feat(check): make check fails when a service imports another service's sdk at startup

README.md

@@ -2,7 +2,7 @@
 
 Copier template for a Python backend, either as a `backend/` part next to other parts or alone at the root of the project (`layout`): a uv project with one Docker image and one `python -m <module>` entrypoint per service (`api`, `bot`, `userbot`, `worker`, `scheduler`), pydantic-settings, rich logging, optional Dishka, MongoDB or PostgreSQL, Redis, taskiq (in-memory, Redis or PostgreSQL broker), CryptoPay, pydantic-ai and a DynamicConfig stored in the database.
 
-Ships `backend/docker-compose.yml` with root-relative paths and profiles per service, `docker-compose.override.yml.example` (published ports and the `caddy` network aliases, copied by `make env`), a `Makefile` with `fmt`, `check`, `build` and service-specific targets, `.env.example` and `CLAUDE.md`. Applied on top of the `infra` template, `layout: parts` or `layout: single` respectively.
+Ships `backend/docker-compose.yml` with root-relative paths and profiles per service, `docker-compose.override.yml.example` (published ports and the `caddy` network aliases, copied by `make env`), a `Makefile` with `fmt`, `check` (ruff, ty and `scripts/check_imports.py`, which keeps each service from importing the others' SDKs at startup), `build` and service-specific targets, `.env.example` and `CLAUDE.md`. Applied on top of the `infra` template, `layout: parts` or `layout: single` respectively.
 
 `DB__HOST`/`DB__PORT` and `REDIS__HOST`/`REDIS__PORT` say where the service really is. The bundled container takes the host as its network alias and listens on the port, the override publishes it on the machine. For an external database, point them at it and leave its profile out of `COMPOSE_PROFILES`.
 

template/{{ part_dir }}/Makefile.jinja

@@ -30,7 +30,8 @@ check:
 	uv run ruff format --check
 	uv run ruff check
 	uv run ty check
-{% if svc_modules %}
+{% if svc_modules %}	uv run python scripts/check_imports.py
+{% endif %}{% if svc_modules %}
 build:
 	$(COMPOSE) build {{ svc_modules[0] }}
 

template/{{ part_dir }}/scripts/{% if 'kurigram_userbot' in backend_services %}session{% endif %}/create.py.jinja

@@ -2,7 +2,7 @@ import asyncio
 
 import anyio
 
-from userbot import PyroClient
+from userbot.modules.client import PyroClient
 
 
 async def main() -> None:

template/{{ part_dir }}/scripts/{% if backend_services %}check_imports.py{% endif %}.jinja

@@ -0,0 +1,60 @@
+import os
+import subprocess
+import sys
+
+HEAVY = ["aiogram", "pyrogram", "fastapi", "google.genai"]
+SERVICES = {
+{%- if 'api' in backend_services %}
+    "api": (["api.app"], {"fastapi"}),
+{%- endif %}
+{%- if 'aiogram_bot' in backend_services %}
+    "bot": ({% if include_payments %}["bot"]{% else %}["bot.common", "bot.handlers"]{% endif %}, {"aiogram"}),
+{%- endif %}
+{%- if 'kurigram_userbot' in backend_services %}
+    "userbot": (["userbot.runner", "userbot.handlers"], {"pyrogram"}),
+{%- endif %}
+{%- if 'taskiq_worker' in backend_services %}
+    "worker": (["worker.broker", "worker.tasks"], {% if 'api' in backend_services %}{"fastapi"}{% else %}set(){% endif %}),
+{%- elif 'scheduler' in backend_services %}
+    "scheduler": (["scheduler"], set()),
+{%- endif %}
+}
+PROBE = """
+import importlib, sys
+for module in sys.argv[1].split(","):
+    importlib.import_module(module)
+print(" ".join(name for name in sys.argv[2:] if name in sys.modules))
+"""
+{%- if 'aiogram_bot' in backend_services %}
+ENV = {**os.environ, "BOT__TOKEN": "1:check"}
+{%- else %}
+ENV = dict(os.environ)
+{%- endif %}
+
+
+def loaded(modules: list[str]) -> tuple[set[str], str]:
+    result = subprocess.run(  # noqa: S603
+        [sys.executable, "-c", PROBE, ",".join(modules), *HEAVY],
+        capture_output=True,
+        text=True,
+        cwd="src",
+        env=ENV,
+        check=False,
+    )
+    error = (result.stderr.strip().splitlines() or ["exit code"])[-1]
+    return set(result.stdout.split()) & set(HEAVY), error if result.returncode else ""
+
+
+def main() -> int:
+    failed = False
+    for service, (modules, allowed) in SERVICES.items():
+        found, error = loaded(modules)
+        extra = sorted(found - allowed)
+        status = error or ("imports " + ", ".join(extra) if extra else "")
+        print(f"{service:10s} {'FAIL: ' + status if status else 'ok'}")
+        failed |= bool(status)
+    return int(failed)
+
+
+if __name__ == "__main__":
+    sys.exit(main())

