# forge.ta.envelopes

```python
forge.ta.envelopes(source: ArrayLike, period: int = 14, deviation: float = 0.1, method: str = 'sma', mode: str = 'percent') -> dict[str, np.ndarray]
```

A moving average with a band above and below it.

``middle`` is the moving average named by ``method``. In ``percent`` mode the bands are
``middle * (1 + deviation / 100)`` and ``middle * (1 - deviation / 100)``; in ``fixed`` mode
they are ``middle + deviation`` and ``middle - deviation`` in price units.

Since Forge API 1.

## Class forge.ta.Envelopes

```python
forge.ta.Envelopes(**inputs: Any) -> None
```

A moving average with a band a set distance above and below it.

middle = the moving average named by method

percent: upper = middle * (1 + deviation / 100), lower = middle * (1 - deviation / 100)

fixed: upper = middle + deviation, lower = middle - deviation

Since Forge API 1.