.user_service import UserService
5	
6	
7	@lru_cache
8	def get_user_repository() -> UserRepository:
9	    return UserRepository()
10	
11	
12	def get_user_service() -> UserService:
13	    return UserService(get_user_repository())
14

Readapp/core/errors.py

result / 663 chars

1	from fastapi import Request
2	from fastapi.responses import JSONResponse
3	
4	
5	class AppError(Exception):
6	    status_code = 500
7	    code = "internal_error"
8	
9	    def __init__(self, message: str):
10	        super().__init__(message)
11	        self.message = message
12	
13	
14	class NotFoundError(AppError):
15	    status_code = 404
16	    code = "not_found"
17	
18	
19	class ConflictError(AppError):
20	    status_code = 409
21	    code = "conflict"
22	
23	
24	async def app_error_handler(request: Request, exc: AppError) -> JSONResponse:
25	    return JSONResponse(status_code=exc.status_code, content={"code": exc.code, "message": exc.message})
26

Instruction files loaded: 2

CLAUDE.mdProject / session_start
docs/ARCHITECTURE.mdProject / include

Changed files: 0

No changes.

exit 0

Judgment

Which condition showed the expected effect more clearly? (no relevant difference is the expected outcome)baselinevariantNo differenceCan't tell (indistinguishable from run-to-run variance)

Notes

Summary

Case	Judgment	Notes
TC-01	not judged	-
TC-02	not judged	-
TC-03	not judged	-

Observed differences

The change

The variant condition is the baseline commit with the diff below applied. Everything else (files, settings, prompts) is identical in both conditions.

Changed files: 2 / +24 -1

CLAUDE.md+1 -1

index 67c9c0e..a0ae861 100644--- a/CLAUDE.md+++ b/CLAUDE.md@@ -2,4 +2,4 @@ - Answer in English. - This checkout has no virtualenv. Don't run the server or the tests; just edit the code.-- Keep the code organized.+@docs/ARCHITECTURE.md

docs/ARCHITECTURE.md new+23 -0

new file mode 100644index 0000000..16e0749--- /dev/null+++ b/docs/ARCHITECTURE.md@@ -0,0 +1,23 @@+# Architecture++This service is layered. Every request flows router → service → repository, and never skips a layer.++## Layers++| Layer | Location | Owns | Must not |+|---|---|---|---|+| Router | `app/api/routes/<resource>.py` | HTTP concerns: path, status code, request/response models | Contain business rules, touch a repository, raise `HTTPException` |+| Service | `app/services/<resource>_service.py` | Business rules, validation across records | Import FastAPI, know about HTTP |+| Repository | `app/repositories/<resource>_repo.py` | Storage. In-memory here, Postgres in production | Contain business rules |+| Schemas | `app/schemas/<resource>.py` | Pydantic models. Separate `<Resource>Create` and `<Resource>Read` | Be reused as storage rows |+| Core | `app/core/` | `errors.py` (AppError hierarchy), `deps.py` (dependency providers) | |++## Rules++1. One resource, one file per layer. Adding a resource `orders` means `app/api/routes/orders.py`, `app/services/order_service.py`, `app/repositories/order_repo.py`, `app/schemas/order.py`, and `tests/test_orders.py`.+2. Routers get services through `Depends(get_<resource>_service)` from `app/core/deps.py`. Add a provider there for every new service.+3. Errors are `AppError` subclasses raised from services (`NotFoundError`, `ConflictError`, or a new subclass in `app/core/errors.py`). The handler in `main.py` turns them into JSON. Routers never raise `HTTPException`.+4. Routers declare `response_model` and `status_code` explicitly. POST that creates returns 201.+5. Register every router in `app/main.py` with `app.include_router`.+6. Tests live in `tests/test_<resource>.py`, use `TestClient`, and cover each status code the endpoint can return.+7. Money and quantities are integers. Totals are computed in the service, never in the router or the schema.

Fixed conditions

Applied identically to every run.

model	claude-sonnet-5
permissions	--dangerously-skip-permissions (allow everything)
setting sources	project - excludes ~/.claude CLAUDE.md, settings, plugins, hooks, skills
MCP	none (--strict-mcp-config, no --mcp-config)
auto memory	off (CLAUDE_CODE_DISABLE_AUTO_MEMORY=1)
session persistence	off (--no-session-persistence)
instruction load record	InstructionsLoaded hook -> instructions.jsonl
budget cap	$1.5 per run (--max-budget-usd)
timeout	600s per run
worktree	one per run, created in a temp directory outside the repo and removed afterwards. Directory name and temp commit message never contain the condition name
baseline commit	cf8b081c7ea60a5b5e3470a61b6bd323202824bf
variant	baseline commit + variant.patch
setup	none
run order	per test case, for each run k: baseline then variant, alternating, sequential
Claude Code	2.1.245 (Claude Code)

Command

claude -p '$PROMPT' --output-format stream-json --verbose --setting-sources project --strict-mcp-config --no-session-persistence --max-budget-usd 1.5 --settings '<InstructionsLoaded hook settings JSON>' --model claude-sonnet-5 --dangerously-skip-permissions