Generate a sample .env file

EnvConfig can export a documented .env template directly from a class declaration. It lists every field with its description, declared type, and (optionally) its default value.

MyConfig.export_env("sample.env", include_defaults=True)

Given:

class MyConfig(EnvConfig):
    env_prefix: str = "MYAPP"
    debug: bool = Field(description="Enable debug mode", default=False)
    database_url: str = Field(description="Database connection URL")
    max_connections: int = Field(description="Maximum DB connections", default=10)
    cache_backends: list[str] = Field(description="Cache backends", type_hint="list")

…the output is:

# debug (bool) [optional]
# Enable debug mode
MYAPP_DEBUG=False

# database_url (str) [required]
# Database connection URL
MYAPP_DATABASE_URL=

# max_connections (int) [optional]
# Maximum DB connections
MYAPP_MAX_CONNECTIONS=10

# cache_backends (list) [required]
# Cache backends
MYAPP_CACHE_BACKENDS=

Options

• include_defaults=True (default) — write the default value to the right of = for optional fields. With False, optional fields render with an empty value, just like required ones.
• The file is written verbatim; existing contents are overwritten.

Custom type labels

For fields that use custom converters, the type label is derived as documented there. Pass type_name= to Field() to force a specific label:

amount: Decimal = Field(
    convert_using=Decimal,
    type_name="Decimal",
    description="Total in USD",
)

renders as:

# amount (Decimal) [required]
# Total in USD
MYAPP_AMOUNT=