Python

How to setup crabenv for Python projects

Dependencies: pydantic, pydantic-settings; monorepo justfile examples use dotenv-cli

# single app
- .env
- .env.example
- src/
    - <package>/
        - env.py

# monorepo
- .env
- .env.example
- apps/
    - api/
        - .env.example
        - src/api/env.py

Crabenv discovers the first env.py under src/ (depth ≤ 4). Env var names are the Field(alias="...") values (typically SCREAMING_SNAKE). Server apps only — no client/public split.

Example

src/api/env.py

from pydantic import Field
from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    database_url: str = Field(alias="DATABASE_URL")
    secret_key: str = Field(min_length=32, alias="SECRET_KEY")
    log_level: str = Field(default="info", alias="LOG_LEVEL")

    model_config = SettingsConfigDict(env_file=".env", extra="ignore")


settings = Settings()

main.py

from api.env import settings


def main() -> None:
    print(settings.database_url)

Monorepo local run (root .env → process env):

_env *cmd:
    dotenv -e ../../.env -- {{ cmd }}

dev *args:
    just _env "uv run python -m api.main {{ args }}"

Use settings in code — not os.environ. Docs and defaults live on Field(...); keep .env.example keys and aliases aligned.

Python

#Example

Example