# General Translation Python SDKs: ContextVarStorageAdapter
URL: https://generaltranslation.com/en-US/docs/python/reference/classes/context-var-storage-adapter.mdx
---

title: ContextVarStorageAdapter
description: Default context-variable storage adapter for the request locale in General Translation Python. API reference for ContextVarStorageAdapter.

---

The default [`StorageAdapter`](/docs/python/reference/classes/storage-adapter) for the request locale, backed by a `contextvars.ContextVar`. It works for both threaded (Flask) and async (FastAPI) contexts, giving each request its own isolated locale automatically.

## Overview [#overview]

[`I18nManager`](/docs/python/reference/classes/i18n-manager) uses this adapter unless you pass a custom `store_adapter`. You rarely construct it yourself.

```python
from gt_i18n import ContextVarStorageAdapter, I18nManager

manager = I18nManager(default_locale="en", store_adapter=ContextVarStorageAdapter())
```

Import `ContextVarStorageAdapter` from `gt_i18n`. It is not re-exported by the framework packages.

## How it works [#how-it-works]

- **Context variable.** It stores the locale in a module-level `ContextVar`, so concurrent requests do not see each other's locale.
- **Locale key only.** It handles only the `"locale"` key; `get_item` returns `None` for any other key, and `set_item` ignores it.
- **Unset default.** When no locale has been set in the current context, `get_item("locale")` returns `None`, and the manager falls back to the default locale.

## Methods [#members]

| Member | Description | Returns |
| --- | --- | --- |
| [`get_item`](#member-get-item) | Read the request locale from the context variable. | `str \| None` |
| [`set_item`](#member-set-item) | Write the request locale to the context variable. | `None` |

### `get_item(key)` [#member-get-item]

Returns the current context's locale when `key` is `"locale"`, otherwise `None`.

### `set_item(key, value)` [#member-set-item]

Sets the current context's locale when `key` is `"locale"`, otherwise does nothing.

## Example [#example]

```python
from gt_i18n import ContextVarStorageAdapter

adapter = ContextVarStorageAdapter()
adapter.set_item("locale", "es")
adapter.get_item("locale")  # "es" (within the same context)
```