template/{{ part_dir }}/src/utils/imports.py

@@ -0,0 +1,6 @@
+import asyncio
+from importlib import import_module
+
+
+async def preload(module: str) -> None:
+    await asyncio.to_thread(import_module, module)

template/{{ part_dir }}/src/utils/logging.py.jinja

@@ -1,5 +1,7 @@
 import logging
-
+{% if 'aiogram_bot' in backend_services %}from importlib.util import find_spec
+from pathlib import Path
+{% endif %}
 from rich.console import Console
 from rich.logging import RichHandler
 from rich.traceback import install
@@ -10,8 +12,12 @@ console = Console(width=env.log.console_width, color_system="auto", force_termin
 
 
 def setup_logging() -> None:
-{% if 'aiogram_bot' in backend_services %}    from aiogram.dispatcher import router  # noqa: PLC0415
-
+{% if 'aiogram_bot' in backend_services %}    aiogram = find_spec("aiogram")
+    suppress = (
+        [str(Path(aiogram.origin).parent / "dispatcher")]
+        if aiogram and aiogram.origin
+        else []
+    )
 {% endif %}    logging.basicConfig(
         level=env.log.level_external,
         format="",
@@ -26,7 +32,7 @@ def setup_logging() -> None:
                 omit_repeated_times=False,
                 show_time=env.log.show_time,
                 {%- if 'aiogram_bot' in backend_services %}
-                tracebacks_suppress=[router],
+                tracebacks_suppress=suppress,
                 {%- endif %}
             )
         ],

template/{{ part_dir }}/src/{% if 'kurigram_userbot' in backend_services %}userbot{% endif %}/__init__.py.jinja

@@ -1,3 +0,0 @@
-from .modules.client import DEVICE_MODEL, PyroClient
-
-__all__ = ["DEVICE_MODEL", "PyroClient"]

template/{{ part_dir }}/src/{% if use_dishka %}dependencies{% endif %}/container.py.jinja

@@ -4,11 +4,7 @@
 {%- if database == 'postgres' %}{% set _ = providers.append('RepositoryProvider()') %}{% endif -%}
 {%- if use_redis %}{% set _ = providers.append('RedisProvider()') %}{% endif -%}
 {%- if use_llm %}{% set _ = providers.append('LlmProvider()') %}{% endif -%}
-{%- if 'aiogram_bot' in backend_services %}{% set _ = providers.append('AiogramProvider()') %}{% endif -%}
-{%- if 'api' in backend_services %}{% set _ = providers.append('FastapiProvider()') %}{% endif -%}
 {%- set third = ['from dishka import make_async_container'] -%}
-{%- if 'aiogram_bot' in backend_services %}{% set _ = third.append('from dishka.integrations.aiogram import AiogramProvider') %}{% endif -%}
-{%- if 'api' in backend_services %}{% set _ = third.append('from dishka.integrations.fastapi import FastapiProvider') %}{% endif -%}
 {%- set first = [] -%}
 {%- if dynamic_config %}{% set _ = first.append('from dependencies.providers.config import ConfigProvider') %}{% endif -%}
 {%- if database != 'none' %}{% set _ = first.append('from dependencies.providers.db import DbProvider') %}{% endif -%}

template/{{ part_dir }}/src/{% if use_dishka %}dependencies{% endif %}/providers/{% if use_llm %}llm.py{% endif %}.jinja

@@ -1,14 +1,20 @@
 from dishka import Provider, Scope, provide
 from pydantic_ai import Agent
-from pydantic_ai.models.google import GoogleModel, GoogleModelSettings
-from pydantic_ai.providers.google import GoogleProvider
 
 from utils.env import env
+from utils.imports import preload
 
 
 class LlmProvider(Provider):
     @provide(scope=Scope.APP)
-    def agent(self) -> Agent:
+    async def agent(self) -> Agent:
+        await preload("pydantic_ai.models.google")
+        from pydantic_ai.models.google import (  # noqa: PLC0415
+            GoogleModel,
+            GoogleModelSettings,
+        )
+        from pydantic_ai.providers.google import GoogleProvider  # noqa: PLC0415
+
         model = GoogleModel(
             env.llm.model.split(":", 1)[-1],
             provider=GoogleProvider(api_key=env.llm.gemini_api_key.get_secret_value()),

template/{{ part_dir }}/{% if layout == 'part' %}CLAUDE.md{% endif %}

@@ -5,3 +5,9 @@ ruff format
 ruff check --fix
 ty check
 ```
+
+## Imports
+Every service imports only what it needs to start. `make check` runs `scripts/check_imports.py`, which fails when a service loads a heavy package it is not allowed; `SERVICES` there is the contract, extend it on purpose.
+- Package `__init__` files don't re-export clients or SDKs.
+- An SDK used by one function is imported inside it. On an async path load it first with `await preload("<module>")` from `utils.imports`, so the event loop never waits on the import.
+- Types used in Dishka provider signatures and `FromDishka[...]` stay real top-level imports.